Universität zu Köln

Hosseini, S. Elaheh ORCID: 0000-0002-3004-6208, Eckart, Andreas ORCID: 0000-0001-6049-3132, Zajaček, Michal ORCID: 0000-0001-6450-1187, Britzen, Silke ORCID: 0000-0001-9240-6734, Bhat, Harshitha K. ORCID: 0000-0002-4408-0650 and Karas, Vladimír ORCID: 0000-0002-5760-0459 (2024). Discovery of a Dense Association of Stars in the Vicinity of the Supermassive Black Hole Sgr A*. The Astrophysical Journal, 975 (2). pp. 1-15. IOP Publishing. ISSN 0004-637X

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Abstract

We focus on a sample of 42 sources in the vicinity of the bow-shock source IRS 1W (N-source region), located at a distance of 6.″05 northeast of the supermassive black hole Sagittarius A* (Sgr A*), within the radius of 1.″35. We present the first proper-motion measurements of N sources and find that a larger subset of N sources (28 sources) exhibit a north–west (NW) flying angle. These sources can be bound by an intermediate-mass black hole (IMBH) or the concentration that we observe is due to a disk-like distribution projection along the line of sight. We detect the N sources in the H , K s , and L′bands. The NW-ward flying sources could be a bound collection of stars. We discuss the tentative existence of an IMBH or an inclined disk distribution to explain the significant overdensity of stars. The first scenario of having an IMBH implies the lower limit of ∼10 4 M ⊙ for the putative IMBH. Our measurements for the first time reveal that the dense association of stars containing IRS 1W is a comoving group of massive, young stars. This stellar association might be the remnant core of a massive stellar cluster that is currently being tidally stripped as it inspirals toward Sgr A*. The second scenario suggests that the appearance of the N sources might be influenced by the projection of a disk-like distribution of younger He-stars and/or dust-enshrouded stars.

Item Type:	Article
Creators:	Creators Email ORCID ORCID Put Code Hosseini, S. Elaheh UNSPECIFIED https://orcid.org/0000-0002-3004-6208 UNSPECIFIED Eckart, Andreas UNSPECIFIED https://orcid.org/0000-0001-6049-3132 UNSPECIFIED Zajaček, Michal UNSPECIFIED https://orcid.org/0000-0001-6450-1187 UNSPECIFIED Britzen, Silke UNSPECIFIED https://orcid.org/0000-0001-9240-6734 UNSPECIFIED Bhat, Harshitha K. UNSPECIFIED https://orcid.org/0000-0002-4408-0650 UNSPECIFIED Karas, Vladimír UNSPECIFIED https://orcid.org/0000-0002-5760-0459 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-792625
Identification Number:	10.3847/1538-4357/ad7d06
Journal or Publication Title:	The Astrophysical Journal
Volume:	975
Number:	2
Page Range:	pp. 1-15
Date:	10 November 2024
Publisher:	IOP Publishing
ISSN:	0004-637X
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute of Physics I
Subjects:	Physics
['eprint_fieldname_oa_funders' not defined]:	Publikationsfonds UzK
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/79262