Day 540

Wednesday.

1310.6735
Hunting for treasure among the Fermi unassociated sources: a multi-wavelength approach
Acero et al

Present a combination of factors that can be used to identify multi-wavelength counterparts to the Fermi unassociated sources [in optical/IR?].  This approach was used to select and investigate seven bright, high-latitude unassociated sources with radio, UV, X-ray and gamma-ray observations.  As a result, four of these sources are candidates to be AGN, and one to be a pulsar, while two do not fit easily into these known categories of sources.  The latter pair of extra-ordinary sources might reveal a new category subclass or a new type of gamma-ray emitters [any characteristics you can give, other than it is only observed in gamma-rays (probably)?].  These results altogether demonstrate the power of a multi-wavelength approach to illuminate the nature of unassociated Fermi sources.

1310.6742
Disk destruction and (re)-creation in the Magellanic clouds
Nidever

Unlike most satellite galaxies in the LG that have long lost their gaseous disks, the MGs are gas-rich dwarf galaxies most-likely on their first pericentric passage allowing us to study disk evolution on the smallest scales.  The MCs show both disk destruction and (re)-creation.  The LMC has a very extended stellar disk reaching to at least 15 kpc (10 radial scale lengths) while its gaseous disk is truncated at ~5 kpc mainly due to its interaction with the hot gaseous halo of the MW.  The stellar disk of the SMC, on the other hand, has essentially been destroyed. The old stellar populations show no sign of rotation (being pressure supported) and have an irregular and elongated shape.  The SMC has been severely disturbed by its close encounters with the LMC (the most recent only 200 Myr ago) which have also stripped out large quantities of gas creating much of the Magellatic stream and the Magellanic bridge.  Amazingly, the SMC has an intact, rotating HI disk indicating that either the inner HI was preserved from destruction, or, more likely, that the HI disk reformed quickly after the last close encounter with the LMC.  

1310.7644
Weak lensing analysis of SZ-selected clusters of galaxies from the SPT and Planck surveys
Gruen, Seitz, Kosyra, Brimioulle, Koppenhoefer, Lee, Bender, Riffeser, Eichner, Weidinger, Bierschenk

Present the WL analysis of WISCy (Wide-Field Imager SZ Cluster of Galaxy) sample, a set of 10 clusters of galaxies selected for their SZ effect.  After developing new and improved methods for background selection and determination of geometric lensing scaling factors from absolute multi-band photometry in cluster fields, compare the WL result with public X-ray and SZ data.  Find consistency with published hydrostatic X-ray masses with no significant bias and an intrinsic scatter sigma(int, log10)=0.13pm0.12.  Independently calibrate the SPT significance-mass relation and find consistency with previous results at an intrinsic scatter of sigma_(int,log10)=0.09+0.15-0.09, with indications for a slightly higher normalization mass and steeper slope.  The comparison of WL mass and Planck Compton parameters, whether extracted self-consistently with a mass-observable relation or using X-ray prior information on cluster size, shows significant discrepancies.  Since the deviations from the MOR strongly correlate with cluster redshift, hypothesize that they are related to a size or redshift dependent bias in either signal extraction in the Planck SZ catalogues or their previous X-ray based mass calibration, or in measurement related excess intrinsic scatter.

1310.6746
ELVIS: Exploring the Local Volume In Simulations
Garrison-Kimmel, Boylan-Kolchin, BUllock, Lee

Introduce high-res dissipation less simulations that model the LG in a cosmological context.  Suite contains 48 galaxy-size haloes, each within high-res volumes that span 2-5 Mpc in size, and each resolving thousands of systems with masses below the atomic cooling limit.  Half of the ELVIS galaxy haloes are in paired configurations similar to the MW and M31; the other half are isolated, mass-matched analogs.  Find no difference in the abundance of kinematics or substructure within the virial radii of isolated versus paired hosts.  On Mpc scales, however, LG-like pairs average almost twice as many companions and the velocity field is kinematically hotter and more complex.  Present a refined abundance matching relation between stellar mass and halo mass that reproduces the observed satellite stellar mass functions of the MW and M31 down to the regime where incompleteness is an issue, M*~1e5 Msun.  Within a larger region spanning 3 Mpc, the same relation predicts that there should be ~1000 galaxies with M*>1e3 Msun awaiting discovery.  Show that up to 50% of haloes within 1 Mpc of the MW or M31 could be systems that have previously been within the virial radius of either giant.  By associating never-accreted halos with gas-rich dwarfs, show that there are plausibly 50 undiscovered dwarf galaxies with HI masses >1e5Msun within the Local Volume.  The radial velocity distribution of these predicted gas-rich dwarfs can be used to inform follow-up searches based on ultra-compact high-velocity clouds found in the ALFALFA survey.

1310.6747
The dark side of galaxy color: evidence from new SDSS measurements of galaxy clustering and lensing
Hearin, … Reyes, … Zentner, et al

The age matching model has been shown to correctly predict the luminosity L and g-r color of galaxies residing within DM halos: older halos tend to host galaxies with older stellar populations.  Here, demonstrate that age matching also correctly predict the g-r color trends exhibited in a wide variety of statistics of the galaxy distribution for stellar mass M* threshold samples.  In particular, present new measurements of the galaxy two-point correlation function and the gg lensing signal as a function of M* and g-r color from SDSS, and show that age matching exhibits remarkable agreement with these and other statistics of low-z galaxies.  Describe how ahem attaching is a specific example of a larger class of Conditional Abundance Matching (CAM) models, a theoretical framework introduced here.  CAM provides a general formalism to study correlations at fixed mass between any galaxy property and any halo property.  The striking success of the simple implementation of CAM provides compelling evidence that this technique has the potential to describe the same set of data as alternative models, but with a dramatic reduction in the required number of parameters.  CAM achieves this reduction by exploiting the capability of contemporary N-body sims to determine DM halo properties other than mass alone, which distinguishes the models from conventional approaches to the galaxy-halo connection.