2014ApJ...794...34N -
Astrophys. J., 794, 34 (2014/October-2)
Extended structure and fate of the nucleus in Henize 2-10.
NGUYEN D.D., SETH A.C., REINES A.E., DEN BROK M., SAND D. and McLEOD B.
Abstract (from CDS):
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 nin∼ 0.6, r_eff, in_∼ 260 pc and nout∼ 1.8, r ∼ 1 kpc. Integrating out to our outermost data point (100'' ∼ 4.3 kpc), we calculate Mg= -19.2 and Mr= -19.8. The corresponding enclosed stellar mass is M{sstarf}∼ (10±3)x109 M☉, ∼3xlarger 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 ∼107 M☉ 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 (∼106 M☉) have τdyn ≲ 200 Myr, and thus Henize 2-10 may represent a rare snapshot of nuclear star cluster formation around a preexisting massive BH.
Abstract Copyright:
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Journal keyword(s):
methods: data analysis - surveys - techniques: spectroscopic
Nomenclature:
Table 3: [NSR2014] NN (Nos 5-11).
Simbad objects:
16
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