Circum-Galactic Medium in the Halo of Quasars

: Riccardo Ottolina, Renato Falomo, Aldo Treves, Michela Uslenghi, Jari K. Kotilainen, Riccardo Scarpa, Emanuele Paolo Farina

Publisher: FRONTIERS MEDIA SA

: 2017

: Frontiers in Astronomy and Space Sciences

: FRONTIERS IN ASTRONOMY AND SPACE SCIENCES

: FRONT ASTRON SPACE

: UNSP 61

: 4

: 61

: 4

: 2296-987X

DOI: https://doi.org/10.3389/fspas.2017.00061

: https://www.frontiersin.org/articles/10.3389/fspas.2017.00061/full

: https://research.utu.fi/converis/portal/detail/Publication/31738334

The properties of circum-galactic gas in the halo of quasar host galaxies are investigated analyzing Mg II 2800 and C IV 1540 absorption-line systems along the line of sight close to quasars. We used optical spectroscopy of closely aligned pairs of quasars (projected distance <= 200 kpc, but at very different redshift) obtained at the VLT and Gran Telescopio Canarias to investigate the distribution of the absorbing gas for a sample of quasars at z similar to 1. Absorption systems of EW >= 0.3 associated with the foreground quasars are revealed up to 200 kpc from the centre of the host galaxy, showing that the structure of the absorbing gas is patchy with a covering fraction quickly decreasing beyond 100 kpc. In this contribution we use optical and near-IR images obtained at VLT to investigate the relations between the properties of the circum-galactic medium of the host galaxies and of the large scale galaxy environments of the foreground quasars.

fspas-04-00061.pdf