Day 270

Monday.  To Oxford today.
Tuesday.  Exhausted this morning, don't know why.  Talking to Lance and Massimo about shape measurements was fun and informal, looking forward to it again today.  Massimo looks like Uros from the front (it turns out that Massimo's from Trieste, a few km to Uros' home town.  Their head shape is similar), and Martin from the back (hair and skin color---I guess I identify European people by their coloring).  It's totally confusing, I felt like I was walking with Martin and talking to Uros.

1206.4999

Chemical abundances of metal-poor RR Lyrae stars in the Magellanic Clouds

Haschke et al

Spectroscopic study of chemical element abundances of metal-poor RR Lyrae stars in the LMC and SMC [why?].  6 RR Lyrae stars in LMC, 3 in SMC, chosen for lowest photometric metallicities: find as low as [Fe/H]_spec=-2.7.  Photometric metallicities systematically too high (for metal poor stars, compare to spectroscopic).  Trend is reversed for even more metal-poor stars. (<-2.8 dex).  Determined abundance ratios for 10 chemical elements.  Good [alpha/Fe] agreement with MW halo.  Plausible that LMC-type galaxies contributed early chemically to MC halo, claimed in cosmological model.

1206.5000
CANDELS: the progenitors of compact quiescent galaxies at z~2
Barro,..  Koo, .. Bell, .. Dekel, ... Grogin, et al


CANDELS: HST imaging with multi-wavelength photometry to track the evolution of structure and activity of massive galaxies at z=1.4-3.  Identify compact, SF galaxies (cSFGs) that are likely progenitors of compact, quiescent, massive galaxies (cQGs) at z=1.5-3 (based on number densities, masses, sizes and SF rates).  At high z (>2) most sSFGs have sSFR half that of typical massive SFGs at the same epoch, and host X-ray luminous AGN 30 times more frequently; suggest cSFGs are formed by gas-rich processes (mergers or disk-instabilities) that induce a compact starburst and feed and AGN, which quench the SF on timescales of few 1e8 yr.  cSFGs continuously being formed at z=2-3 and fade to cQGs by z=1.5.  After this epoch, cSFGs are rare, truncating the formation of new cQGs.  Meanwhile, existing cQGs at z=1 continue to enlarge to match local QGs in size, while less-gas-rich mergers and other secular mechanisms shepherd (larger) SFGs as later arrivals to the red sequence.  In summary, propose tow evolutionary scenarios of QG formation: an early (z>2), fast-formaiton path of rapidly-quenched cSFGs that evolve into cQGs that later enlarge within the quiescent phase, and a slow, late-arrival (z<2) path for SFGs to form QGs without passing through a compact state.

(*) 1206.5002

stellar wind mass retention in star clusters: implications for subsequent episodes of star formation

Naiman, Ramirez-Ruz, Lin

Hydro-sims to explore a wide range of stellar cluster masses, compactness ,metallicities and stellar age combinations to determine the ideal conditions for gas retention.  Find: up to 6.4% of the mass of the star cluster can be made up of retained stellar wind gas at the time of SF is triggered.  Multiple episodes of SF can take place during the lifetime of a star cluster for >1 Gyr.  Faroable SF time interval coincides with AGB phase.  Gas retention is hampered by pulsar outflows or accretion onto compact objects.

1206.5003

Colliding planetary and stellar winds: charge exchange and transit spectroscopy in neutral Hydrogen

Tremblin, Chiang

When transiting, hot Jupiters absorb about 10% of the light in the wings of the stellar Lyman-alpha emission line; the absorption occurs at wavelengths Doppler-shifted from line center by pm100 km/s, much larger than the speeds with which partially neutral, 7000K H escapes from hot Jupiter atmospheres.  Absorption arises from 1e6K H from the host stellar wind, made momentarily neutral by charge exchange with planetary H I.  2d Hydro-sim of collision, augmented by a chemistry module to compute the amount of hot H I produced by charge exchange.  Contact discontinuity is KH unstable, about 20% are in equilibrium.  Simulations show enough hot H I generated to reproduce the transit observations, and amount of absorption converges with both spatial resolution and time.  Provide physical scaling relations that describe how absorption varies with stellar and planetary wind properties.

(*) 1206.5004

How do minor mergers promote inside-out growth of ellipticals, transforming the size, density profile and dark matter fraction?

Hilz, Naab, Ostriker

Observational evidence for inside-out growth of giant elliptical galaxies since z>2-3; many of the 1e11 Msun systems at high z have small sizes (1kpc) and surface brightness profiles with low Sersic indices n.  The most likely descendants at z=0 have, on average, grown by a factor of two in mass and a factor of four in size, with n>5.  Two assumptions can explain the evolution: compact ellipticals predominantly grow by collision less minor 'dry' mergers, and they are embedded in massive DM haloes which support the stripping of merging satellite stars at large radii.  Run simulations with and without DM halos of spheroidal galaxy mergers. Only a few minor mergers (~3-5 with mass-ratios of 1:5) of galaxies embedded in massive DM halos can result in the observed concurrent inside-out growth and the rapid evolution in profile shapes.  Apart from negative stellar metallicity gradients and positive age gradients, such a minor merger scenario also predicts significantly lower DM fractions for z~2 compact quiescent galaxies and their rare present day analogues.  [Why?  How?]

