Alice Eltvedt

Gather.town id
DM08
Poster Title
Galaxy Cluster Masses, Galaxy+Quasar Bias and Dark Haloes via Quasar Lensing
Institution
Durham University
Abstract (short summary)
In this talk I present lensing results from the cross correlation of the VST ATLAS quasar catalogue with galaxy and galaxy cluster catalogues. We also detect strong Quasar - Planck CMB lensing. The quasar-galaxy cross-correlation allows us to fit models to our data to calculate the galaxy bias as a test of the ΛCDM model. We also fit halo models to our data in order to calculate galaxy cluster halo masses and predict velocity dispersions. The Quasar-CMB cross-correlations provide a direct measurement of the quasar bias and quasar host halo masses. We shall also consider the possibility of searching for dark matter haloes using quasar variability data from quasar catalogues from VST ATLAS, KiDS and ultimately the Vera Rubin LSST. We aim to present results from a pilot study using quasar variability data from a new CTIO DECam survey.
Plain text (extended) Summary
Lensing of quasars (via magnification bias) provides an alternative and independent method to galaxy lensing for estimating the masses of foreground galactic structures and, potentially, the cosmological parameters. Moreover, lensing of the CMB {by quasars provides a  powerful route to study the masses and bias of the host galaxies.
Here, we first present results on lensing of quasars from the cross correlation of the VST ATLAS quasar catalogue with galaxy and galaxy cluster catalogues.
Then we present results on lensing by quasars of the CMB from cross-correlating the same ATLAS catalogue with Planck CMB maps.
Finally we propose to use the Vera Rubin LSST to search for dark matter haloes via quasar variability caused by lensing and we present a pilot study using data from a new CTIO DECam survey.
URL
alice.m.eltvedt@durham.ac.uk