Day 582

Thursday.

1401.4454
Simulations of cosmic rays in large-scale structures: numerical and physical effects
Vazza, Gheller, Brüggen

Non-thermal (relativistic) particles are injected into the cosmos by structure formation shock waves, AGN and stellar explosions.  Present sims (up to 2048^3) using a two-fulid model in ENZO, including dynamical effects of CR protons and cover a range of theoretically motivated acceleration efficiencies.  For the bulk of the cosmic volume the modeling of CR processes is rather stable wrt resolution if minimum cell resolution ~ 100 kpc/h is used.  However, the results for the innermost cluster regions depend on the assumptions for the baryonic physics.  Inside clusters, non-radiative runs at high res tend to produce an energy density of CRs that are below available upper limits from the FERMI satellite, while the radiative runs are found to produce a higher budget of CRs.  Show that weak (M=<3-5) shocks and shock-reacceleration are crucial to set the level of CRs in the innermost region of clusters, while in the outer regions the level of CR energy is mainly set via direct injection by stronger shocks, and is less sensitive to cooling and feedback from AGN and SNe.

1401.4457
Scattering outcomes of close-in planets: constraints on planet migration
Petrovich, Tremaine, Rafikov

Many exoplanets in close-in orbits are observed to have relatively high eccentricities and large stellar obliquities.  Explore the possibility that these result from planet-planet scattering by studying the dynamical outcomes from a large number of orbit integrations in systems with 2 and 3 gas-giant planets in close-in orbits (0.05 AU<a<0.15 AU).  Find that at these orbital separations, unstable systems generally lead to planet-planet collisions in which the collision product is a plant on a low-eccentricity, low-incination orbit.  This result is inconsistent with the observations.  Conclude that eccentricity and inclination excitation from planet-planet scattering must precede migration of planets into short-period orbits.  This results constrains theories of planet migration: the semi-major axis must shrink by 1-2 orders of magnitude without damping the eccentricity and inclination.

1401.4459
An uncertainty principle for star formation. I. Why galactic star formation relations break down below a certain spatial scale
Kruijssen, Longmore

Galactic scaling relations between the (surface densities of) the gas mass and the SFR are known to develop substantial scatter or even change form when considered below a certain spatial scale.  Quantify how this behavior should be expected due to the incomplete statistical sampling of independent SF regions.  Other included limiting factors are the incomplete sampling of SF tracers from the stellar IMF and the spatial drift between gas and stars.  Present a simple uncertainty principle explaining how the scatter of SF relations depends on the spatial scale and predicts a scale-dependent bias of the gas depletion time-scale when centering an aperture on gas or SF tracer peaks.  Show how the scatter and bias are sensitive to the physical size and time-scales involved in the SF process (such as its duration of the molecular cloud lifetime), and illustrate how formalism provides a powerful tool to constrain these largely unknown quantities.  Thanks to its general form, the uncertainty principle can also be applied to other astrophysical systems, e.g. addressing the time-evolution of SF cores, protoplanetary disks, or galaxies and their nuclei.

1401.4469
A cosmic web filament revealed in Lyman-alpha emission around a luminous high-redshift quasar
Cantalupo, .. Prochaska, Hennawi, Madau, et al

Report observation of a cosmic web filament in Ly-a emission, discovered during a survey for cosmic gas fluorescently "illuminated" by bright quasars at z=2.3.  With a projected size of approximately 460 physical kpc, the Ly-a emission surrounding the radio-quiet quasar UM287 extends well beyond the virial radius of any plausible associated DM halo.  The estimated cold gas mass of the nebula from the observed emission is at least 10x larger than what is typically found by cosmological simulations, suggesting that a population of intergalactic gas clumps with sub-kpc sizes may be missing within current numerical models.

Day 581

Tuesday.  Wednesday.

1401.4065
Cosmological parameter uncertainties from SALT-II Type Ia supernova light curve models
Mosher, … Sako, … et al

Use simulated SN Ia samples to validate cosmology analysis using SALT-II light curve model.  Validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and the bias in the DE EoS parameter w.  Make similar dataset to SNLS3.  Vary input spectral model, the model of intrinsic scatter, and the smoothing parameters during SALT-II model training.  Biases indistinguishable from each other within uncertainty; average bias on w is -0.014pm0.007.

1401.4094
Herschel-ATLAS/GAMA: SDSS cross-correlation induced by weak lensing
González-Nuevo et al

H-ATLAS z>1.5 galaxies and SDSS/GAMA galaxies at 0.2<z<0.6 has 10 sigma spatial correlation; this is explained by weak lensing (sub-mm galaxies amplified by FG structures, mu<2).  Sims show measured amplitude and range of angular scales of signal are larger than can be accounted for GGL (weak lensing).  For scales <2 arcmin, signal can be reproduced if SDSS/GAMA galaxies act as signposts of galaxy groups/clusters with halo masses of range 1e13.2-14.5 Msun.  The signal detected on large scales appears to reflect the clustering of such halos.  Make use of simulations to show that lensing can induce an apparent clustering of randomly distributed BG galaxies, but the amplitude of the corresponding angular correlation function is at least a factor of 10 per than observed between H-ATLAS and SDSS/GAMA galaxies; the gravitational magnification effects on counts of sub-mm sources are nevertheless dominated by GGL (strong lensing).

1401.4169
Implementation of robust image artifact removal in SWarp through clipped mean stacking
Gruen, Seitz, Bernstein

Implement and algorithm for detecting and removing artifacts from astronomical images by means of outlier rejection during stacking---addresses both CR (small and significant artifacts) and, by applying a filtering technique to generate single frame masks, ghosts of bright stars (larger area but lower SB features).  In contrast to the common method of building a median stack, the clipped or outlier-filtered mean stacked PSF is a linear combination of the single frame PSFs as long as the latter are moderately homogeneous, a property of great importance for WL shape measurement or model fitting photometry.  In addition, it has superior noise properties, allowing a significant reduction in exposure time compared to median stacking.  Make publicly available a modified version of SWarp that implements clipped mean stacking and SW to generate single frame masks from the list of outlier pixels.

1401.4170
Detection of ultraviolet halos around highly inclined galaxies
Hodges-Kluck, Bregman

Discovery of diffuse UV around late-type galaxies out to 5-20 kpc from the mid plane using Swift and GALEX images.  Consistent with the stellar outskirts in the early-type galaxies, but not in the late-type galaxies, where the emission is quite blue and consistent with a reflection nebula powered by light escaping from the galaxy and scattering off dust in the halo.  Fitting a simple reflection nebula model to the halo SEDs points to SMC-type dust (lacking a UV bump), and the halo colors and luminosities are consistent with this scenario.  Results agree with expectations from halo dust discovered (at larger radii) in extinction by Menard+ (2010) to within a few kpc of the disk and imply a comparable amount of hot and cold gas in galaxy halos (a few e8 Msun within 20 kpc) if the dust resides primarily in Mg II absorbers.

1401.4182
An eccentricity-mass relation for galaxies from tidally disrupting satellites
Chakrabarti et al

Infer the past orbit of Sgr dwarf galaxy by integrating backwards from observed position and proper motions, including dynamical friction effects.  Show that there is a power-law relation between e of Sgr's orbit and the mass of MW (M_T) in the limit of no dynamical friction.  At fixed MW mass, the dynamical friction term increases the mean eccentricity of the orbit and lowers the spread in eccentricities in proportion to the mass of Sgr dwarf.  Explore the implications of various observational constraints on Sgr's epicenter on the e-M relation.  Assuming Belokurov+2014's observation represents farthest point of Sgr's stream, then MW masses in excess of 2e12 Msun are excluded for M_Sgr >~ 1e10 Msun.  Deeper observations of Sgr's tidal debris, from upcoming surveys such as GAIA, will allow better measurement of MW mass and the Sgr dwarf.

