Day 618

Monday.

1403.7203
The zCOSMOS redshift survey: evolution of the light in bulges and discs since z~0.8
Tasca, .. Le Fevre, Ilbert, Lilly, Koekemoer, … et al

Study the chronology of galactic bulge and disc formation by analyzing the relative contributions of these components to the B-band rest-frame luminosity density at different epochs.  Present the first estimate of the evolution of the fraction of rest-frame B-band light in galactic bulges and discs since z~0.8.  Perform a bulge-to-disc decomposition of HST/ACS images of 3266 galaxies in the zCOSMOS-bright survey with spectra z with the range 0.7<z<0.9.  Find that the fraction of B-band light in bulges is 26pm4 and 74pm4, respectively.  When compared with rest-frame B-band measurements of galaxies in the local Universe in the same mass range 1e9 Msun<M<1e11.5 Msun, find that the B-band light in discs decreases by ~30% from z~0.7-0.9 to z~0, while the light from the bulge increases by ~30% over the same period of time.  Interpret this evolution as the consequence of SF and mass assembly processes, as well as morphological transformation, which gradually shift stars formed at half the age of the Universe from SF late-type/irregular galaxies to earlier times and ultimately into spheroids.

1403.7205
Touching the void: a striking drop in stellar halo density beyond 50 kpc
Deason, Belokurov, Koposov, Rockosi

Use A-type stars selected from SDSS DR9 to measure the outer slope of the MW stellar halo density profile beyond 50 kpc.  A likelihood-based analysis is employed that models the ugr photometry distribution of blue horizontal branch (BHB) and blue straggler (BS) stars.  In the magnitude range, 18.5<g<20.5, these stellar populations span a heliocentric distance range of: 10 kpc< D_BS<75 kpc, 40 kpc < D_BHB < 100 kpc.  Contributions from contaminations, such as QSOs, and the effect of photometric uncertainties, are also included in the modeling procedure.  Find evidence for a very steep outer halo profile, with power-law index alpha ~ 6 beyond Galactocentric radii r=50 kpc, and even steeper slopes favored (alpha~6-10) at larger radii.  This result holds true when stars belonging to known over densities, such as the Sagittarius stream, are included or excluded.  Show that, by comparison to numerical simulations, stellar haloes with shallower slopes at large distances tend to have more recent accretion activity.  Thus, it is likely that the MW has undergone a relatively quiets accretion history over the past several Gyr.  Measurement of the outer stellar halo profile may have important implications for dynamical mass models of the MW, where the tracer density profile is strongly degenerate with total mass-estimates. 

1403.7235
What the "simple renormalization group" approach to dark matter clustering really was
McDonald

The past approach (McDonald 2007) to improving PT calculations of the DM PS, with a derivation based on the idea of renormalization group flow with time.  In spite of a questionable approximation made in deriving it, subsequent comparisons by several groups between the predictions of the resulting equation and the N-body simulations showed remarkable improvement relative the standard PT (SPT) at similar order.  In this note, show that the same final equation can be derived cleanly from the point of view not of flowing with time but with NL coupling strength, i.e., gradually dialing the coupling from the trivial value zero to the physical one.  This understanding makes it clear how to extend the approach to higher order and other statistics. While this is not necessarily the best approach among many, it may be interesting in that it contains a unique way of suppressing UV sensitivity.  In passing, remind the reader of references demonstrating that SPT works remarkably well without improvement (except near z=0, where, fortunately for SPT, there is very little volume in the Universe).

1403.7303
Did gamma ray burst induce Cambrian explosion?
Chen, Ruffini

Cambrian explosion of bio-diversity happened around 540 million years ago (Mya).  Suggest that a nearby GRB event ~500 parsecs away, which should occur about once per 5 Gy, might have triggered it.  Due to a relatively lower cross section and the conservation of photon number in Compton scattering, a substantial fraction of the GRB photons can reach the sea level and would induce DNA mutations in organisms protected by a shallow layer of water or soil, thus expediting the bio-diversification.  This possibility of inducing genetic mutations is unique among all candidate sources for major incidents in the history of bio-diversification.  A possible evidence would be the anomalous abundance of certain nuclear isotopes with long half-lives transmuted by the GRB photons in geological records from the Cambrian period.  Notation also imposes constraints on the evolution of exoplanet organisms and the migration of panspermia.

1403.7309
A new method for PSF correction using the ellipticity of re-smeared artificial images in weak gravitational lensing shear analysis
Okura, Futamase

Propose a new method for PSF correction in WL analysis using an artificial image wit the same ellipticity as the lensed image.  This avoids the systematic error associated with the approximation in PSF correction used in previous approaches.  Test the new method with simulated objects which have Gaussian or Sersic profiles smeared by Gaussian PSF, and confirm that there is no systematic error.

1403.7463
The wavelength dependence of high-redshift galaxy structure in the rest-frame ultraviolet
Bond, … Coe, Grogin, Gawiser, … et al

Present the rest-frame UV wavelength dependence of the Petrosian-like HLR (r_50) and the concentration parameter for a sample of 198 SF galaxies at 0.5<z<1.5.  Find a ~5% decrease in HLR from 1500A to 3000A, with HLR at 3000A ranging from 0.6 kpc to 6 kpc.  Also find a decrease in concentration of ~0.07 (1.9<C_3000<3.9).  The lack of strong relationship between HLR and wavelength is consistent with a model in which clumpy SF is distributed over length scales comparable to the galaxy's rest-frame optical light.  While the wavelength dependence of HLR is independent of size at all redshifts, concentration decreases more sharply in the FUV (~1500A) for large galaxies at z~1.  This decrease in concentration is caused by a flattening of the inner ~20% of the light profile in disk-like galaxies, indicating that the central regions have different UV colors than the rest of the galaxy.  Interpret this as a bulge component with older stellar populations and/or more dust.  The size-dependent decrease in concentration is less dramatic at z~2, suggesting that bulges are less dusty, younger, and/or less massive than the rest of the galaxy at higher redshifts.

1403.7520
The Gemini planet imager: first light
Macintosh, Graham, … et al

Combines a high-order AO system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution; tuned for maximum sensitivity to faint planets near bright stars.  During first light observations, achieved an estimated H band Strehl ratio of 0.89 and 5-sigma contrast of 1e6 at 0.75 arc seconds and 1e5 at 0.35 arc seconds.  Observation of Beta Pictrois clearly detect the planet in a single 60-second exposure with minimal post-processing.  Beta Pictoris b is observed at a separation of 434pm6 milli-arcseconds and position angle 211.8 deg.  Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions.  The planet orbits at a semi-major axis of 9AU near the 3:2 resonance with the previously-known 6 AU asteroidal belt and is aligned with the inner warped disk.  The observations give a 4% posterior probability of a transit of the planet in late 2017.

Day 617

Saturday.  Sunday.

1402.1165
Dancing in the dark: galactic properties trace spin swings along the cosmic web
Dubois et al

Investigate alignment between the spin of galaxies and large-scale cosmic filaments above z=1, using large-scale hydro cosmo sims.  Analysis of more than 150k galaxies with morphological diversity in a 100 Mpc/h comoving box size shows that the spin of low-mass, rotation-dominated, blue, SF galaxies is preferentially aligned with their neighboring filaments.  High-mass, dispersion-dominated, red, quiescent galaxies tend to have a spin perpendicular to nearby filaments.  The orientation of the spin of massive galaxies is provided by galaxy mergers which are significant in the mass build up of high-mass galaxies.  Find the the stellar mass transition from alignment to misalignment happens around 3.1e10 Msun.  This is consistent with earlier findings of DM mass transition for the orientation of the spin of haloes 5.1e11 Msun at the same redshift.  With these numerical evidence, advocate a scenario in which galaxies form in the vorticity-rich neighborhood of filaments, and migrate towards the nodes of the cosmic web as they convert their orbital angular momentum into spin.  The signature of this process can be traced to the physical and morphological properties of galaxies, as measured relative to the cosmic web.  Argue that a strong source of feedback such as AGN is mandatory to quench in situ SF in massive galaxies.  It allows mergers to play their key role by reducing post-merger gas inflows and, therefore, keeping galaxy spins misaligned with cosmic filaments.  It also promotes diversity amongst galaxy properties.

