Radio emission of a pulsed cosmic source of X-rays with 1-keV energy

1994 ◽  
Vol 35 (11-12) ◽  
pp. 569-574
Author(s):  
A. Yu. Matronchik
Keyword(s):  
Radio Emission ◽  
X Rays ◽  
Cosmic Source

scholarly journals On the origin of radio emission in Radio-Quiet AGN and their connection to X-rays

2015 ◽  
Author(s):  
Francesca Panessa ◽  
Loredana Bassani ◽  
Angela Bazzano ◽  
Geoffrey Bicknell ◽  
Paola Castangia ◽  
...  
Keyword(s):  
Radio Emission ◽  
X Rays

scholarly journals A unified accretion-ejection paradigm for black hole X-ray binaries

2019 ◽  
Vol 626 ◽  
pp. A115 ◽  
Author(s):  
G. Marcel ◽  
J. Ferreira ◽  
M. Clavel ◽  
P.-O. Petrucci ◽  
J. Malzac ◽  
...  
Keyword(s):  
Radio Emission ◽  
Accretion Disk ◽  
Ad Hoc ◽  
Emission Model ◽  
X Rays ◽  
Temperature Plasma ◽  
X Ray ◽  
Fitting Procedure ◽  
High Level ◽  
X Ray Binaries

Context. Transient X-ray binaries (XrB) exhibit very different spectral shapes during their evolution. In luminosity-color diagrams, their behavior in X-rays forms q-shaped cycles that remain unexplained. In Paper I, we proposed a framework where the innermost regions of the accretion disk evolve as a response to variations imposed in the outer regions. These variations lead not only to modifications of the inner disk accretion rate ṁin, but also to the evolution of the transition radius rJ between two disk regions. The outermost region is a standard accretion disk (SAD), whereas the innermost region is a jet-emitting disk (JED) where all the disk angular momentum is carried away vertically by two self-confined jets. Aims. In the previous papers of this series, it has been shown that such a JED–SAD disk configuration could reproduce the typical spectral (radio and X-rays) properties of the five canonical XrB states. The aim of this paper is now to replicate all X-ray spectra and radio emission observed during the 2010–2011 outburst of the archetypal object GX 339-4. Methods. We used the two-temperature plasma code presented in two previous papers (Papers II and III) and designed an automatic ad hoc fitting procedure that for any given date calculates the required disk parameters (ṁin,rJ) that fit the observed X-ray spectrum best. We used X-ray data in the 3–40 keV (RXTE/PCA) spread over 438 days of the outburst, together with 35 radio observations at 9 GHz (ATCA) dispersed within the same cycle. Results. We obtain the time distributions of ṁin(t) and rJ(t) that uniquely reproduce the X-ray luminosity and the spectral shape of the whole cycle. In the classical self-absorbed jet synchrotron emission model, the JED–SAD configuration also reproduces the radio properties very satisfactorily, in particular, the switch-off and -on events and the radio-X-ray correlation. Although the model is simplistic and some parts of the evolution still need to be refined, this is to our knowledge the first time that an outburst cycle is reproduced with such a high level of detail. Conclusions. Within the JED–SAD framework, radio and X-rays are so intimately linked that radio emission can be used to constrain the underlying disk configuration, in particular, during faint hard states. If this result is confirmed using other outbursts from GX 339-4 or other X-ray binaries, then radio could be indeed used as another means to indirectly probe disk physics.

scholarly journals Cygnus X-3: Orbital Modulation in X-Rays and Radio

2004 ◽  
Vol 194 ◽  
pp. 216-216 ◽  
Author(s):  
L. Hjalmarsdotter ◽  
P. J. Hakala ◽  
O. Vilhu ◽  
D. C. Hannikainen ◽  
M. McCollough ◽  
...  
Keyword(s):  
Radio Emission ◽  
Monitoring Data ◽  
X Rays ◽  
X Ray ◽  
Orbital Modulation

