scholarly journals Multiwavelength analysis as a probe of accretion and radiative processes in LINERs

2012 ◽  
Vol 8 (S290) ◽  
pp. 355-356
Author(s):  
George Younes ◽  
Delphine Porquet
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Characteristics ◽  
Spectral Energy ◽  
X Ray ◽  
Radiative Processes ◽  
Central Engine ◽  
Galactic Black Hole ◽  
X Ray Binaries

AbstractWe study the multiwavelength properties of an optically selected sample of Low Ionization Nuclear Emission-line Regions (LINERs), in an attempt to determine the accretion mechanism powering their central engine. We show how their X-ray spectral characteristics, and their spectral energy distribution compare to luminous AGN, and briefly discuss their connection to their less massive counter-parts galactic black-hole X-ray binaries.

scholarly journals The Spectral Energy Distribution of Quiescent Black Hole X‐Ray Binaries: New Constraints fromSpitzer

2007 ◽  
Vol 670 (1) ◽  
pp. 600-609 ◽  
Author(s):  
Elena Gallo ◽  
Simone Migliari ◽  
Sera Markoff ◽  
John A. Tomsick ◽  
Charles D. Bailyn ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
X Ray ◽  
X Ray Binaries

scholarly journals On the nature of the soft γ-ray emission in the hard state of the black hole transient GRS 1716−249

2020 ◽  
Vol 494 (1) ◽  
pp. 571-583 ◽  
Author(s):  
T Bassi ◽  
J Malzac ◽  
M Del Santo ◽  
E Jourdain ◽  
J-P Roques ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Component ◽  
Coronal Magnetic Field ◽  
Spectral Energy ◽  
Emission Model ◽  
X Ray ◽  
Hard State ◽  
Γ Ray

ABSTRACT The black hole transient GRS 1716−249 was monitored from the radio to the γ-ray band during its 2016–2017 outburst. This paper focuses on the spectral energy distribution (SED) obtained in 2017 February–March, when GRS 1716−249 was in a bright hard spectral state. The soft γ-ray data collected with the INTEGRAL/SPI telescope show the presence of a spectral component that is in excess of the thermal Comptonization emission. This component is usually interpreted as inverse Compton emission from a tiny fraction of non-thermal electrons in the X-ray corona. We find that hybrid thermal/non-thermal Comptonization models provide a good fit to the X-/γ-ray spectrum of GRS 1716−249. The best-fitting parameters are typical of the bright hard state spectra observed in other black hole X-ray binaries. Moreover, the magnetized hybrid Comptonization model belm provides an upper limit on the intensity of the coronal magnetic field of about 106 G. Alternatively, this soft γ-ray emission could originate from synchrotron emission in the radio jet. In order to test this hypothesis, we fit the SED with the irradiated disc plus Comptonization model combined with the jet internal shock emission model ishem. We found that a jet with an electron distribution of p ≃ 2.1 can reproduce the soft γ-ray emission of GRS 1716−249. However, if we introduce the expected cooling break around 10 keV, the jet model can no longer explain the observed soft γ-ray emission, unless the index of the electron energy distribution is significantly harder (p < 2).

scholarly journals Hard X-ray-to-radio energy distributions in starburst galaxies

1999 ◽  
Vol 193 ◽  
pp. 592-593 ◽  
Author(s):  
Miguel Cerviño ◽  
J. Miguel Mas-Hesse
Keyword(s):  
Energy Distribution ◽  
Mechanical Energy ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Starburst Galaxies ◽  
Spectral Energy ◽  
X Rays ◽  
X Ray ◽  
High Energy Emission ◽  
X Ray Binaries

We present in this contribution the predictions on the multiwavelength spectral energy distribution of our evolutionary population synthesis models including single and binary stellar systems. The high energy computations include the emission associated to X-ray binaries and supernovae remnants, as well as the mechanical energy released into the interstellar medium, which can be partially reprocessed into thermal X-rays. With these components we compute the spectral energy distribution of starburst galaxies from X-ray to radio ranges, and analyze finally the effects of the high energy emission on the H and He ionizing continuum.

scholarly journals Central X-Ray Point Sources Found to Be Abundant in Low-mass, Late-type Galaxies Predicted to Contain an Intermediate-mass Black Hole

2021 ◽  
Vol 923 (2) ◽  
pp. 246
Author(s):  
Alister W. Graham ◽  
Roberto Soria ◽  
Benjamin L. Davis ◽  
Mari Kolehmainen ◽  
Thomas Maccarone ◽  
...  
Keyword(s):  
Black Hole ◽  
Spectral Energy Distribution ◽  
Star Clusters ◽  
Virgo Cluster ◽  
Point Sources ◽  
Spectral Energy ◽  
Late Type ◽  
Intermediate Mass ◽  
X Ray ◽  
X Ray Binaries

