Roediger et al. 2012, ApJ (in print) arXiv:1201.6361 Stellar migrations and more in cluster disk galaxies Joe Joel C. . Roed oedig iger (Queen’s) Stéphane Courteau (Queen’s) Patricia Sánchez-Blázquez (UNAM) Michael McDonald (MIT)
Disk galaxies come in many Types (I) Bland-Hawthorn et al. (2005); Vlaji ć et al. (2009) Typ ype I Sur Surface Exponential brig brightn tness NGC 300 00 (> 5 R d ) pro profil ile Fractio Fra ion of of fi fiel eld 20% disk popu population on (Gu (Guti tierr rrez et et al al. 20 2011) See also NGC 7793 For Formati tion Inside-out (Vlaji ć et al. 2011) scen sc enario Type I ’s should have nega egati tive stellar age and metallicity gradients (Ferguson & Clarke 2001; Mollá & Diaz 2005; Naab & Ostriker 2006)
Disk galaxies come in many Types (II) Erwin et al. (2008) Ro šk ar et al. (2008) Typ ype II Sur Surface Down-bending brig brightn tness double pro profil ile exponential Fr Fractio ion of of fi fiel eld 50% disk popu population on (Guti (Gu tierr rrez et et al al. 20 2011) Inside-out + For Formati tion stellar scen sc enario migrations Stellar ages should in incr crease beyond break in Type II ’s (Ro š kar et al. 2008; Sánchez-Blázquez et al. 2009; Martínez-Serrano et al. 2009) Fie ield ld Type II ’s exhibit upturns in their age gradients (de Jong et al. 2007; Barker et al. 2011; Yoachim et al. 2012; Radburn-Smith et al. 2012)
Disk galaxies come in many Types (III) Younger et al. (2007) Typ ype III Sur Surface Up-bending brig brightn tness double pro profil ile exponential Fractio Fra ion of of fi fiel eld 30% disk popu population on (Gu (Guti tierr rrez et et al al. 20 2011) For Formati tion Minor sc scen enario merger(s) Type III ’s might also harbour uptu turn rns in Outer disk built up from in inner er disk isk star stars, akin to stellar migrations (Younger et al. 2007) their age gradients
What about cluster disks? McD cDonald ld et et al. al. (2011 2011) – g, r, i, z & H surface photometry for 286 Virgo galaxies Morp rphol ology N B/ B/T i Lum Lumin inosity (M (M i ) Su Surfa rface br brigh ightn tnes ess ( μ e,i e,i ) Size Size (r e,i e,i ) 21.3 – 23.3 mag arcsec -2 Sa-Sm 44 0 – 0.24 -17.4 – -21.0 mag 1.9 – 5.5 kpc Roe Roedig iger et et al. al. (2011 2011a,b ,b) ) – colour/stellar population analysis of McDonald et al. data
Outer disk structure depends on enrivonment Typ ype co composition Environment Morp rphologies I II III Sa – Im Virgo a 0.32 0.36 0.32 S0 – Sm Field b 0.20 0.50 0.30 a analysis of deeper imaging (< 28 mag arcsec -2 ) may alter these numbers b values from Gutierrez et al. (2011)
Age upturns are found in all disk Types ... I Bootstrap linear fits to inner and outer gradients of upturning age II profiles Large Lar e ra rang nge e in in up uptu turn stren strength th! III
... and those upturns correlate with the breaks in Virgo Type II’s ... (as predicted by simulations; Ro š kar et al. 2008, Sánchez-Blázquez et al. 2009; Martínez-Serrano et al. 2009) Theory Vir irgo Upturns also offset from breaks in field field Type ype II s (Yoachim et al. 2012)
... but upturns are not that common overall Virgo go I Type Ty Positi Po tive Flat Fla Nega Negati tive Up Uptu turn 7 8 2 3 I 8 3 3 8 II 7 5 2 6 III II Models Type Ty Po Positi tive Fla lat Ne Nega gati tive Up Uptu turn I II III III
Why do cluster and field disks differ? Upturn Age gradients within Virgo disks Flat and positive age gradients are do do not t co corre rrela late with their structure found most often near ear clu clust ster co core re
Summary Future work 1. 1. Typ ype II dis disks s are are rarer rarer in in For observ servers: clu cluste ters s than than in in the the field field Analyse deeper imaging (< 28 r-mag • outer structure of disks sensitive arcsec -2 ) for cluster disks to produce to repeated tidal forcing unmatched description of outer disk 2. 2. Age ge uptu pturn ph phen enomenon fou found structure in dense environments am amongst t al all l dis disk k Type ypes s in in Vir Virgo go (e.g., NGVS). • stellar migrations a generic For theo theorists ts: aspect of disk galaxy evolution? Produce high-res hydrodynamic 3. 3. Flat lat an and d po positi sitive ag age e grad gradients s simulations of cluster galaxies, do dominate te am amongs gst t Virg Virgo dis disks ks including ram pressure stripping • tides and ram pressure stripping and harassment. mix and quench outer disks See Roediger et al. (2012), arXiv:1201.6361
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