1402.1168
What is the physical origin of strong Lya emission? II. Gas kinematics and distribution of Lya Emitters
Shibuya et al

Present statistical study of velocities if Lya, interstellar (IS) absorption, and nebular lines and gas covering fraction for Lya emitters (LAEs) at z~2.  Make a sample of 22 LAEs with a large Lya EW of >50A based on deep observations, in conjunction with spectra data taken and from literature.  Estimate the average velocity offset of Lya from a systemic z determined with nebular lines to be dv_Lya=234pm9 km/s.  Using a KS test, confirm the previous claim of Hashimoto+2013 that the average dv_Lya of LAEs is smaller than that of LBGs.  Data successfully identify blue-shifted multiple IS absorption ones in the UV continua of four LAEs on an individual basis.  The average velocity offset is IS absorption lines from a systemic redshift is dv_IS=204pm27 km/s, indicating LAE's gas outflow with a velocity comparable to typical LBGs.  Thus, the ratio, R^Lya_IS = dv_Lya/dv_IS of LAEs, is around unity, suggestive of low impacts on Lya transmission by resonant scattering of neutral hydrogen in the IS medium.  Find an anti-correlation between Lya EW and the covering fraction, f_c, estimated from the depth of absorption lines, where f_c is an indicator of average neutral hydrogen column density, N_HI.  The results of the study support the idea that N_HI is a key quantity determining Lya emissivity.

1402.1172
ZENS IV. Similar morphological changes associated with Mass- and environment-quenching, and the relative importance of bulge growth versus the fading of disks
Carollo et al

Study the dependence of the quenched satellite fraction and of the morphological mix of these quenched satellites, on three different environmental parameters: group halo mass, halo-centric distance and large-scale structure over-density.  The fraction of quenched satellites is independent of halo mass and the surrounding large-scale overdensity, but increases towards the centers of the haloes, as previously found.  The morphological mix is, however, constant with radial position, indicating that the well-known morphology-density relation results form the increasing fraction of quenched galaxies towards the centers of haloes.  The constancy of the morphological outcome suggests that mass-quenching and satellite quenching have the same effect on the morphologies of the galaxies.  The quenched satellites have larger B/T and smaller half-light radii than the SF satellites.  These are mostly due to differences in the disks.  The bulges in quenched satellites have very similar luminosity's and surface brightness profiles, and any mass growth of the bulges associated with quenching cannot greatly change these quantities.  The quenched disks are fainter and have smaller scale lengths than in SF satellites.  This can be explained either by a differential fading of the disks or if disks were generally smaller in the past, both of which are expected in an inside-out growth of disks.  At least at low z, the structure of massive quenched satellites is produced by processes that operate before quenching takes place.  A comparison with SAMs argues for a reduction in the efficiency of group haloes in quenching their disk satellites and for mechanisms to increase the B/T of low mass quenched satellites.

1402.1215
Design for minimum energy in starship and interstellar communication
Messerschmitt

The design of an interstellar digital communication system at radio wavelengths and interstellar distances is considered, with application to communication with starship and extraterrestrial civilizations.  The distances involved are large, resulting in a need for large transmitted power and/or large antennas.  In light of a fundamental tradeoff between wider signal bandwidth and lower signal energy per bit delivered to the receiver, the design uses unconstrained bandwidth and thus minimizes delivered energy.  One major challenge for communication with civilizations is the initially uncoordinated design and, if the distances are greater, new impairments introduced by the ISM.  Unconstrained bandwidth results in a simpler design, helping overcome the absence of coordination.  An implicit coordination strategy is proposed based on approaching the fundamental limit on energy delivered to the receiver in the face of jointly observable impairments due to the ISM (dispersion, scattering, and scintillation) and motion.  It is shown that the CMB is the only fundamental limitation on delivered energy per bit, as the remaining impairments can be circumvented by appropriate signal design and technology.  A simple design that represents information by the sparse location of bundles of energy in time and frequency can approach that fundamental energy limit as signal bandwidth grows.  Individual energy bundles should fall in an interstellar coherence hole, which is a time-duration and bandwidth limitation on waveforms rendering them impervious to medium and motion impairments.

1402.1342
The cross-correlation of MgII absorption and galaxies in BOSS
Pérez-Ràfols, Miralda-Escudé, et al

Use the DR11 galaxy sample of BOSS and DR7 quasar spectra.  The X-corr is measured by stacking quasar absorption spectra shifted to the redshift of galaxies that are within a certain impact parameter bin of the quasar, after dividing by a quasar continuum model. This results in an average MgII equivalent width as a function of impact parameter from a galaxy, ranging from 50 kpc to more than 10 Mpc in proper units, which includes all MgII absorbers.  Show that special care needs to be taken to use an unbiased quasar continuum estimator, to avoid systematic errors in the measurement of the mean stacked MgII EW.  The measured X-corr follows the expected shape of the galaxy correlation function, although measurement errors are large.  Use the X-corr amplitude to derive the bias factor of MgII absorbers, finding b_MgII=1.20pm0.19, where the error accounts only for the statistical uncertainty in measuring the mean EW.  This result indicates that MgII absorbers at z~0.5 are spatially distributed on large scales similarly to galaxies with L~L*.  

1402.1456
Dusty star-forming galaxies at high redshift
Casey, Narayanan, Cooray

[review] FIR and submillimeter wavelength surveys have established the important role of dusty, SF galaxies (DSFGs) in the assembly of stellar mass and the evolution of massive galaxies in the Universe.  The brightness of these galaxies have IR luminosities >1e13 Lsun with implied SFRs of 1000s of Msun per year.  They represent the most intense starbursts in the universe, yet many are completely optically obscured.  Their easy detection at submm wavelengths is due to dust heated by UV radiation of newly forming stars.  When summed up, all of the dusty, SF galaxies in the universe produce an IR radiation field that has an equal energy density as the direct starlight emission from all galaxies visible at UV and optical wavelengths.  The bulk of this IR extragalactic BG light emanates from galaxies as diverse as gas-rich disks to mergers of intense SB galaxies.  Major advances in FIR instrumentation in recent years, both space-based and ground-based, has led to the detection of nearly a million DSFGs, yet the understanding of the underlying astrophysics that govern the star and end of the dusty SB phase is still in nascent stage.  This review is aimed at summarizing the current status of DSFG studies, focusing especially on the detailed characterization of the best-understood subset (sub millimeter galaxies, who were summarized in the last review of this field over a decade ago, Blain+2002), but also the selection and characterization of more recently discovered DSFG populations.  Review DSFG population statistics, their physical properties including dust, gas and stellar contents, their environments, and current theoretical models related to the formation and evolution of these galaxies.

Day 616

Friday.

1403.6827
Statistics of dark matter substructure: I. model and universal fitting functions
Jiang, van den Bosch

Present a SAM describing the evolution of DM sub haloes.  The model uses merger trees constructed using the method of Parkinson+2008 to describe the masses and redshifts of sub haloes at accretion, which are subsequently evolved using a simple model for the orbit-averaged mass loss rates.  The model is extremely fast, treats sub haloes of all orders, accounts for scatter in orbital properties and halo concentrations, and uses a simple recipe to convert sub halo mass to maximum circular velocity.  The model accurately reproduces the average sub halo mass in excess of 80% of its infall mass during its first radial orbit within the host halo.  Demonstrate that the total mass fraction in sub haloes is tightly correlated with the 'dynamical age' of the host halo, defined as the number of halo dynamical times that have elapsed since its formation.  Using this relation, present universal fitting functions for the evolved and involved sub halo mass and velocity functions that are valid for any host halo mass, at any redshift, and for any LCDM cosmology.

1403.6828
The effects of varying cosmological parameters on halo substructure
Dooley et al

Investigate how different cosmo params (e.g. WMAP and Planck) affect the nature and evolution of Dm halo substructure.  Use a series of flat LCDM cosmo N-body sims of structure formation, each with a different PS but the same initial white noise field.  Fiducial sim is based on WMAP7 cosmology.  Systematically vary the spectral index, matter density, and sigma8 for 7 unique sims.  Across these, study variations in the sub halo mass function, mass fraction, maximum circular velocity function, spatial distribution, concentration, formation times, accretion times, and peak mass.  Eliminate dependence of sub halo properties on host halo mass and average over many hosts to reduce variance.  While the "same" sub haloes from identical initial overdensity peaks in higher sigma8, ns, and Omega_m simulations accrete earlier and end up less massive and closer to the halo center at z=0, the process of continuous sub halo accretion and destruction leads to a steady state distribution of these properties across all sub haloes in a given host.  This steady state mechanism eliminates cosmological dependence on all properties listed above except sub halo concentration and V_max, which remain greater for higher sigma8, n_s and Omega_m sims, and sub halo formation time, which remains earlier.  Also find that the numerical technique for computing scale radius and the halo finder used can significantly affect the concentration-mass relationship computed for a simulation.