Day 580

Sunday.  Monday.
1401.3745
The VIMOS public extragalactic redshift survey (VIPERS).  Never mind the gaps: comparing techniques to restore homogeneous sky coverage
Cucciati, .. Iovino, … Peacock, … et al

In galaxy redshift surveys: non-uniform sampling, gaps in sky coverage common: these effects can degrade galaxy counts-in-cells and density estimates.  Carry out a comparison of methods that aim to fill the gaps to correct for the systematic effects.  VIPERS is a flux-limited (i<22.5) survey, on-pass observations with VIMOS, with gaps covering 25% of the surveyed area and a mean sampling rate of 35%.  Compare 1) two algorithms based on photo-z that assign z to galaxies based on the spectroscopic redshifts of the nearest neighbors, 2) two Bayesian methods, the Wiener filter and the Poisson-Lognormal filter.  Using galaxy mock catalogues, quantify the accuracy of the counts-in-cells measurements on scales of R=5 and 8 Mpc/h after applying each of these methods.  Also study how they perform to account for spectroscopic z error and inhomogeneous and sparse sampling rate.  Find that in VIPERS the error in counts-in-cells measurements on R<10 Mpc/h scales are dominated by the sparseness of the sample.  All methods under predict by 20-35% the counts at high densities.  This systematic bias is of the same order as random errors.  No method outperforms the others.  Random and systematic errors decrease for larger cells.  Show that it is possible to separate the lowest and highest densities on scales of 5 Mpc/h at 0.5<z<1.1, over a large volume such as in VIPERS; vital for the characterization of cosmic variance and rare populations (e.g., brightest galaxies) in environmental studies at these redshifts.

1401.3749
Stellar haloes outshine disc truncations in low-inclined spirals
Martín-Navarro, et al

The absence of stellar disc truncations in low-inclined spiral galaxies has been a matter of depute in the last decade.  Disc truncations are often observed in highly inclined galaxies but no obvious detection of this feature has so far been made in face-on spirals.  Show using a simple exp disc plus stellar halo model based on current observational constraints, that truncations in face-on projections occur at surface brightness levels comparable to the brightness of stellar haloes at the same radial distance.  In this sense, stellar haloes outshine the galaxy disc at the expected position of the truncations, forcing their studies only in highly inclined (edge-on) orientations.

1401.3919
Mapping the large scale structure around a z=1.46 galaxy cluster in 3-D using two adjacent narrow-band filters
Hayashi et al

Novel method to estimate accurate redshifts of SF galaxies by measuring the flux ratio of the same emission line observed through two adjacent narrow-band filters.  Apply this method to NB912 and data taken with Suprime-Cam on cluster XMMXCS J2215.9-1738, at z=1.46 and its surrounding structures.  Obtain redshifts for 170 [OII] emission line galaxies at z~1.46 among which 41 galaxies are spectroscopically confirmed, showing accuracy of sigma(delta z)/(1+z_spec)=0.002.  Reveals filamentary structures that penetrate towards the center of the galaxy cluster and intersect with other structures, consistent with the picture of hierarchical cluster formation.  Also find that the projected celestial distribution does not precisely trace the real distribution of galaxies, indicating the importance of the 3d view of structures to properly identify and quantify galaxy environments.  Investigate the environment dependence of galaxy properties with local density, confirming that the median color of galaxies becomes redder in higher density region while the SFR of SF galaxies does not depend strongly on local environment in this structure.  This implies that the SF activity in galaxies in truncated on a relatively short time scale in the cluster center.

Day 579

Friday.

1401.3334
Galaxy Zoo: an independent look at the evolution of the bar fraction over the last eight billion years from HST-COSMOS
Melvin, … Nichol, … etal

z evolution of 2380 disk galaxies in COSMOS from Galaxy Zoo: find overall bar fraction decreases by a factor of two, from 22% at z=0.4 (4.2 Gyr) to 11% at z=1.0 (7.8 Gyr), not redshift dependent biases.  Decrease in mass most prominent in the highest mass bin; lower mass show a more modest evolution.  Include sample of 98 red disc galaxies---they have high bar fraction (45%) and are missing from other COSMOS samples which used SED fitting or colors to identify high redshift disks.  Results consistent with a picture in which the evolution of massive disc galaxies begins to be affected by slow (secular) internal process at z~1.  Discuss possible connections of the decrease in bar fraction to the redshift, including the growth of stable disc galaxies, mass evolution of the gas content in disc galaxies, as well as the mass dependent effects of tidal interactions.

1401.3352
Type Ia supernova Hubble residuals and host-galaxy properties
Kim et al

Simulations possibly capturing features of SNIa diversity arising from progenitor stellar evolution.

1401.3356
Hubble space telescope/advanced camera for surveys confirmation of the dark substructure in A520
Jee, Hoekstra, Mahdavi, Babul

ACS imageing, 109 source galaxies per sq. arcmin. [!]  Remove CTI and PSF.  Confirm that a substantial amount of dark mass is present between two luminous sub clusters.  Dark matter centroid coincides with X-ray emission peak; M/L = 813pm80 Msun/Lrun; A520 can be sued to establish a lower limit of the self-interacitng cross-section of DM.

1401.3694
Cosmology with Doppler Lensing
Bacon et al

Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities.  Objects falling into an over density appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts [?].  How to utilize as a probe in cosmology with forthcoming surveys.  Present cosmo sims of Doppler and gravitational lensing effects based on Millennium simulation.  Show that Doppler lensing can be detected around stacked voids or unvirialized over-densities.  New PS and correlation functions are proposed which are designed to be sensitive to Doppler lensing.  Consider impact of gravitational lensing and intrinsic size correlations on these quantities.  Compute the correlation functions and forecast the error for realistic forthcoming surveys, providing predictions for constraints on cosmological parameters.  Finally, demonstrate how to make 3-d potential maps of large volumes of the Universe using Doppler lensing.

1401.3742
Constraining dark energy through the stability of cosmic structures
Pavlidou, etal

For a general DE EoS, estimate the maximum possible radius of massive structures that are not destabilized by the acceleration of the cosmological expansion.  A comparison with known stable structures constrains the equation of state.  The robustness of the constrain can be enhanced through the accumulation of additional astrophysical data and a better understanding of the dynamics of bound cosmic structures.

Day 578

Thursday.

Special topics
Citizen scientists discover gravitational lens at record speed
Symmetrymagazine.org

55k citizen scientists went to Spacewarps.org, and over 72 hours make 6 million image classifications on CFHT and VISTA survey areas, searching for gravitational lensing in the IR.  Found handful of new GLs, including one confirmed system that was followed up immediately by eMerlin (radio telescope).  

1401.2984
Observations of environmental quenching in groups in the 11 Gyr since z=2.5: different quenching for central and satellite galaxies
Tal, Dekel, Oesch, … van Dokkum, … Rix, … et al

Direct observational evidence for SF quenching in galaxy groups in 0<z<2.5.  Utilize a large sample of 6000 groups selected by fixed cumulative number density from 3 photometric catalogs, to follow the evolving quiescent fractions of central and satellite galaxies over ~11 Gyr.  At z~0, central galaxies in the sample range in M* from MW/M31 analogs (6.5e10 Msun) to nearby massive ellipticals (1.5e11 Msun).  Satellite galaxies in the same groups reach masses as low as twice that of the LMC (6.5e9 Msun).  Using statistical BG subtraction, measure the average rest-frame colors of galaxies in groups and calculate the evolving quiescent fractions of centrals and satellites over 7 z bins.  Analysis shows clear evidence for SF quenching in group halos, with a different quenching onset for centrals and their satellite galaxies.  Using halo mass estimates for central galaxies, find that SF shuts off in centrals when typical halo masses reach between 1e12 and 1e13 Msun, consistent with predictions from the halo quenching model.  In contrast, satellite galaxies in the same groups most likely undergo quenching by environmental processes, whose onset is delayed wrt their central galaxy.  Although SF is suppressed in all galaxies over time, the processes that govern quenching are different for centrals and satellites.  While mass plays an important role in determining the SF activity of central galaxies, quenching in satellite galaxies is dominated by the environment in which they reside.

