Dust emission from clusters of galaxies: statistical detection

摘要: The detection of the IR emission from individual galaxy clusters is a difficult task due to extremely low level this and fluctuations sky, galactic cirrus background galaxies. We have statistically detected significant toward at 12 μm, 25 60 μm 100 by co-adding IRAS maps total 11 507 extracted CDS database. This process averages sky astrophysical survey noise very in all four bands. obtained an averaged central wavelengths, with intensity 2685 ± 573 Jy/sr, 2127 742 16 253 670 Jy/sr 34 011 1391 respectively. These detections been confirmed against possible spurious or systematic signals using different test methods. origin discussed. free-free contribution can be ruled out. Both its spectrum favor interpretation terms dust emission. However exact location remains unknown: intergalactic dust, simply included galaxies clusters? last question will discussed forthcoming paper.