1403.7186
The Blanco cosmology survey: an optically-selected galaxy cluster catalog and a public release of optical data products
Bleem, … Busha, Gladders, High, Rest, Wechsler et al

The Blanco cosmology survey is a griz-band optical-imaging survey that covers 80 sq deg of the southern sky.  The survey consists of two fields roughly centered at ra,dec = 23h,-55d and 5h30m,-53d with imaging designed to reach depths sufficient for the detection of L* galaxies out to a redshift of one.  In this paper, describe the reduction of the survey data, the creation of calibrated source catalogs and a new method for the separation of stars and galaxies.  Search these catalogs for galaxy clusters at z<0.75 by identifying spatial over-densities of red-sequence galaxies.  Report the coordinates, redshift, and optical richness, Lambda, for 764 detected galaxy clusters at z<0.75.  This sample, >85% of which are new discoveries, has a median redshift of 0.52 and median richness Lambda(0.4L*) of 16.4.  Accompanying this paper, also release data products including the reduced images and calibrated source catalogs.  These products available over the web.

Day 615

Thursday.

1403.6469
Satellite masses compared to LCDM subhaloes
Tollerud, Boylan-Kolchin, Bullock

Compare the kinematics of M31's satellite galaxies to the mass profiles of the sub haloes they are expected to inhabit in LCDM.  Consider the most massive sub haloes of an approximately M31-sized halo, following the assumption of a monotonic galaxy luminosity-to-subhalo mass mapping.  While this abundance matching relation is consistent with the kinematic data for galaxies down to the luminosity of the bright satellites of the MW and M31, it is not consistent with kinematic data for fainter dwarf galaxies (those with L<~1e8 Lsun).  Comparing the kinematics of M31's dSph satellites to the sub haloes reveals that M31's dSph satellites are too low density to be consistent with the sub haloes' mass profiles.  A similar discrepancy has been reported between MW dSphs and their predicted sub haloes, the "too big to fail" problem.  By contrast, total mass profiles of the dwarf Elliptical (and similarly bright) satellites are consistent with the sub haloes.  However, they suffer from large systematic uncertainties in their DM content because of substantial (and potentially dominant) contributions from baryons within their half-light radii.

1403.6470
Evidence of very low metallicity and high ionization state in a strongly lensed, star-forming dwarf galaxy at z=3.417
Amorin et al

Investigate the gas-phase metallicity and Ly continuum escape fraction of a SL, extreme emission-line galaxy at z=3.417 in CANDELS.  Derive ionization and metallicity sensitive emission-line ratios from H+K band medium resolution spectroscopy.  The galaxy shows high ionization conditions, as evidenced by its enhanced [OIII]/[OII] and [OIII]/Hbeta ratios.  Consistently, strong-line methods based on the available line ratios suggest that this galaxy is an extremely metal-poor galaxy, with a metallicity of 12+log(O/H)<7.44 (<5% solar), placing it among the most metal-poor SF galaxies at z>3 discovered so far.  In combination with its low stellar mass (2e8 Msun) and high SFR (5 Msun/yr), the metallicity of this galaxy is consistent with the extrapolation to low masses of the mass-metallicity relation traced by Ly-break galaxies at z>3, but it is 0.55 dex lower than predicted by the fundamental metallicity relation at z<2.5.  These observations suggest the picture of a rapidly growing galaxy, possibly fed by the massive accretion of pristine gas.  Additionally, deep LBT/LBC in the UGR bands are used to derive a limit to the LyC escape fraction, thus allowing exploration of sub-L* galaxies at z>3.  Find a 1 sigma upper limit to the escape fraction of 23%, which adds a new observational constraint to recent theoretical models predicting that sub-L* galaxies at high-z have high escape fractions and thus are responsible for the reionization of the Universe.

1403.6591
Statistical properties of filaments in weak gravitational lensing
Higushi, Oguri, Shirasaki

Study WL properties of filaments that connect clusters of galaxies through large N-body sims.  Select 4k halo pairs with masses higher than 1e14 Msun/h from the simulations and investigate DM distributions between two haloes with ray-tracing simulations.  In order to classify filament candidates, estimate convergence profiles and perform profile fitting.  Find that matter distributions between haloes can be classified in a plane of fitting parameters, which allow selection of staring filaments from the ray-tracing simulations.  Also investigate statistical properties of these filaments, finding them to be consistent with previous studies.  Find that 35% of halo pairs possess strain filaments, 4% of which can directly be detected at S/N>2 with WL.  Furthermore, study statistical properties of haloes at the edges of filaments. Find that haloes are preferentially elongated along filamentary structures and are less massive with increasing filament masses.  However, the dependence of these halo properties on masses of straight filaments is weak.

1403.4932
The assembly histories of quiescent galaxies since z=0.7 from absorption line spectroscopy
Choi, Conroy, Moustakas, Graves, … Brown, van Dokkum, et al

Present results from modeling the optical spectra of a large sample of quiescent galaxies between 0.1<z<0.7 from SDSS and the AGN and AGES.  Examine how the stellar ages and abundance patters of galaxies evolve over time as a function of stellar mass from 1e9.6-11.8 Msun.  Galaxy spectra are stacked in bins of mass and redshift, and modeled over a wavelength range from 4000A to 5500A.  Full spectrum stellar population synthesis modeling provides estimates of the age and the abundances of the elements Fe, Mg, C, N, and Ca.  Find negligible evolution in elemental abundances at fixed stellar mass over roughly 7 Gyr of cosmic time.  In addition, the increase in stellar ages with time for massive galaxies is consistent with passive evolution since z=0.7.  Taken together, these results favor a scenario in which the inner ~0.3-3 Re of massive quiescent galaxies have been passively evolving over the last half of cosmic time.  Interestingly, the derived light-weighted ages are considerably younger than the age of the Universe at all epochs, suggesting an effective single-burst SF epoch of z<1.5.  These young stellar population ages coupled with the existence of massive quiescent galaxies at z>1 indicate the inhomogeneous nature of the z<0.7 quiescent population.  The data also permit the addition of newly-quenched galaxies at masses below ~1e10.5 Msun at z<0.7.  Additionally, analyze very deep Keck DEIMOS spectra of the two brightness quiescent galaxies in a cluster at z=0.83.  There is tentative evidence that these galaxies are older than their counterparts in low density environments.  In an Appendix, demonstrate that the full spectrum modeling technique allows for accurate and reliable modeling of galaxy spectra to low S/N and/or low spectral resolution
1403.4936
Predictions for microlensing planetary events from core accretion theory
Zhu, Penny, Mao, Gould, Gendron

Conduct the first microlensing simulation in the context of planet formation model.  THe planet population is taken from the Ida&Lin core accretion model of 0.3 Msun stars.  with 6690 microlensing events, find for a simplified Korea Microlensing Telescopes Network (KMTNet) the fraction of planetary events is 2.9%, out of which 5.8% show multiple-planet signatures.  The number of super-Earths, super-Neptunes and super-Jupiters detected are expected to be almost equal.  Simulation shows that high-magnification events and massive planets are favored by planet detections, which is consistent with previous expectation.  However, notice that extremely high-magnification events are less sensitive to planets, which is possibly because the 10 min sampling of KMTNet is not intensive enough to capture the subtle anomalies that occur near the peak.  This suggests that while KMTNet observations can be systematically analyzed without reference to any follow-up data, follow-up observations will be essential in extracting the full science potential of very high-magnification events.  The uniformly high-cadence observations expected for KMTNet also result in ~55% of all detected planets being non-caustic-crossing, and more low-mass planets even down to Mars-mass being detected via planetary caustics.  Also find that the distributions of orbital inclinations and planet mass ratios in multiple-planet events agree with the intrinsic distributions.

1403.4947
Relativistic weak lensing from a fully non-linear cosmological density field
Thomas, Bruni, Wands

In WL, observables are computed by ray-tracing through Newtonian N-body simulations, taking into account solely the Newtonian potential.  This has not previously been shown to be valid on non-linear scales.  Examine WL on NL scales and show that there are Newtonian and relativistic contributions, and that the latter can also be extracted from standard Newtonian simulations.  Use the post-Friedmann formalism, a post-Newtonian type framework for dealing with relativistic effects in the universe on all scales, to derive the full WL deflection angle valid on NL scales.  Deflection angle includes terms that are quadratic in the first order deflection, the first post-Newtonian corrections to the two scalar gravitational potentials and the effects of the vector and tensor contributions to the metric.  Show that the only contributing term that is quadratic in the first order deflection is the expected Born correction and lens-lens coupling term.  This deflection angle is valid for any metric theory of gravity.  The strength of this approach is that the form of the metric is well motivated, and the metric components are clearly related to the matter content once the gravitation theory has been specified.  Thus, specifying GR, write down a complete set of equations for a GR LCDM universe for computing all of the possible lensing terms from Newtonian N-body simulations.  Illustrate this with the vector potential and show that, in a LCDM universe, its contribution to the E-mode is negligible with respect to that of the Newtonian scalar potential, even on NL scales.  Thus, under the standard assumption that Newtonian N-body sims give a good approximation of the matter dynamics, this paper validates the standard ray tracing approach for a LCDM cosmology.