1401.2990
Possible origin of the G2 cloud from the tidal disruption of a known giant star by Sgr A*
Guillochon, Loeb, MacLeod, Ramirez-Ruiz

Propose that G2 formed out the debris stream produced by removal of mass from the outer envelope of a nearby giant star.  Perform hydrodynamical simulations of the returning tidal debris stream with cooling, and find that the stream condenses into clumps that fall to Sgr A* approximately once per decade.  Propose that one of these clumps is the observed G2 cloud, with the rest of the stream being detectable at lower Br-gamma emissivity along a trajectory that would trace from G2 to the star that was partially disrupted.  By simultaneously fitting the orbits of S2, G2, and ~2000 candidate stars, and by fixing the orbital plane of each candidate star to G2 (as is expected for a tidal disruption), find that the late-type star S1-34 has an orbit that is compatible with the notion that it was tidally disrupted to produce G2.  If S1-34 is indeed the star that was disrupted, it last encountered Sgr A* in the late 18th century, and will likely be disrupted again in several hundred years.  However, while S1-34's orbit is compatible with the giant disruption scenario given its measured position and proper motion, its radial velocity is currently unknown.  If S1-34's radial velocity is measured to be compatible with a disrupted orbit, it would strongly suggest that a tidal disruption of S1-34 produced G2.

1401.2998
A theory for the excitation of CO in star forming galaxies
Narayanan, Krumholz

Necessary to deduce molecular gas masses from observations of CO emission.  Find: while the shape of the spectral line energy distribution is ultimately determined by difficult-to-observe quantities such as the gas density, temperature, and optical depth distributions, all of these quantities are well-correlated with the galaxy's mean SFR surface density (Sigma_SFR), which is observable.  Use this result to develop a model for the CO SLED in terms of Sigma_SFR, and show that this model quantitatively reproduces the SLEDs of galaxies over a dynamic range of ~200 in SFR surface density, at 0<z<6.  This model should make it possible to significantly reduce the uncertainty in deducing molecular gas masses from observations of high-J CO emission.

1401.2999
Dust reverberation mapping in the era of big optical surveys and its use as a standard ruler in cosmology
Hoenig

The time lag between optical and NIR flux variability can be taken as a means to determine the sublimation radius of the dusty "torus" around SMBHs in AGN.  Show that data from big optical survey telescopes (LSST) can be used to measure dust sublimation radii as well.  Uses Wein tail of the hot dust emission as it reaches into the optical and can be reliably recovered with high-quality photometry.  Simulations show that dust sublimation radii for a large sample of AGN can be reliably established out to 0.1<z<0.2 with LSST.  Propose to use  AGN dust time lags as "standard rulers" for cosmology.

1401.3001
Optical galaxy clusters in the Deep Lens Survey
Ascaso, Wittman, Dawson

882 optically selected galaxy clusters in DLS, selected with the Bayesian Cluster Finder, 0.1<z<1.2, M200>=1.2e14 Msun.  Verify with other optical, WL, X-ray and spectra surveys which overlap the DLS footprint.  Spectro redshift good at z>0.25, richness estimates consistent with available dynamical mass estimates (from SHeLS), optical mass maps correlate to 3sigma with WL mass maps, and MF derived consistent with CDM.  Investigate correlation with BCG properties and host cluster properties with a broader range in z (0.25<z<0.8) and mass (>=2.4e14Msun) than in previous work.  Find that the slope of the BCG magnitude-redshift relation throughout this z range is consistent with that found at lower z.  This result supports an extrapolation to higher redshift of passive evolution of the BCG within the hierarchical scenario.

1401.3162
A simple model linking galaxy and dark matter evolution
Birrer, Lilly, Amara, Paranjape, Refregier

Construct a simple phenomenological model for the evolving galaxy population by incorporating pre-defined baryonic prescriptions into a DM hierarchical merger tree.  Specifically, the model is based on the simple gas-regulator model introduced by Lilly+2013 coupled with the empirical quenching rules of Peng+2010,2012.  The simplest model does well in reproducing, without adjustable parameters, observables including the MS sSFR-mass relation, the faint end slope of the galaxy mass function and the shape of the SF and passive MS.  Model also qualitatively reproduces the evolution of the MS sSFR and SFRD SFR density relations, the M_s-M_h stellar-to-halo mass relation and the SFR-M_h relation.  SHort points: ratio of quenched to SF galaxies around Ms is not high enough, and evolution of sSFR and SFRD not steep enough, Ms-Mh relation not quite peaked enough  Deficiencies related and they can be simultaneously solved by allowing galaxies to re-ingest some of the gas previously expelled in winds, in a mass-dependent and epoch-dependent way, allowing the model to reduce any inherent tendency to saturate their SF efficiency.  Emphasizes how efficient galaxies around M* are in converting baryons into stars and highlights an apparent coincidence that quenching occurs just at the point when galaxies are rapidly approaching the maximum possible efficiency of converting baryons into stars.  [if it weren't for quenching, would the SF efficiency be higher?]

1401.3317
The data release of the Sloan digital sky survey-II supernova survey
Sako, et al

As the title says, 10k variable and transient sources along Stripe 82 (300 deg sq) along the celestial equator.  Spectra on 889 transients from BOSS spectrograph; photometric classification show 4607 transients likely to be, or spectroscopically confirmed, SNe.  677 SNIa candidates, determine Omega_m=0.315pm0.093 and a non-zero cosmological constant at 5.7 sigma.

1401.3741
Enduring quests-daring visions (NASA astrophysics in the next three decades)
Kouveliotou et al
First decade: JWST, WFIRST, Euclid, Gaia, and more.  Second decade: Gravitational wave surveyor, CMB polarization surveyor, Far IR surveyor, LUVOIR surveyor, X-ray surveyor.  Third decade: Gravitational wave mapper, cosmic dawn mapper (radio), ExoEarth mapper, Black Hole mapper.

Day 577

Tuesday.

1401.2458
Jumping the gap: the formation conditions and mass function of Pebble-Pile Planetesimals
Hopkins

In a turbulent proto-planetary disk, dust grains undergo large density fluctuations and under the right circumstances, these grain over densities can overcome shear, turbulence, and gas pressure support to collapse under self-gravity (forming a 'pebble pile' planetesimal).  Using insights from simulations and a new analytic model for the fluctuations, calculate the rate-of-formation and mass function of self-gravitating, collapsing planetesimal-mass bodies formed by this mechanism.  Statistics depend on size/stopping time of largest grains, disk surface density, and turbulent Mach numbers.  When collapse occurs, predict that the resulting planetesimal mass function is broad and quasi-universal, with a slope dN/dM~1/M, spanning a size/mass range ~10-1e4 km (1e-9-5.0 M_Earth).  Collapse to planetesimal through super-Earth masses is possible.  The key condition is that grain density fluctuations reach large amplitudes on large scales, where gravitational instability proceeds most easily (collapse of small grains is strongly suppressed by turbulent vorticity).  Show this leads to a new criterion for 'pebble-pile' formation in terms of the dimensionless particle stopping time (tau_stop>f(Q,Z,alpha)).  In a MMSN [?], this requires grains larger than a=(50,1,0.1)cm at r=(1,30,100) au.  At large radii, this can easily occur and seed core accretion.  At small radii, it would depend on the existence of large boulders.  However, because density fluctuations depend super-exponentially on tau_stop (inversely proportional to disk surface density), lower-density disks are more unstable.  In fact, predict that cm-sized grains at ~1au will form pebble piles in a disk with ~10% of the MMSN density, so planet formation at ~au may generically occur late, as disks are evaporating.

1401.2460
Environmental dependence of bulge-dominated galaxy sizes in hierarchical models of galaxy formation.  Comparison with the local Universe
Shankar, Mei, … Sheth, et al

Compare SAMs as well as SHAMs with a large sample of early-type galaxies from SDSS at z<0.3.  Focus on dependence of median sizes of central galaxies on host halo mass.  The data do not show any difference in the structural properties of early-type galaxies with environment, at fixed stellar mass.  All hierarchical models considered in this work instead tend to predict a moderate to strong environmental dependence, with the median size increasing by a factor of about 1.5-3 when moving from low to high mass host haloes.  At face value the discrepancy with the data is highly significant, especially at the cluster scale, for haloes above M_halo>1e14.  The convolution with (correlated) observational errors reduces some of the tension.  Despite the observational uncertainties, the data tend to disfavor hierarchical models characterized by a relevant contribution of disc instabilities to the formation of spheroids, strong gas dissipation in (major) mergers, short dynamical friction timescales, and very short quenching timescales in infalling satellites.  Also discuss a variety of additional related issues, such as the slope and scatter in the local size-stellar mass relation, the fraction of gas in local early-type galaxies, and the general predictions on satellite galaxies.