1206.5006

A general class of Lagrangian smoothed particle hydrodynamics methods and implications for fluid mixing problems

Hopkins

Smooth-particle hydrodynamics (SPH): intended to resolve certain difficulties in the treatment of fluid mixing instabilities.  Show how a class of alternative SPH equations of motion (EOM) can be derived self-consistently from a discrete particle Lagrangian (guaranteeing manifest conservation of energy, entropy, momentum and angular momentum) in a manner which tremendously improves treatment of these instabilities and contact discontinuities.  Derive a general EOM for any choice of volume element (particle 'weights') and method of determining smoothing lengths, specify this to a 'pressure-entropy formulation' which resolves problems in the traditional treatment of fluid interfaces.  Implement in a new version of GADGET code, show that it works well, and conserves physical quantities.  No additional computational expense.

(*) 1206.5007

Detecting the rise and fall of the first stars by their impact on cosmic reionization

Ahn, Illiev, Shapiro, Mellema, Koda, Mao

The first stars forming in mini haloes of 1e5-8 Msun at z~40: their contribution have been ignored for cosmic reionization so far.  Show reionization began much earlier with mini halo sources than without, and was greatly extended, which boosts the intergalactic electron-scattering optical depth and the large-angle polarization fluctuations of the CMB significantly (although within WMAP uncertainties).  Should be readily detectable by Planck.

(*) 1206.5010

Precise abundance analysis of the outer halo globular cluster M 75

Kacharov, Koch

M75 has high metallicity and shows signs of at least two generation of stars, formed on a short timescale.  Discuss r-and s-process element abundances in the context of the earliest cluster enrichment phases.

1206.5016

Supernovae and their host galaxies. I. the SDSS DR8 database and statistics

Hakobyan et al

Creation of a large database: of host galaxies, for 3800 SNe in 3600 host galaxies from SDSS DR8, check host galaxy statistics on apparent mags, diameters, axial ratios, position angles, morphology from g-band image.  

1206.5020

Galaxy zoo: quantifying morphological indicators of galaxy interaction

Casteels et al

Study morphological signatures of interaction between similar-mass galaxy pairs in SDSS.  Find: observable features correlate with projected pair separation: disturbance, tidal tails (obvious); but spiral arms and bars as well.  Robustly quantified using a control sample.  Find: presence of spiral features enhanced at scales < 70 kpc/h, probably due to both increased SF and the formation of tidal tails.   Bar decreases in paris with separations < 30 kpc/h, suggesting that bars are suppressed by close interactions between galaxies of similar mass.  Morphological indicators of physical interactions provide a way of significantly refining standard estimates for the frequent of close pair interactions, based on velocity offset and projected separation.  Presence of loosely wound spiral arms is found to be a particularly reliable signal of an interaction, for projected pair separations up to ~100 kpc/h.  Use this indicator to demonstrate method of constraining the fraction of low-redshift galaxies in truly interacting pairs with M*>1e9.5 Msun and mass ratio <4 to be between 0.4-2.7 %.

1206.5022

Toward a unified AGN structure

Kazanas, Fukumura, Behar, Contopoulos, Shrader

Present a unified model for the structure and appearance of accretion powered sources across their entire luminosity range from galactic X-ray binaries to luminous quasars, with emphasis on AGN and their phenomenology.  Notion of MHD winds launched from the accretion disks that power these objects is central.  AGN phenomenology in 3 parameters: the wind mass flux in units of Eddington value, the observer's inclination angle, and the logarithmic slope between the O/UV and X-ray fluxes.  The correlations of two parameters implied by this model appear to extend to and consistent with the characteristics of galactic X-ray sources, suggesting the presence of a truly unified underlying structure for accretion powered sources.

(*) 1206.5032

Gravity theories, transverse Doppler and gravitational redshifts in galaxy clusters

Zhao, Peacock, Li

Testing alternative gravity theories using gravitational redshifts in clusters; but the redshift signal cannot directly distinguish between the Einsteinian and f(R) gravity theories, because the mass of the cluster dark halo must be treated as an unknown fitting parameter, whose value must vary according to the theory adopted, otherwise the system would be in equilibrium in one gravity theory and out of equilibrium in another.

1206.5034

Cosmological post-Newtonian approximation compared with perturbation theory

Noh, Hwang

Correspondences with 1PN equations are available only in certain gauge conditions in the perturbation theory.  Perturbed velocity and gravitational potential in the zero-shear gauge coincide with Newtonian equations which is valid even to 1PN order (and perturbed velocity in the comoving gauge); equations of perturbed density in the zero-shear gauge and the uniform-expansion gauge coincide to 1 PN order.  Other correspondences available.