1403.5173
Complementarity of neutrino less double beta decay and cosmology
Dodelson, Lykken

Neutrinoless double beta decay experiments constrain one combination of neutrino parameters, while cosmic surveys constrain another.  This complementarity opens up an exciting range of possibilities.  If neutrinos are Majorana particles, and the neutrino masses follow an inverted hierarchy, then the upcoming sets of both experiments will detect signals.  The combined constraints will pin down not only the neutrino masses but also constrain one of the Majorana phases.  If the hierarchy is normal, then a beta decay detection with the upcoming generation of experiments is unlikely, but cosmic surveys could constrain the sum of the masses to be relatively heavy, thereby producing a lower bound for the neutrino less double beta decay rate, and therefore an argument for a next generation beta decay experiment.  In this case, a combination of the phases will be constrained.

1403.5231
Steps to reconcile inflationary tensor and scalar spectra
Miranda, Hu, Adshead

The recent BICEP2 B-mode polarization determination of an inflationary tensor-scalar ratio r=0.2 is in tension with simple scale-free models of inflation due to a lack of a corresponding low multipole excess in the temperature PS which places a limit of r<0.11 (95% CL) on such models.  Single-field inflationary models that reconcile these two observations, even those where the tilt runs substantially, introduce a scale into the scalar PS.  To cancel the tensor excess, and simultaneously explain the excess already present in LCDM, ideally the model should introduce this scale as a relatively sharp transition in the tensor-scalar ratio around the horizon at recombination.  Consider models which generate such a step in this quantity and find that they can improve the joint fit to the temperature and polarization data by up to 2 Delta ln L~-17 without changing cosmological parameters.  Precision E-mode polarization measurements should be able to test this explanation.

1403.5237
J-PAS: The Javalambre-Physics of the Accelerated Universe Astrophysical Survey
Benitez, et al

J-PAS is a narrow-band, very wide field cosmological survey to be carried out in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7 sq. deg camera with 1.2 Gpix.  Starting in late 2015, J-PAS will observe 8500 sqdeg of the Northern Sky and measure 0.003(1+z) photo-z for 9e7 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~14 Gpc^3 up to z=1.3 and becoming the first radial BAO experiment to reach Stage IV.  J-PAS will detect 7e5 galaxy clusters and groups, seeing constraints on DE which rival those obtained from its BAO measurements.  Thanks to the superb characteristics of the site (seeing ~0.7"), J-PAS is expected to obtain a deep, sub-arcsec image of the Northern sky, which combined with its unique photo-z precision will produce one of the most powerful cosmological lensing surveys before the arrival of Euclid.  J-PAS unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure sigma_z~0.5% redshifts of ~4000 SNeIa and ~900 core-collapse SNe.  The key to the J-PAS potential is its innovative approach: a contiguous system of 54 filters with 145 A width, placed 100 A apart over a multi-degree FoV is a powerful "redshift machine", with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build.  The J-PAS camera is equivalent to a 4.7 sqdeg IFU and it will produce a time-resolved, 3d image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby universe and the study of resolved stellar populations.

Day 614

Wednesday.

1403.6114
Variations in the initial mass function in early-type galaxies: a critical comparison between dynamical and spectroscopic results
Smith

Present a comparison between published dynamical and spectroscopic constraints on the stellar IMF in early-type galaxies, using the 34 galaxies in common between the two works.  Both studies infer an average IMF mass factor alpha (the stellar mass relative to Kroupa-IMF population of similar age and metallicity) greater than unity, i.e. both methods favor an IMF which is heavier than that of the MW, on average over the sample.  However, on a galaxy-by-galaxy basis, there is no correlation between alpha inferred from the two approaches.  Investigate how the two estimates of alpha are correlated systematically with the galaxy velocity dispersion, sigma, and with the Mg/Fe abundance ratio.  The spectroscopic method, based on the strengths of metal absorption lines, yields a correlation only with metal abundance ratios:at fixed Mg/Fe, there is no residual correlation with sigma.  The dynamical method, applied to exactly the same galaxy sample, yields the opposite result: the IMF variation correlates only with dynamics, with no residual correlation with Mg/Fe after controlling for sigma.  Hence although both methods indicate a heavy IMF on average in ellipticals, they lead to incompatible results for the systematic trends, when applied to the same set of galaxies.  Although other explanations are possible, the sense of the disagreement suggest that one (or both) of the methods has not accounted fully for the main confounding factors, i.e. element abundance ratios or DM contributions.

1403.6123
The birth of a galaxy - III. propelling reionisation with the faintest galaxies
Wise et al

...Find that low mass galaxies are just as efficient at producing ionizing photons per unit mass as atomic cooling haloes.  However, they are gradually photo-suppressed as they are engulfed in ionizing regions, giving way for larger galaxies to dominate the latter half of reionization.  …   Work suggests that a yet-to-be observed population of low-mass galaxies was responsible for starting reionization at very high z.

1403.6124
Why stellar feedback promotes disc formation in simulated galaxies
Übler et al

Study how feedback influences baryon infall onto galaxies using cosmological, zoom-in simulations of haloes with present mass Mvir=6.9e11 Msun to 1.7e12 Msun.  Starting at z=4 from identical IC, implementations of weak and strong stellar feedback produce bulge- and disc-dominated galaxies, respectively.  Strong feedback favors disc formation: (1) because conversion of gas into stars is suppressed at early times, as required by abundance matching arguments, resulting in flat SFH and higher gas fractions; (2) because 50% of the stars form in situ from recycled disc gas with angular momentum only weakly related to that of the z=0 dark haloes; (3) because late-time gas accretion is typically an order of magnitude stronger and has higher specific angular momentum, with recycled gas dominated over primordial infall; (4) because 25-30% of the total accreted gas is ejected entirely before z~1, removing primarily low angular momentum material which enriches the nearby IGM.  Most recycled gas roughly conserves its angular momentum, but material ejected for long times and to large radii can gain significant angular momentum before re-accretion.  These processes lower galaxy formation efficiency in addition to promoting disc formation.

1403.6125
The X-ray spectra of the first galaxies: 21cm signatures
Paucci et al

X-ray SED can have a significant impact on interferometric observations.  These galaxies ave ubiquitous, subu-keV thermal emission from the hot ISM, which generally dominates the soft X-ray luminosities (with energies below 1 keV, sufficiently low to significantly interact with the IGM)….IGM temperature fluctuations in the early universe would be substantially increased if the X-ray spectra of the first galaxies were dominated by the hot ISM, compared with X-ray binaries with harder spectra.  Show that the peak in the redshift evolution of the large-scale (k=0.2/Mpc) 21cm power is a robust probe of the soft-band SED of the first galaxies, and is not degenerate with their bolometric luminosities.

1403.6310
How much can we learn about the physics of inflation?
Dodelson

The recent BICEP2 measurement of B-modes in the polarization of the CMB suggests that inflation was driven by a field at an energy scale of 2e16 GeV.  Explore the potential of upcoming CMB polarization experiments to further constrain the physics underlying inflation.  If the signal is confirmed, then two sets of experiments covering larger area will shed light on inflation.  Low resolution measurements can pin down the tensor to scalar ratio at the percent level, thereby distinguishing models from one another.  A high angular resolution experiment will be necessary to measure the tilt of the tensor spectrum, testing the consistency relation that relates the tilt to the amplitude.

Day 613

Tuesday.

1403.5559
The extent of the MgII absorbing circum-galactic medium of quasars
Farina et al

Investigate the extent and the properties of the MgII cool, low-density absorbing gas located in the halo and in the circum-galactic environment of quasars, using a sample of 31 projected quasar pairs with impact parameter pd<200kpc in the range 0.4<z<1.6.  In the transverse direction, detect 18 MgII absorbers associated with the FG quasars, while no absorption system originated by the gas surrounding the quasar itself is found along the LoS.  This suggests that the quasar emission induces an anisotropy in the absorbing gas distribution.  Observations indicate that the covering fraction (fc) of MgII absorption systems with rest frame equivalent width Wr(2796)>0.3 A. ranges from fc~1.0 at pd<65kpc to fc~0.2 at pd>150kpc, and appears to be higher than for galaxies.  Findings support a scenario where the luminosity/mass of the host galaxies affect the extent and the richness of the absorbing MgII circum-galactic medium.

