A close quasar pair in a disk–disk galaxy merger at z= 2.17
In: Nature, Jg. 616 (2023-04-06), Heft 7955, S. 45-49
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Zugriff:
Galaxy mergers produce pairs of supermassive black holes (SMBHs), which may be witnessed as dual quasars if both SMBHs are rapidly accreting. The kiloparsec (kpc)-scale separation represents a physical regime sufficiently close for merger-induced effects to be important1yet wide enough to be directly resolvable with the facilities currently available. Whereas many kpc-scale, dual active galactic nuclei—the low-luminosity counterparts of quasars—have been observed in low-redshift mergers2, no unambiguous dual quasar is known at cosmic noon (z≈ 2), the peak of global star formation and quasar activity3,4. Here we report multiwavelength observations of Sloan Digital Sky Survey (SDSS) J0749 + 2255 as a kpc-scale, dual-quasar system hosted by a galaxy merger at cosmic noon (z= 2.17). We discover extended host galaxies associated with the much brighter compact quasar nuclei (separated by 0.46″ or 3.8 kpc) and low-surface-brightness tidal features as evidence for galactic interactions. Unlike its low-redshift and low-luminosity counterparts, SDSS J0749 + 2255 is hosted by massive compact disk-dominated galaxies. The apparent lack of stellar bulges and the fact that SDSS J0749 + 2255 already follows the local SMBH mass–host stellar mass relation, suggest that at least some SMBHs may have formed before their host stellar bulges. While still at kpc-scale separations where the host-galaxy gravitational potential dominates, the two SMBHs may evolve into a gravitationally bound binary system in around 0.22 Gyr.
Titel: |
A close quasar pair in a disk–disk galaxy merger at z= 2.17
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Autor/in / Beteiligte Person: | Chen, Yu-Ching ; Liu, Xin ; Foord, Adi ; Shen, Yue ; Oguri, Masamune ; Chen, Nianyi ; Di Matteo, Tiziana ; Holgado, Miguel ; Hwang, Hsiang-Chih ; Zakamska, Nadia |
Link: | |
Zeitschrift: | Nature, Jg. 616 (2023-04-06), Heft 7955, S. 45-49 |
Veröffentlichung: | 2023 |
Medientyp: | serialPeriodical |
ISSN: | 0028-0836 (print) ; 1476-4687 (print) |
DOI: | 10.1038/s41586-023-05766-6 |
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