1206.5035

Detecting candidate cosmic bubble collisions with optimal filters

McEwen, Feeney, Johnson, Peiris

Review an optimal-filter-based algorithm for detecting candidate sources of unknown and differing size embedded in a stochastic BG, and its application to detecting candidate cosmic bubble collision signatures in WMAP7.  8 new candidate bubble collision signatures detected for follow-up analysis.

(*) 1206.5044

The Earth's figure axis determined from the polar motion data

Kubo

Polar motion data analyzed to obtain accurate position of the figure axis referred to the Earth-fixed frame [?] (variation of figure axis is the basic object to which the geophysical events are linked).  Relation between the rotational and the figure axes is derived.  The obtained figure axis exhibits stable annual and semi-annual variations while it has no component with the period of the Chandler wobble.  Besides this general feature, it shows different patterns from year to year as well as small irregularities with shorter periods, most of which are considered to be significant but not attributed to the observational errors.  Further, a simple model is introduced for the cause of the seasonal variation of the figure axis.  The model explains both the variation of the figure axis obtained above and that of the rotational speed which is so far known.  [?]

1206.5053

Why do compact active galactic nuclei at high redshift scintillate less?

Koay et al

Interstellar Scintillation at radio wavelengths:

Partially linked to the steepening of source spectral indices with redshift, caused either by selection biases or AGN evolution.

1206.5056

Cosmic acceleration from causal backreaction with recursive nonlinearities

Bochner

Revisit the causal back reaction paradigm, in which the need for DE is eliminated via the generation of an apparent cosmic acceleration from the causal flow of inhomogeneity information coming in towards each observer from distant structure-forming regions.  ...

1206.5058

The Swift short gamma-ray burst rate density: prospects for detecting binary neutron star mergers by aLIGO

Coward et al

Present: 30% of sGRBs have accurate redshifts, highly biased by the limited sensitivity of Swift to detect sGRBs.  Calculate a realistic sGRB rate density out to z=0.5.  detection rate limits of 1-180 per Yr by aLIGO and Virgo coincidence search.  Consistent with extrapolations.

1206.5091

Accurate classification of 29 objects detected in the 39 months Palermo Swift/BAT hard X-ray catalogue

Parisi et al

Optical spectroscopy for 29 counterparts of unclassified or poorly studied hard X-ray emitting objects detected with Swift/BAT and listed in the Palermo catalogue.  28 sources AGN (7 type 1, 21 type 2), remaining object a galactic cataclysmic variable.  

1206.5097

The role of star formation for the galactic dynamo

Elstner, Gressel

B-field amplification by fast dynamo is seen in local box simulations of SN-driven ISM turbulence.  Derive scaling laws of the turbulent transport coefficients in dependence of the SN rate, density and rotation.  Present dynamo models for different rotation curves and radial density distributions.

1206.5133

Searching for X-ray emission from AGB stars

Ramstedt Montez, Kastner, Vlemmings

Inconclusive.  B-fields measured around AGB stars of all chemical types using maser polarization observations.  If present, a large-scale B field would lead to X-ray emission.

1206.5207

Titan's transport-driven methane cycle

Mitchell

The strength of Titan's methane cycle, as measured by precipitation and evaporation, is key to interpreting fluvial erosion and other indicators of the surface-atmosphere exchange of liquids.  But the mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed.  Insolation only 1% (0.04W/m^2), not strong enough to be responsible for driving atmospheric convection.  In contrast, climate simulations that allow atmospheric motion indicate a robust methane cycle with substantial cloud formation and/or precipitation.  Argue that the top-of-atmosphere radiative imbalance is diagnostic of horizontal heat transport by Titan's atmosphere, and this constrains the strength of the methane cycle.  This is calculated to be 0.5-1 W/m^2 at equatorial region; implies 2-3 MW of latitudinal heat transport by the atmosphere. ...

[Mon **/44] Jun 25

Day 269

Friday.  Today is summer solstice party!


1206.4688
Keck/NIRC2 imaging of the warped, asymmetric debris disk around HD 32297
Currie et al


A disk model for a single dust belt including a phase function with two components and a 5-10 AU pericenter offset explains the disk's warped structure, and reproduces some of the surface brightness profile's shape but more poorly reproduces the disk's brightness asymmetry.  Agreement between mm peak emission  consistent with over density of very small, sub-blowout-sized dust and large, 0.1-1mm-sized grains at ~45AU tracing the same parent population of planetesimals. ...