1401.2463
Microlens masses from astrometry and parallax in space-based surveys: from planets to black holes
Gould, Yee

Show that space-based microlensing experiments can recover lens masses and distances for a large fraction of all events (those with individual photometric errors <~0.01 mag) using a combination of 1d micro lens parallaxes and astrometric microlensing.  This will provide a powerful probe of the mass distributions of planets, BHs, and NS, the distribution of planets as a function of Galactic environment, and the velocity distributions of BHs and NSs.  While systematics are in principle a significant concern, show that it is possible to vet against all systematics (known and unknown) using single-epoch precursor observations with the HST roughly 10 years before the space mission.

1401.2593
HEIDI: an automated process for the identification hand extraction of photometric light curves from astronomical images
Todd

As the title says.  Seems thoroughly tested (on a single-night exposure following astroid 939 Isberga, and on various Linux platforms).

1401.2636
Resampling images in Fourier domain
Bernstein, Gruen

For sky image simulation, using pixellated image + some interpolation kernel, and produce a new sampled image representing this galaxy as it would appear with a different PSF, rotation, shearing, magnification, and/or different pixel scale.  These operations are sometimes only possible, or most efficiently executed, as resampling of the Fourier transform F(u) of the image onto a u-space grid that differs from the one produced by a discrete Fourier transform (DFT) of the samples.  In some applications, it is essential that the resampled image be accurate to better than 1e-3, so in this paper, use standard Fourier techniques to show that Fourier-domain interpolation with a wrapped since function yields the exact value of F(u) in terms of the input samples and kernel.  This operations scales with image dimension as N^4 and can be prohibitively slow, so investigate the error accrued from approximating the since function with a compact kernel.  Show that these approximations produce a multiplicative error plus a pair of ghost images (in each dimension) in the simulated image.  Standard Lanczos or cubic interpolators, when applied in Fourier domain, produce unacceptable artifacts.  Find that errors <1e-3 can be obtained by (1) 4-fold zero-padding of the original image before executing the z=>u DFT, followed by (2) resampling to the desired u grid using a 6-pt, piecewise-quintic interplant that is designed expressly to minimize the ghosts, then (3) executing the DFT back to x-domain.

Day 576

Monday.

1401.0548
Fermi-LAT detection of gravitational lens delayed gamma-ray flares from Blazar B0218+357
Cheung et al

A known double-image lensed system, showing a clear gamma-ray measurement of delay between flares from a blazar.  Peak fluxes consistently observed to reach >20-50 times its previous average flux.  Delay of 11.46 pm 0.16 days (1sigma) from cross-correlation function., ~1 day greater than previous measurements.  Decompose individual sequences of superposing gamma-ray flares/delayed emissions.  Find flux ratios consistent with ~1; systematically smaller than those from radio observations.  Flux doubling timescales of 3=6 hours observed, implying extremely compact gamma-ray emitting regions.

1401.0601
Calculating the Habitable Zone of multiple star systems (http://astro.twam.info/hz)
Mueller, Haghighipour

Calculating HZ of multiple star systems from spectral weight factors, calculating contribution of each star (based on SED) to the total flux received at the top of the atmosphere of an Earth-like planet, and use HZ of the Sun to determine the boundaries of HZ.

1401.0706
A clear and measurable signature in the galaxy velocity field
Hellwing, … Frenk, … Cole et al

The velocity field of the DM and galaxies reflects the continued action of gravity through cosmic history.  Show that the low-order moments of the pairwise velocity distribution, v_12, are a powerful diagnostic of the laws of gravity on cosmological scales.  The projected LoS galaxy parities velocity dispersion, sigma_12(r), is very sensitive to the presence of modified gravity.  Use N-body sims to compute the pairwise velocity distribution, and its projected LoS dispersion for a class of modified gravity theories:  f(R) and  Galileon (cubic and quartic).  Deviation from GR at 5 to 10 sigma level shown.  Examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys.  

1401.0737
A physical understanding of how reionization suppresses accretion onto dwarf halos
Noh, McQuinn

Develop a physically motivating theory for how the interplay between gravity, pressure, cooling and self-shielding set the z-dependent mass scale at which haloes can accrete intergalactic gas.  This theory provides a physical explanation for the halo mass scale that can accrete unshocked intergalactic gas, which has been explained with ad hoc criteria tuned to reproduce the results of a few simulations.  Furthermore, it provides an intuitive explanation for how this mass scale depends on the reionization redshift, the amplitude of the ionizing background, and the redshift.  Show that accretion is inhibited onto more massive halos that had been [previously] thought because previous studies had focused on the gas fraction of halos rather than the instantaneous mass that can accrete gas.  A halo as massive as 1e11 Msun cannot accrete intergalactic gas at z=0, even through typically its progenitors were able to accrete gas at higher redshifts.  Describe a simple algorithm that can be implemented in SAMs, and compare this algorithm implemented on top of a halo merger tree to the results in the simulations.  

1401.0745
Is there a maximum star formation rate in high-redshift galaxies?
Barger et al

From GOOD-N field observations in FIR/submm/radio, get spectro-z for ~65% of radio sources; determine SFRs of the sub millimeter sources based on there radio powers and their sub millimeter and find that they agree well.  The radio data are deep enough to detect SF galaxies with SFRs > 2000 Msun /yr to z~6.  Find galaxies with SFRs up to ~6k Msun/yr over 1.5<z<6, but see evidence for a turn-down in the SFR distribution function above 2000 Msun/yr.

1401.1193
A WISE measurement of the ISW effect
Ferraro, Sherwin, Spergel

ISW measures the decay of the gravitational potential due to cosmic acceleration and is thus a direct probe of DE.  Measure cross-power of galaxies and AGN from WISE with CMB from WMAP9 to provide an independent measurement of the ISW amplitude.  Cross-correlations with the recently released Planck lensing potential maps are used to calibrate the bias and contamination fraction of the sources, thus avoiding systematic effects that could be present when using auto-spectra to measure bias.  Find amplitude of cross power of A=1.24 from galaxies and A=0.88 for AGN, fully consistent with the LCDM prediction of A=1.  ISW S/N is 2.7 and 1.2, respectively, giving a combined significance close to 3 sigma.  Comparing the amplitudes of galaxy and AGN cross-correlations, which arise from different redshifts, find no evidence for z evolution in DE properties, consistent with cosmological constant.

1401.1208
The dynamics of isolated Local Group galaxies
Kirby, Bullock, Boylan-Kolchin, Kaplinghat, Cohen

Measure velocities of 862 individual red giant stars in 7 isolated dwarf galaxies in the Local Group.  None of the isolated galaxies is denser than the densest LG satellite galaxy.  Furthermore, the isolated dwarf galaxies have no obvious distinction in the velocity dispersion-HLR plane from the satellite galaxies of the MW and M31.  The similarity of the isolated and satellite galaxies' dynamics and structural parameters imposes limitations on environmental solutions to the too-big-to-fail problem, wherein there are fewer dense dwarf satellite galaxies than would be expected from CDM simulations.  This data set also has many other applications for dwarf galaxy evolution, including the transformation of dwarf irregular into dwarf spheroidal galaxies, to be explored in future work.

