scholarly journals Multi-Wavelength Studies of the GX 339-4 2010 outburst

2012 ◽  
Vol 8 (S290) ◽  
pp. 17-20
Author(s):  
Marion Cadolle Bel ◽  
S. Corbel ◽  
A. Veledina ◽  
J. Rodriguez ◽  
P. D'Avanzo ◽  
...  
Keyword(s):  
Black Hole ◽  
Optical Emission ◽  
Electromagnetic Spectrum ◽  
X Ray ◽  
Relative Contribution ◽  
Multi Wavelength

AbstractThe microquasar GX 339-4 experienced an outburst in 2010. We focus on observations that are quasi-simultaneous with those made by INTEGRAL and RXTE in March–April 2010 with radio, NIR, optical and UV data. X-ray transients are extreme systems, often harboring a black hole, known to emit throughout the whole electromagnetic spectrum in outburst. We studied the source evolution and correlated changes in all wavelengths. The bolometric flux increased from 0.8 to 2.9 × 10−8 erg cm−2 s−1 while the relative contribution of the hot medium decreased. The radio, NIR and optical emission from jets was detected and observed to fade as the source softened; reprocessing in the disc was strong at the end.

scholarly journals Prolonged sub-luminous state of the new transitional pulsar candidate CXOU J110926.4−650224

2019 ◽  
Vol 622 ◽  
pp. A211 ◽  
Author(s):  
Francesco Coti Zelati ◽  
Alessandro Papitto ◽  
Domitilla de Martino ◽  
David A. H. Buckley ◽  
Alida Odendaal ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Broad Band ◽  
Optical Emission ◽  
Bimodal Distribution ◽  
X Ray ◽  
The Past ◽  
Upper Limits ◽  
Photon Index ◽  
Multi Wavelength ◽  
Absorbed Power

We report on a multi-wavelength study of the unclassified X-ray source CXOU J110926.4−650224 (J1109). We identified the optical counterpart as a blue star with a magnitude of ∼20.1 (3300–10500 Å). The optical emission was variable on timescales from hundreds to thousands of seconds. The spectrum showed prominent emission lines with variable profiles at different epochs. Simultaneous XMM-Newton and NuSTAR observations revealed a bimodal distribution of the X-ray count rates on timescales as short as tens of seconds, as well as sporadic flaring activity. The average broad-band (0.3–79 keV) spectrum was adequately described by an absorbed power law model with photon index of Γ = 1.63  ±  0.01 (at 1σ c.l.), and the X-ray luminosity was (2.16  ±  0.04)  ×  1034 erg s−1 for a distance of 4 kpc. Based on observations with different instruments, the X-ray luminosity has remained relatively steady over the past ∼15 years. J1109 is spatially associated with the gamma-ray source FL8Y J1109.8−6500, which was detected with Fermi at an average luminosity of (1.5  ±  0.2)  ×  1034 erg s−1 (assuming the distance of J1109) over the 0.1–300 GeV energy band between 2008 and 2016. The source was undetected during ATCA radio observations that were simultaneous with NuSTAR, down to a 3σ flux upper limit of 18 μJy beam−1 (at 7.25 GHz). We show that the phenomenological properties of J1109 point to a binary transitional pulsar candidate currently in a sub-luminous accretion disk state, and that the upper limits derived for the radio emission are consistent with the expected radio luminosity for accreting neutron stars at similar X-ray luminosities.

scholarly journals X-ray Flux and Spectral Variability of the TeV Blazars Mrk 421 and PKS 2155-304

Galaxies ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 64
Author(s):  
Alok C. Gupta
Keyword(s):  
Black Hole ◽  
Time Series Data ◽  
Series Data ◽  
Physical Parameters ◽  
Electromagnetic Spectrum ◽  
Black Hole Mass ◽  
Spectral Variability ◽  
Massive Black Hole ◽  
X Ray ◽  
Northern And Southern Hemispheres

We reviewed X-ray flux and spectral variability properties studied to date by various X-ray satellites for Mrk 421 and PKS 2155-304, which are TeV emitting blazars. Mrk 421 and PKS 2155-304 are the most X-ray luminous blazars in the northern and southern hemispheres, respectively. Blazars show flux and spectral variabilities in the complete electromagnetic spectrum on diverse timescales ranging from a few minutes to hours, days, weeks, months and even several years. The flux and spectral variability on different timescales can be used to constrain the size of the emitting region, estimate the super massive black hole mass, find the dominant emission mechanism in the close vicinity of the super massive black hole, search for quasi-periodic oscillations in time series data and several other physical parameters of blazars. Flux and spectral variability is also a dominant tool to explain jet as well as disk emission from blazars at different epochs of observations.