Abstract Building upon three late-type galaxies in the Virgo cluster with both a predicted black hole mass of less than ∼105 M ⊙ and a centrally located X-ray point source, we reveal 11 more such galaxies, more than tripling the number of active intermediate-mass black hole candidates among this population. Moreover, this amounts to a ∼36 ± 8% X-ray detection rate (despite the sometimes high, X-ray-absorbing, H i column densities), compared to just 10 ± 5% for (the largely H i-free) dwarf early-type galaxies in the Virgo cluster. The expected contribution of X-ray binaries from the galaxies’ inner field stars is negligible. Moreover, given that both the spiral and dwarf galaxies contain nuclear star clusters, the above inequality appears to disfavor X-ray binaries in nuclear star clusters. The higher occupation, or rather detection, fraction among the spiral galaxies may instead reflect an enhanced cool gas/fuel supply and Eddington ratio. Indeed, four of the 11 new X-ray detections are associated with known LINERs or LINER/H ii composites. For all (four) of the new detections for which the X-ray flux was strong enough to establish the spectral energy distribution in the Chandra band, it is consistent with power-law spectra. Furthermore, the X-ray emission from the source with the highest flux (NGC 4197: L X ≈ 1040 erg s−1) suggests a non-stellar-mass black hole if the X-ray spectrum corresponds to the “low/hard state”. Follow-up observations to further probe the black hole masses, and prospects for spatially resolving the gravitational spheres of influence around intermediate-mass black holes, are reviewed in some detail.

scholarly journals Particle acceleration in low-power hotspots: modelling the broad-band spectral energy distribution

2020 ◽  
Vol 495 (2) ◽  
pp. 1593-1607 ◽  
Author(s):  
G Migliori ◽  
M Orienti ◽  
L Coccato ◽  
G Brunetti ◽  
F D’Ammando ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Energy Distribution ◽  
Low Power ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Broad Band ◽  
Spectral Energy ◽  
X Rays ◽  
X Ray ◽  
Radiative Processes

ABSTRACT The acceleration and radiative processes active in low-power radio hotspots are investigated by means of new deep near-infrared (NIR) and optical Very Large Telescope (VLT) observations, complemented with archival, high-sensitivity VLT, radio Very Large Array (VLA), and X-ray Chandra data. For the three studied radio galaxies (3C 105, 3C 195, and 3C 227), we confirm the detection of NIR/optical counterparts of the observed radio hotspots. We resolve multiple components in 3C 227 West and in 3C 105 South and characterize the diffuse NIR/optical emission of the latter. We show that the linear size of this component (≳4 kpc) makes 3C 105 South a compelling case for particles’ re-acceleration in the post-shock region. Modelling of the radio-to-X-ray spectral energy distribution (SED) of 3C 195 South and 3C 227 W1 gives clues on the origin of the detected X-ray emission. In the context of inverse Compton models, the peculiarly steep synchrotron curve of 3C 195 South sets constraints on the shape of the radiating particles’ spectrum that are testable with better knowledge of the SED shape at low (≲GHz) radio frequencies and in X-rays. The X-ray emission of 3C 227 W1 can be explained with an additional synchrotron component originating in compact (<100 pc) regions, such those revealed by radio observations at 22 GHz, provided that efficient particle acceleration (γ ≳ 107) is ongoing. The emerging picture is that of systems in which different acceleration and radiative processes co-exist.

scholarly journals Spectral Energy Distribution in X-Ray Beam as a Function of Wavelength*

1952 ◽  
Vol 42 (1) ◽  
pp. 6 ◽  
Author(s):  
M. A. Greenfield ◽  
R. D. Specht ◽  
P. M. Kratz ◽  
Katherine Hand
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
X Ray

scholarly journals Broad-band spectral energy distribution of the X-ray transient Swift J1745−26 from outburst to quiescence

2020 ◽  
Vol 637 ◽  
pp. A2
Author(s):  
Sylvain Chaty ◽  
Francis Fortin ◽  
Alicia López-Oramas
Keyword(s):  
Energy Distribution ◽  
Light Curve ◽  
Spectral Energy Distribution ◽  
Broad Band ◽  
Spectral Energy ◽  
X Ray ◽  
Upper Limit ◽  
Spectral Break ◽  
Hard State ◽  
Low Mass

