Webb detects most distant black hole merger to date

[oldpaddoboy]

https://phys.org/news/2024-05-webb-distant-black-hole-merger.html

"An international team of astronomers have used the NASA/ESA/CSA James Webb Space Telescope to find evidence for an ongoing merger of two galaxies and their massive black holes when the universe was only 740 million years old. This marks the most distant detection of a black hole merger ever obtained and the first time that this phenomenon has been detected so early in the universe.

 

Astronomers have found supermassive black holes with masses of millions to billions times that of the sun in most massive galaxies in the local universe, including in our Milky Way galaxy. These black holes have likely had a major impact on the evolution of the galaxies they reside in. However, scientists still don't fully understand how these objects grew to become so massive.

The finding of gargantuan black holes already in place in the first billion years after the Big Bang indicates that such growth must have happened very rapidly, and very early. Now, the James Webb Space Telescope is shedding new light on the growth of black holes in the early universe."

 

full article at link

The paper:

https://academic.oup.com/mnras/article/531/1/355/7671512?login=false

GA-NIFS: JWST discovers an offset AGN 740 million years after the big bang

ABSTRACT:

" A surprising finding of recent studies is the large number of Active Galactic Nuclei (AGN) associated with moderately massive black holes (⁠log⁡(M∙/M⊙)∼6−8⁠), in the first billion years after the big bang (z > 5). In this context, a relevant finding has been the large fraction of candidate dual AGN, both at large separations (several kpc) and in close pairs (less than a kpc), likely in the process of merging. Frequent black hole merging may be a route for black hole growth in the early universe; however, previous findings are still tentative and indirect. We present JWST/NIRSpec-IFU observations of a galaxy at z = 7.15 in which we find evidence for a log⁡(M∙/M⊙)∼7.7 accreting black hole, as traced by a broad component of H β emission, associated with the Broad Line Region (BLR) around the black hole. This BLR is offset by 620 pc in projection from the centroid of strong rest-frame optical emission, with a velocity offset of ∼40 km s^–1. The latter region is also characterized by (narrow) nebular emission features typical of AGN, hence also likely hosting another accreting black hole, although obscured (Type 2, narrow-line AGN). We exclude that the offset BLR is associated with Supernovae or massive stars, and we interpret these results as two black holes in the process of merging. This finding may be relevant for estimates of the rate and properties of gravitational-wave signals from the early universe that will be detected by future observatories like LISA."

 

 

10 CONCLUSIONS

"' The results presented in this work highlight the power of NIRSpec-IFU observations in the study of high-z galaxies, mergers, and the detection of moderately massive black holes through imaging-spectroscopy. Our observations provide clear and robust evidence for a massive black hole involved in a merger with another galaxy, likely hosting another accreting black hole, at z = 7.15, only 740 Myr after the big bang. Overall, our results seem to support a scenario of an imminent massive black hole merger in the early universe, highlighting this as an additional important channel for the early growth of black holes. Together with other recent findings in the literature, this suggests that massive black hole merging in the distant universe is common. Our observations may be used as guidance for the modelling of gravitational-wave events originating from massive black hole mergers that will be detectable with future observatories like LISA (e.g. Haehnelt 1994; Jaffe & Backer 2003; Sesana et al. 2005; Valiante et al. 2021; Amaro-Seoane et al. 2023)."

Edited May 16 by oldpaddoboy

[Vmedvil]

On 5/16/2024 at 6:00 PM, oldpaddoboy said:

https://phys.org/news/2024-05-webb-distant-black-hole-merger.html

"An international team of astronomers have used the NASA/ESA/CSA James Webb Space Telescope to find evidence for an ongoing merger of two galaxies and their massive black holes when the universe was only 740 million years old. This marks the most distant detection of a black hole merger ever obtained and the first time that this phenomenon has been detected so early in the universe.

 

Astronomers have found supermassive black holes with masses of millions to billions times that of the sun in most massive galaxies in the local universe, including in our Milky Way galaxy. These black holes have likely had a major impact on the evolution of the galaxies they reside in. However, scientists still don't fully understand how these objects grew to become so massive.

The finding of gargantuan black holes already in place in the first billion years after the Big Bang indicates that such growth must have happened very rapidly, and very early. Now, the James Webb Space Telescope is shedding new light on the growth of black holes in the early universe."

 

full article at link

The paper:

https://academic.oup.com/mnras/article/531/1/355/7671512?login=false

GA-NIFS: JWST discovers an offset AGN 740 million years after the big bang

ABSTRACT:

" A surprising finding of recent studies is the large number of Active Galactic Nuclei (AGN) associated with moderately massive black holes (⁠log⁡(M∙/M⊙)∼6−8⁠), in the first billion years after the big bang (z > 5). In this context, a relevant finding has been the large fraction of candidate dual AGN, both at large separations (several kpc) and in close pairs (less than a kpc), likely in the process of merging. Frequent black hole merging may be a route for black hole growth in the early universe; however, previous findings are still tentative and indirect. We present JWST/NIRSpec-IFU observations of a galaxy at z = 7.15 in which we find evidence for a log⁡(M∙/M⊙)∼7.7 accreting black hole, as traced by a broad component of H β emission, associated with the Broad Line Region (BLR) around the black hole. This BLR is offset by 620 pc in projection from the centroid of strong rest-frame optical emission, with a velocity offset of ∼40 km s^–1. The latter region is also characterized by (narrow) nebular emission features typical of AGN, hence also likely hosting another accreting black hole, although obscured (Type 2, narrow-line AGN). We exclude that the offset BLR is associated with Supernovae or massive stars, and we interpret these results as two black holes in the process of merging. This finding may be relevant for estimates of the rate and properties of gravitational-wave signals from the early universe that will be detected by future observatories like LISA."

 

 

10 CONCLUSIONS

"' The results presented in this work highlight the power of NIRSpec-IFU observations in the study of high-z galaxies, mergers, and the detection of moderately massive black holes through imaging-spectroscopy. Our observations provide clear and robust evidence for a massive black hole involved in a merger with another galaxy, likely hosting another accreting black hole, at z = 7.15, only 740 Myr after the big bang. Overall, our results seem to support a scenario of an imminent massive black hole merger in the early universe, highlighting this as an additional important channel for the early growth of black holes. Together with other recent findings in the literature, this suggests that massive black hole merging in the distant universe is common. Our observations may be used as guidance for the modelling of gravitational-wave events originating from massive black hole mergers that will be detectable with future observatories like LISA (e.g. Haehnelt 1994; Jaffe & Backer 2003; Sesana et al. 2005; Valiante et al. 2021; Amaro-Seoane et al. 2023)."

Wow, Interesting.