Seminars are organized jointly by the Trieste Astronomical Observatory (INAF/OATS) and the Astronomy Unit of the Physics Dept. of the Trieste University (UNI/TS). They usually take place on Wednesdays at 11:30, in the seminar room (Sala Ovale) of Villa Bazzoni in via Bazzoni 2, TS.

Tue, JUN 20 , 2017 -- EXTRA SEMINAR @ 12:00
SPEAKER: Isha Pahwa (Inter-University Centre for Astronomy and Astrophysics, Pune, IN)
TITLE: Analytical halo model of galactic conformity

ABSTRACT: Galactic conformity is an observation that satellite galaxies in groups whose central galaxy is red are preferentially red, even when the groups are restricted to reside in dark matter halos of the same mass. In this talk, I will present a fully analytical halo model of colour-dependent clustering which incorporates the effects of galactic conformity in a halo occupation distribution (HOD) framework. This model describes conformity through a correlation between the colour of a galaxy and the concentration of its parent halo, leading to a correlation between central and satellite galaxy colours at fixed halo mass. The strength of the correlation is set by a tunable ‘group quenching efficiency'. I will show that our model can separately describe the group-level correlations between galaxy colour (1-halo conformity) and large scale correlations induced by assembly bias (2- halo conformity). Further, I will talk about our analytical clustering results and compare them with that of mock galaxy catalogs, showing that this model is accurate at the 10-20 percent level for a wide range of luminosities and length scales.