scholarly journals Evolving optical polarisation of the black hole X-ray binary MAXI J1820+070

2019 ◽  
Vol 623 ◽  
pp. A75 ◽  
Author(s):  
Alexandra Veledina ◽  
Andrei V. Berdyugin ◽  
Ilia A. Kosenkov ◽  
Jari J. E. Kajava ◽  
Sergey S. Tsygankov ◽  
...  
Keyword(s):  
Black Hole ◽  
Optical Emission ◽  
Position Angle ◽  
Stokes Parameters ◽  
X Ray ◽  
Before And After ◽  
Stokes Vectors ◽  
The Magnetic Field ◽  
Optical Polarisation ◽  
Polarisation Measurements

Aims. The optical emission of black hole transients increases by several magnitudes during the X-ray outbursts. Whether the extra light arises from the X-ray heated outer disc, from the inner hot accretion flow, or from the jet is currently debated. Optical polarisation measurements are able to distinguish the relative contributions of these components. Methods. We present the results of BVR polarisation measurements of the black hole X-ray binary MAXI J1820+070 during the period of March-April 2018. Results. We detect small, ∼0.7%, but statistically significant polarisation, part of which is of interstellar origin. Depending on the interstellar polarisation estimate, the intrinsic polarisation degree of the source is between ∼0.3% and 0.7%, and the polarisation position angle is between ∼10 ° −30°. We show that the polarisation increases after MJD 58222 (2018 April 14). The change is of the order of 0.1% and is most pronounced in the R band. The change of the source Stokes parameters occurs simultaneously with the drop of the observed V-band flux and a slow softening of the X-ray spectrum. The Stokes vectors of intrinsic polarisation before and after the drop are parallel, at least in the V and R filters. Conclusions. We suggest that the increased polarisation is due to the decreasing contribution of the non-polarized component, which we associate with the the hot flow or jet emission. The low polarisation can result from the tangled geometry of the magnetic field or from the Faraday rotation in the dense, ionised, and magnetised medium close to the black hole. The polarized optical emission is likely produced by the irradiated disc or by scattering of its radiation in the optically thin outflow.

scholarly journals Chandra Observations of the Guitar Nebula

2003 ◽  
Vol 214 ◽  
pp. 135-136 ◽  
Author(s):  
Diane S. Wong ◽  
James M. Cordes ◽  
Shami Chatterjee ◽  
Ellen G. Zweibel ◽  
John P. Finley ◽  
...  
Keyword(s):  
Proper Motion ◽  
Hot Spot ◽  
Optical Emission ◽  
Position Angle ◽  
Bow Shock ◽  
Radio Pulsar ◽  
X Ray ◽  
Multi Wavelength ◽  
Pulsar Wind

As part of a multi-wavelength study, we report on a 50 ks Chandra/ACIS observation of the Guitar Nebula, a bow shock nebula associated with the radio pulsar B2224+65. We see a “hot spot” at the tip of the bow shock. We also notice a “jet” of X-ray emission at position angle (PA) −69°. However, the proper motion of the pulsar and the axis of optical emission is at PA 52°.1. We discuss the resulting interpretations of the relativistic pulsar wind and the surrounding ISM.

scholarly journals X-ray Studies of Planetary Nebulae

2016 ◽  
Vol 12 (S323) ◽  
pp. 104-108
Author(s):  
Rodolfo Montez
Keyword(s):  
Mass Transfer ◽  
Planetary Nebulae ◽  
Central Star ◽  
Electromagnetic Spectrum ◽  
Stellar Winds ◽  
X Ray ◽  
New Directions ◽  
Multi Wavelength ◽  
Formation And Evolution ◽  
Compact Sources

