Evidence for Three Accreting Black Holes in a Galaxy at z ~ 1.35: A Snapshot of Recently Formed Black Hole Seeds?
One of the key open questions in cosmology today pertains to understanding when, where, and how supermassive black holes form. While it is clear that mergers likely play a significant role in the growth cycles of black holes, the issue of how supermassive black holes form, and how galaxies grow around them, still needs to be addressed. Here, we present Hubble Space Telescope Wide Field Camera 3/IR grism observations of a clumpy galaxy at z = 1.35, with evidence for 106-107 M ⊙ rapidly growing black holes in separate sub-components of the host galaxy. These black holes could have been brought into close proximity as a consequence of a rare multiple galaxy merger or they could have formed in situ. Such holes would eventually merge into a central black hole as the stellar clumps/components presumably coalesce to form a galaxy bulge. If we are witnessing the in situ formation of multiple black holes, their properties can inform seed formation models and raise the possibility that massive black holes can continue to emerge in star-forming galaxies as late as z = 1.35 (4.8 Gyr after the big bang).Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Institute. STScI is operated by the association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555.
The Astrophysical Journal
- Pub Date:
- December 2011
- galaxies: active;
- galaxies: high-redshift;
- galaxies: Seyfert;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- Accepted for publication in ApJ Letters. 6 pages, 4 figures, 1 table