Day 782

Monday.

1411.1755
Intrinsic alignments of SDSS-III BOSS LOWZ sample galaxies
Singh, Mandelbaum, More

Present results of IA measurements of galaxies on 0.1-200 Mpc/h scales using the LOWZ sample, in 0.16<z<0.36.  Extend the existing IA measurements for spectroscopic LRGs to lower luminosities, and show that the luminosity dependence of large-scale IA can be well-dscribed by a power law.  Within the limited z and color range of the sample, observe no significant z or color dependence of IA.  Measure the halo mass of LOWZ galaxies using gg lensing, and show that the mass dependence of large-scale IA is also well described by a power law.  Detect variation in the scale dependence of IA with mass and luminosity, which underscores the need to use flexible templates in order to remove the IA signal.  Also study the environment dependence of IA by splitting the sample into field and group galaxies, which are future split into satellite and central galaxies.  Show that group central galaxies are aligned with their haloes at small scales and also are aligned with the tidal fields out to large scales.  Also detect the radial alignments of satellite galaxies within groups, which results in a null detection of large-scale IA for satellites.  These results can be used to construct better IA models for removal of this contaminant of the WL signal.

1411.1761
The search for failed supernovae with the Large Binocular Telescope: first candidates
Gerke, Kochanek, Stanek

Monitoring 27 galaxies within 10 Mpc; Use LBT to search for  failed SNe, massive stars that collapse to form a BH without a SN explosion.  Yielded 3 successful SNe during the 4 year survey period.  Only one candidate approaches the luminosity needed to address the absence of higher mass red supergiant SN progenitors.  Under the assumption that further observations show that 1, 2 or 3 candidates are failed SN, the median fractions are f~0.30, 0.40, 0.48 respectively with symmetric 90% confidence limits of 0.07<f<0.062, 0.15<f<0.69, 0.22<f<0.69.  If follow up data eliminates these candidates, find an upper limit on the fraction of core collapses leading to a failed SN of f<0.40 at 90% confidence.  As the duration of the survey continues to increase, it will have no difficulty constraining the f~20-30% failure rates needed to explain the absence of massive SN progenitors.

1411.1828
Molecular gas and star formation in voids
Das, Saito, Iono, Honey, Ramya

Although void galaxies lie in the most underdense parts of the universe, a significant fraction of them are gas rich, spiral galaxies that show signatures of ongoing star formation.  Not much is known about their cold gas content of SF properties.  In this study, searched for molecular gas in 5 void galaxies using the NRO.  The galaxies were selected based on their relatively higher IRAS fluxes of Ha line luminosities.  CO(1-0) emission was detected in 4 galaxies  and the derived molecular gas masses lie between (1-8e9 Msun.  The Ha imaging observations of three galaxies detected in CO emission indicates ongoing SF and the derived SFRs vary between 0.2-1.0 Msun/yr, which is similar to that observed in local galaxies.  Study shows that although void galaxies reside in under dense regions, their disks may contain molecular gas and have SFRs similar to galaxies in denser environments.