Q&A: Galaxies, Galaxy Clusters, AGN, and Quasars
The approximate center of the Bootes field is given on our web-page as:
Coordinates (J2000): RA 14h 32m 00.00s | Dec +34 deg 06 min 00.0 s
At most directions in the sky the number of black holes and galaxies will
outnumber the stars from our galaxy. This Bootes X-ray image is not a deep
exposure at all and would have found many more black holes with more
observing time. Good examples of this are the Chandra deep fields which are
much deeper and manage to find hundreds of black holes despite covering
much smaller regions of the sky.
These black hole catalogs are themselves incomplete, since "normal"
galaxies likely contain dormant supermassive black holes (plus many smaller
black holes) that don't shine brightly in X-rays.
If you look towards the center of a dense globular cluster you will have
more stars from the galaxy than supermassive black holes in the background.