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arXiv · 1712.02619

Circum-galactic medium in the halo of quasars

Riccardo Ottolina·Renato Falomo·Aldo Treves·Michela Uslenghi·Jari K. Kotilainen·Riccardo Scarpa·Emanuele P. Farina
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Abstract

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 $\leq$ 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$\sim$1. Absorption systems of EW $\geq$ 0.3 $\rmÅ$ 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.

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Riccardo Ottolina, Renato Falomo, Aldo Treves, Michela Uslenghi, Jari K. Kotilainen, Riccardo Scarpa, Emanuele P. Farina. 2017-12-07. Circum-galactic medium in the halo of quasars. https://doi.org/10.3389/fspas.2017.00061

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