Hibbard

Spitzer Observations of Hickson Compact Groups of Galaxies: 

J. E. Hibbard (NRAO), K. Johnson (P.I., UVa), A. Heiderman (NRAO REU), S. C. Gallagher, K. C. Peterson (UCLA), A. E. Hornschemeier (GSFC) andamp; J. C. Charlton (PSU), Spitzer Observations of Hickson Compact Groups of Galaxies

Compact Groups: : 

Compact Groups: Hickson 1982 Richness: Nandgt;3 with mandlt;m1+3mag Isolation: Rneighborandgt;3Rgroup Compactness: Gandlt;26 mag/arcsec2 (selected off of red plates, so bias towards early types) May be stage in evolution to cluster core, field early type, or 'fossil group', or 'dry merger remnants' (c.f. yesterdays talk by Emanuela Pompei) Stay tuned to meeting - 6 more CG talks on schedule!

Spitzer Survey of HCGs: : 

Spitzer Survey of HCGs: Kelsey Johnson (UVa) P.I. IRAC and MIPS imaging of 12 close HCGs spanning a range of evolutionary states Use MIR to conduct a complete census of activity (AGN; star formation) and dust content of HCGs This is VERY MUCH a work in progress! (some photometry completed yesterday). See Kelsey’s presentation andamp; Amanda’s poster at January AAS (Washington D.C) for actual results!

Spitzer IRAC 3.6, 4.5, 5.8, 8 m bands+ MIPS 24m : 

Spitzer IRAC 3.6, 4.5, 5.8, 8 m bands + MIPS 24m Radio ---andgt; Brent Groves, 2005 Starburst SED Models Dust Stars Spitzer 3.6m 8m 24m

Spitzer IRAC & MIPS Mid-IR Imaging: 

3.6 m 5.8 m 8 m 4.5 m Spitzer IRAC andamp; MIPS Mid-IR Imaging 24 m Mostly Stars, some PAHs Just Stars Some Stars, mostly PAHs PAHs Hot dust

So whats a nice radio astronomer like me involved for?: 

Nearby galaxies Virgo Virgo core Huchtmeier 1997 So whats a nice radio astronomer like me involved for? Compact groups are deficient in HI with respect to field galaxies of the same type Compact groups

Slide7: 

Verdes-Montenegro et al. 2001 Compact groups Virgo Coma Coma I group

Slide8: 

HI properties of 324 isolated galaxies: Haynes andamp; Giovanelli, 1984

Slide9: 

(L. Verdes-Montenegro, 2001) Evaluate evolution of HCGs, especially with respect to their cold gas content and proposed evolutionary scenario

Can this help us understand “quenching” of star formation in massive galaxies??: 

Can this help us understand 'quenching' of star formation in massive galaxies??

In models, continued infall slows color evolution of remnants: 

In models, continued infall slows color evolution of remnants (Somerville 2005)

SAMs can reproduce observed bimodality by truncating SF when bulge gets above some critical value: 

SAMs can reproduce observed bimodality by truncating SF when bulge gets above some critical value (Somerville 2005) Mcrit~2x1010 Mo

Spitzer IRAC 3.6m, 4.5m, 5.0m, 8.0m color images: 

Spitzer IRAC 3.6m, 4.5m, 5.0m, 8.0m color images

Slide14: 

(L. Verdes-Montenegro, 2001) Phase 1: HI in individual galaxies. HCG 02 HCG 61 HCG 59 HCG 19* HCG 22* HCG 07** *=at least one member HIdef **=all members HIdef

HCG 61 (N=3): 

HCG 61 (N=3) R-band Halpha IRAC Log Lxandlt;41.6 24um X Not HI Def Vilchez andamp; Iglesias-Paramo 1998

HCG 19 (N=3+2): 

HCG 19 (N=3+2) IRAC Optical+HI No X-ray 24um X Optical A C B D VLA Archive Not HI Def *

HCG 22 (N=3): 

HCG 22 (N=3) Optical+HI X X Optical A C B D E IRAC 24um ATCA Archive, thanks to B. Koribalski Mulchaey et al. 2003 ROSAT A=dSy2 (Log Lx=40.6) DefHI=0.59 *

HCG 07 (N=4): 

R-band Halpha IRAC IRAC+HI Log Lxandlt;41.7 24um HCG 07 (N=4) VLA Archive Vilchez andamp; Iglesias-Paramo 1998 DefHI=0.64 * * * *

Slide19: 

(L. Verdes-Montenegro, 2001) Phase 2: HI being tidal removed from galaxies. HCG 31** HCG 16** *=at least one member HIdef **=all members HIdef

HCG 16 (N=4+2): 

HCG 16 (N=4+2) R-band Halpha IRAC Optical+HI 24um XMM Verdes-Montenegro 2001 Vilchez andamp; Iglesias-Paramo 1998 A=LNR B=Sy2 C=SBNG D=LNR Log Lx=41.0 DefHI=0.41 * * *

HCG 31 (N=4+2): 

HCG 31 (N=4+2) R-band Halpha IRAC Optical+HI Log Lxandlt;41.2 24um Verdes-Montenegro 2001 DefHI=0.57 * Vilchez andamp; Iglesias-Paramo 1998

Slide22: 

(L. Verdes-Montenegro, 2001) Phase 4: X-ray medium. no HI in central galaxies; deficient galaxies in the outskirts HCG 48? HCG 90** HCG 62? ?=no HI map **=all members HIdef

HCG 90 (N=4+1): 

Optical+HI Mulchaey et al. 2003 HCG 90 (N=4+1) ROSAT IRAC and#x1A;A and#x1A;C and#x1A;B and#x1A;D A=Sy2 D=LNR Log Lx=40.8 DefHI=1.4 * *

HCG 42 (N=4): 

HCG 42 (N=4) IRAC 24um and#x1A;A and#x1A;C and#x1A;B and#x1A;D Mulchaey et al. 2003 ROSAT A=dLNR Log Lx=41.8 E dominated

HCG 62 (N=4): 

HCG 62 (N=4) IRAC and#x1A;A and#x1A;C and#x1A;B and#x1A;D Chandra Log Lx=42.9 E dominated

So what can we do with the MIR data?: 

So what can we do with the MIR data? SEDs give dominant activity Spatially separate SED

Def vs. MIR SEDs: 

HCG7C: Def=0.55 HCG7D Def=0.55 HCG7B Defandgt;1.3 HCG7A Def=0.85 Def vs. MIR SEDs PAHs PAHs + warm dust Stars

Trends with MIR Colors: 

Trends with MIR Colors [4.5]-[8.0] (mag) [3.6]-[4.5] (mag) stars AGN PAHs Blue=not HI Def Red=HI Def

Nuclear vs. Extranuclear MIR SEDs: 

Nuclear vs. Extranuclear MIR SEDs HCG 90 Mostly starlight PAHs andamp; Hot dust HCG 90D DefHIandgt;2.0

Conclusions:: 

Conclusions: None yet. But track down Kelsey or Amanda Heiderman at January AAS Meeting