Elliptical galaxiesFundamental Plane (Dressler et al. 87; Djorgovski & Davis 87;) Colour-magnitude relation (Baum 59; Bower et al. 92; Kodama & Arimoto 97)Simple, red and dead Why?Hubble (1936): tuning fork diagramFrom www.smv.org/hastings/M87

Abundant gas in ellipticalsExtended gas in 75% of nearby Es by SAURON (Sarzi et al. 2006)Mass loss (30-90%) occurs in all starsMergers between gas-rich galaxies (Toomre & Toomre 1972)

Red Supergiant V838 Monocerotis (STScI)

Ellipticals in LCMDM. Steinmetz simulationCMB (WMAP)LSS formation (T. Kimm & S.K.Yi)

Ellipticals in Hierarchical Merger Picture continue to show residual SF 500 cluster Es (Khochfar) zWhat controls Residual SF?

FeedbackWhy arent Es forming stars? Preventing gas from coolingSN feedbackBH feedback (Silk & Rees 98; di Matteo+ 05; Croton+ 06)Still qualitativeGalactic Centre (Genzel)NGC4261 (STScI)

Galex-derived Star formation history of elliptical galaxiesSukyoung K. Yi (Yonsei)Kevin Schawinski, Sugata Kaviraj, Sadegh Khochfar (Oxford)and the GALEX TeamAre ellipticals really not forming stars at all?

GALEX-SDSS matchAnd visual inspection gives ~103 volume-limited close bright (>L*) early-types

CriterionReasonr < 16.5Robust morphology (from COMBO-17 comparison)0.05 0.95de Vaucouleurs profileBPT analysisAGN removal for emission line galaxies with S/N > 3L(radio) > 1022 W Hz-1Further removal of possible AGN

Searching for ellipticals 100 Mpc

Ellipticals seen by GALEXQuiescent (QST) Recent star formation (RSF)Blue: UVYellow: Optical

CMRg r u r NUV rYi et al. 2005, ApJ, 619, L111Schawinski et al. 2006, ApJS; astro-ph/0601036Optical red sequence galaxies>30% formed stars in the last Gyr

Effect of density and massLocal densityStellar massDynamical mass

Schawinski et al. 2006, ApJS; astro-ph/0601036

Are recent mergers responsible for RSF? Brighter Es at z=0 had their latest merger more recentlyKaviraj et al. 2006, ApJS; astro-ph/0602347Last mergerredshiftMr

Hierarchical merger modelsdynamically younger but form their stars earlier Last merger age (Gyr)Stellar massMvzDRY MERGER!Kaviraj et al. 2006, ApJS; astro-ph/0602347

Recent SF sigma relationDynamical mass Stellar massSchawinski et al. 2006, Nature, 744, 888

The MBH-s relation(Silk & Rees 1998; King 2003)Tremaine et al. 2002

Critical MBH s relationSchawinski et al. 2006, Nature, 744, 888MBH,C s3.2MBH,C s3.6

How do black holes grow?Schawinski et al. 2006, Nature, 744, 888

Mdisk ~ 1011 Msun, MBH ~ 106 Msun x 10

ME ~ 1012 Msun, MBH ~ 109 Msun

Galaxy mergers

Summary First UV Colour-magnitude relation>30% of bright ETGs are forming stars at ~1% level (c.f. Rose 85; Worthey 94; Trager+ 2000; Bressans talk on FIR)BH feedback may have some control over the RSFGrowth of black holesDifferent types of mergers for large and small Es NASA/JPL-Caltech/T. Pyle.