1206.4692
Evolutionary connection between QSOs and SMGs: molecular gas in far-infrared luminous QSOs at z~2.5
Simpson Smail, et al


Two FIR-luminous QSOs, selected to have SMBH masses similar to those thought to reside in SMGs (sub-mm galaxies) at z~2.5, to study systems in transition from ULIRG phase to a sub-mm faint, unobscured, QSO.  The 2 have similar dynamical but lower gas masses than SMGs by ~50pm23% (warm/dense gas).  QSOs lack the extended, cool reservoir of gas seen in SMGs, suggests that they are at a different evolutionary stage.  Consistent with the hypothesis that FIR bright QSOs represent a short (1Myr) but ubiquitous phase in the transformation of dust obscured, gas-rich, starburst-dominated SMGs into unobscured, gas-poor, QSOs.


1206.4693
Molecular and atomic line surveys of galaxies I: the dense, star-forming phase as a beacon
Geach, Papadopoulos


Predict the space density of molecular gas reservoirs in the Universe; place lower limits on CO, HCN, CII lines in blind z-surveys in submm-cm spectral regime.  Model (A) HCN SLEDs (spectral line energy distribution) of local LIRGs, (b) SFR/M_dense(H_2), (c) model for the IR luminosity density.  CO SLED calculated from HCN SEDs.  Include CII as cooling lines.  Then, ALMA could potentially detect very distant (z~10-12) CII emitters in the >ULIRGs at a rate of 0.1~1 per hour, SKA: z>3 low CO emitters at 40-70/hour.  CII lines can detect metal-poor systems with extensive reservoirs of CO-dark molecular gas.


1206.4694
Disrupting primordial planet signatures: the close encounter of two single-planet ecosystems in the Galactic disc
Veras, Moeckel


During their MS lifetimes, majority of Galactic stars must endure at least one stellar intruder passing within a few hundred AU.  Observations of planet-star separations near or beyond this distance suggest that these close encounters may fundamentally shape orbital architectures, and hence obscure primordial orbital features.  Investigate resulting change in orbital ellipticity  and semi major axis from fast close encounter of one planet systems.  Derive analytical limit.  Find each wide-orbit planet has a few percent chance of escape, and an eccentricity that will typically change by at least 0.1.  Tight-orbit exoplanets are likely to be disrupted.


1206.4697
Evidence for asymmetric distribution of circumstellar material around Type Ia Supernovae
Förster et al


Find EW distribution of NaI and CaII absorption lines differ significantly between + and - nebular velocity shifts (v_neb), with generally stronger absorption for SNe Ia with v_neb > 0.  Similar results for distribution of colors.  Results suggest that (1) a significant part of these differences in color should be attributed to extinction (2) Extinction caused by asymmetric distribution of circumstellar material, and (3) the CSM absorption is generally stronger on the side of the ejecta opposite to where the ignition occurs.  Argue that asymmetry of CSM originated after explosion by stronger ionizing flux on the side of the ejecta where ignition occurs, probably due to a stronger shock breakout and/or more exposed radioactive material on one side of the ejecta.  


1206.4699
Moleculare and atomic line surveys of galaxies II: unbiased estimates of their star formation mode
Papadopoulos, Geach


Use ISM emission model of Paper I to examine the utility of key line ratios in surveys of SF 'mode' traced by M_dense(H_2)/M_total(H_2) = xi_SF, a sensitive, extinction-free discriminators of rapid starburst/merger-driven vs. secular quiescent/disk-like stellar mass assembly, with the most promising diagnostic to be applied in the near-future being CO/[Ci].  These lines accessible across 0<z<2 (covers bulk of galaxy evolution) with ALMA.  With SKA, can discover H_2-rich galaxies with very low xi_SF.  


1206.4702
The comic infrared background experiment (CIBER): the wide-field imagers
Bock, Sullivan, Arai, Battle, Cooray, ... et al


Developed and characterized an imaging instrument to measure the spatial properties of the diffuse near-infrared extragalactic BG light in search for fluctuations from z>6 galaxies during the epoch of reionization.  For CIBER, designed to observe the extragalactic BG light above the Earth's atmosphere during a suborbital sounding rocket flight.  4 sqdeg FoV (for 10 arcmin fluctuation detection) and 7"x7" pixels (remove lower z galaxies--reduce the low-z galaxy clustering FG below instrumental sensitivity [?]).  At wavelengths where the EM spectrum of reionization extragalactic BG is thought to peak, and complements fluctuations measurements by AKARI and Spitzer at longer wavelengths.


1206.4705
Deriving the comic ray spectrum from gamma-ray observations
Kachelreiss, Ostapchenko


Fundamental problem of CR physics: determination of the average properties of Galactic CRs outside the Solar System.  PAMELA (80 GeV-230 GeV) consistent with Fermi-LAT (1-2 GeV) spectra from molecular clouds.


1206.4718
Kepler-36: A pair of planets with neighboring orbits and dissimilar densities
Carter, Agol, et al


Find exoplanet system with 2 close-orbit planets (10% difference in orbital distance), but one being a super-Earth, and the other being more like a Neptune.


