NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-22 T11:31:43 PDT
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For refcode 2015ApJ...799...98M:
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2015ApJ...799...98M X-Ray Constraints on the Local Supermassive Black Hole Occupation Fraction Miller, Brendan P.; Gallo, Elena; Greene, Jenny E.; Kelly, Brandon C.; Treu, Tommaso; Woo, Jong-Hak; Baldassare, Vivienne Abstract. Distinct seed formation mechanisms are imprinted upon the fraction of dwarf galaxies currently containing a central supermassive black hole. Seeding by Population III remnants is expected to produce a higher occupation fraction than is generated with direct gas collapse precursors. Chandra observations of nearby early-type galaxies can directly detect even low-level supermassive black hole activity, and the active fraction immediately provides a firm lower limit to the occupation fraction. Here, we use the volume-limited AMUSE surveys of ~200 optically selected early-type galaxies to characterize simultaneously, for the first time, the occupation fraction and the scaling of L_X_ with M_star_, accounting for intrinsic scatter, measurement uncertainties, and X-ray limits. For early-type galaxies with M_star_ < 10^10^ M_sun_, we obtain a lower limit to the occupation fraction of >20% (at 95% confidence), but full occupation cannot be excluded. The preferred dependence of log L_X_ upon log M_star_ has a slope of ~0.7-0.8, consistent with the "downsizing" trend previously identified from the AMUSE data set, and a uniform Eddington efficiency is disfavored at ~2sigma. We provide guidelines for the future precision with which these parameters may be refined with larger or more sensitive samples. Key words: black hole physics, galaxies: nuclei
Retrieve 198 NED objects in this reference.
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