1403.5563
Galaxies in filaments have more satellites: the influence of the cosmic web on the satellite luminosity function in the SDSS
Guo, Tempel, Libeskind

Investigate if the satellite luminosity function (LFs) of primary galaxies identified in SDSS DR8 depends on whether the host galaxy is in a filament or not.  Isolated primary galaxies are identified in the SDSS spectra sample while potential satellites are searched for in the much deeper photometric sample.  Filaments are constructed from the galaxy distribution by the "Bisous" process.  Isolated primary galaxies are divided into two subsamples: those in filaments and those not in filaments.  Examine the stacked mean LF of each sample and found that, in the mean, the satellite LFs of primary galaxies (extending to at least 4 magnitude fainter than the primary galaies) in filaments is significant higher than those of primary galaxies not in filaments.  The filamentary environment can increase the abundance of the brightest satellites (Msat<Mprim+2), by a factor of ~2 compared with non-filament galaxies.  This result is independent of primary galaxy magnitude, although the satellite LF of galaxies in the faintest magnitude bin is too noisy to determine if such a dependent exists.  Since filaments are extracted from a flux-limited sample, consider the possibility that the difference in satellite LF is due to a z, color, or environment bias, finding these to be insufficient to explain the result.  The dependence of the satellite LF on the cosmic web suggests that the filamentary environment may have a strong effect on the efficiency of galaxy formation.

1403.5755
Absolute-magnitude distributions of supernovae
Richardson et al

As the title says.  For 7 SN types.

1403.5898
Background power subtraction in Lyman-alpha forest
Irsic, Slosar

When measuring the 1d PS of the Lya forest, it is common to measure the PS in flux fluctuations red-ward of the Lya emission of quasars and subtract this power form the measurements of the Lya flux power spectrum.  This removes excess power present in the Lya forest which is believed to be dominated by metal absorption by the low-redshift metals uncorrelated with the neutral hydrogen absorbing in Lya.  In this report, note that assuming the contaminants are additive in optical depth, the correction contains a second order term.  Estimate the magnitude of this term for two currently published measurements of the 1d Lya flux PS and show that it is negligible for the current generation of measurements.  However, future measurements will have to take this into account when errors improve by a factor of 2 or more.

0511164
Galaxy halo mass and satellite fractions from galaxy-galaxy lensing in the SDSS: stellar mass, luminosity, morphology, and environment dependencies
Mandelbaum, Seljak, Kauffmann, Hirata, Brinkmann

The relationship between galaxies and DM can be characterized by the halo mass of the central galaxy and the fraction of galaxies that are satellites.  Present observational constraints from the SDSS on these quantities as a function of r-band luminosity and stellar mass using gg WL, with a total of 351k lenses.  Use stellar masses derived from spectroscopy and virial halo masses derived from WL to determine the efficiency with which baryons in the halo of the central galaxy have been converted into stars.  Find that an L* galaxy with a stellar mass of 6e10 Msun is hosted by a halo with mass 1.4e12 Msun/h, independent of morphology, yielding baryon conversion efficiencies of 17 (early) and 16 (late)% at the 95% CL (statistical, not including systematic uncertainty due to assumption of a universal IMF).  Find that for a given stellar mass, the halo mass is independent of morphology below M*=1e11 Msun, in contrast to typically a factor of 2 difference in halo mass between ellipticals and spirals at a fixed luminosity.  This suggests that stellar mass is a good proxy for halo mass in this range and should be used preferentially whenever a halo mass selected sample is needed.  For higher stellar masses, the conversion efficiency is a declining function of stellar mass, and the differences in halo mass between early and late types become larger, reflecting the fact that most group and cluster haloes with masses above 1e13 Msun host ellipticals at the center, while even the brightest central spirals are hosted by haloes of mass below 1e13 Msun.

Day 612

Thursday.  Monday.

1403.4599
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Signs of neutrino mass in current cosmological datasets
Beutler, Saito, … Percival, Ross, Ross, Samushia, Seo, Tinker, et al

Investigate the cosmological implications of the growth of structure measurements from BOSS CMASS DR11 with particular focus on the sum of neutrino masses.  Examine the robustness of the cosmological constraints from BAO scale, the Alcock-Paczynski effect and redshift-space distortions (D_v/r_s, F_AP, f*sigma_8), when introducing a neutrino mass in the PS template.  Any shift in the CMASS constraints is below 0.5 sigma when changing Sum m_nu from 0eV to 0.4 eV, which roughly represents the currently allowed range for this parameter.  Then discuss how the neutrino mass relaxes discrepancies between the CMB and other low-z measurements within LCDM.  Combining cosmo constraints with WMAP9 yields Sum m_nu=0.36pm0.14 eV, which represents a 2.6 sigma preference for neutrino mass.  The significance can be increase to 3.3 sigma when including WL results and other BAO constraints, yielding Sum m_nu=0.35pm0.10 eV.  However, combining CMASS with Planck reduces the preference for neutrino mass to ~2 sigma.  When removing the CMB lensing effect in the Planck temperature PS (by marginalizing over A_L), see shifts of ~1 sigma in sigma_8 and Omega_m, which have a significant effect on the neutrino mass constraints.  In case of CMASS plus Planck without the A_L-lensing signal, find a preference for a neutrino mass of Sum m_nu=0.34pm0.14 eV, in excellent agreement with the WMAP9+CMASS value.  The constraint can be tightened to 3.4 sigma yielding Sigma m_nu=0.36pm0.10eV when WL data and other BAO constraints are included.

1403.5265
Temporal self-organization in galaxy formation
CenFind a relation between the number of SF peaks per unit time and the size of the temporal smoothing window function.  This relation holds over the range of Delta t = 10 to 1000 Myr that can be reliably computed, using a large sample of galaxies obtained from cosmo hydro sims.  This means that the temporal distribution of SF peaks in galaxies as a population is fractal.  This reveals that the superficially chaotic process of galaxy formation is underlined by a temporal self-orgainziattion up to at least 1 Gyr.  Given the known existence of spatial fractals (such as the power-law 2pt function of galaxies), there is a joint spatio-temporal self-organization in galaxy formation.  From an observational perspective, it will be urgent to devise diagnostics to probe SF histories of galaxies with good temporal resolution to facilitate a test of this prediction.  If confirmed, it would provide unambiguous evidence for a new picture of galaxy formation that is interaction driven, cooperative and coherent in and between time and space.  Unravelling its origin may hold the key to understanding galaxy formation.

1403.5269
Bulge mass is king: the dominant role of the bulge in determining the fraction of passive galaxies in the Sloan digital sky survey
Bluck, … Moreno, et al

Investigate the origin of galaxy bimodality by quantifying the relative role of intrinsic and environmental drivers to the cessation (or `quenching') of star formation in over half a million local SDSS galaxies.  Sample contains a wide variety of galaxies at z=0.02-0.2, with stellar masses of 8<log(M*/Msun)<12, spanning the entire morphological range from pure disks to spheroids, and over four orders of magnitude in local galaxy density and halo mass.  Utilize published SFRs and add to this the recent GIM2D photometric and stellar mass bulge+disk decompositions from the group.  Find that the passive fraction of galaxies increases steeply with stellar mass, halo mass, and bulge mass, with a less steep dependence on local galaxy density and bulge-to-total stellar mass ratio (B/T).  At fixed internal properties, find that central and satellite galaxies have different passive fraction relationships.  For centrals, conclude that there is less variation in the passive fraction at a fixed bulge mass, than for any other variable, including total staler mass, halo mass, and B/T.  This implies that the quenching mechanism must be most tightly coupled to the bulge.  Argue that radio mode AGN feedback offers the most plausible explanation of the observed trends.

1403.5271
CMB polarization can constrain cosmology better than CMB temperature
Galli, et al

Demonstrate that for a cosmic variance limited experiment, CMB E polarization alone places stronger constraints on cosmo params than CMB temperature.  Show that EE can constrain parameters better than TT by a factor of 2.8 when a multipole range of ell=30-2500 is considered.  Expose the physical effects at play behind this result and study how it depends on the multipole range included in the analysis.  In most relevant cases. TE or EE surpass the TT based cosmological constraints.  This result is important as the small scale astrophysical FGs are expected to have much reduced impact on polarization, thus opening the possibility of building cleaner and more stringent constraints of the LCDM model.  This is relevant specially for proposed future CMB satellite missions, such as CORE or PRISM, that are resigned to be cosmic variance limited in polarization till very large multipoles.  Perform the same analysis for a Planck-like experiment, and conclude that even in this case TE alone should determine the constrain on Omega_c h^2 better than TT by 15%, while determining Omega_b h^2, n_s and theta with comparable accuracy.  Explore a few classical extensions of the LCDM model and show again that CMB polarization alone provides more stringent constraints than CMB temperature in case of a cosmic variance limited experiment.

