scholarly journals Super- and sub-Eddington accreting massive black holes: a comparison of slim and thin accretion discs through study of the spectral energy distribution

2016 ◽  
Vol 458 (2) ◽  
pp. 1839-1858 ◽  
Author(s):  
N. Castelló-Mor ◽  
H. Netzer ◽  
S. Kaspi
Keyword(s):  
Black Holes ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Accretion Discs ◽  
Spectral Energy ◽  
Massive Black Holes

scholarly journals What makes a galaxy radio-loud?

2011 ◽  
Vol 7 (S284) ◽  
pp. 221-223
Author(s):  
R. A. Ortega-Minakata ◽  
J. P. Torres-Papaqui ◽  
H. Andernach ◽  
R. Coziol ◽  
J. M. Islas-Islas ◽  
...  
Keyword(s):  
Black Holes ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Characteristics ◽  
Spectral Energy ◽  
Isolated Galaxies ◽  
Accretion Rates ◽  
The Masses ◽  
Lower Luminosity ◽  
Eddington Limit

AbstractWe compare the Spectral Energy Distribution (SED) of radio-loud and radio-quiet AGNs in three different samples observed with SDSS: radio-loud AGNs (RLAGNs), Low Luminosity AGNs (LLAGNs) and AGNs in isolated galaxies (IG-AGNs). All these galaxies have similar optical spectral characteristics. The median SED of the RLAGNs is consistent with the characteristic SED of quasars, while that of the LLAGNs and IG-AGNs are consistent with the SED of LINERs, with a lower luminosity in the IG-AGNs than in the LLAGNs. We infer the masses of the black holes (BHs) from the bulge masses. These increase from the IG-AGNs to the LLAGNs and are highest for the RLAGNs. All these AGNs show accretion rates near or slightly below 10% of the Eddington limit, the differences in luminosity being solely due to different BH masses. Our results suggests there are two types of AGNs, radio quiet and radio loud, differing only by the mass of their bulges or BHs.

scholarly journals Elusive Accretion Discs in Low Luminosity AGN

2016 ◽  
Vol 12 (S324) ◽  
pp. 192-195
Author(s):  
J.A. Fernández-Ontiveros ◽  
M.A. Prieto Escudero ◽  
S. Markoff ◽  
L. Reb ◽  
D. Espada ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Energy Distribution ◽  
Accretion Disk ◽  
Spectral Energy Distribution ◽  
Unified Model ◽  
Accretion Discs ◽  
Continuum Emission ◽  
Spectral Energy

AbstractLow luminosity AGN (LLAGN) represent the vast majority of the AGN population in the near universe. However, they show intrinsic differences when compared to the Unified Model scenario, i.e. a lack of both the big blue bump and the IR bump in their spectral energy distribution (SED), which are the signatures of an accretion disk and a torus, respectively. In this work we present SED for a sample of six LLAGN in the nearby Universe obtained from subarcsec resolution observations. The nature of the IR continuum emission is discussed in the context of non-thermal radiation powered by compact jets.

scholarly journals Active galactic nuclei at z ∼ 1.5 – I. Spectral energy distribution and accretion discs

2014 ◽  
Vol 446 (4) ◽  
pp. 3427-3446 ◽  
Author(s):  
D. M. Capellupo ◽  
H. Netzer ◽  
P. Lira ◽  
B. Trakhtenbrot ◽  
Julián Mejía-Restrepo
Keyword(s):  
Energy Distribution ◽  
Active Galactic Nuclei ◽  
Spectral Energy Distribution ◽  
Galactic Nuclei ◽  
Accretion Discs ◽  
Spectral Energy

scholarly journals Jets at lowest mass accretion rates

2010 ◽  
Vol 6 (S275) ◽  
pp. 82-86 ◽  
Author(s):  
Dipankar Maitra ◽  
Andrew Cantrell ◽  
Sera Markoff ◽  
Heino Falcke ◽  
Jon Miller ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Energy Distribution ◽  
Galactic Center ◽  
Spectral Energy Distribution ◽  
Jet Physics ◽  
Spectral Energy ◽  
Time Lags ◽  
Accretion Rates ◽  
Sgr A

AbstractWe present results of recent observations and theoretical modeling of data from black holes accreting at very low luminosities (L/LEdd ≲ 10−8). We discuss our newly developed time-dependent model for episodic ejection of relativistic plasma within a jet framework, and a successful application of this model to describe the origin of radio flares seen in Sgr A*, the Galactic center black hole. Both the observed time lags and size-frequency relationships are reproduced well by the model. We also discuss results from new Spitzer data of the stellar black hole X-ray binary system A0620–00. Complemented by long term SMARTS monitoring, these observations indicate that once the contribution from the accretion disk and the donor star are properly included, the residual mid-IR spectral energy distribution of A0620–00 is quite flat and consistent with a non-thermal origin. The results above suggest that a significant fraction of the observed spectral energy distribution originating near black holes accreting at low luminosities could result from a mildly relativistic outflow. The fact that these outflows are seen in both stellar-mass black holes as well as in supermassive black holes at the heart of AGNs strengthens our expectation that accretion and jet physics scales with mass.

scholarly journals Influence of Microlensing on Spectral Anomalies of the Lensed Objects

2011 ◽  
Vol 20 (3) ◽  
Author(s):  
S. Simić ◽  
L. Č. Popović ◽  
P. Jovanović
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Angular Size ◽  
Black Body ◽  
Spectral Energy

AbstractHere we consider the influence of microlensing on the spectrum of a lensed object with the angular size 5 μas accepting that the composite emission of this object originates from three different regions arranged around its center. We assume that the lensed object has three concentric regions with a black-body emission; the temperatures of these regions are 10 000 K, 7500 K and 5000 K. We investigate how the integral spectral energy distribution (SED) of such stratified source changes due to microlensing by a group of solarmass stars. We find that the SED and flux ratios in the photometric B, V and R passbands show considerable changes during a microlens event. This indicates that the flux anomaly observed in some lensed quasars may be caused by microlensing of a stratified object.

scholarly journals Galaxy And Mass Assembly: the evolution of the cosmic spectral energy distribution from z = 1 to z = 0

2017 ◽  
Vol 470 (2) ◽  
pp. 1342-1359 ◽  
Author(s):  
S. K. Andrews ◽  
S. P. Driver ◽  
L. J. M. Davies ◽  
P. R. Kafle ◽  
A. S. G. Robotham ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Mass Assembly
Sign in / Sign up

Export Citation Format

Share Document