AbstractX-ray emission from planetary nebulae (PNe) provides unique insight on the formation and evolution of PNe. Past observations and the ongoing Chandra Planetary Nebulae Survey (ChanPlaNS) provide a consensus on the two types of X-ray emission detected from PNe: extended and compact point-like sources. Extended X-ray emission arises from a shocked “hot bubble” plasma that resides within the nebular shell. Cooler than expected hot bubble plasma temperatures spurred a number of potential solutions with one emerging as the likely dominate process. The origin of X-ray emission from compact sources at the location of the central star is less clear. These sources might arise from one or combinations of the following processes: self-shocking stellar winds, spun-up binary companions, and/or accretion, perhaps from mass transfer, PN fallback, or debris disks. In the discovery phase, X-ray studies of PNe have mainly focused on the origin of the various emission processes. New directions incorporate multi-wavelength observations to study the influence of X-ray emission on the rest of the electromagnetic spectrum.

scholarly journals Observational Progress in Identifying and Characterizing Tidal Disruption Flares

2016 ◽  
Vol 12 (S324) ◽  
pp. 93-98
Author(s):  
S. Bradley Cenko
Keyword(s):  
Black Hole ◽  
Optical Spectra ◽  
Starburst Galaxies ◽  
Electromagnetic Spectrum ◽  
Speed Of Light ◽  
Tidal Disruption ◽  
Massive Black Hole ◽  
X Ray ◽  
Tidal Forces

AbstractI present an overview of observational efforts across the electromagnetic spectrum to identify and study tidal disruption flares (TDFs), when a star wanders too close to a super-massive black hole and is torn apart by tidal forces. In particular I will focus on four unexpected surprises that challenge the most basic analytic picture of these events: 1) large inferred radii for the optical/UV-emitting material; 2) the ubiquity of outflows, detected at radio, X-ray, and UV wavelengths, ranging from speeds of 100 km/s to near the speed of light; 3) the peculiar atomic abundances observed in the UV and optical spectra of these objects; and, 4) the preference for these events to occur in post-starburst galaxies.

scholarly journals Multi-wavelength Observations of AT2019wey: a New Candidate Black Hole Low-mass X-ray Binary

2021 ◽  
Vol 920 (2) ◽  
pp. 120 ◽  
Author(s):  
Yuhan Yao ◽  
S. R. Kulkarni ◽  
Kevin B. Burdge ◽  
Ilaria Caiazzo ◽  
Kishalay De ◽  
...  
Keyword(s):  
Black Hole ◽  
X Ray ◽  
Multi Wavelength ◽  
Low Mass

scholarly journals Exceptionally bright optical emission from a rare and distant gamma-ray burst

2021 ◽  
Author(s):  
Gor Oganesyan ◽  
Sergey Karpov ◽  
Martin Jelinek ◽  
Gregory Beskin ◽  
Samuele Ronchini ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Massive Stars ◽  
Optical Emission ◽  
Gamma Ray Bursts ◽  
Additional Component ◽  
Relativistic Jets ◽  
X Ray ◽  
Forward Shock ◽  
Multi Wavelength ◽  
Wavelength Emission

Abstract Long gamma-ray bursts (GRBs) are produced by the dissipation of ultra-relativistic jets launched by newly-born black holes after the collapse of massive stars. Right after the luminous and highly variable gamma-ray emission, the multi-wavelength afterglow is released by the external dissipation of the jet in circumburst medium. We report the discovery of a very bright (10 mag) optical emission 28 s after the explosion of the extremely luminous and energetic GRB 210619B located at redshift 1.937. Early multi-filter observations allowed us to witness the end of the shock wave propagation into the GRB ejecta. We observed the spectral transition from a bright reverse to the forward shock emission, demonstrating that the early and late GRB multi-wavelength emission is originated from a very narrow jet propagating into an unusually rarefied interstellar medium. We also find evidence of an additional component of radiation, coming from the jet wings which is able explain the uncorrelated optical/X-ray emission.

scholarly journals Stellar X-Ray Sources

1974 ◽  
Vol 60 ◽  
pp. 383-399
Author(s):  
Harvey D. Tananbaum
Keyword(s):  
Black Hole ◽  
Radio Emission ◽  
Optical Emission ◽  
Close Correlation ◽  
X Ray ◽  
Radio Outburst ◽  
The Relationship ◽  
Optical Behavior

Data are presented for Cygnus X-1, Cygnus X-3, and Scorpius X-1 from radio to X-ray wavelengths. The evidence for Cygnus X-1's being a black hole is now quite convincing. New data for Cygnus X-3 show the presence of X-ray activity at the time of the giant radio outburst. The data for Scorpius X-1 show a close correlation between the X-ray and optical behavior, but coverage was not sufficiently complete to fully assess the relationship (if any) between the X-ray and optical emission and the radio emission.

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