1403.5274
Frequent spin reorientation of galaxies due to local interactions
Cen

Study the evolution of angular momenta of M*=1e10-12 Msun galaxies utilizing large-scale ultra-high resolution cosmological hydro sims and find that spin of the stellar component changes direction frequently, caused by major mergers, minor mergers, significant gas inflows and toques by nearby systems.  The rate and nature of change of spin direction can not be accounted for by large-scale tidal torques, because the latter fall short in rates by orders of magnitude and because the apparent random swings of the spin direction are inconsistent with alignment by linear density field.  The implications for galaxy formation as well as intrinsic alignment of galaxies are profound.  Assuming the large-scale tidal field is the sole alignment agent, a new picture emerging is that intrinsic alignment of galaxies would be a balance between slow large-scale coherent torquing and fast spin reorientation by local interactions.  What is still open is whether other processes, such as feeding galaxies with gas and stars along filaments or sheets, introduce coherence for spin directions of galaxies along the respective structures.

1403.5466
New observations of z~7 galaxies: evidence for a patchy reioinzation
Pentericci et al

New results from z~7 galaxy search from deep spectra observations of candidate z-dropouts in the CANDELS fields.  Despite the extremely low flux limits achieved by the observations, only 2 galaxies have robust redshift identifications, one from Lya emission at z=6.65, the other from its Lyman-break, consistent with z=6.42, but with no emission line.  In addition, for 23 galaxies, present deep limits in the Lya EW derived from the non detections in ultra-deep observations.  Using this new data as well as previous samples, assemble a total of 68 candidate z~7 galaxies with deep spectroscopic observations, of which 12 have a line detection.  With this much enlarged sample, can place solid constraints on the declining fraction of Lya emission in z~7 Lyman break galaxies compared to z~6, both for bright and faint galaxies.  Applying a simple analytical model, show that the present data favor a patchy reionization process rather than a smooth one.

1403.5499
A universal density profile for cosmic voids
Hamaus, Sutter, Wandelt

Present a simple empirical function for the average density profile of cosmic voids, identified via the LCDM N-body sims.  This function is universal across void size and z,  accurately describing the entire radial range of scales around void centers with only two free parameters. In analogy to halo density profiles, these parameters describe the scale radius and the central density of voids.  Initially start with a more general 4-parameter model, find two of its parameters to be redundant, as they follow linear trends with the scale radius in two distinct regimes of the void sample, separated by its compensation scale.  Assuming linear theory, derive an analytic formula for the velocity profile of voids and find an excellent agreement with the numerical data as well.  In the companion paper, the presented density profile is shown to be universal even across tracer type, properly describing voids defined in halo- and galaxy distributions of varying sparsity, allowing to relate various void populations by simple rescalings.  This provides a powerful framework to match theory and simulations with observational data, opening up promising perspectives to constrain competing models of cosmology and gravity.

*** Galaxy-galaxy lensing review section ***

9503073
Measuring galaxy masses using galaxy-galaxy gravitational lensing
Brainerd, Blandford, Smail

Detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies due to gravitational lensing by FG galaxies.  A mean image polarization of <p>=0.011pm0.006 is measured for 3203 pairs of source galaxies with 23<r<=24 and lens galaxies with magnitudes 20<=r<=23.  The signal remains strong for lens-source separations <90", consistent with quasi-isothermal galaxy haloes extending to large radii (100 kpc/h).  Observations thus provide the first evidence from WL of large scale dark haloes associated with individual galaxies.  The observed polarization is also consistent with the signal expected on the basis of simulations incorporating measured properties of local galaxies and modest extrapolations of the observed z distribution of faint galaxies.  From the simulations, derive a best-fit halo circular velocity of V~220 km/s and characteristic radial extant of s~100 kpc/h on the order of 1e12 Msun/h, in good agreement with recent dynamical estimate of the masses of local spiral galaxies.  This is particularly encouraging as the lensing and dynamical mass estimators rely on different sets of assumptions.  Contamination of the gravitational lensing signal by a population of tidally distorted satellite galaxies can be ruled out with reasonable confidence.  The prospects for corroborating and improving this measurement seem good, especially using deep HST archival data.

9711341
Galaxy-galaxy lensing in the Hubble deep field: the halo Tully-Fisher relation at intermediate redshift
Hudson, Gwyn, Dahle, Kaiser

A tangential distortion of background source galaxies around foreground lens galaxies in the HDF is detected at 88.3% CL.  An important element of the analysis is the use of photometric redshifts to determine distances of lens and source galaxies and rest-frame B-band luminosities of the lens galaxies.  The lens galaxy haloes obey a TF relation between halo circular velocity and luminosity; the typical lens galaxy, at z=0.6, has a circular velocity of 210pm40 km/s at M_B=-18.5, if q_0=0.5.  Control tests, in which lens and source positions and source ellipticities are randomized, confirm the significance level of the detection quoted above.  Furthermore, a marginal signal is also detected from an independent, fainter sample of source galaxies without photo-z.  Potential systematic effects, such as contamination by aligned satellite galaxies, the distortion of source shapes by the light of the FG galaxies, PSF anisotropies, and contributions from mass distributed on the scale of galaxy groups are shown to be negligible.  A comparison of the result with the local TF relation indicates that intermediate-z galaxies are fainter than local spirals by 1pm0.6 B mag at a fixed circular velocity.  This is consistent with some spectroscopic studies of the rotation curves of intermediate-z galaxies.  This result suggest that the strong increase in the global luminosity density with z is dominated by evolution in the galaxy number density.

9912119
Weak lensing with SDSS commissioning data: the galaxy-mass correlation function to 1/h Mpc
SDSS Collaboration, Fischer, et al

Present measurements of gg lensing from early commissioning imaging data from SDSS.  Measure a mean tangential shear around a stacked sample of FG galaxies in 3 bandpasses out to angular radii of 600", detecting the shear signal at very high statistical significance.  The shear profile is well described by a power-law.  A variety of rigorous tests demonstrate the reality of the gravitational lensing signal and confirm the uncertainty estimates.  Interpret results by modeling the mass distributions of the FG galaxies as approximately isothermal spheres characterized by a velocity dispersion and truncation radius.  The velocity dispersion is constrained to be 150-190 km/s at 95% confidence (145-195 km/s including systematic uncertainties), consistent with previous determinations but with smaller error bars.  Detection of shear at large angular radii sets a 95% confidence lower limit s>140", corresponding to a physical radius of 260 kpc/h, implying that galaxy haloes extend to very large radii.  However, it is likely that this is being biased high by diffuse matter in the haloes of groups and clusters.  Also present a preliminary determination of the galaxy-mass correlation function finding a correlation length similar to the galaxy autocorrelation function and consistency with a low matter density universe with modest bias.  The full SDSS will cover an area 44 times larger and provide spectroscopic z for the FG galaxies, making it possible to greatly improve the precision of these constraints, measure additional parameters such as halo shape, and measure the properties of DM haloes separately for many different classes of galaxies.

0108013
Galaxy mass and luminosity scaling laws determined by weak gravitational lensing
McKay, Sheldon, … Fischer, Seljak, et al

New measurements of scaling laws relating the luminosity of galaxies to the amplitude and shape of their dark matter haloes.  Early imaging and spectroscopic data from SDSS are used to make WL measurements of the surface mass density contrast Delta Sigma_+ around classes of lens objects.  This surface mass density contrast as a function of radius is a measure of the galaxy-mass correlation function (GMCF).  Because spectroscopic z are available for all lens objects, the mass and distance scales are well constrained.  The GMCF measured around ~31,000 lenses is well fit by a power law of the form Delta Sigma_+=.24 (R/1 Mpc)^-0.8 h Msun / pc^2.  Compare this GMCF to galaxy luminosity, type, and environment, and find that it varies strongly with all three.  Quantify these variations by comparing the normalization of a fit to the inner 260 kpc/h M_260, to the galaxy luminosity.  While M_260 is not strongly related to luminosity in bluest band u', there is a simple, linear relation between M_260 and luminosity in redder bands (g', r', i' and z').  Test the universality of these M/L scalings by independently measuring them for spiral and elliptical galaxies, and for galaxies in a variety of environments.  Find remarkable consistency in these determinations in the red bands, especially i' and z'.  This consistency across a wide range of systems suggests that the measured scaling represents an excellent cosmic average, and that the integrated SFH of galaxies is strongly related to the dark matter environments in which they form.

