Extra-galactic far-infrared emission as seen by ISO X-ray to radio properties of faint far-infrared sources in the Lockman Hole K. Kawara, (IoA, UT), S. Oyabu (IoA, UT), H. Matsuhara (ISAS/JAXA), H. Okuda (GAO), Y. Taniguchi, T. Murayama (Tohoku U.), Y. Sato (NAOJ/NINS), Y. Sofue (IoA, UT), K. Wakamatsu (Gifu U.), D.B. Sanders, L.L. Cowie (UH), Min S. Yun (UMass) and S. Veilleux (U. of Maryland)

Cosmic ray impacts -> drift of responsivity 90 & 170um survey in two fields of Lockman Hole -- each has 44’x44’ ,observed with ISO in 1996 Cosmic ray impacts -> drift of responsivity

Deep Far-Infrared Survey in the Lockman Hole LHEX IRAS100μm LHNW Depth 90μｍ – 100mJy 170um – 200mJy Confusion limited Kawara et al.1998 Kawara et al. 2004 44’x44’ 90μm 170μm

Number Counts Upturn in 90um counts ⇓ New population Bulge formation? Low-z counterpart of SCUBA sources Very faint in optical Matsuhara et al. 2000, Kawara et al. 2004

Contribution to CIB from faint ISO sources CIB strengths 90um--25 nW/m2/sr 170um--15 nW/m2/sr compiled by Hauser & Dwek 2001 ISO FIR sources 90um S>70mJy – 10% x CIB S>10mJy – 100% x CIB 170um S>100mJy – 10% x CIB S>10mJy – 100% X CIB If Herschel or SPICA could go 3-4 times deeper than ISO, most of CIB at 60 – 200 um would be resolved into galaxies. Note that 3-4 times improvement in sensitivity is expected for observations limited by source confusion.

Other wavelength data in LHEX ROSAT UDS 0.5-2 keV Lehman et al. 2001 ASCA 1-7 keV Ishisaki et al. 2001 XMM 0.5-2, 2-10KeV Mainieri et al. 2002 VLA 20cm de Ruiter et al. 1997 VLA 6cm Ciliegi et al. 2003 SCUBA 850um Scott et al. 2002 New observations VLA 20cm(ultra-deep) Yun et al. 2005 Imaging & spectroscopy Oyabu et al. 2005 UH2.2m, WIYN3.5m, Keck10m, Subaru8m Optical IDs of UDS sources Lehman et al. 2001 94 X-ray – 90% IDed 57 AGN I, 13 AGN II, 10 CoG

High ID-rate with radio => FIRS are mostly star-forming galaxies Tow-step idenfitication procedure LR(likelihood ratio) method – LR>1, Reliability > 0.75 ID with RSX (radio, submm, x-ray) => ID with optical Identification rate RSX 90um 170um VLA 20cm 0.28(41/148) 0.43(31/72) 0.65(22/34) UDS X-ray 0.06-0.15(6-14/94) 0.10(6/62) 0.00-0.28(0-9/32) Submm 0.06(2/35) 0.50(2/4) 0.00(0/1) Radio X-ray High ID-rate with radio => FIRS are mostly star-forming galaxies

Comparing local rate of 0.4-1.4% implies…. Identification rate RSX 90um 170um VLA 20cm 0.28(41/148) 0.43(31/72) 0.65(22/34) UDS X-ray 0.06-0.15(6-14/94) 0.10(6/62) 0.0-0.28(0-9/32) Submm 0.06(2/35) 0.50(2/4) 0.00(0/1) Local ID rate is not well known ROSAT ALL SKY SURVEY (RASS) – limit of 10^-12 cgs, 1000 times shallower than UDS IRAS --limit of a few Jy at 100 um, 10 times shallower than ours Local X-ray/FIR associations = 1.4%(197/14315) of IRAS galaxies Boller et al. 1998 0.4% RASS galaxies Boller et al. 1998 Comparing local rate of 0.4-1.4% implies…. Srong evolution ….More dusty AGNs toward high redshift in agreement with suggestions that more obscured AGNs are needed to account for the shape of CXB. 10% of FIR CIB can be powered by AGNs, if star-formation is not important in x-ray emitting ISO galaxies, Probably consistent with that 10% of ISO mid-IR sources are X-ray emitting sources – Fadda et al. 2002. Further observations with a small beam are requested for confirmation!

Extreme IR excess source L(IR)/L(opt) is 10 times greater than Arp220 low-z counterparts of SCUBA sources? Extreme ULIRG-like Nearby galaxies Undeveloped sytellar systems? If so, we may be looking at bulge formation. Need spectroscopic observations.