1. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 J. E. Hibbard (NRAO), with: K. Johnson (P.I., UVa), A. Heiderman (NRAO REU), S. Gallagher (UCLA), A. Hornschemeier (GSFC) & J. Charlton (PSU) Spitzer Observations of Hickson Compact Groups of Galaxies

2. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Compact Groups: Hickson 1982 –Richness: N>3 with m<m 1 +3mag –Isolation: R neighbor >3R group –Compactness:  G <26 mag/arcsec 2 –(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!

3. 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!

4. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Spitzer IRAC 3.6, 4.5, 5.8, 8  m bands + MIPS 24  m Radio ---> Brent Groves, 2005 Starburst SED Models Dust Stars Spitzer 3.6  m 8  m 24  m

5. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 3.6  m 5.8  m8  m 4.5  m Spitzer IRAC & MIPS Mid-IR Imaging 24  m Mostly Stars, some PAHs Just Stars Some Stars, mostly PAHs PAHs Hot dust

6. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 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

7. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Verdes-Montenegro et al. 2001 Compact groups Virgo Coma Coma I group

8. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HI Deficiency: HI properties of 324 isolated galaxies: Haynes & Giovanelli, 1984 Def HI = log[ M(HI:L) pred ] - log[ M(HI:L) obs ] (positive for systems more deficient than isolated galaxies of same type)

9. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 (L. Verdes-Montenegro, 2001) Evaluate evolution of HCGs, especially with respect to their cold gas content and proposed evolutionary scenario

10. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Can this help us understand “quenching” of star formation in massive galaxies??

11. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 In models, continued infall slows color evolution of remnants (Somerville 2005)

12. 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 (Somerville 2005) M crit ~2x10 10 M o

13. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Spitzer IRAC 3.6  m, 4.5  m, 5.0  m, 8.0  m color images

14. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 (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

15. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 02 (N=3) R-bandHalpha IRAC Optical+HI Log Lx<41.1 24um X Verdes-Montenegro 2001 Vilchez & Iglesias-Paramo 1998 Not HI Def

16. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 61 (N=3) R-bandHalpha IRAC Log Lx<41.6 24um X Not HI Def Vilchez & Iglesias-Paramo 1998

17. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 59 (N=4) IRAC Log Lx<41.7 Optical A C B D E X Not HI Def

18. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 19 (N=3+2) IRAC Optical+HI No X-ray 24um X Optical A C B D VLA Archive Not HI Def *

19. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 22 (N=3) Optical+HI X X Optical A C B D E IRAC24um ATCA Archive, thanks to B. Koribalski Mulchaey et al. 2003 ROSAT A=dSy2 (Log Lx=40.6) Def HI =0.59 *

20. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 R-bandHalpha IRAC IRAC+HI Log Lx<41.7 24um HCG 07 (N=4) VLA Archive Vilchez & Iglesias-Paramo 1998 Def HI =0.64 * * * *

21. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 (L. Verdes-Montenegro, 2001) Phase 2: HI being tidal removed from galaxies. –HCG 31* –HCG 16* *=at least one member HIdef **=all members HIdef

22. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 16 (N=4+2) R-bandHalpha IRAC Optical+HI 24umXMM Verdes-Montenegro 2001 Vilchez & Iglesias-Paramo 1998 A=LNR B=Sy2 C=SBNG D=LNR Log Lx=41.0 Def HI =0.41 * * *

23. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 31 (N=4+2) R-bandHalpha IRAC Optical+HI Log Lx<41.2 24um Verdes-Montenegro 2001 Def HI =0.57 * Vilchez & Iglesias-Paramo 1998

24. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 (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

25. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Optical+HI Mulchaey et al. 2003 HCG 90 (N=4+1) ROSAT IRAC A C B D A=Sy2 D=LNR Log Lx=40.8 Def HI =1.4 * *

26. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 48 (N=4) IRAC 24um A C B D ROSAT Mulchaey et al. 2003 Log Lx=41.6 Def HI =0.82

27. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 42 (N=4) IRAC 24um A C B D Mulchaey et al. 2003 ROSAT A=dLNR Log Lx=41.8 E dominated

28. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 62 (N=4) IRAC A C B D Chandra Log Lx=42.9 E dominated

29. 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

30. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG7C: Def=0.55 HCG7D Def=0.55 HCG7B Def>1.3 HCG7A Def=0.85 Def vs. MIR SEDs PAHs PAHs + warm dust Stars

31. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Trends with MIR Colors [4.5]-[8.0] (mag) [3.6]-[4.5] (mag) stars AGN PAHs Blue=not HI Def Red=HI Def

32. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Trends with MIR-FIR Colors [4.5]-[8.0] (mag) [8]-[24] (mag) stars Blue=not HI Def Red=HI Def hot dust cool dust no dust stars + cool dust

33. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 MIR and FIR Colors vs. DEF [4.5]-[8.0] (mag) [8]-[24] (mag) [4.5]-[8.0] (mag) [3.6]-[4.5] (mag)

34. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 SFR[24um] vs. Def

35. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 Nuclear vs. Extranuclear MIR SEDs HCG 90 Mostly starlight PAHs & Hot dust HCG 90D Def HI >2.0

36. 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

37. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005

38. HCG 02 IRACOptical+HI

39. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 IRACOptical+HI HCG 07

40. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 16 IRACOptical+HI

41. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 19 IRACOptical+HI

42. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 22 IRACOptical+HI

43. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 31 IRACOptical+HI

44. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 42 IRACOptical+HI Map Not Available

45. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 48 IRACOptical+HI Map Not Available

46. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 59 IRACOptical+HI Map Not Available

47. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 61 IRACOptical+HI Map Not Available

48. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 62 IRACOptical+HI Map Not Available

49. J. Hibbard ESO Workshop: Groups of Galaxies Dec 5-9 2005 HCG 90 IRACOptical+HI

50. 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  m) imaging by the end of Cycle 1.