0211633
Lensing bay galaxies in CNOC2 fields
Hoekstra, Franx, Kuijken, Carlberg, Yee

Observed two blank fields of approximate 30'x23'; the fields have been studied as part of the CNOC2 survey, and spec-zs are available for 1125 galaxies in the two fields.  Measured the leaning signal caused by large scale structure, and found the the result is consistent with current, more accurate measurements.  Study the gg lensing signal of 3 overlapping samples of lenses, and detect a significant signal in all cases.  The estimates for the velocity dispersion of an L* galaxy agree well for the various samples.  The best fit singular isothermal sphere model to the ensemble averaged tangential distortion around the galaxies with redshifts yields a velocity dispersion of sigma_*=130km/s, in agreement with other studies.  Use a maximum likelihood analysis, where a parameterized mass model is compared to the data, to study the extent of galaxy DM haloes.  Making use of all available data, find sigma*=111 km/s (68.3% CL) for a truncated isothermal sphere model in which all galaxies have the same M/L ratio.  The value of the truncation parameter is not constrained that well, and find s*=260 kpc/h (68.3% CL).  The gg lensing analysis allows estimation of the average M/L ratio of the field, which can be used to estimate Omega_m.  The current result, however, depends strongly on the assumed scaling relation for s.

0312036
The galaxy-mass correlation function measured from weak lensing in the SDSS
Sheldon, Johnston, Frieman, Scranton, McKay, Connolly, Budavari, Zehavi, Bahcall, Brinkmann, Fukugita

Present gg lensing measurements over scales 0.025 to 10 Mpc/h in the SDSS.  Using a flux-limited sample of 127k lens galaxies with spec-z and mean luminosity <L>=L* and 9M source galaxies with photo-z, invert the lensing signal to obtain the galaxy-mass correlation function xi_{gm}.  Find xi_{gm} is consistent with a power-law, xi_gm=(r/r0)^-gamma, with best-fit parameters gamma=1.79pm0.06 and r0=5.4pm0.7(0.27/Omega_m)^{1/gamma} Mpc/h.  At fixed separation, the ratio xi_gg/xi_gm= b/r where b is the bias and r is the correlation coefficient.  Comparing to the galaxy auto-correlation function for a similarly selected sample of SDSS galaxies, find that b/r is approximately scale independent over scales 0.2-6.7 Mpc/h, with mean <b/r>=1.3 (Omega_m/0.27).  Also find no scale dependence in b/r for a volume limited sample of luminous galaxies (-23<Mr<-21.5).  The mean b/r for this sample is <b/r>_{Vlim}=2(Omega_m/0.27).  Split the lens galaxy sample in to subsets based on luminosity, color, spectral type, and velocity dispersion, and see clear trends of the lensing signal with each of these parameters.  The amplitude and logarithmic slope of xi_gm increases with galaxy luminosity.  For high luminosities (L~5L*), xi_gm deviates significantly from a power law.  These trends with luminosity also appear in the subsample of red galaxies, which are more strongly clustered than blue galaxies.

0403698
Large scale bias and stochasticity of halos and dark matter
Seljak, Warren

On large scales galaxies and their haloes are usually assumed to trace the dark matter with a constant bias and DM is assumed to trace the linear density field.  Test these assumption using several large N-body sims with 384^3-1024^3 part ices and box sizes between 100-1000 h/Mpc, which can both resolve the small galactic size haloes and sample the large scale fluctuations.  Explore the average halo bias relation as a function of halo mass and show that existing fitting formulae overestimate the halo bias by up to 20% in the regime just below the NL mass.  Propose a new expression that fits simulations well.  Find that the halo bias is nearly constant, b~0.65-0.7, for masses below 1/10th of the NL mass.  Explore next the relation between the initial and final DM in individual Fourier modes and show that there are significant fluctuations in their ratio, ranging from 10% rms at k~0.03 h/Mpc to 50% rms at k~0.1 h/Mpc.  Argue that these large fluctuations are caused by perturbative effects beyond the linear theory, which are dominated by long wavelength modes with large random fluctuations.  Similar or larger fluctuations exist between halos and DM and between haloes of different mass. While these fluctuations are small compared to the sampling variance, they are significant for attempts to determine the bias by relating directly the maps of galaxies and DM or the maps of different galaxy populations, which would otherwise be immune to sampling variance.

0605476
Density profiles of galaxy groups and clusters from SDSS galaxy-galaxy weak lensing
Mandelbaum, Seljak, Cool, Blanton, Hirata, Brinkmann

Present results of a measurement of the shape of the density profile of galaxy groups and clusters traced by 43k LRGs with spec-z from SDSS.  The galaxies are selected such that they are the brightest within a cylindrical aperture, split into two luminosity samples, and modeled as the sum of stellar and DM components.  Present a detailed investigation of many possible systematic effects that could contaminate the signal and develop methods to remove them, including a detected intrinsic alignment of galaxies within 100 kpc/h of LRGs which is removed using photo-z information.  The resulting lensing signal is consistent with NFW profile DM haloes; the SIS profile is ruled out at the 96 (conservatively) and 99.96% CL for the fainter and brighter lens samples (respectively) when they are fit using lensing data between 40 kpc/h and 2Mpc/h with total S/N of 19 and 25 for the two lens maples.  The lensing signal amplitude suggests that the faint and bright sample galaxies typically reside in haloes of mass 2.9e13 Msun/h and 6.7e13 Msun/h respectively, in good agreement with predictions based on halo spatial density with normalization lower that the 'concordance' sigma_8=0.9. When fitting for the concentration parameter in the NFW profile, find c=5.0 and 5.6 for the faint and bright samples, consistent with LCDM simulations.  Also split the bright sample further to determine masses and concentrations for cluster-mass haloes, finding mass 1.3e14 Msun/h for the sample f LRGs brighter than -22.6 in r.

2006A&A…544..441K
Weak lensing measurements of dark matter haloes of galaxies from COMBO-17
Kleineinrich, Schneider, Rix, Erben, Wolf, Schirmer, Meisenheimer, Borch, Dye, Kovacs, Wisotzki

Present mass estimates for DM haloes around galaxies from the COBMO-17 survey using weak gravitational lensing.  COMBO-17, with photometry in 17 optical filters, provides precise photometric redshifts and spectral classification for objects with R<24.  This permits to select and sort lens and source galaxies by their redshifts and lens luminosity or color, which bypasses many uncertainties in other WL analysis arising from broadly estimated source and lens redshifts.  Study the shear created by DM haloes around 12k galaxy lenses at 0.2<z<0.7 by fitting the mass normalization of either singular isothermal spheres (SIS) or NFW profiles to BG source orientations around the whole lens sample.  Also consider haloes around blue and red subsamples separately and constrain the scaling of halo mass with light.  For the NFW model, find virial masses M*_vir=3.9e11 Msun/h for blue and 7.1e11 Msun/h for red galaxies of L*=1e10 Lsun/h^2, respectively.  The 1 sigma uncertainty on log M*vir for the whole lens sample is about 0.2.  Compare results to those obtained from RCS and SDSS. Taking differences in the actual modeling into account, find very good agreement with these surveys.

0707.1698
The masses and shapes of dark matter halos from galaxy-galaxy lensing in the CFHTLS
Parker, Hoekstra, Hudson, Van Waerbeke, Mellier

Present the first gg WL results using early data from CFHTLS.  These results are based on ~22 sq deg of i' data.  From this data, estimate the average velocity dispersion for an L* galaxy at z~0.2 to be 137 km/s, with virial mass M200 of 1.1e12 Msun/h and a rest frame R-band M/L ratio of 173 h Msun/Lsun.  Also investigate various possible sources of systematic error in detail.  Additionally, separate lens sample into two sub-samples, divided by apparent magnitude, thus average redshift.  From this early data, do not detect significant evolution in galaxy DM halo M/L ratios in 0.45<z<0.27.  Finally, test for non-spherical galaxy dark matter haloes.  Results favor a DM halo with an ellipticity of ~0.3 at the 2 sigma level when averaged over all galaxies.  If the sample of FG lens galaxies is selected to favor ellipticals, the mean halo ellipticity and significant of this result increase.