1206.4722
Detection of pulsar beams deflected by the black hole in Sgr A*: effects of black hole spin
Nampalliwar, Price, Creighton, Jenet


Calculate the odds of observability of rotating SMBH from pulsar timing analysis of deflected pulses.


1206.4724
The dependence of neutrino mechanism of chore-collapse supernovae on the equation of state
Couch


Study the dependence of the delayed neutrino-heating mechanism for core-collapse SNe on the equation of state [aka "as the title says"].  1d and 2d simulations; test 3 different EoS commonly used in core-collapse simulations.  ...


1206.4734
Models of the contribution of blazars to the anisotropy of the extragalactic diffuse gamma-ray background
Harding, Abazajian


Relation between the measured anisotropies in the extragalactic diffuse gamma-ray background (DGRB) and its spectral intensity, and their potential origin from the unresolved blazar population.  Find: blazars can account for the observed anisotropy of the DGRB consistent with their observed source-count distribution, but are in turn constrined in contributing significantly to the observed DGRB intensity.  Best fit: boasars contribute 4.3+4.1-1.1% (1 sigma) of the DGRB intensity above 1GeV.  [some limitation on the "LDDE model".]   ...


1206.4735
Measurement of the intracluster light at z~1
Burke, Collins, Stott, Hilton


Significant fraction of light in clusters are in ICL, which extends 100s of kpc from the core.  ICL reveal details of evolutionary histories and processes occurring within galaxy clusters, but low surface brightness makes it hard to detect.  Measure fraction of ICL with deep J-band (1.2 um) on VLT.  Look at 6 X-ray selected clusters at 0.8<z<1.2; find ICL below surface brightness of 22 mag/arcsec2 constitutes 1-4% of the total cluster light within radius R500; broadly consistent with simulations;  ICL light increase by 2-4x since z~1.  Find: fraction of total cluster light contained within BCG: 2.0-6.3% (larger than the fraction of the ICL component), different from nearby clusters.  Suggests evolution in cluster cores involves substantial stripping activity at late times, in addition to the early build up of the BCG stellar mass through merging.  


1206.4758
Tentative wiggle in the cosmic ray electron/positron spectrum at $/sim$ 100GeV: a dark matter annihilation signal in accordance with the 130 GeV $\gamma-$ray line?
Feng, Yuan, Fan


130 GeV gamma-ray line signal identified--DM annihilation signal?  Wiggles at 100 GeV seen in ATIC and PAMELA, could be result of annihilation of 140 GeV DM particles into e-/e+ with weighted cross section <sigma v>~1e-26 to 1e-25 cm^3/s.  Need more accurate measurements.


1206.4828
A comparison between the stellar and dynamical masses of six globular clusters
Sollima, Belazzini, Lee


Stellar mass are on average smaller than those predicted by canonical integrated stellar evolution models because of the shallower slope of their mass function.  Also systematically smaller than the dynamical mass by ~40% (but possibly systematics).  Modest amount of DM?


1206.4887
Late time anisotropy as a n imprint of cosmological backreaction
Marozzi, Uzan


Backreaction effects of the large scale structure on the background dynamics have been claimed to lead a renormalization of the background dynamics that may account for the late time acceleration of the cosmic expansion [?].   ...  Isotropy of the Hubble flow may allow to constrain the backreaction approach to DE.


1206.4889
Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records
Schrijver, Beer, ...


Proxy records of flare energies based on SEP [??] in principle may offer the longest time base to study infrequent large events.  Nitrate concentrations in polar ice cores does not may reliably to SEP events.  Concentrations of select radionuclides also not so reliable--calibration depends on multiple poorly known properties and processes (cannot determine the flare energy frequency distribution).  Combine solar flare (direct) observations with stellar flare observations [for frequency study, I suppose].  Use Kepler for stellar studies.


1206.4895
Cusp-core transformations in dwarf galaxies: observational predictions
Teyssier, Pontzen, Dubois, Read


DM core in the central kpc of many dwarf galaxies has been a long standing problem in galaxy formation theories based on standard CDM.  SPH and strong-feedback sims show that it's possible to form extended cores using baryonic processes related to a more realistic treatment of the ISM.  Use AMR with stronger SNe feedback in RAMSES, show that it is also possible to form prominent DM core within the well-controlled framework of an isolated, initially cuspy, 1e10 Msun DM halo.  Inner profile a pseudo-isothermal profile, core radius of 800 pc.  Observational predictions: (i) bursty SF history with peak to trough ratio of 5-10, and duty cycle comparable to the local dynamical time; (ii) stellar distribution that is hot with v/sigma=1.  Compare the observational properties of model galaxy with recent measurement of the isolated dwarf WLM; show spatial and kinematical distribution of stars and HI gas are in agreement with observations, supporting the fundamental role played by stellar feedback in shaping both the stellar and DM distribution.

