Upper limits on the masses of 105 supermassive black holes from Hubble Space Telescope / space telescope imaging spectrograph archival data
Beifiori, A.; Sarzi, M.; Corsini, E.M.; Bonta, E.D.; Pizzella, A.; Coccato, L.; Bertola, F.
Citation: Beifiori , A , Sarzi , M , Corsini , E M , Bonta , E D , Pizzella , A , Coccato , L & Bertola , F 2009 , ' Upper limits on the masses of 105 supermassive black holes from Hubble Space Telescope / space telescope imaging spectrograph archival data ' Astrophysical Journal , vol 692 , no. 1 , pp. 856-868 . , 10.1088/0004-637X/692/1/856
Based on the modeling of the central emission-line width measured over subarcsecond apertures with the Hubble Space Telescope, we present stringent upper bounds on the mass of the central supermassive black hole, M •, for a sample of 105 nearby galaxies (D < 100 Mpc) spanning a wide range of Hubble types (E–Sc) and values of the central stellar velocity dispersion, σc (58-419 km s–1). For the vast majority of the objects, the derived M • upper limits run parallel and above the well-known M •-σc relation independently of the galaxy distance, suggesting that our nebular line-width measurements trace rather well the nuclear gravitational potential. For values of σc between 90 and 220 km s–1, 68% of our upper limits falls immediately above the M •-σc relation without exceeding the expected M • values by more than a factor 4.1. No systematic trends or offsets are observed in this σc range as a function of the galaxy Hubble type or with respect to the presence of a bar. For 6 of our 12 M • upper limits with σc <90 km s–1, our line-width measurements are more sensitive to the stellar contribution to the gravitational potential, either due to the presence of a nuclear stellar cluster or because of a greater distance compared to the other galaxies at the low-σc end of the M •-σc relation. Conversely, our M • upper bounds appear to lie closer to the expected M • in the most massive elliptical galaxies with values of σc above 220 km s–1. Such a flattening of the M •-σc relation at its high-σc end would appear consistent with a coevolution of supermassive black holes and galaxies driven by dry mergers, although better and more consistent measurements for σc and K-band luminosity are needed for these kinds of objects before systematic effects can be ruled out.
Original article can be found at: http://www.iop.org/EJ/journal/apj Copyright American Astronomical Society. DOI: 10.1088/0004-637X/692/1/856 [Full text of this article is not available in the UHRA]