European Astronomical Society | 2019 Jun 27
Astronomers discovered eight buried dual AGN candidates, the largest sample of hidden accreting supermassive black holes in late stage galaxy mergers, selected using NASA’s Wide-Field Infrared Survey Explorer (WISE) space telescope. ...
Observational campaigns and theoretical studies have shown both that supermassive black holes (SMBHs) reside at the centers of most galaxies and that galaxy interactions are ubiquitous in the universe. As a result, galaxies grow and evolve hierarchically through collisions, which also fuel and consequently grow the SMBHs at their centers.Morphological and X-ray properties of the galaxy merger sample. Figure
1 displays the SDSS tricolor images for the full sample of 15 late stage
galaxy mergers and Figure 2 displays the Chandra X-ray 0.3-8 keV images
with SDSS r-band contours overlaid on each panel. Credit: Pfeifle et al.
Late-stage mergers should in fact host dual accreting SMBHs, or active galactic nuclei (AGN) -- unambiguous evidence for an ongoing merger -- with pair separations smaller than 10 kpc and are predicted to facilitate the most rapid growth of the black holes. Decades of observational campaigns have demonstrated, however, the exceeding rarity of dual accreting SMBHs.
Not only do the existence, frequency, and accretion rates of such dual AGN systems have important astrophysical implications on the formation and growth of SMBHs and their connection to the host galaxies in which they reside, they are the precursors of SMBH mergers, which will be the most titanic gravitational wave events in the universe -- a topic that is of current interest. ...
Buried Black Hole Growth in IR-selected Mergers: New Results from Chandra ~ Ryan W. Pfeifle et al
- Astrophysical Journal 875(2):117 (2019 Apr 20) DOI: 10.3847/1538-4357/ab07bc
- arXiv.org > astro-ph > arXiv:1904.10955 > 24 Apr 2019