scholarly journals Black hole masses, accretion rates and hot- and cold-mode accretion in radio galaxies at z ∼ 1

2014 ◽  
Vol 447 (2) ◽  
pp. 1184-1203 ◽  
Author(s):  
C. A. C. Fernandes ◽  
M. J. Jarvis ◽  
A. Martínez-Sansigre ◽  
S. Rawlings ◽  
J. Afonso ◽  
...  
Keyword(s):  
Black Hole ◽  
Radio Galaxies ◽  
Accretion Rates ◽  
Black Hole Masses

scholarly journals Radiatively inefficient accretion disks in low-luminosity AGN†

2006 ◽  
Vol 2 (S238) ◽  
pp. 273-276 ◽  
Author(s):  
Ferdinando D. Macchetto ◽  
Marco Chiaberge
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
Hubble Space Telescope ◽  
Seyfert Galaxies ◽  
Radio Galaxies ◽  
Black Hole Mass ◽  
Limited Sample ◽  
Radiative Efficiency ◽  
Accretion Rates ◽  
Black Hole Masses

AbstractWe study a complete and distance-limited sample of 25 LINERs, 21 of which have been imaged with the Hubble Space Telescope to study their physical properties and to compare their radio and optical properties with those of other samples of local AGNs, namely Seyfert galaxies and low-luminosity radio galaxies (LLRG). Our results show that the LINERs population is not homogeneous, as there are two subclasses: i) the first class is similar to LLRG, as it extends the population of radio-loud nuclei to lower luminosities; ii) the second is similar to Seyferts, and extends the properties of radio-quiet nuclei towards the lowest luminosities. The different nature of the various classes of local AGN are best understood when the fraction of the Eddington luminosity they irradiate, Lo/LEdd, is plotted against the nuclear radio-loudness parameter: Seyferts are associated with relatively high radiative efficiencies Lo/LEdd ≳ 104 (and high accretion rates onto low mass black holes); LLRG are associated with low radiative efficiencies (and low accretion rates onto high black hole masses); all LINERs have low radiative efficiency (and accretion rates), and can be radio-loud or radio quiet depending on their black hole mass.

scholarly journals The estimation of black-hole masses in distant radio galaxies

2011 ◽  
Vol 55 (4) ◽  
pp. 302-309 ◽  
Author(s):  
M. L. Khabibullina ◽  
O. V. Verkhodanov
Keyword(s):  
Black Hole ◽  
Radio Galaxies ◽  
Black Hole Masses

scholarly journals Uncertainties of the masses of black holes and Eddington ratios in AGN

2006 ◽  
Vol 2 (S238) ◽  
pp. 111-116
Author(s):  
Suzy Collin
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Reverberation Mapping ◽  
Line Region ◽  
Region I ◽  
Accretion Rates ◽  
Unknown Structure ◽  
The Masses ◽  
Empirical Size ◽  
Black Hole Masses

AbstractBlack hole masses in Active Galactic Nuclei have been determined in 35 objects through reverberation mapping of the emission line region. I mention some uncertainties of the method, such as the “scale factor” relating the Virial Product to the mass, which depends on the unknown structure and dynamics of the Broad Line Region.When the black hole masses are estimated indirectly using the empirical size-luminosity relation deduced from this method, the uncertainties can be larger, especially when the relation is extrapolated to high and low masses and/or luminosities. In particular they lead to Eddington ratiosof the order of unity in samples of Narrow Line Seyfert 1. As the optical-UV luminosity is provided by the accretion disk, the accretion rates can be determined and are found to be much larger than the Eddington rates.So, accretion must be performed at a super-critical rate through a slim disk, resulting in rapid growth of the black holes. The alternative is that the mass determination is wrong at this limit.

scholarly journals Black Hole Masses and Accretion Rates in Nearby AGN

2009 ◽  
Vol 5 (S267) ◽  
pp. 207-207
Author(s):  
Stuart Lumsden ◽  
Jonathan Digby-North ◽  
Olivia Jones ◽  
Hazel Rogers ◽  
Sam Rushforth ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rates ◽  
Black Hole Masses

AbstractWe present results from a survey of the properties of the central black holes in nearby AGN. This shows that AGN radiating near Eddington are on average less massive now than at z ~ 1.

Radio galaxies with and without emission lines

2020 ◽  
Vol 15 (S359) ◽  
pp. 396-401
Author(s):  
Grażyna Stasińska ◽  
Natalia Vale Asari ◽  
Dorota Kozieł-Wierzbowska
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Equivalent Width ◽  
Galactic Nuclei ◽  
Optical Emission ◽  
Radio Galaxies ◽  
Emission Lines ◽  
The Common ◽  
Black Hole Masses

AbstractUsing the recent ROGUE I catalogue of galaxies with radio cores (Kozie_l-Wierzbowska et al. 2020) and after selecting the objects which are truly radio active galactic nuclei, AGNs, (which more than doubles the samples available so far), we perform a thorough comparison of the properties of radio galaxies with and without optical emission lines (galaxies where the equivalent width of Hα is smaller than 3Å are placed in the last category). We do not find any strong dichotomy between the two classes as regards the radio luminosities or black hole masses. The same is true when using the common classification into high- and low-excitation radio galaxies (HERGs and LERGs respectively).

scholarly journals Starbursts and black hole masses in X-shaped radio galaxies: Signatures of a merger event?

