2002/08/27 by D. L. Clements, Jonathan McDowell, J. C. McDowell +9 · 2 citations
Medicine · Physics and Astronomy · #Acis #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Luminosity #Medicine #Nucleus #Physics #Point source #astro-ph
paper · pdf · doi:10.1086/344439
published as Astrophys.J. 581 (2002) 974-980 · Accepted for publication in ApJ
arxiv created 2002/08/27 · openalex publication_date 2002/12/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the first results from 60 ks of observations of Arp 220 using the ACIS-S instrument on Chandra . We report the detection of several sources near the galaxy's nucleus, including a point source with a hard spectrum that is coincident with the western radio nucleus B. This point source is mildly absorbed ( N H ~ 3 × 10 22 cm -2 ) and has an estimated luminosity of 4 × 10 40 ergs s -1 . In addition, a fainter source may coincide with the eastern nucleus A. Extended hard X-ray emission in the vicinity raises the total estimated nuclear 2-10 keV X-ray luminosity to 1.2 × 10 41 ergs s -1 , but we cannot rule out a hidden active galactic nucleus behind columns exceeding 5 × 10 24 cm -2 . We also detect a peak of soft X-ray emission to the west of the nucleus and a hard point source 2.5 kpc from the nucleus with a luminosity of 6 × 10 39 ergs s -1 .