1401.1209
What is the physical origin of strong Lya emission?  I.  Demographics of Lya emitter structures
Shibuya, et al

Present structure analysis for 426 LAEs at z~2.2 observed with HST.  Merger fraction and average ellipticity of LAE's stellar component are 10-30% and 0.4-0.6, respectively, that are comparable with previous study results.  Successfully identify that some LAEs have a spatial offset between Lya and stellar-continuum emission peaks, d_Lya, by ~2.5-4 kpc beyond statistical errors.  To uncover the physical origin of strong Lya emission found in LAEs, investigate Lya EW dependences of merger fraction, d_Lya, and ellipticity in the range EW(Lya)=20-250A.  Contrary to expectations,, find that merger fraction does not significantly increase with Lya EW.  Reveal an anti-correlation between d_Lya and EW(Lya).  There is a trend that the LAEs with a large Lya EW have a small ellipticity, consistent with recent theoretical claims that Lya photons can more easily escape from face-on disks having a small ellipticity, due to less inter-stellar gas along the LoS, although KS test indicates that this trend is not statistically significant.  Results of Lya-EW dependence generally support the idea that an EI column density is a key quantity determining Lya emissivity.

1401.1216
Dependence of the outer density profiles of halos on their mass accretion rate
Diemer, Kravtsov

Present systematic study of density profiles of halos forming in LCDM cosmology, focusing on the outer regions of halos, 0.1<r/Rvir<9.  Show that the median and mean density profiles of halo samples of a given peak height exhibit significant deviations from the universal analytic profiles (NFW, Einasto), at radii r>0.5 R200m.  In particular, the logarithmic slope of medan density profiles of massive or rapidly accreting halos steepens more sharply than predicted, with the steepening becoming more pronounced with increasing mass accretion rate.  The steepest profile occurs at r~R200m, and its absolute value increases with increasing peak height or mass accretion rate, reaching slopes of --4 and steeper.  Find that the outermost density profiles at r>R200m are remarkably self-similar when radii are rescaled by R200m.  This self-similarlity indicates that radii defined wrt the mean density are preferred for describing the structure and evolution of the outer profiles.  However, they under density profiles are most self-similar when radii are rescaled by R200c, a radius enclosing a fixed over density wrt the critical density of the universe.  Propose a new fitting formula that describes the profiles at all radii out to r~9 Rvir, including the transition region around r~R200m where the steepening occurs.  The formula fits the median and mean density profiles of halo samples selected by their peak height or mass accretion rate with accuracy <10% at all redshifts and masses studied, 0<z<4 and Mvir>1.7e10 Msun/h.  Discuss observational signatures of the density profile features described above, and show that the steepening of the outer profile should be detectable in future WL analysis of massive clusters.

1401.1246
Constraining Halo Occupation Distribution and cosmic growth rate using multiple power spectrum
Hikage

Propose a new method of measuring HOD together with cosmic growth rate using multipole components of galaxy power spectrum P_l(k).  The NL z-space distortion due to the random motion of satellite galaxies (FoG) generates high-l multipole anisotropy in galaxy clustering such as the l=4 (hexadecapole) and l=6 (tetra-hexadecapole), which are sensitive to the fraction and the velocity dispersion of satellite galaxies.  Using simulated samples following the HOD of LRG, find that the input HOD is successfully reproduced using P_l(k) even when directly fitting the central and satellite HOD values at different bins of mass without assuming any functional form.  Also show that the measurements of the cosmic growth rate as well as the satellite fraction and velocity dispersions are significantly improved by adding the small-scale information of high-l multipoles.

1401.1317
Magnetic fields and haloes in spiral galaxies
Krause

B-field patter which is spiral along the disk and X-shape in the halo [profile?], sometimes accompanied by strong vertical fields above and below the central region of the disk; strength of B-fields comparable.  The total and turbulent B-field strength is (weakly) increasing with SF, though there are indications that stronger SF reducers the B-field regularity globally.  B-field thought to be amplified by dynamo action; During the galaxy's formation and evolution, the turbulent dynamo amplifies the field strength to energy equipartition with the turbulent gas, while the large-scale (mean-field) dynamo mainly orders the B-field.  Hence, the large-scale B-field pattern evolves with time.  SN explosions causes further continuous injection of turbulent B-fields.  Assuming that small-scale field injection is situated only within the spiral arm region (where SF mostly occurs) lead to a large-scale field structure in which the B-field regularity is stronger in the inter arm region as observed in several nearby spiral galaxies.  The detection of similar scale heights in several spiral galaxies of different Hubble type SF implies a relation between the galactic wind, the total B-field strength and the SF in the galaxy.  A galactic wind may be essential for an effective dynamo action.  Strong tidal interaction, however, seems to disturb the balance leading to deviating and locally different scale heights as observed in M82 and NGC 4631.

1401.1342
The AGN content of deep radio surveys and radio emission in radio-quiet AGN.  Why every astronomer should care about deep radio fields
Padovani, et al

The main messages to non-radio astronomers is that radio surveys are reaching such faint limits that, while previously they were mainly useful for radio quasars and radio galaxies, they are now detecting mostly SFing galaxies and radio-quiet AGN, i.e., the bulk of the extragalactic sources studied in the IR, optical, and X-ray bands.

1401.1371
Circular polarization of the CMB: a probe of the first stars
De, Tashiro

Faraday conversion (FC) ude to SN remnants of the First stars (Pop III stars), in presence of B-field and scattering of photons with relativistic electrons.  Amplitude of l(l+1) Clvv / 2pi > 0.001 in units of micro kelvin squared for l>100, with the age of the Pop III SN remnant to be 10k years and frequency of CMB observation as 30 GHz.  

1401.1389
The cosmological parameters 2014
Lahav, Liddle

For Review of Particl Physics 2014 (aka the Particle Data Book).  Topics include: parameterizing the universe; extensions to the standard model; probes; brining observations together, outlook.

1401.1499
The atmospheres of Earth-like planets after giant impact events
Lupu et al

Explore the atmospheric chemistry, photochemistry, and spectral signatures of post-giant-impact terrestrial planets enveloped by thick atmospheres consisting predominantly of CO2, and H2O.  Self-consistent computation for atmospheres in equilibrium with hot surfaces with composition reflecting either the bulk silicate Earth (crust, mantle, atmosphere and oceans) or Earth'c continental crust.  Account for all opacity sources including collision-induced absorption.  Find that these atmospheres are dominated by H2O and CO2, while the formation of CH4, and NH3 is quenched due to short dynamical timescales.  Other important constituents are HF, HCl, NaCl, and SO2.  These are apparent in the emerging spectra, and can be indicative that an impact has occurred .  THe use of comprehensive opacities results in spectra that are a factor of 2 lower in surface brightness in the spectral windows than predicted by previous models.  The estimated luminosities show that the hottest post-giant-imact planets will be detectable with near-IR coronagraphs on the planned 30m-class telescopes.  The 1-4um region will be most favorable for such detections, freeing bright features and better contrast between the planet and potential debris disk.  Derive cooling timescales on the order of 1e5-6 Myrs, based on the modeled effective temperatures.  THis leads to the possibility of discovering tens of such planets in future surveys.

1401.1501
The SLUGGS survey: breaking degeneracies between dark matter, anisotropy and the IMF using globular cluster subpopulations in the giant elliptical NGC 5846
Napolitano, et al

Study the mass and anisotropy distribution of NGC 5846 using stars, as well as the red and blue GC subpopulations.  Use different phase space distributions of the two GC subpopulations to unambiguously constrain the mass of the galaxy and the anisotropy of the GC system.  Red GCs show the same spatial distribution and behavior and the starlight, whereas blue GCs have a shallower density profile, a larger velocity dispersion and a lower kurtosis, all of which suggest a different orbital distribution.  Use a dispersion-kurtosis Jeans analysis and find that the solutions of separate analyses for the two GC subpopulations overlap in halo parameter space.  The solution coverless on a massive DM halo, consistent with expectations from LCDM and WAMP7 cosmology in terms of M_DM~10e13.3 Msun and concentration c ~ 8.  This is the first example of this method; improves the uncertainties on the halo parameter determinations by 2x and opens new avenues for the use of elliptical galaxy dynamics as tests of predictions from cosmological simulations.  The implied stellar M/L ratio derived from the dynamical modeling is fully consistent with a Salpeter IMF and rules out a bottom light IMF.  The different GC subpopulations show markedly distinct orbital distributions at large radii, with red GCs having an anisotropy parameter beta~0.4 outside r ~ 3R_e, and the blue GCs having beta~0.15 at the same radii, while centrally ~1R_e they are both isotropic.  Discuss implications of findings within the 2-phase formation scenario for early-type galaxies.

