Extended structure and fate of the nucleus in Henize 2-10
- Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States)
- National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)
- Department of Physics, Texas Tech University, 2500 Broadway Street, Lubbock, TX 79409 (United States)
- Harvard-Smithsonian Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)
We investigate the structure and nuclear region of the black hole (BH) hosting galaxy Henize 2-10. Surface brightness profiles are analyzed using Magellan/Megacam g- and r-band images. Excluding the central starburst, we find a best-fit two-component Sérsic profile with n {sub in} ∼ 0.6, r {sub eff,} {sub in} ∼ 260 pc and n {sub out} ∼ 1.8, r ∼ 1 kpc. Integrating out to our outermost data point (100'' ∼ 4.3 kpc), we calculate M{sub g} = –19.2 and M{sub r} = –19.8. The corresponding enclosed stellar mass is M {sub *} ∼ (10 ± 3) × 10{sup 9} M {sub ☉}, ∼3 × larger than previous estimates. Apart from the central ≲500 pc, with blue colors and an irregular morphology, the galaxy appears to be an early-type system. The outer color is quite red, (g – r){sub 0} = 0.75, suggesting a dominant old population. We study the nuclear region of the galaxy using archival Gemini/NIFS K-band adaptive optics spectroscopy and Hubble Space Telescope imaging. We place an upper limit on the BH mass of ∼10{sup 7} M {sub ☉} from the NIFS data, consistent with that from the M {sub BH}-radio-X-ray fundamental plane. No coronal lines are seen, but a Brγ source is located at the position of the BH with a luminosity consistent with the X-ray emission. The starburst at the center of Henize 2-10 has led to the formation of several super star clusters, which are within ∼100 pc of the BH. We examine the fate of the nucleus by estimating the dynamical masses and dynamical friction timescales of the clusters. The most massive clusters (∼10{sup 6} M {sub ☉}) have τ{sub dyn} ≲ 200 Myr, and thus Henize 2-10 may represent a rare snapshot of nuclear star cluster formation around a preexisting massive BH.
- OSTI ID:
- 22370498
- Journal Information:
- Astrophysical Journal, Vol. 794, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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