Halos of Galaxies & Quasars Doron Chelouche (IAS) The Gaseous Halos of Galaxies and Quasars Doron Chelouche Institute for Advanced Study, Princeton and… B. Ménard (CITA), D. Bowen (Princeton), O. Gnat (Caltech/TAU) and many others! Strong MgII Absorbers A Proposed Model Quasar Halos Outline

Halos of Galaxies & Quasars Doron Chelouche (IAS) observations Bahcall & Spitzer (1969): Absorbers are related to galaxies

Halos of Galaxies & Quasars Doron Chelouche (IAS) Galaxies : L * Unit covering factor up to R max R max ~ L α (α~0.1 ― 0.4) Metalicity (~0.1 solar) No correlation w/galaxy inclination and or rotation Steidel et al. ( ) R max Mo & Miralda-Escude (1996) Fukugita & Peebles (2005) observations

Halos of Galaxies & Quasars Doron Chelouche (IAS) SDSS: 10 6 photometric quasars Several dozens of close (<100kpc) separation pairs (observed w/APO & HET) observations Covering factor for REW>0.6A absorber

Rauch et al. (2002) Halos of Galaxies & Quasars Doron Chelouche (IAS) a model Lanzetta & Bowen 1992 adopted from Rao et al. (2006)

a model Halos of Galaxies & Quasars Doron Chelouche (IAS) For an L* (MgII absorbing)

Halos of Galaxies & Quasars Doron Chelouche (IAS) Quasars

Halos of Galaxies & Quasars Doron Chelouche (IAS) Christensen et al Quasars Emission line [ID] Luminosity [erg/s] Size (50%) [kpc] HI Lα CIV λ15485∙ OVI λ10354∙ NV λ12382∙ CIII λ9778∙ OVIII λ18.972∙ [OIII] λ50078∙ SiIV λ13985∙ HI Hβ5∙ NIII λ19913∙ NeX λ12.145∙ HeI λ MgII λ28003∙

Questions Halos of Galaxies & Quasars Doron Chelouche (IAS) Do MgII absorbers lie in special environments (massive halos? groups?) How different are quasar environments from galaxy ones Unification on large scales Implications for galaxy/quasar reionization effects? Studying absorbers by emission (metalicity/mass) ~10L* ~1L* ~0.1L*

~10L* ~1L* ~0.1L*