scholarly journals Upper limits on the central black hole masses of 47 Tuc and NGC 6397 from radio continuum emission

2006 ◽  
Vol 368 (1) ◽  
pp. L43-L46 ◽  
Author(s):  
S. De Rijcke ◽  
P. Buyle ◽  
H. Dejonghe
Keyword(s):  
Black Hole ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Central Black Hole ◽  
Upper Limits ◽  
Black Hole Masses

Radio Continuum Emission from Sculptor Galaxies

1986 ◽  
Vol 6 (3) ◽  
pp. 325-329 ◽  
Author(s):  
J . I. Harnet
Keyword(s):  
Radio Emission ◽  
Blue Light ◽  
Hii Regions ◽  
Radio Continuum ◽  
Radial Dependence ◽  
Continuum Emission ◽  
Upper Limits ◽  
Peak Flux

AbstractThe five major members of the Sculptor Group of galaxies and NGC 45 have been observed with the Molonglo observatory synthesis telescope. NGC 247 and NGC 300 were not detected and upper limits to their 843 MHz flux densities are given. Radio emission from NGC 7793 is discussed with particular attention to its morphology, radial dependence compared with that of the blue light and possible coincidences between HII regions and 843 MHz peak flux densities.

Central Black Hole Masses in Active Galactic Nuclei Inferred from X‐Ray Variability

1998 ◽  
Vol 500 (2) ◽  
pp. 642-659 ◽  
Author(s):  
Kiyoshi Hayashida ◽  
Sigenori Miyamoto ◽  
Shunji Kitamoto ◽  
Hitoshi Negoro ◽  
Hajime Inoue
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Central Black Hole ◽  
X Ray ◽  
Black Hole Masses

scholarly journals A Multi-Frequency Study of the Milky Way-Like Spiral Galaxy NGC 6744

2018 ◽  
Vol 35 ◽  
Author(s):  
Miranda Yew ◽  
Miroslav D. Filipović ◽  
Quentin Roper ◽  
Jordan D. Collier ◽  
Evan J. Crawford ◽  
...  
Keyword(s):  
Black Hole ◽  
Milky Way ◽  
Formation Rate ◽  
Radio Continuum ◽  
Starburst Galaxy ◽  
Radio Sources ◽  
Wide Field ◽  
Central Black Hole ◽  
X Ray ◽  
Continuum Data

AbstractWe present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.

scholarly journals Center Black Hole Mass Determinations for Fermi Blazars

2012 ◽  
Vol 8 (S290) ◽  
pp. 209-210
Author(s):  
J. H. Fan ◽  
Y. Liu ◽  
J. H. Yang ◽  
Y. H. Yuan ◽  
Y. Li ◽  
...  
Keyword(s):  
Black Hole ◽  
Time Scales ◽  
Black Hole Mass ◽  
Central Black Hole ◽  
Γ Ray ◽  
Black Hole Masses

AbstractIn this paper, we estimated the black hole mass for some blazars with available variability time scales by assuming that the γ-ray emissions are from a distance of 200Rg from the center. The results show that the central black hole masses are in the range of log (M/M⊙) = 6.45 to 8.30.

Central black hole masses of galaxies

2003 ◽  
Vol 12 (11) ◽  
pp. 1310-1316 ◽  
Author(s):  
Fan Jun-Hui
Keyword(s):  
Black Hole ◽  
Central Black Hole ◽  
Black Hole Masses

scholarly journals Accretion and outflow of gas in Markarian 509

2012 ◽  
Vol 8 (S290) ◽  
pp. 45-48
Author(s):  
Jelle Kaastra ◽  
Pierre-Olivier Petrucci ◽  
Massimo Cappi ◽  
Nahum Arav ◽  
Ehud Behar ◽  
...  
Keyword(s):  
Black Hole ◽  
Chemical Composition ◽  
Time Scales ◽  
Time Dependent ◽  
Central Black Hole ◽  
Solar Mass ◽  
X Ray ◽  
The Core ◽  
Upper Limits ◽  
Central Regions

AbstractA major uncertainty in models for photoionised outflows in AGN is the distance of the gas to the central black hole. We present the results of a massive multiwavelength monitoring campaign on the bright Seyfert 1 galaxy Mrk 509 to constrain the location of the outflow components dominating the soft X-ray band. Mrk 509 was monitored by XMM-Newton, Integral, Chandra, HST/COS and Swift in 2009. We have studied the response of the photoionised gas to the changes in the ionising flux produced by the central regions. We were able to put tight constraints on the variability of the absorbers from day to year time scales. This allowed us to develop a model for the time-dependent photoionisation in this source. We find that the more highly ionised gas producing most X-ray line opacity is at least 5 pc away from the core; upper limits to the distance of various absorbing components range between 20 pc up to a few kpc. The more lowly ionised gas producing most UV line opacity is at least 100 pc away from the nucleus. These results point to an origin of the dominant, slow (v<1000 km s−1) outflow components in the NLR or torus-region of Mrk 509. We find that while the kinetic luminosity of the outflow is small, the mass carried away is likely larger than the 0.5 Solar mass per year accreting onto the black hole. We also determined the chemical composition of the outflow as well as valuable constraints on the different emission regions. We find for instance that the resolved component of the Fe-K line originates from a region 40–1000 gravitational radii from the black hole, and that the soft excess is produced by Comptonisation in a warm (0.2–1 keV), optically thick (τ~ 10–20) corona near the inner part of the disk.

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