2012 ◽  
Vol 544 ◽  
pp. A36 ◽  
Author(s):  
M. Mezcua ◽  
V. H. Chavushyan ◽  
A. P. Lobanov ◽  
J. León-Tavares
Keyword(s):  
Black Hole ◽  
Radio Galaxies ◽  
Merger Event ◽  
Black Hole Masses

scholarly journals Jet production efficiency in the sample of the youngest radio galaxies

2018 ◽  
Vol 14 (S342) ◽  
pp. 278-279
Author(s):  
Anna Wójtowicz ◽  
Łukasz Stawarz ◽  
Emily Kosmaczewski
Keyword(s):  
Black Hole ◽  
High Resolution ◽  
Production Efficiency ◽  
Radio Galaxies ◽  
Fundamental Plane ◽  
X Ray ◽  
Jet Production ◽  
Radiative Efficiency ◽  
Accretion Rates ◽  
Very High

AbstractWe investigate the sample of 16 the youngest radio galaxies with measured kinematic ages and available X-ray data from high-resolution Chandra or XMM-Newton observations. We characterize the accretion properties and derive the jet kinetic luminosities for our sources. We found high accretion rates (>1% Eddington) and very high jet production efficiency for all the sources from our sample.This, along with the fact that the analyzed objects seem over-luminous in radio on the fundamental plane for the black hole activity, implies also that the radiative efficiency of the compact lobes is much higher than in the case of the evolved radio galaxies.

Quasar black hole masses and accretion rates across cosmic time

2019 ◽  
Vol 15 (S359) ◽  
pp. 57-61
Author(s):  
Michael Brotherton ◽  
Jaya Maithil ◽  
Adam Myers ◽  
Ohad Shemmer ◽  
Brandon Matthews ◽  
...  
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Cosmic Time ◽  
Small Samples ◽  
Host Galaxy ◽  
Black Hole Mass ◽  
Reverberation Mapping ◽  
Scaling Relationships ◽  
Accretion Rates ◽  
Black Hole Masses

AbstractQuasar black hole masses are most commonly estimated using broad emission lines in single epoch spectra based on scaling relationships determined from reverberation mapping of small samples of low-redshift objects. Several effects have been identified requiring modifications to these scaling relationships, resulting in significant reductions of the black hole mass determinations at high redshift. Correcting these systematic biases is critical to understanding the relationships among black hole and host galaxy properties. We are completing a program using the Gemini North telescope, called the Gemini North Infrared Spectrograph (GNIRS) Distant Quasar Survey (DQS), that has produced rest-frame optical spectra of about 200 high-redshift quasars (z = 1.5–3.5). The GNIRS-DQS will produce new and improved ultraviolet-based black hole mass and accretion rate prescriptions, as well as new redshift prescriptions for velocity zero points of high-z quasars, necessary to measure feedback.

scholarly journals FR0CAT: a FIRST catalog of FR 0 radio galaxies

2017 ◽  
Vol 609 ◽  
pp. A1 ◽  
Author(s):  
R. D. Baldi ◽  
A. Capetti ◽  
F. Massaro
Keyword(s):  
Black Hole ◽  
Active Phase ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Host Galaxies ◽  
Large Space ◽  
Single Class ◽  
Extended Radio ◽  
Wide Range ◽  
Black Hole Masses

With the aim of exploring the properties of the class of FR 0 radio galaxies, we selected a sample of 108 compact radio sources, called FR0CAT, by combining observations from the NVSS, FIRST, and SDSS surveys. We included in the catalog sources with redshift ≤0.05, with a radio size ≲5 kpc, and with an optical spectrum characteristic of low-excitation galaxies. Their radio luminosities at 1.4 GHz are in the range 1038 ≲ νL1.4 ≲ 1040 erg s-1. The FR0CAT hosts are mostly (86%) luminous (−21 ≳ Mr ≳ −23) red early-type galaxies with black hole masses 108 ≲ MBH ≲ 109M⊙. These properties are similar to those seen for the hosts of FR I radio galaxies, but they are on average a factor ~1.6 less massive. The number density of FR0CAT sources is ~5 times higher than that of FR Is, and thus they represent the dominant population of radio sources in the local Universe. Different scenarios are considered to account for the smaller sizes and larger abundance of FR 0s with respect to FR Is. An age-size scenario that considers FR 0s as young radio galaxies that will all eventually evolve into extended radio sources cannot be reconciled with the large space density of FR 0s. However, the radio activity recurrence, with the duration of the active phase covering a wide range of values and with short active periods strongly favored with respect to longer ones, might account for their large density number. Alternatively, the jet properties of FR 0s might be intrinsically different from those of the FR Is, the former class having lower bulk Lorentz factors, possibly due to lower black hole spins. Our study indicates that FR 0s and FR I/IIs can be interpreted as two extremes of a continuous population of radio sources that is characterized by a broad distribution of sizes and luminosities of their extended radio emission, but shares a single class of host galaxies.

scholarly journals A sample of radio galaxies spanning three decades in radio luminosity - I. The host galaxy properties and black hole masses

2004 ◽  
Vol 351 (1) ◽  
pp. 347-361 ◽  
Author(s):  
Ross J. McLure ◽  
Chris J. Willott ◽  
Matt J. Jarvis ◽  
Steve Rawlings ◽  
Gary J. Hill ◽  
...  
Keyword(s):  
Black Hole ◽  
Radio Galaxies ◽  
Host Galaxy ◽  
Radio Luminosity ◽  
Black Hole Masses
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