Extended structure and fate of the nucleus in Henize 2-10

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_in∼ 0.6, r_eff, in ∼ 260 pc and n_out∼ 1.8, r ∼ 1 kpc. Integrating out to our outermost data point (100″ ∼ 4.3 kpc), we calculate M_g= -19.2 and M_r= -19.8. The corresponding enclosed stellar mass is M ∼ (10 ± 3) × 10⁹M, ∼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)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 ∼10⁷M from the NIFS data, consistent with that from the MBH-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 (∼10⁶M) have τ_dyn≲ 200 Myr, and thus Henize 2-10 may represent a rare snapshot of nuclear star cluster formation around a preexisting massive BH.