Day 268

Thursday.  SUMMER SOLSTICE!  and Journal Club today.  Want to finish coding WL Fisher...  I still don't understand the last term in the intrinsic alignment, rho bar not.


1206.4302
Small-scale hero: massive-star enrichment in the Hercules dwarf spheroidal
Koch, Matteucci, Feltzing


Dwarf spheroidal galaxies are often conjectured to be the sites of the first stars.  Check out chemical imprints from enrichment from massive objects are the ultra faint dwarfs (UFDs).  Evidence for low heavy element abundances in metal poor Hercules UFD.  [that seems to be inconsistent to the theory?]  Proceedings.


1206.4303
The stellar population and star formation rates of z~1.5-1.6 [O II] emitting galaxies selected from narrow-band emission-line surveys
Ly, Malkan, Kashikawa, Hayashi, Nagao, Shimasaku, Ota, Ross


SF galaxies at z~1.5, selected by O II emission lines (1300 emitters, z=1.47 and 1.62 with EW>13AA), 2-color id successful (99%).  Analyze 1200 with best photometry, can be categorized as BzK (NIR gals) or "BX/BM" (UV) galaxies, and are more complete.  Higher OII EW have somewhat bluer continua, have half the stellar mass of galaxies with lower OII EW.  


1206.4304
Constrainats on the shapes of galaxy dark matter haloes from weak gravitational lensing
van Uitert, Hoekstra, Schrabback, Gilbank, Gladders, Yee


Study the shapes of galaxy DM haloes by measuring the anisotropy of the WL signal around galaxies in RCS2.  Study lens galaxy color dependence, environmental dependence.  Find: satellite preferentially reside near the major axis of the lenses.  [why is all != <blue + red>?]  For an elliptical NFW profile, the ratio of e_h/e_g=1.5 (so the halo ellipticity is larger).  For isolated galaxies of 'all' sample, the average shear anisotropy increases to 0.51 pm 0.25 [what is this?] and e_h/e_g = 4.7, while for clustered galaxies the signal is consistent with zero [???].


1206.4305
Precision Near infrared photometry for exoplanet transit observations - I : ensemble spot photometry for an all-sky survey
Clanton et al


NIR observation for detection of exoplanets using the transit technique.  Lab experiment on Teledyne Hawaii-2RG detector to emulate an dialyzed star-field.


1206.4306
Star-galaxy classification in multi-band optical imaging
Fadely, Hogg, Willman


Photometric classification techniques on stars and galaxies with intrinsic FWHM < 0.2 arc sec.  Consider SED template fitting (unsupervised) and data-driven Support Vector Machines (supervised).  Testing with COSMOS ugriz data.  No algorithm delivers perfect performance.  Conclude that a well trained SVM will outperform template-fitting methods, but a normally trained SVM performs worse.  Conclude hierarchical Bayesian template fitting may prove to be the optimal method for source classification in future surveys.


1206.4307
Parsec-scale dust emission from the polar region in the type 2 nucleus of NGC 424
Hoenig, Kishimoto, et al


Study the circumnuclear dust distribution of AGN ("dust torus").  Observe, conclude that majority of pc-scale MIR emission in this type 2 AGN originates from optically thin dust in the polar region of the AGN.  Suggest that a readiatively-driven dusty wind (launched in a puffed-up region of the inner hot part of the torus) is responsible for the polar dust.  The torus dominates the NIR emission to 5um, while the polar dust is main contributor of MIR flux.


1206.4310
The SWELLS survey - V. A Salperter stellar initial mass function in the bulges of massive spiral galaxies
Dutton et al


Investigation variations of the IMF within individual galaxies, use SL and gas kinematics to measure the normalization of the IMF of the bulge and disk components of 5 massive spiral galaxies.  Find bulge mass data consistent with SPS color fits by assuming Salpeter-like normalization of the IMF.  Disk masses are less well constrained due to degeneracies with the DM halo, but are consistent with MW type IMFs in agreement with previous studies.  Disks sub maximal and baryon dominated at 2.2 disk scale lengths.  Provide evidence for non-universal IMF within different components of spiral galaxies.


1206.4311
The stellar initial mass function in red-sequence galaxies: 1-micron spectroscopy of Coma Cluster galaxies with Subaru/FMOS
Smith, Lucey, Carter


Investigate possible variations in the IMF in red-sequence galaxies; obtain 92 red galaxy spectra in Coma cluster.  Derive composite spectra in 9600-10500 A range for galaxies grouped according to their velocity dispersion of Mg/Fe ratio.  Measure FeH and CaI line (strong in cool dwarf stars, reflect the form of IMF at low mass <0.5 Msun).  Compare measured indices against predictions from SPS models matched to the element abundances estimated from optical data.  Best reproduced by models with Salpeter IMF.  No clear evidence for an increase in dwarf-star content with velocity dispersion.  IMF depends on the mode of star formation, with intense rapid-star bursts generating a larger population of low-mass stars.


