Day 1333

Monday.

1711.00856
Does the existence of a plane of satellites constrain properties of the Milky Way?
Pawlowski

Find no evidence for strong correlations that would allow conclusions the host halo properties from the mere existence of the VPOS (the Vast Polar Structure) around our Galaxy.  Looked at correlations between properties of satellite galaxy planes fitted to cosmo sims in the ELVIS suite and properties of their host DM haloes.


1711.00860
Hunting faint dwarf galaxies in the field using integrated light surveys
Danieli, van Dokkum, Conroy

Discuss an alternative approach for future systematic searches of low mass dwarf galaxies, <~1e6 Msun.  By exploring the limiting surface brightness-spatial resolution (mu_eff,lim - theta) parameter space, suggest that dwarfs in the Local Volume, between 3 and 10 Mpc, are expected to be detected very effectively and in large numbers using integrated light photometric surveys, complementary to the classical star counts method.  Use a sample of dwarf galaxies in the Local Group to construct relations between their photometric and strutctural parameters, M* - mu_eff,V and M* - R_eff.  Use these relations, along with assumed functional forms for the halo mass function and the stellar mass - halo mass relation, to calculate the lowest detectable stellar masses in the Local Volume and the expected number of galaxies as a function of the limiting surface brightness and spatial resolution.  The number of detected galaxies depends mostly on the limiting surface brightness for distances >3 Mpc while spatial resolution starts to play a role for galaxies at distances >8 Mpc.  Surveys with mu_eff,lim ~ 30 mag/arcsec^2 should be able to detect galaxies with stellar masses down to ~1e4 M* [Msun?] in the Local Volume.  Depending on the form of the SMHM relation, the expected number of dwarf galaxies with distances between 3 and 10 Mpc is 0.04-0.35 per square degree, assuming a limiting surface brightness of ~29-30 mag/arcsec^2 and a spatial resolution < 4".  Plan to search for a population of low mass dwarfs by performing a blank photometric survey with the Dragonfly Telephoto Array, an imaging system optimized for the detection of extended ultra-low surface brightness structures.


1711.01184
Quasi-stellar objects acting as strong gravitational lenses in the SDSS-III BOSS survey
Meyer, Delubac, Kneib, Courbin

Present a sample of 12 QSOs potentially acting as SL on BG emission line galaxies (ELGs) or Lyman-alpha emitters (LAEs).  The candidates are selected through a systematic search of the 350793 QSOs spectra in the SDSS-III DR12 within BOSS.  Candidates are identified by looking for compound spectra, where additional emission lines cannot be associated with the spectral features of the QSOs.  The narrow diameter of BOSS fibers (2") ensures that the object responsible for the additional emission lines must lie close to the LoS of the QSO.  Focus the search on additional objects securely identified at higher redshifts than the QSOs.  Among the 12 candidates identified, 9 have definite evidence for the presence of BG ELG identified by at least 4 higher-z emission lines.  The remaining 3 probable candidates present a strong asymmetrical emission line attributed to a higher-redshift LAE.  The QSO-Galaxy lens candidates have QSO redshifts in the range 0.24 < z_QSO < 0.66 and background galaxy redshifts in the range 0.48 <~ z_s <~ 0.94 whereas the QSO-LAE lens candidates have 0.75 < z_QSO < 1.23 and source LAE z in the range 2.17 < z_s < 4.48.  Upon confirmation of the lensing nature of the systems, this sample may quadruple the number of known QSOs acting as SLs.  Further imaging of the full sample will allow to model the radial mass profile of QSO host galaxies and study the scaling relations between SMBHs and their host galaxies.