Aims. We aim to analyse our study of the X-ray transient Swift J1745−26, using observations obtained from its outburst in September 2012, up to its decay towards quiescence in March 2013. Methods. We obtained optical and infrared observations, through override programme at ESO/VLT with FORS2 and ISAAC instruments, and added archival optical (VLT/VIRCAM), radio and X-ray (Swift) observations, to build the light curve and the broad-band spectral energy distribution (SED) of Swift J1745−26. Results. We show that, during its outburst and also during its decay towards quiescence, Swift J1745−26 SED can be adjusted, from infrared up to X-rays, by the sum of both a viscous irradiated multi-colour black body emitted by an accretion disc, and a synchrotron power law at high energy. In the radio domain, the SED arises from synchrotron emission from the jet. While our SED fitting confirms that the source remained in the low/hard state during its outburst, we determine an X-ray spectral break at frequency 3.1 ≤ νbreak ≤ 3.4 × 1014 Hz, and a radio spectral break at 1012 Hz ≤ νbreak ≤ 1013 Hz. We also show that the system is compatible with an absorption AV of ∼7.69 mag, lies within a distance interval of D ∼ [2.6 − 4.8] kpc with an upper limit of orbital period Porb = 11.3 h, and that the companion star is a late spectral type in the range K0–M0 V, confirming that the system is a low-mass X-ray binary. We finally plot the position of Swift J1745−26 on an optical-infrared – X-ray luminosity diagram: its localisation on this diagram is consistent with the source staying in the low-hard state during outburst and decay phases. Conclusions. By using new observations obtained at ESO/VLT with FORS2 and ISAAC, and adding archival optical (VLT/VIRCAM), radio and X-ray (Swift) observations, we built the light curve and the broad-band SED of Swift J1745−26, and we plotted its position on an optical-infrared – X-ray luminosity diagram. By fitting the SED, we characterized the emission of the source from infrared, via optical, up to X-ray domain, we determined the position of both the radio and X-ray spectral breaks, we confirmed that it remained in the low-hard state during outburst and decay phases, and we derived its absorption, distance interval, orbital period upper limit, and the late-type nature of companion star, confirming Swift J1745−26 is a low-mass X-ray binary.

scholarly journals Extracting the thermal SZ signal from heterogeneous millimeter data sets

2020 ◽  
Vol 228 ◽  
pp. 00007
Author(s):  
H. Bourdin ◽  
A.S. Baldi ◽  
A. Kozmanyan ◽  
P. Mazzotta
Keyword(s):  
Energy Distribution ◽  
Galaxy Clusters ◽  
Spectral Energy Distribution ◽  
Sparse Representations ◽  
Component Separation ◽  
Spectral Energy ◽  
Data Sets ◽  
X Ray ◽  
Multi Scale

Complementarily to X-ray observations, the thermal SZ effect is a powerful tool to probe the baryonic content of galaxy clusters from their core to their peripheries. While contaminations by astrophysical and instrumental backgrounds require us to scan the thermal SZ signal across various frequencies, the multi-scale nature of cluster morphologies require us to observe such objects at various angular resolutions. We developed component separation algorithms that take advantage of sparse representations to combine these heterogeneous pieces of information, separate the thermal SZ signal from its contaminants, detect and map the thermal SZ signal of galaxy clusters from nearby to more distant clusters of the Planck catalogue. Spatially weighted likelihoods allow us in particular to connect parametric fittings of the component Spectral Energy Distribution with wavelet and curvelet imaging, but also to combine signals registered with beams of various width. Such techniques already allow us to detect sub-structures in the peripheries of nearby clusters with Planck, and could be extended to observations performed at higher angular resolutions.

SPECTRAL ENERGY DISTRIBUTION IN THE UV - X RAY REGION OF TWO QUASARS

2004 ◽  
Author(s):  
S. A. R. HARO-CORZO ◽  
L. BINETTE ◽  
E. BENITEZ ◽  
M. RODRIGUEZ-MARTINEZ ◽  
Y. KRONGOLD
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
X Ray

scholarly journals A NuSTAR view of powerful γ-ray loud blazars

2019 ◽  
Vol 627 ◽  
pp. A72 ◽  
Author(s):  
G. Ghisellini ◽  
M. Perri ◽  
L. Costamante ◽  
G. Tagliaferri ◽  
T. Sbarrato ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Spectral Energy Distribution ◽  
Peak Frequency ◽  
High Energy ◽  
Spectral Energy ◽  
X Rays ◽  
X Ray ◽  
Γ Ray ◽  
The Universe ◽  
Jet Power

We observed three blazars at z >  2 with the NuSTAR satellite. These were detected in the γ-rays by Fermi/LAT and in the soft X-rays, but have not yet been observed above 10 keV. The flux and slope of their X-ray continuum, together with Fermi/LAT data allows us to estimate their total electromagnetic output and peak frequency. For some of them we were able to study the source in different states, and investigate the main cause of the different observed spectral energy distribution. We then collected all blazars at redshifts greater than 2 observed by NuSTAR, and confirm that these hard and luminous X-ray blazars are among the most powerful persistent sources in the Universe. We confirm the relation between the jet power and the disk luminosity, extending it at the high-energy end.

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