ﻻ يوجد ملخص باللغة العربية
We stack Spitzer 24 micron images for ~7000 galaxies with 0.1<z<1 in the Chandra Deep Field South to probe the thermal dust emission in low-luminosity galaxies over this redshift range. Through stacking, we can detect mean 24 micron fluxes that are more than an order of magnitude below the individual detection limit. We find that the correlations for low and moderate luminosity galaxies between the average L_IR/L_UV and rest-frame B-band luminosity, and between the star formation rate (SFR) and L_IR/L_UV, are similar to those in the local Universe. This verifies that oft-used assumption in deep UV/optical surveys that the dust obscuration-SFR relation for galaxies with SFR < 20 solar mass per year varies little with epoch. We have used this relation to derive the cosmic IR luminosity density from z=1 to z=0.1. The results also demonstrate directly that little of the bolometric luminosity of the galaxy population arises from the faint end of the luminosity function, indicating a relatively flat faint-end slope of the IR luminosity function with a power law index of 1.2+-0.3.
Spitzer-MIPS 24 micron and ground-based observations of the rich galaxy cluster Abell 851 at z=0.41 are used to derive star formation rates from the mid-IR 24 micron and from [O II] 3727 emission. Many cluster galaxies have SFR(24 um)/SFR([O II]) >>
Observations with the Spitzer Space Telescope have revealed a population of red-sequence galaxies with a significant excess in their 24-micron emission compared to what is expected from an old stellar population. We identify 900 red galaxies with 0.1
The Spitzer Space Telescope has undertaken the deepest ever observations of the 24 micron sky in the ELAIS-N1 field as part of GOODS Science Verification observations. We present the shape of the 24 micron source counts in the flux range 20-1000 micr
We investigate the close environment of 203 Spitzer 24 micron-selected sources at 0.6<z<1.0 using zCOSMOS-bright redshifts and spectra of I<22.5 AB mag galaxies, over 1.5 sq. deg. of the COSMOS field. We quantify the degree of passivity of the LIRG a
We employ X-ray stacking techniques to examine the contribution from X-ray undetected, mid-infrared-selected sources to the unresolved, hard (6-8 keV) cosmic X-ray background (CXB). We use the publicly available, 24 micron Spitzer Space Telescope MIP