Day 596

Tuesday.

1402.5412
The pulsar spin-down luminosity: simulations in general relativity
Ruiz, Paschalidis, Shapiro

Method of matching general relativistic, ideal MHD to its force-free limit [?], perform the first systematic simulations of force-free pulsar magnetospheres in GR.  Endow the NS with a GR dipole B-field, model the interior with ideal MHD, and adopt force-free electrodynamics in the exterior.  Comparing the spin-down luminosity to its corresponding Minkowski value, find that GR effects give rise to a modest enhancement: the maximum enhancement for n=1 prolytropes is ~23%.  Evolving a rapidly rotating n=0.5 polytrope, find an even greater enhancement of ~35%.  Using simulation, derive fitting formulae for the pulsar spin-down luminosity as a function of the NS compaction, angular speed, and dipole B moment.  Expect stiffer EoS and more rapidly spinning NSs to lead to even larger enhancements in the spin-down luminosity.  [no, i don't understand what's going on.]

1402.5420
A UV to Mid-IR study of AGN selection
Chung, Kochanek, … Stern, Jannuzi, Gonzalez, et al

Classify SEDs of 431k sources in NDWFS (9 sq deg).  Up to 17 bands of data available, from UV, optical, NIR, and MIR, as well as 20k spectroscopic redshifts, primarily from the AGN and Galaxy Evolution Survey (AGES).  Fit galaxy, AGN, stellar, and brown dwarf templates to the observed SEDs, which yield spectral classes for the Galactic sources and photometric redshifts and galaxy/AGN luminosities for the extragalactic sources.  The photo-z precision of the galaxy and AGN samples are sigma/(1+z)=0.040 and 0.169, respectively, with the worst 5% outliers excluded.  Based on the reduced chi-squared of the SED fit for each SED model, able to distinguish between Galactic and extragalactic sources for sources brighter than I=23.5.  Compare the SED fits for a galaxy-only model and galaxy+AGN model.  Using known X-ray and spectroscopic AGN samples, confirm that SED fitting can be successfully used as a method to identify large populations of AGN, including spatially resolved AGN with significant contributions from the host galaxy and objects with the emission line ratios of "composite" spectra.  Also use results to compare the X-ray, MIR, optical color and emission line ratio selection techniques.  For an F-ratio threshold of F>10, find 16k AGN candidates brighter than I=23.5 and a surface density of ~1900 AGN / deg^2.

1402.5454
Spot scan probe of lateral field effects in a thick fully-depleted CCD
O'Connor

Flat-field images with thick, fully-depleted CCDs exhibit response variations near the edges of the chip and at other locations, such as the regions bordering mid-frame blooming stop implants.  Two possible origins for these response variations have been suggested: either photometric response (quantum efficiency) or effective pixel area is modified in these regions.  In the latter case, source position and shape distortions would be expected in these regions, with consequent impact on astrometric and WL measurements.  As an experimental check to distinguish between the two effects and to gauge the magnitude of distortion, perform a measurement scanning an artificial star image across the affected region of one device.

1402.5526
Effects of the environment on galaxies in the catalog of isolated galaxies: physical satellites and large scale structure
Argudo-Fernández et al

Aim to identify and quantify the effects of the satellite distribution around a sample of galaxies in CIG, as well as the effects of the LSS using SDSS-DR9.  To recover the physically bound galaxies, focus on the satellites which are within the escape speed of each CIG galaxy [using spectra of the satellite for LoS velocity?].  Also propose a more conservative method using the stacked Gaussian distribution of the velocity difference of the neighbors.  The tidal strengths affecting the primary galaxy are estimated to quantify the effects of the local and LSS environments.  Also define the projected number density parameter at the 5th nearest neighbor to characters the LSS around the CIG galaxies.  Out of the 386 CIG galaxies considered, at least 340 have no physically linked satellite.  Out of the 386 CIG galaxies, 327 have no physical companion within a projected distance of 0.3 Mpc.  The CIG galaxies are distributed following the LSS of the local Universe, although presenting a large heterogeneity in their degree of connection with it.  A clear segregation appears between early-type CIG galaxies with companions and isolated late-type CIG galaxies.  Isolated galaxies are in general bluer, with likely younger stellar populations and rather high SF with respect to older, redder CIG galaxies with companions.  Reciprocally, the satellites are redder and with an older stellar populations around massive early-type CIG galaxies, while they have a younger stellar content around massive late-type CIG galaxies.  This suggests that the CIG is composed of a heterogeneous population of galaxies, sampling from old to more recent, dynamical systems of galaxies.

1402.5545
Study of dust and ionized gas in early-type galaxies
Kulkarni et al

Observations of 40 nearby early-type galaxies.  The morphology and extend of ionized gas is found similar to those of dust, indicating possible coexistence of dust and ionized gas in these galaxies.  The absence of any apparent correlation between blue luminosity and normalized IRAS dust mass is suggestive of merger related origin of dust and gas in these galaxies.

1402.5654
Galaxy and mass assembly (GAMA): the evolution of bias in the radio source population to z~1.5
Lindsay, et al

Large scale clustering analysis of radio galaxies in GAMA survey area, limited to S1.4 GHz > 1 mJy with r<19.8 (spec-z) and r<22 (photo-z).  For the GAMA spec-z matches, present the z-space and projected correlation functions, the latter of which yielding a correlation length r0~8.2 Mpc/h and linear bias of ~1.9 at z~0.34.  Furthermore, use the angular 2-pt correlation function w(theta) to determine spatial clustering properties at higher z.  Find r0 [correlation length] to increase from ~6 to ~14 Mpc/h between z=0.3 and 1.55, with the corresponding bias increasing from ~2 to ~10 over the same range [as you go to higher z, the intrinsic radio luminosity must become brighter, and hence more bias].  Results consistent with the bias prescription implemented in the SKADS simulations at low z, but exceed these predictions at z>1.  This is indicative of an increasing (rather the fixed) halo mass and/or AGN fraction at higher z or a larger typical halo mass for the more abundant FRI sources.

1402.5752
The evolution of galaxy size and morphology at z~0.5-3.0 in the GOODS-N region with HST/WFC3 data
Morishita, Ichikawa, Kajisawa

Study the formation and evolution of Quiescent galaxies (QGs) with Sersic profiles of 299 QGs and 1k SFGs at z~0.5-3.0; find the evolution of re and n of M*>1e10.5 Msun QGs while weaker evolution of SFGs and less massive (M*<1e10.5Msun) QGs.  The regression of the size evolution of massive QGs follows re~(1+z)-alpha re [? not an exponent?] with alpha re = 1.06 (a factor of ~2.2 increase from z~2.5 to 0.5) which is consistent with the general picture of the significant size growth.  For the further understanding of the evolution scenario, study the evolution of Sersic index, n, and find that of massive QGs to significantly evolve as n~(1+z)-apha n with alpha n = 0.74 (n~1 to 4 at z~2.5 to 0.5, respectively), while those of the other populations are unchanged (n~1) over the redshift range.  The results in the present day are consistent with both of observation and numerical simulations, where gas-poor minor merger is believed to be the main evolution scenario.  By taking account of the connection with less massive QGs and SFGs, discuss the formation and evolution of the massive QGs over "Cosmic High Noon", or the peak of SF in the universe.