Chandra data has revealed 25 bright point-like X-ray sources in Arp 299, 14 of which are categorized as "ULXs".
X-ray: NASA/CXC/Univ of Crete/K. Anastasopoulou et al, NASA/NuSTAR/GSFC/A. Ptak et al; Optical: NASA/STScI
2016-11-01 12:13:45
Chandra X-ray Observatory, <a rel="nofollow" class="external free" href="http://chandra.harvard.edu/photo/2017/arp299/arp299_lg.jpg">http://chandra.harvard.edu/photo/2017/arp299/arp299_lg.jpg</a>