1. 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)

2. 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

3. 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

4. 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

5. 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.

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

7. 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 um um
VLA 20cm (41/148) (31/72) (22/34)
UDS X-ray (6-14/94) (6/62) (0-9/32)
Submm (2/35) (2/4) (0/1)
Radio X-ray
High ID-rate with radio => FIRS are mostly star-forming galaxies

8. Comparing local rate of 0.4-1.4% implies….
Identification rate
RSX um um
VLA 20cm (41/148) (31/72) (22/34)
UDS X-ray (6-14/94) (6/62) (0-9/32)
Submm (2/35) (2/4) (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 % 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
Further observations with a small beam are requested for confirmation!

9. 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.