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Transforming Spirals: From COMBO-17 to SkyMapper. Christian Wolf (Oxford, Mt Stromlo). Nature vs. Nurture. genes vs. environment. “ A Weird Bunch of Nebulae ”.
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Transforming Spirals:From COMBO-17 to SkyMapper Christian Wolf (Oxford, Mt Stromlo)
Nature vs. Nurture genes vs. environment
“A Weird Bunch of Nebulae” Max Wolf 1901 (Coma Cluster):“…108 nebulae within the area of a full moon…mostly round and small…so close together, one is outright startled by the view”
Trends Dressler 1980 S+Irr S0 E Lewis et al. 2002
1. Expect… Mergers in Abell 901
2. Expect… Gravity NGC 4438/5
3. Expect… Hot gas CGCG 97-073 Boselli et al. 1995
Mergers gas & stars,profoundGravity gas & stars Hot gas gas
Anaemic Spirals van den Bergh 1976
Bulge Growth or Disk Fading? Christlein & Zabludoff 2004 Binggeli et al. 1988
z/(1+z) ~ 0.005 5 Mpc QE (%) λ/ nm Our Work: Abell 901ab+902 Wolf, Meisenheimer & Röser 1999, 2001 Wolf et al. 2003/4/5/6/7/8/9 Gray, Wolf et al. 2009 COMBO-17
Old Red vs. Dusty Red Wolf et al. 2005
Dusty Red Galaxies = Anemic Spirals Wolf et al. 2009
Red Spirals: More Obscured SF Optically passive, but FIR-bright:SFR ~1/2 dex semi-suppressed Wolf et al. 2005, 2009 Kenney at al. 2008 Centrally-concentrated, moreobscured SF in Virgo spirals
Density & Mass Dependence Galaxy Zoo, Bamford et al. 2009 Wolf et al. 2005, 2009 log M*/M=[10,10.5] log M*/M=[10.5,11] log M*/M=[9.5,10]
Aspects of Transformation Examples
Rotation Curves Ha & OII Gas velocity asymmetry Stellar light asymmetry ~100 VLT spectra in Abell 901 Bösch, Böhm, Wolf et al. 2013
Gas Disks field
Time Scales TE RPS Boselli & Gavazzi 2006
E+A Galaxies • Dressler & Gunn 1983 • Quenched star formation • Strong A star population • EWHd-abs > 5Å • tquenching < 200 Myr • Poggianti et al. 1996 • Strong low-M population in Coma • None in Virgo Pracy et al. 2012
Slow & Fast Quenching Moran et al. 2007
Local & Total Quenching SDSS fiber 4 kpc @ z=0.1 CALIFA survey, Husemann et al. 2013
SkyMapper atomic & stellar Balmer break extragalactic “Balmer” break = 4000Å-break g-i Keller et al. 2007 u-v -0.2(g-i)
Balmer Breaks in Galaxies D4000 ~ f(SFR,<age>) Ha ~ f(SFR) BB365 ~ f(d/dt SFR) ageing Hd > 5Å *burst quenching d/dt SFR >0 d/dt SFR <0 Ha - NGC 4654
SkyMapper BBC* * Balmer Break Cluster survey Shallow: (11 min, free)SkyMapper Southern Survey= full Southern hemisphere incl. Fornax, Eridanus… Deep u/v: (3 hours)Virgo, Leo, Coma…up to 150 ° Ferrarese et al. 2012 S/N=5 110 sec 11 min
Challenges… S/N~30 in (u−v)-colour! Shallow: inner disksDeep: outer disks Crucial: Flatfields, ghosts, atmosphere,fore-/background… Maltby et al. 2012
High VelocityAsymmetries Stellar light asymmetry
Old red Dusty red Blue Age The STAGES collaboration 2008 blue Dust old dusty E S0 Sa Sb Sc Sd Irr Wolf, Gray & Meisenheimer 2005: COMBO-17 Dusty Red Galaxies
Type-Density Relation • Dusty red galaxies: • Intermediate ages • Intermediatedensity • Intermediate luminosity • Intermediate morphology • Non-virialized kinematics infall population? WGM 2005
Selecting The Cluster Sample zphot = 0.170 ± 0.006 795 galaxies within cz = 1900 km/s 1575 = 3.7 x 3.5 x 120 (Mpc/h)3
2-D Clustering Old red = cluster cores Dusty red ~ blue cloud
(x,y): old red = cluster cores dusty red ~ blue cloud (y,z): old red ~ dusty red blue cloud = ‘voids’ v ~ 1400 km/s v ~ 550 km/s
Balogh+ 2004 van den Bergh 1976 Intermediate Population? • What is between…? • Blue star-forming galaxies in the field and • Red old ones in cluster cores • Fast SF truncation? • No transition population in SFR • Slow quenching? • Weak H absorption • Morphological change slower • Optically-passive spirals a.k.a. anemic spirals (van den Bergh 1976, Poggianti+ 1999, Goto+ 2003) • Red colour, smooth arms
Kauffmann+ 2004 Schawinski+ 2007 SF & AGN by Mass, Density • Empirically: • Low z: SF and AGN activity decline with density • High z: SF and AGN more concentrated to overdensities • But: different mass dependence • Connection? • Star formation regulated by • Internally: winds & ionization by AGN, stellar winds, supernovae • Externally: harassment, RPS, strangulation, tidal truncation, merging, induced starbursts
SF decline over density Passive spirals, dusty red galaxies, truncated SF disks - all the same?! What drives truncation of SF disk from the outside in? SF shutoff Hot & massive ICM cores Leaves H signature Role of AGN? Density axis ~ time axis? SDSS Fossil record SF history of cluster spirals Quenching template? Infall timing? Resolving red spirals Low-z SDSS colour maps SF disk truncation just Virgo or general? Evolutionary link Fading & SF disk truncation sufficient to turn blue spiral into red spiral into S0? Conclusions & Future Work