1. 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

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

3. Halos of Galaxies & Quasars Doron Chelouche (IAS) Galaxies : 0.07-3L * 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. (1994-1997) R max Mo & Miralda-Escude (1996) Fukugita & Peebles (2005) observations

4. 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

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

6. a model Halos of Galaxies & Quasars Doron Chelouche (IAS) For an L* (MgII absorbing) galaxy @z~1:

7. Halos of Galaxies & Quasars Doron Chelouche (IAS) Quasars

8. Halos of Galaxies & Quasars Doron Chelouche (IAS) Christensen et al. 2006 Quasars Emission line [ID] Luminosity [erg/s] Size (50%) [kpc] HI Lα10 44 75 CIV λ15485∙10 43 85 OVI λ10354∙10 43 50 NV λ12382∙10 43 70 CIII λ9778∙10 42 90 OVIII λ18.972∙10 42 12 [OIII] λ50078∙10 41 110 SiIV λ13985∙10 41 110 HI Hβ5∙10 41 80 NIII λ19913∙10 41 100 NeX λ12.145∙10 39 10 HeI λ1083010 39 100 MgII λ28003∙10 38 120

9. 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*

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