1401.1510
Sub-millimeter galaxies as progenitors of compact quiescent galaxies
Toft et al

At z=2 (3 Gyrs after BB), half of the most massive galaxies were already old, quiescent systems with little to no residual SF and extremely compact with stellar mass densities at least an order of magnitude larger than in low z ellipticals, their descendants.  Dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr 1-2 Gyr earlier (3<z<6).  Simulations show that gas-rich major mergers can give rise to such starbursts which produce dense remnants.  Sub-millimeter galaxies (SMGs) are prime examples of intense, gas-rich, SBs.  With a new representative spectroscopic sample of compact quiescent galaxies at z=2 and a statistically well-understood sample of SMGs, show that z=3-6 SMGs are consistent with being the progenitors of z=2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses and internal velocities.  Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42 (+40/-29) Myr (consistent with independent estimates), which indicates that the bulk of stars in these massive galaxies were formed in a major, early surge of star formation.  These results suggests a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent SF through their appearance as high stellar-density galaxy cores and their ultimate fate as giant ellipticals.


1401.1728
Variability in Ultra-luminous X-ray sources
Webb

Variable ULX's are thought to be accreting BHs for the most part.

1401.1814
The astronomical reach of fundamental physics
Burrows, Ostriker

Derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the Universe in terms of just a few fundamental constants.  This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the Cosmos we inhabit.  Focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a WD, and the mass of a typical galaxy.  To zeroth order, show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekhar mass, in combination with various dimensionless quantities.  With these examples, expose the deep interrelationships imposed by Nature between disparate realms of the Universe and the amazing consequences of the unifying character of physical law.

1401.1817
Galaxy and mass assembly (GAMA): ugrizYJHK S\'ersic luminosity functions and the cosmic spectral energy distribution by Hubble type
Kelvin, et al

Report morphological classification of 3727 galaxies from GAMA with M_r<-17.4 mag and 0.025<z<0.06 (2.1e5 Mpc^3) into E, S0-Sa, SBo-SBa, Sab-Scd, SBab-SBcd, Sd-Irr an little blue spheroid classes.  Approximately 70% of galaxies in sample are disk dominated systems, with the remaining ~30% spheroid dominated.  Establish the robustness of classifications, and use them to derive morphological-type luminosity functions and luminosity densities in the ugrizYJHK passbands, improving on prior studies that split by global color or light profile shape alone.  Find the the total galaxy luminosity function is best described by a double-Schechter function while the constituent morphological-type luminosity functions are well described by a single-Schechter function.  These data are also used to derive the SFR densities for each Hubble class, and the attenuated and unattenuated (corrected for dust) cosmic SEDs, i.e., the instantaneous energy production budget.  While the observed optical/NIR energy budget is dominated by 58:42 by galaxies with a significant spheroidal component, the actual energy projection rate is reversed, i.e., the combined disk dominated populations generate ~1.3x as much energy as the spheroid dominated populations.  On the grandest scale, this implies that chemical evolution in the local universe is currently confined to mid-type spiral classes like our MW.

1401.1830
60Fe-60Ni chronology of core formation in Mars
Tang, Dauphas

The timescales of accretion, core formation, and magmatic differentiations in planetary bodies can be constrained using extinct radionuclide systems.  Ni becomes more siderophile [dissolves into (solid) Fe readily, causing them to sink deeper into the Earth's Fe-rich core] with decreasing pressure, which is reflected in the progressively higher Fe/Ni ratios in the mantles of Earth, Mars and Vesta.  Mars formed rapidly and its mantle has a high Fe/Ni ratio, so the 60Fe-60Ni decay system (2.62 Myr half-life) is well suited to establish the timescale of core formation in this object.  Report new measurements of 60Ni/58Ni ratios in bulk SNC/martian meteorites and chondrites [meteorites that have not been modified due to melting or differentiation of the parent body].  The difference in epsilon-60Ni ratios in between SNC meteorites and the building blocks of Mars assumed to be chondritic (55% ordinary chondrites +45% enstatite chondrites) is +0.028pm0.023 (95% CL).  Using a model of growth of planetary embryo, this translate into a time for Mars to have reached ~44% of its present size of 1.9=0.8+1.7 Myr with a strict lower limit of 1.2 Myr after solar system formation, which agrees with a previous estimate based on 182Hf-182W systematics.  The presence of Mars when planetesimals were still being formed may have influenced the formation of chondrules through bow shocks or by inducing collisions between dynamically excited planetesimals.  Constraints on the growth of large planetary bodies are scarce and this is a major development in our understanding of the chronology of Mars.  

1401.1867
Nonparametric 3d map of the IGM using the Lyman-alpha forest
Cisewski et al

Visualizing the high-z Universe is difficult due to the dearth of available data; however, Lyman-alpha forest provides a means to map the IGM at redshifts no accessible to large galaxy surveys.  large-scale structure surveys, such as BOSS, have collected WSO spectra that enable the reconstruction of HI density fluctuations.  The at a fall on a collection of lines defined by the LoS of the QSO, and a major issue with producing a 3d reconstruction is determining how to model the regions between the LoS.  Present a method that produces a 3d map of this relatively uncharted portion of the Universe by employing local polynomial smoothing, a nonparametric methodology.  The performance of the method is analyzed on simulated data that mimics the varying number of LoS expected in real data, and then is applied to a sample region selected from BOSS.  Evaluation of the reconstruction is assessed by considering various features of the predicted 3d maps including visual comparison of slices, PDFs, counts of local minima and maxima, and standardized correlation functions.  This 3d reconstruction allows for an investigation of the topology of this portion of the Universe using persistent homology.

1401.2060
Subhaloes gone Notts: Subhaloes as tracers of the dark matter halo shape
Hoffmann, .. Gaztanaga, … et al

Study the shapes of sub halo distributions from 4 DM only simulations of MW hype halos (Springel et al 2008).  The sub haloes have been identified by ten sub halo finders at up to 5 different resolution levels (Onions+ 2012).  Comparing the shapes derived from the sub halo distributions at high resolution to those of the underlying DM fields, find the former to be more triaxial if the analysis is restricted to massive sub haloes.  For 3 of the 4 analyzed halos the increased triviality of the distributions of massive sub haloes can be explained by a systematic effect caused by the low number of objects.  Subhaloes of the fourth halo show indications for anisotropic accretion via their strong triaxial distribution and orbit alignment wrt the DM field.  At low resolution levels the shape measurements of the sub halo distributions consisting of the 13 most massive objects identified by the different sub halo finders are strongly scattered.  Comparing the shape of the observed MW satellite distribution to those of high-res sub halo samples from simulations, find an agreement for samples of bright satellites, but significant deviations if faint satellites are included in the analysis.  These deviations might result from observational incompleteness.

1401.2087
The XXL survey: detection of the Sunyaev-Zel'dovich effect of the redsfhit 1.9 galaxy cluster XLSSU J021744.1-034536 with CARMA
Mantz et al

Photo-z determined SZ cluster at z=1.9pm0.2, the most distant for which the SZ effect has been measured.  Estimate a mass M500~1-2e14 Msun from X-ray flux and SZ signal.

1401.2134
10 simple rules for the care and feeding of scientific data
Goodman, et al

As the title says.

1401.2159
The impact of rotation on the line profiles of Wolf-Rayet stars
Shenar et al

Model emission line width of rotating WR stars.  The rotational velocities are difficult to measure, due to their expanding atmospheres, but some WR stars have peculiarly broad and round emission lines.  Assume a rotational velocity field consisting of an inner co-rotating domain and an outer domain, where the angular momentum is conserved.  Find that rotation can reproduce the unique spectra, but the inferred rotational velocities at the stellar surface are large (~200 km/s) and the inferred co-rataion radii (~10 stellar radii) suggest the existence of very strong photospheric magnetic fields (~20 kG).

