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Spitzer Observations of Hickson Compact Groups of Galaxies. J. E. Hibbard (NRAO), with: K. Johnson (P.I., UVa), A. Heiderman (NRAO REU), S. Gallagher (UCLA), A. Hornschemeier (GSFC) & J. Charlton (PSU). Compact Groups:. Hickson 1982 Richness: N>3 with m<m 1 +3mag
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Spitzer Observations of Hickson Compact Groups of Galaxies J. E. Hibbard (NRAO), with: K. Johnson (P.I., UVa), A. Heiderman (NRAO REU), S. Gallagher (UCLA), A. Hornschemeier (GSFC) & J. Charlton (PSU) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Compact Groups: • Hickson 1982 • Richness: N>3 with m<m1+3mag • Isolation: Rneighbor>3Rgroup • Compactness: G<26 mag/arcsec2 • (selected off of red plates, so bias towards early types) • May be stage in evolution to cluster core, field early type, “fossil group”, or “dry merger remnants” (c.f. yesterdays talk by Emanuela Pompei) • Stay tuned to meeting - 6 more CG talks on schedule! J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
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 & Amanda’s poster at January AAS (Washington D.C) for actual results! J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Spitzer IRAC 3.6, 4.5, 5.8, 8 m bands+ MIPS 24m Starburst SED Models Spitzer Dust Stars 3.6m 8m24m Radio ---> Brent Groves, 2005 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Spitzer IRAC & MIPS Mid-IR Imaging 3.6 m 4.5 m Mostly Stars, some PAHs Just Stars 5.8 m 8 m 24 m Some Stars, mostly PAHs PAHs Hot dust J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
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 Nearby galaxies Virgo Compact groups Virgo core Huchtmeier 1997 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Verdes-Montenegro et al. 2001 Compact groups Virgo Coma I group Coma J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HI Deficiency: DefHI = log[ M(HI:L)pred ] - log[ M(HI:L)obs ] (positive for systems more deficient than isolated galaxies of same type) HI properties of 324 isolated galaxies: Haynes & Giovanelli, 1984 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Evaluate evolution of HCGs, especially with respect to their cold gas content and proposed evolutionary scenario (L. Verdes-Montenegro, 2001) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Can this help us understand “quenching” of star formation in massive galaxies?? J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
In models, continued infall slows color evolution of remnants (Somerville 2005) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
SAMs can reproduce observed bimodality by truncating SF when bulge gets above some critical value Mcrit~2x1010 Mo (Somerville 2005) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Spitzer IRAC 3.6m, 4.5m, 5.0m, 8.0m color images J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
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 (L. Verdes-Montenegro, 2001) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Not HI Def HCG 61 (N=3) R-band Halpha X Vilchez & Iglesias-Paramo 1998 24um IRAC Log Lx<41.6 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Not HI Def HCG 19 (N=3+2) Optical+HI Optical A C B * X D VLA Archive No X-ray IRAC 24um J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 22 (N=3) DefHI=0.59 Optical Optical+HI A C * B X X E ATCA Archive, thanks to B. Koribalski D ROSAT A=dSy2 (Log Lx=40.6) IRAC 24um Mulchaey et al. 2003 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 07 (N=4) DefHI=0.64 R-band Halpha IRAC+HI * * * * Vilchez & Iglesias-Paramo 1998 VLA Archive 24um IRAC Log Lx<41.7 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Phase 2: HI being tidal removed from galaxies. • HCG 31* • HCG 16* *=at least one member HIdef **=all members HIdef (L. Verdes-Montenegro, 2001) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 16 (N=4+2) DefHI=0.41 Optical+HI R-band Halpha * * * Vilchez & Iglesias-Paramo 1998 Verdes-Montenegro 2001 24um XMM IRAC B=Sy2 A=LNR C=SBNG D=LNR Log Lx=41.0 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Optical+HI HCG 31 (N=4+2) R-band Halpha * Vilchez & Iglesias-Paramo 1998 Verdes-Montenegro 2001 DefHI=0.57 24um IRAC Log Lx<41.2 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
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 (L. Verdes-Montenegro, 2001) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 90 (N=4+1) DefHI=1.4 A=Sy2 IRAC A Optical+HI * B C * D ROSAT Log Lx=40.8 D=LNR Mulchaey et al. 2003 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 42 (N=4) E dominated IRAC C ROSAT A B D 24um A=dLNR Log Lx=41.8 Mulchaey et al. 2003 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 62 (N=4) E dominated Chandra IRAC B C A D Log Lx=42.9 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
So what can we do with the MIR data? • SEDs give dominant activity • Spatially separate SED J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Def vs. MIR SEDs Stars HCG7C: Def=0.55 PAHs HCG7D Def=0.55 HCG7B Def>1.3 HCG7A Def=0.85 PAHs + warm dust J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Trends with MIR Colors Blue=not HI Def Red=HI Def AGN [3.6]-[4.5] (mag) PAHs stars [4.5]-[8.0] (mag) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Trends with MIR-FIR Colors Blue=not HI Def Red=HI Def hot dust stars + cool dust cool dust [8]-[24] (mag) no dust stars [4.5]-[8.0] (mag) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
MIR and FIR Colors vs. DEF [3.6]-[4.5] (mag) [4.5]-[8.0] (mag) [8]-[24] (mag) [8]-[24] (mag) [4.5]-[8.0] (mag) [3.6]-[4.5] (mag) J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
SFR[24um] vs. Def J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Nuclear vs. Extranuclear MIR SEDs • HCG 90 PAHs & Hot dust Mostly starlight HCG 90D DefHI>2.0 J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Conclusions: • None yet. But track down Kelsey or Amanda Heiderman at January AAS Meeting J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 02 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 07 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 16 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 19 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 22 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 31 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 42 Optical+HI IRAC Map Not Available J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 48 Optical+HI IRAC Map Not Available J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 59 Optical+HI IRAC Map Not Available J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 61 Optical+HI IRAC Map Not Available J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 62 Optical+HI IRAC Map Not Available J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
HCG 90 Optical+HI IRAC J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005
Project Goals • Optical images of the 12 Hickson Compact Groups (Hickson 1982) in the sample; they were chosen for this study based on distance (closest), angular extent (< 8 arcmin diameter), and membership (at least 3 galaxies with redshifts within 1000 km s-1 of the mean). • Dotted blue lines enclose the groups with complete Spitzer data to date; the remainder will have a full suite of IRAC and MIPS (24 and 70 mm) imaging by the end of Cycle 1. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005