1206.4314
On the structure of hot gas in halos: Implications for the Lx-Tx relation & missing baryons
Sharma, McCourt, Parrish, Quataert


1d models of hot gas in DM haloes (predict existence of cool cores and explain their structure).  Filaments of cold (1e4 K) gas condense out of the ICM in hydrostatic and thermal equilibrium when the ratio of the thermal instability timescale to the free-fall time scale falls below 5-10; corresponds to an upper limit on the density of the ICM and motivates a model in which a density core form wherever the ratio is < 10.  Predicts larger and  more tenuous cores for lower-mass haloes.  For halo masses < 1e13 Msun, the core size approaches the virial radius.  Most of the baryons in such haloes cannot be in the hot ICM, but either in the form of stars or in the form of hot gas beyond the virial radius.  Because the smaller mass in the ICM and much larger mass available for star formation, the majority of the baryons in low mass haloes (<1e13 Msun) can be expelled beyond the virial radius due to SNe feedback.  This can account for the baryons 'missing' from low mass haloes, such as the Galactic halo.


1206.4315
Light bosons and photospheric solutions to the solar abundance problem
Vincent, Scott, Trampedach


Current spectroscopic determinations of the chemical composition of the Sun are starkly at odds with the metallicity implied by helioseismology.  Propose: discrepancy may be due to conversion of photons to a new light boson in the solar photosphere [wtf?]


1206.4317
The nonlinear matter and velocity power spectra in f(R) gravity
Li et al


Study the matter and velocity divergence power spectra in a f(R) gravity theory and their time evolution measured from several large-volume N-body simulations with varying box sizes and resolution.


1206.4318
Galaxies behind the Galactic plane: first results and perspectives from the VVV survey
Amores et al


Vista Variables in the Via Lactea (VVV): ESO variability survey in NIR bands (ZYJHKs) toward the Galactic bulge and part of the disk 3 mag deeper than 2MASS.  Searched for BG galaxies near the galactic plane using photometry (1.6 sq deg).  Find 204 new galaxies candidates from color, size and visual inspection, 10x more than previously known.


1206.4322
The morphologies of massive galaxies at 1<z<3 in the CANDELS-UDS field: compact bulges, and the rise and fall of massive disks
Bruce et al


Study the morphological properties of the most massive galaxies at high z from HST images of 200 galaxies with 1<z_phot<3 and M*>1e11 Msun.  Fit to single Sersic or bulge+disk, 90% show good fit.  Indicate that these massive galaxies lie both on and below the local size-mass relation, with median R_e~2.6 kpc, a factor of 2.3 smaller than comparably massive local galaxies.  Find: bulge-dominated objects in particular show evidence for a growing bimodality in the size-mass relation with increasing z, and by z>2 the compact bulges display effective radii 4x smaller than local ellipticals of comparable mass.  Trend appear to extend to the bulge components of disk-dominated galaxies, and vice versa [what vice versa?].  Also find: at 1<z<2 massive galaxies are predominantly mixed bulge+disk systems, and by z>2 they are mostly disk-dominated (at low z, massive galaxies are elliptical dominated).  Majority of the disk-domianted galaxies are actively forming stars, but this is also true for many of the bulge-dominated systems.  Significant fraction (25-40%) of the most quiescent galaxies have disk-dominated morphologies.  Results show that the massive galaxy population is undergoing dramatic changes at this epoch, but they also suggest that the physical mechanisms which quench SF activity are not simply connected to those responsible for the morphological transformation of massive galaxies into present-day giant ellipticals.


1206.4382
A systematic review of strong gravitational lens modeling software
Lefore, Futamase, Akhlaghi


First systematic review of SL modeling software.


1206.4396
A possible signature of primordial stellar populations in $z=3$ Lyman $\alpha$ emitters
Inoue


Examine stellar population which simultaneously accounts for the strength of the LyC and spectral slope of non-ionizing ultraviolet of the LAEs.  Stellar populations with metallicity Z>1/50 Zsun can explain the observed LyC strength only with a very top-heavy initial mass function. ...


1206.4437
Prospects for weak lensing studies with new radio telescopes
Brown


Proceedings.  Prospects for performing WL studies with new generation of radio telescopes: use polarization observations in radio WL analysis, which can remove contamination signal from intrinsic alignments [how??].  SKA is promising due to its high reolusion, large are surveys which it will perform.  Near term: e-MERLIN in UK offers high sensitivity and sub-arcsec resolution required to prove WL techniques in the radio band.  Describe the SuperCLASS survey.