1401.2274
Discovery of four doubly imaged quasar lines from the Sloan Digital Sky Survey
Inada, Oguri, Rusu, Kayo, Morokuma

As the title says.  From SDSS, with follow-up observations.

1401.2392
Superhabitable worlds
Heller, Armstrong

Superhabitable == worlds that offer more benign environments to life ethan Earth does.  Illustrate how tidal heating can render terrestrial or icy worlds habitable beyond the stellar HZ. [what does "more habitable than Earth" mean?  wouldn't that narrow the range of habitable zone?]

Day 575

Friday.  Sunday.

1401.0535
A millisecond pulsar in a stellar triple system
Random et al

Gravitational three-body systems: studied for 100s of years, common in our Galaxy, show complex orbital interactions, which can constrain compositions, masses and interior structures of the bodies, and test theories of gravity if sufficiently precise measurements available.  Report precision timing and multi-wavelength observations of PSR J0337+1715, a millisecond pulsar in a hierarchical triple system with two other stars.  Strong gravitational interactions are apparent and provide the masses of the pulsar (1.4378 Msun), and the two WD companions (0.29651Msun and 0.4101 Msun), as well as they inclinations of the orbits (both approximately 39.2 degrees).  The unexpectedly coplanar and nearly circular orbits indicate a complex and exotic evolutionary past that differs from those of known stellar systems.  The gravitational field of the outer WD strongly accelerates the inner binary containing the NS, and the system will thus provide an dial laboratory in which to test the strong equivalence principle of GR.

1401.0536
Similarity of ionized gas nebulae around unobscured and obscured quasars
Liu, Zakamska, Greene

Quasar feedback is suspected to play a key role in the evolution of massive galaxies, by removing or reheating gas in quasar host galaxies and thus limiting the amount of star formation.  Continue investigation of quasar-driven winds on galaxy-wide scales.  Integral field unit on type 1 (unobscured) quasars to determine the morphology and kinematics of ionized gas around these objects, mostly via O III 5007 emission line.  Find that ionized gas nebulae extend out to ~13 kpc from the quasar, that they are smooth an round, and that their kinematics are strikingly similar to those of ionized gas around type 2 (obscured) quasars with matched [O III] luminosity, with marginal evidence that nebulae around unobscured quasars are slightly more compact.  In samples of obscured and unobscured quasars carefully matched in O III matched luminosity, find support for the standard geometry-based unification model of AGN, in that the intrinsic properties of quasars, of their hosts and of their ionized gas appear to be very similar.  Given the apparent ubiquity of extended ionized regions, forced to conclude that either the quasar is at least partially illuminating preexisting gas or that both samples of quasars are seen during advanced stages [?] of quasar feedback.  In the latter case, may be biased by the OIII selection against quasars in the early "blow-out" phase, for example due to dust obscuration.

1401.0537
Probing dark energy with lensing magnification in photometric surveys
Schneider

Present an estimator for the angular cross-correlation of two tracers of the cosmological LSS that utilizes z info to isolate separate physical contributions.  The estimator is derived by solving the Limber equation for a re-wieghting of the FG tracer that nulls either clustering or lensing contributions to the cross-correlation function.  Applied to future photometric surveys, the estimator can enhance the measurement of gravitational lensing magnification effects to provide a competitive independent constraint on the DE EoS.

Day 574

Thursday.

1312.5981
Weak gravitational lensing
Hoekstra

Lecture notes on gravitational lensing.

1312.6318
The Atlas3D project -- XXXVII. Cold gas and the colors and ages of early-type galaxies
Young et al

Early-type (elliptical and lenticular) galaxies are not as gas-poor as previously thought, and at least 40% of local early-type galaxies are now known to contain molecular and/or atomic gas.  This cold gas offers the opportunity to study recent galaxy evolution through the processes of cold gas acquisition, consumption (SF), and removal.  Molecular and atomic gas detection rates range from 10% to 34% in red sequence early-type galaxies, depending on how the red sequence is defined, and from 50% to 70% in blue early-type galaxies.  Massive red sequence early-type galaxies (M*>5e10 Msun derived from dynamical models [how?]) are found to have HI masses up to M(HI)/M* ~ 0.06 and H2 masses up to M(H2)/M*~0.01.  Some 20% of all massive early-type galaxies may have retained atomic and/or molecular gas through their transition to the red sequence.  However, kinematic and metallicity signatures of external gas accretion (either from satellite galaxies or the IGM) are also common, particularly at M*<=5e10 Msun, where such signatures are found in ~50% of H2-rich early-type galaxies.  Data are thus consistent with a scenario in which fast rotator early-type galaxies are quenched former spiral galaxies with have undergone some bulge growth processes, and in addition, some of them also experience cold gas accretion which can initiate a period of modest SF activity.  Discuss implications for the interpretation of color-magnitude diagrams.

1312.6330
Detecting ancient supernovae at z~5-12 with CLASH
Whalen, Smidt, Johnson, Holz, Stiavelli, Fryer

Possible with JWST, WFIRST and next generation of extremely large telescopes.  SL by massive clusters, like those in CLASH, could reveal such events now by magnifying their flux by factors of 10 or more.  Find that CLASH will likely discover at least 2-3 core-collapse SNe at 5<z<12 and perhaps as many as ten.  Future surveys of cluster lenses similar in scope to CLASH by the JWST might find hundreds out to z~15-17.  Besides revealing the masses of early stars, these ancient SNe will also constrain cosmic SFRs in the era of first galaxy formation.

1312.6645
Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background
POLARBEAR collaboration, et al

As the title says: 4.0 sigma evidence; presence of a lensing B-mode at 2.3 sigma.  Demonstrate that results are not biased by instrumental and astrophysical systematic errors by performing null-tests, checks with simulated and real data, and analytical calculations.  This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a new probe of cosmology and astrophysics.

1312.6692
Generalized microlensing effective timescale
Gould [!!]

Microlensing effective timescale t_eff=beta*t_E is used frequently in high-magnification (beta <<1) microlensing events, because it is better constrained than either the impact parameter beta or the einstein timescale t_E separately.  It also facilitates intuitive understanding of light curves prior to determination of a model.  Similar considerations may apply to very low magnification events.  Therefore, provide a generalization of this quantity to all events: t_eff = beta * t_E * sqrt((1+beta^2/2)(1+beta^2/4)).  

1312.6693
Astrophysics source code library: Incite to Cite!
DuPrie et al

ASCL: http://ascl.net: online registry of >700 source codes that are of interest to astrophysicists, with more being added regularly.  Description of ASCL.

1312.6694
Constraining sub-parsec binary supermassive black holes in quasars with multi-epoch spectroscopy.  II.  The population with kinematically offset board Balmer emission lines
Liu, Shen, Bian, Loeb, Tremaine

A small fraction of quasars have long been known to show bulk velocity offsets in the broad Balmer lines wrt the systemic redshift of the host galaxy.  Models to explain these offsets usually invoke broad line region gas kinematics/asymmetry around single BHs, orbital motion of massive (~sub-pc) binary BHs (BBHs), or recoil BHs, but single-epoch spectra are unable to distinguish between these scenarios.  The LoS radial velocity shifts from long-term spectroscopic monitoring can be used to test the BBH hypothesis.  Select a sample of 399 quasars with offset broad H-beta lines from the SDSS DR7 quasar catalog, and have conducted second-epoch optical spectroscopy for 50 of them.  Combined wit hthe existing SDSS spectra, the new observations enable LOS RV shift constraint on broad H-beta lines with a rest-frame baseline of a few years to nearly a decade.  Using cross-correlation analysis, detect (99% CL) radial accelerations in the broad H-beta lines in 24/50 objects.  Suggest that 9/24 detections are sub-pc BBH candidates, which show consistent velocity shifts independently measured from a second broad line (either H-alpha or Mg II) without significant changes in the broad line profiles.  Combining the results on the general quasar population studied in Paper I, find a tentative anti-correlation between the velocity offset in the first-epoch spectrum and the average acceleration between two epochs, which could be explained by orbital phase modulation when the time separation between two epochs is a non-negligible fraction of the orbital period of the motion causing the line displacement.  DIscuss the implications of results for the identification of sub-pc BBH candidates in offset-line quasars and for the constraints on their frequency and orbital parameters.

