scholarly journals Spectral energy distribution of the inner accretion flow around Sgr A* – clue for a weak outflow in the innermost region

2018 ◽  
Vol 483 (4) ◽  
pp. 5614-5622 ◽  
Author(s):  
Ren-Yi Ma ◽  
Shawn R Roberts ◽  
Ya-Ping Li ◽  
Q Daniel Wang
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Accretion Flow ◽  
Sgr A ◽  
Innermost Region

scholarly journals Nature of the Dusty S-cluster Object (DSO/G2): Pre-main-sequence star with non-spherical dusty envelope

2016 ◽  
Vol 11 (S322) ◽  
pp. 231-232
Author(s):  
M. Zajaček ◽  
M. Valencia-S. ◽  
B. Shahzamanian ◽  
F. Peissker ◽  
A. Eckart ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Main Sequence ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Main Sequence Star ◽  
Continuum Emission ◽  
Spectral Energy ◽  
Galactic Centre ◽  
Infrared Excess ◽  
Sgr A

AbstractNear-infrared observations reveal several infrared-excess sources near the Galactic Centre with emission lines present in their spectra. One of these objects, DSO/G2, which moves around the supermassive black hole (Sgr A*) on a highly eccentric orbit, passed the pericentre at approximately 160 AU in 2014. It remained compact, which implies that at least in this case it is a star embedded in a dusty envelope. The spectral energy distribution and the detection of polarized continuum emission indicate that it is probably a pre-main-sequence star surrounded by a dense envelope with bipolar cavities. In addition, the star associated with DSO/G2 plausibly develops a bow shock due to its supersonic motion. The model of the star surrounded by the non-spherical dusty envelope can reproduce the main characteristics of the DSO/G2 source: 1. spectral energy distribution in near-infrared bands; 2. linear polarization in Ks band; and 3. the overall compact behaviour.

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

scholarly journals Modeling the spectral energy distribution of ULIRGs

2007 ◽  
Vol 477 (1) ◽  
pp. 95-104 ◽  
Author(s):  
M. S. Clemens ◽  
O. Vega ◽  
A. Bressan ◽  
G. L. Granato ◽  
L. Silva ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy
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