1206.4454
The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods
Paciani et al


Use SDSS optical data and UV GALEX observations to estimate the thermal-disk emission contribution.  This source went through (optical) flux enhancement by 15-30x in the past 6 years, and 10x in 6 months.  Flare-up = transition from accretion-disk dominated to synchrotron-jet dominated?  Estimate mass of the central BH using the width of the CIV emission line.  Analysis of the gamma-ray data taken during flaring episodes indicates a flat gamma-ray spectrum with an extension of up to 15 GeV, with no statistically-relevant sign of absorption from the broad line region, suggesting that the blazar-zone is located beyond the broad line region [??].  Result confirmed by modeling the broad-band SED of the flaring activity periods, and by the accretion disk luminosity and BH mass estimated from archival data.


1206.4479
A hydrodynamical approach to CMB mu-distortions
Pajer, Zaldarriaga


Spectral distortion of CMB can probe primordial perturbations on very small scales by performing large-scale measurements.  Discuss all relevant physical phenomena involved in the production and evolution of he mu-type spectral distortion.  Main results agree with previous estimates.  Also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon leading and photon heat conduction.  Calculae the transfer function for mu-distortions between the end of the mu-era and now.


1206.4486
Broad band photometric reverberation mapping of NGC 4495
Edri, Rafter, Chelouche, Kaspi, Behar


RM to measure the radius of the broad line region and BH mass in the nearby, low luminosity AGN.  9 consecutive night observation, 3 light curves each, over 250 data points in SDSS gri bands.  g and r contain time variable contributions from Hbeta and Halpha plus continuum, i band is free of broad lines and is exclusively continuum.  Look for correlations for all combinations of filters, and get a reliable estimate of the time lag necessary to compute M_BH.  Lag = 3.6 pm 0.8 hours, giving M_BH = (4.9pm2.6)e4 Msun.


1005.1926
Polarization as an indicator of intrinsic alignment in radio weak lensing
Brown, Battye


Polarization orientation angle unaffected by lensing.  Polarization coupled with galaxy morphology orientation.  Combine these two, and you can infer the original shape position angle, relative to the lensed image.  This gets rid of intrinsic alignment effects.


1206.4493
Running a distributed virtual observatory: US Virtual Astronomical Observatory operations
McGlynn, Hanisch, Berriman, Thakar


Intimidating data volumes and rapid technological change, lack of direct control of the underlying and scattered data resources, and the distributed nature of the observatory itself.  Discuss how the VAO has addressed these challenges.  Facilitation of heterogeneous datasets is a fundamental reason for the virtual observatory.  Key aspect of approach: continuous monitoring and validation of VAO and VO services and the datasets provided by the community, monitoring of user requests to optimize access, caching for large datasets, and providing distributed storage services that allow user to collect results near large data repositories.  Distributed nature of the VAO requires careful attention to what can be a straightforward operation at a conventional observatory (web site organization/collection and combined analysis of logs).  


1206.4536
Two modified ILC methods to detect point sources in cosmic microwave background maps
Vio, Andreani, Ramos, da Silva


Two modifications of the "internal linear combination" method (used to separate the various components that contribute to the CMB.  Main advantage of this approach (esp. in handling multi-frequency maps of the same region) is that it doesn't require the 'a priori' knowledge of the spatial power-spectrum of either the CMB and /or the Galactic foreground, and hence more robust and more intuitive to use.  [What does it do, though?  no description in the abstract.]


1206.4550
Submillimeter observations of millimeter bright galaxies discovered by the South Pole Telescope
Greve et al


Present 11 representative samples of the rare, extremely bright (1.4mm > 15mJy), dust-dominated millimeter-selected galaxies discovered by SPT.  All detected with LABOCA (870 um) with 40-130 mJy, approximately and order of magnitude higher than the canonical SMG population.  Model SED using simple modified black body and perform the same analysis on samples of SMGs of known redshift (these calibration samples inform the distribution of dust temperature for similar SMG populations, and dust temperature then allows derivation of photo-z and FIR luminosity of the sources).  Find median redshift of <z>=3, higher than the <z>=2.2 inferred for the normal SMG population.  Apparent size larger tan unlensed calibration sample: these sources are probably gravitationally magnified.


1206.4569
Multilevel Bayesian framework for modeling the production, propagation and detection of ultra-high energy cosmic rays
Soiaporn, Chernoff, Loredo, Ruppert, Wasserman


Sources of UHECRs are unknown but are likely nearby galaxies.  Develop Bayesian framework to assess association of UHECRs and candidate sources.  Need for more complex models; MCMC methods to implement the approach to model data on 69 UHECRs observed, using 17 nearby AGN as candidate sources.  No significant evidence for association of UHECRs with nearby AGNs versus an isotropic population of sources.  If the association model is adopted, the fraction of UHECRs associated with these AGN is likely nonzero but well below 50%.  Relatively small B-field deflections favored; models that assign a large fraction of UHECRs to a single nearby sources are ruled out unless very large deflections are specified a priori.  Including Period 1 data alters the conclusions significantly (it had a E threshold applied), and simulation suggest Period 1 data are anomalous, presumably due to tuning.  Accurate and optimal analysis of future data will likely require more complete disclosure of the data.


[Thu **/41] Jun 21