0805.3459
Relative clustering and the joint halo occupation distribution of red-sequence and blue-cloud galaxies in COMBO-17
Simon, Hetterscheidt, Wolf, Meisenheimer, Hildebrandt, Schneider, Schirmer, Erben

Study the relative spatial distribution of red-sequence and blue-cloud galaxies, and their relation to the dark matter distribution in the COMBO-17 survey as function of scale down to z~1.  Measure the 2nd order auto-and cross-correlation functions of galaxy clustering and express the relative biasing by using aperture statistics.  Also estimated is the relation between the galaxies and the DM distribution exploiting GGL.  All observables are further interpreted interns of a halo mode.  To fully explain the galaxy clustering cross-correlation function with a halo model, need to introduce a new parameter, R, that describes the statistical relation between numbers of red and blue galaxies within the same halo.  Find that red and blue galaxies are clearly differently clustered.  A significant evolution of the relative clustering with redshift was not found.  There is evidence for a scale-dependence of relative biasing.  The relative clustering, the GGL and, with some tension, the galaxy numbers can be explained consistently within a halo model.  For the cross-correlation function one requires a HOD variance that becomes Poisson even for relatively small occupancy numbers.  For the sample, this rules out with high confidence a "Poisson satellite" scenario as found in SAM.  Red galaxies have to be concentrated towards the halo center, either by a central red galaxy or bay a concentration parameter above that for DM.  The value of R depends on the presence or absence of central galaxies: if no central galaxies or only red central galaxies are allowed, R is consistent with zero, whereas a positive correlation R=0.5pm0.2 is needed if both blue and red galaxies can have central galaxies.

1104.0928
New constraints on the evolution of the stellar-to-dark matter connection: a combined analysis of galaxy-galaxy lensing, clustering, and stellar mass functions from z=0.2 to z=1
Leauthaud et al

Using data from COSMO, perform the first joint analysis of gg WL, galaxy spatial clustering, and galaxy number densities.  Carefully accounting for sample variance and for scatter between stellar and halo mass, model all 3 observables simultaneously using a novel and self-consistent theoretical framework.  Results provide strong constraints on the shape and z evolution of the stellar-to-halo mass relation (SHMR) from z=0.2 to 1.  At low stellar mass, find that halo mass scales with Mh ~ M*^0.46 and that this scaling does not evolve significantly with redshift to z=1.  Show that the dark-to-stellar ratio, Mh/M*, varies from low to high masses, reaching a minimum of Mh/M*~27 at M*=4.5e10 Msun and Mh=1.2e12 Msun.  This minimum is important for models of galaxy formation because it marks the mass at which the accumulated stellar growth of the central galaxy has been the most efficient.  Describe the SHMR at this minimum in terms of the "pivot stellar mass", M*piv, the "pivot halo mass", Mhpiv, and the "pivot ratio", (Mh/M*) piv.  Thanks to a homogeneous analysis of a single data set, report the first detection of mass downsizing trends for both Mhpiv and M*piv.  The pivot stellar mass decreases from M*piv=5.75e10 Msun at z=0.88 to M*piv=3.55e10Msun at z=0.37.  Intriguingly, however, the corresponding evolution of Mhpiv leaves the pivot ratio constant with redshift at (Mh/M*)piv~27.  Use simple arguments to show how this result raises the possibility that SF quenching may ultimately depend on Mh/M* and not simply Mh, as is commonly assumed.  Show that simple models with such a dependence naturally lead to downsizing in the sites of SF.  Finally, discuss the implications of realists in the context of popular quenching models, including disk instabilities and AGN feedback.

1107.4093
Galaxy-galaxy lensing constraints on the relation between baryon and dark matter in galaxies in the red sequence cluster survey 2
van Uitert, Hoekstra, Velander, Glibank, Gladders, Yee

Present the results of a study of WL by galaxies using image data that were obtained as part of RCS2.  In order to compare to the baryonic properties of the lenses, focus on the ~300 sq deg that overlap with DR7 of SDSS.  The depth and image quality of the RCS2 enables significantly to improve upon earlier work for luminous galaxies at z>=0.3.  Comparison with dynamical masses from the SDSS shows a good correlation with the lensing mass for early-type galaxies.  For low luminosity (stellar mass) early-type galaxies, find a satellite fraction of ~40% which rapidly decreases to <10% with increasing luminosity (stellar mass).  The satellite fraction of the late-types has a value in the range 0-15%.  Find that early-types in the range 1e10<L_r<1e11.5 Lsun have virial masses that are about five times higher than those of late-type galaxies and that the mass scales as M_200 ~ L^2.34.  Also measure the viral M/L ratio, and find for L_200<1e11 Lsun a value of M200/L200=42 for early types, which increases for higher luminosities to values that are consistent with those observed for groups and clusters of galaxies.  For late-type galaxies, find a lower value of M200/L200=17.  Measurements also show that early- and late-type galaxies have comparable halo masses for stellar masses M*<1e11 Msun, whereas the virial masses of early-type galaxies are higher for higher stellar masses.  Finally, determine the efficiency with which baryons have been converted into stars.  Results for early-type galaxies suggest a variation in efficiency with a minimum of ~10% for a stellar mass M*,200=1e12 Msun.  The results for the late-type galaxies are not well constrained, but do suggest a larger value.

1207.1120
Cosmological parameter constraints from galaxy-galaxy lensing and galaxy clustering with the SDSS DR7
Mandelbaum, Slosar, Baldauf, Seljak, Hirata, Nakajima, Reyes, Smith

Studies have show that the cross-correlation coefficient between galaxies and DM is very close to unity on scales outside a few virial radii of galaxy haloes, independent of the details of how galaxies populate DM haloes.  The finding makes it possible to determine the DM clustering from measurements of GG WL and galaxy clustering.  Present new cosmological parameter constraints banished on large-scale measurements of spectroscopic galaxy samples from SDSS DR7.  Generalise the approach of Baldauf+2010 to remove small scale information (<2 and 4 Mpc/h for lensing and clustering measurements, respectively), where the cross-correlation coefficient differs from unity.  Derive constraints for 3 galaxy samples covering 7131 sq deg, containing 69k, 62k, and 35k galaxies with mean z of 0.11, 0.28, 0.40.  Clearly detect scale-dependent galaxy bias for the more luminous galaxy samples, at a level consistent with theoretical expectations.  When vary both sigma_8 and Omega_m (and marginalize over NL galaxy bias) in a flat LCDM model, the best-constrained quantity is sigma_8(Omega_m/0.25)^0.57=0.80 (1sigma, stat+sys), where statistical and systematic errors have comparable contributions, and n_s=0.96 and h=0.7 are fixed.  These strong constraints on the matter clustering suggest that this method is competitive with cosmic shear in current data, while having very complementary and in some ways less serous systematics.  Therefore expect that this method will play a prominent role in future WL surveys.  When combine these data with WMAP7 CMB data, constraints on sigma_8, Omega_m, H0, w_de and Sum m_nu become 30-80% tighter than with CMB data alone, since WL data break several parameter degeneracies.

1304.4265
CFHTLenS: the relation between galaxy dark matter haloes and baryons from weak gravitational lensing
Velander et al

Present a study of the relation between DM halo mass and the baryonic content of host galaxies, quantified via luminosity and stellar mass.  Investigation uses 154 deg2 of CFHTLenS lensing and photometric data.  Employ a gg lensing halo model which allows constraining the halo mass and satellite fraction.  Analysis is limited to lenses at 0.2<z<0.4.  Express the relationship between halo mass and baryonic observable as a power law.  For the luminosity-halo mass relation, find a slope of 1.32pm0.06 and a normalization of 1.19pm0.06e13 Msun/h70 for red galaxies, while for blue galaxies the best-fit slope is 1.09pm0.15 and the normalization if 0.18pm0.04e13 Msun/h70.  Similarly, find a best-fit slope of 1.36 and a normalization of 1.43pm0.1e13 Msun/h70 for the stellar mass-halo mass relation of red galaxies, while for blue galaxies the corresponding values are 0.98pm0.07 and 0.84pm0.2e13 Msun/h70.  For red lenses, the fraction which are satellites tend to decrease with luminosity and stellar mass, with the sample being nearly all satellites for a stellar mass of 2e9 Msun/h70^2.  The satellite fractions are generally close to zero for blue lenses, irrespective of luminosity of stellar mass.  This, together with the shallower relation between halo mass and baryonic tracer, is a direct confirmation from gg lensing that blue galaxies reside in less clustered environments than red galaxies.  Also find that the halo model, while matching the lensing signal around red lenses well, is prone to over-predicting the large-scale signal for faint and less massive blue lenses.  This could be a further indication that these galaxies tend to be more isolated than assumed.