1312.6698
Observational evidence for black holes
Narayan, McClintock

Two populations of BHs: (i) stellar mass (5-30 Msun), millions present in each galaxy, and (ii) SMBHs (1e6-10 Msun), one each in the nucleus of every galaxy.  Strong circumstantial evidence that these are true BHs with even horizons.  SMBH masses strongly correlated with properties of their host galaxies, suggesting that these black holes have strong influence on the formation and evolution of entire galaxies.  Spin parameters have recently been measured for a handful of BHs.  Indication that the kinetic power of at least one class of relativistic jet ejected from accreting BHs may be correlated with BH spin.  If verified, it would suggest that these jets are powered by a generalized Penrose process mediated by B-fields.

1312.6135
Jellyfish: evidence of extreme ram-pressure stripping in massive galaxy clusters
Ebeling, Stephenson, Edge

A jellyfish-like (ram-pressure stripping: shock compressed and then removed from galaxies falling into the cluster) galaxy, can be bright enough to outshine the BCG.

1312.7297
New method to measure proper motions of microlensed sources: Application to candidate free-floating-planet event MOA-2011-BLG-262
Skowron, … Gould, et al

Take advantage of the fact that the source position is known from the event itself  Apply to a system of high proper (relative) motion of 20mas/yr or 12 mas/yr (depending on the model).  Characteristics imply that the lens could be a brown dwarf or a massive planet with a roughly Earth-mass "moon".  

1312.7619
Inflationary paradigm after Planck 2013
Guth, Kaiser, Nomura

"Cosmic inflation is on a stronger footing than ever before."

1312.7877
Self-calibration of BICEP1 three-year data and constraints on astrophysical polarization rotation
Kaufman et al

B-mode CMB signature from inflationary gravitational waves; also have the potential to constrain cosmic birefringence [?], which would produce non-zero expectation values for the CMB's TB and EB spectra.  However, instrumental systematic effects can also cause these TB and EB correlations to be non-zero (overall miscalibration of the polarization orientation of the detectors; also produces small bias in the BB spectrum).  Revise estimate of systematic error on the polarization rotation angle from the two-year analysis by comparing multiple calibration methods.  Investigate the polarization oration for the 100 GHz and 150 GHz separately to investigate theoretical models that produce frequency-denendent cosmic birefringence.  Find no evidence in the data supporting either these models or Faraday rotation of the CMB polarization by the MW's B-field.  Assuming that there is no cosmic birefringence, can use the TB and EB spectra to calibrate detector polarization orations, thus reducing bias of the cosmological B-mode spectrum from leaked E-modes due to possible polarization orientation miscalibration.  After applying this "self-calibration" process, find that the upper limit on the tensor-to-scalar ratio decreases slightly, from r<0.70 to r<0.65 at 95% CL.

1401.0046
Dark Energy: A short review
Mortonson, Weinberg, White

Briefly summarize theories for the origin of cosmic acceleration and the observational methods being used to test these theories.  Discuss current observational state of the field, with constraints from CMB, BAO, SN Ia, direct measurements of H0, and measurements of galaxy and matter clustering.  Assuming a flat universe and DE with a constant EoS parameter w = P/rho, the combination of Planck CMB T anisotropies, WMAP CMB polarization, Union2.1 SN compilation, and a compilation of BAO measurements yields w=-1.10pm0.08, consistent with a cosmological constant w=-1.  However, with these constraints the cosmological constant model predicts a value of H0 that is lower than several of the leading recent estimates, and it predicts a parameter combination sigma8 Omega_m^0.5 that is higher than many estimates from WL, galaxy clusters, and z-space distortions.  Individually these tensions are only significant at the 2 sigma level, but they arise in multiple data sets with independent statistics and distinct sources of systematic uncertainty.  The tensions are stronger with Planck CMB data than they were with WMAP because of the smaller statistical errors and the higher central value of Omega_m.  Wit hthe improved measurements expected from the next generation of data sets, these tensions may diminish, or they may sharpen in a way that points towards a more complete physical understanding of cosmic acceleration.

1401.0197
A new hybrid framework to efficiently model lines of sight to gravitational lenses
McCully, Keeton, Wong, Zabludoff

SL systems affected by other mass long the LoS; shear and convergence can be used to approximate the contributions from objects projected far from the lens, but higher-order effects need to be included for objects that are closer.  Develop a framework for multi-plane lensing that can handle arbitrary combination of planes treated with shear and convergence and planes treated exactly (including higher order terms).  This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modeling that incudes LoS effects.  It balances accuracy with efficiency.  Identify a generalized multi-plane mass sheet degeneracy in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors.

1401.0385
Super-sample covariance in simulations
Li, Hu, Takada

Using separate universe simulations, accurately quantify super-sample covariance (SSC), type typically dominant sampling error for matter PS estimators in a finite volume, which arises from the presence of super survey modes.  By quantifying the PS response to BG mode, this approach automatically captures the separate effects of beat coupling in the quasilinear regime, halo sample variance in the NL regime and a new dilation effect which changes scales in the PS coherently across the survey volume, including the BAO scale.  It models these effects at typically the few percent level or better with a handful of small volume simulations for any survey geometry compared with directly using many thousands of survey volumes in a suite of large volume simulations.  The stochasticity of the response is sufficiently small that in the quasilinear regime, SSC can be alternately included by fitting the mean density in the volume with these fixed templates in parameter estimation.  Also test the halo model prescription and find agreement typically at better than the 10% level for the response.  

1401.0392
Galaxy-wide outflows: cold gas and star formation at high speeds
Zubovas, King

Several active galaxies show strong evidence for fast (~1000 km/s) massive (dot M=1e3 Msun/yr) gas outflows.  Such outflows are expected on theoretical grounds once the central SMBH reaches the mass set by the M-sigma relation, and may be what makes galaxies become red and dead.  Despite their high velocities (imply T far above those necessary for molecule dissociation) the outflows contain large amounts of molecular gas.  To understand this surprising result, investigate the gas cooling and show that the outflows cannot stably persist in high-T states.  Instead the outflowing gas forms a two-phase medium, with cold dense molecular clumps mixed with hot tenuous gas, as observed.  Also show that efficient cooling leads to SF, providing an observable outflow signature.  The central parts of the outflows can be intrinsically luminous gamma-ray sources, provided that the central BH is still strongly accreting.  Note also that these outflows can persist for ~1e8 yr after the central AGN has turned off, so that many observed outflows (particularly with high speeds) otherwise assumed to be driven by starbursts might also be of this type.

1401.0484
Parallax beyond a kilo parsec from spatially scanning the wide field camera 3 on the Hubble space telescope
Riess, … Filippenko, et al

Use spatial scanning (a newly developed observing mode on HST and WFC3) to increase source sampling 1000x and measure changes in source positions to a precision of 20-40 microarcseconds, more than an order of magnitude better than attainable in pointed observations.  This observing mode can usefully measure the parallaxes of bright stars at distances of up to 5 kpc, a factor of 10 farther than achieved thus far with HST.  Long-period classical Cepheid variable stars in the MW, nearly all of which reside beyond 1kpc, are especially compelling targets for parallax measurements from scanning ,as they may be used to anchor determination of the Hubble constant to ~1%.  Illustrate the method by measuring to high precision the parallax of a classical Cepheid, SY Aurigae, at a distance of >2kpc, using 5 epochs of spatial-scan data obtained at intervals of 6 months.  Rapid spatial scans also enable photometric measurements of bright MW Cepheids---which would otherwise saturate even in the shorted possible pointed observations --- on the same flux scale as extragalactic Cepheids, which is a necessity for reducing a leading source of systematic error in the Hubble constant.  Demonstrate this capability with photometric measurements of SY Aur on the same system used for Cephids in Type Ia SN host galaxies.  While the technique and results presented here are preliminary, an ongoing program with HST is collecting such parallax measurements for another 18 Cepheids to produce a better anchor for the distance scale.