The orbital modulation of the X-ray and radio emission of Cyg X-3 was studied using monitoring data from CGRO/BATSE, RXTE/ASM, GBI and the Ryle telescope as well as recent INTEGRAL observations. The depth of the X-ray modulation was found to be the same at X-ray energies ranging from 1.5 up to at least 20 keV, but the shape of the lightcurves changes gradually with energy. No modulation was found in radio.

scholarly journals The MAVERIC Survey: Variable Jet-accretion Coupling in Luminous Accreting Neutron Stars in Galactic Globular Clusters

2021 ◽  
Vol 923 (1) ◽  
pp. 88
Author(s):  
Teresa Panurach ◽  
Jay Strader ◽  
Arash Bahramian ◽  
Laura Chomiuk ◽  
James C. A. Miller-Jones ◽  
...  
Keyword(s):  
Black Holes ◽  
Neutron Star ◽  
Radio Emission ◽  
Neutron Stars ◽  
Globular Clusters ◽  
Radio Continuum ◽  
X Rays ◽  
X Ray ◽  
Galactic Globular Clusters ◽  
X Ray Binaries

Abstract Accreting neutron stars in low-mass X-ray binaries show outflows—and sometimes jets—in the general manner of accreting black holes. However, the quantitative link between the accretion flow (traced by X-rays) and outflows and/or jets (traced by radio emission) is much less well understood for neutron stars than for black holes, other than the general observation that neutron stars are fainter in the radio at a given X-ray luminosity. We use data from the deep MAVERIC radio continuum survey of Galactic globular clusters for a systematic radio and X-ray study of six luminous (L X > 1034 erg s−1) persistent neutron star X-ray binaries in our survey, as well as two other transient systems also captured by our data. We find that these neutron star X-ray binaries show an even larger range in radio luminosity than previously observed. In particular, in quiescence at L X ∼ 3 × 1034 erg s−1, the confirmed neutron star binary GRS 1747–312 in Terzan 6 sits near the upper envelope of the black hole radio/X-ray correlation, and the persistently accreting neutron star systems AC 211 (in M15) and X1850–087 (in NGC 6712) show unusual radio variability and luminous radio emission. We interpret AC 211 as an obscured “Z source” that is accreting at close to the Eddington limit, while the properties of X1850–087 are difficult to explain, and motivate future coordinated radio and X-ray observations. Overall, our results show that neutron stars do not follow a single relation between inflow and outflow, and confirm that their accretion dynamics are more complex than for black holes.

scholarly journals LSI +61°303: A Pulsar Wind Nebula in a Binary?

2004 ◽  
Vol 218 ◽  
pp. 219-220
Author(s):  
D. A. Leahy
Keyword(s):  
Radio Emission ◽  
Gamma Rays ◽  
Confining Pressure ◽  
Rapid Expansion ◽  
Photon Flux ◽  
Relativistic Electrons ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton ◽  
Pulsar Wind

LSI +61°303 outbursts are modeled as a pulsar wind nebula expanding inside the environment provided by the Be companion star's stellar wind and photon flux. A set of equations describing the system is developed and solved numerically for representative sets of parameters. Emission in X-rays through gamma-rays is due to inverse Compton emission from relativistic electrons around the pulsar. The radio emission is due to synchrotron emission of varying optical depth, which yields a varying spectral index. The peak of X-ray emission is near periastron and the peak of the radio emission is near apastron, due to reduced confining pressure on the relativistic electron cloud and its subsequent rapid expansion.

scholarly journals Search for Nonthermal X-Rays from Supernova Remnant Shells

1998 ◽  
Vol 188 ◽  
pp. 117-120
Author(s):  
R. Petre ◽  
J. Keohane ◽  
U. Hwang ◽  
G. Allen ◽  
E. Gotthelf
Keyword(s):  
Radio Emission ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Cosmic Ray ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Nonthermal Radio ◽  
Cosmic Ray Acceleration ◽  
Nonthermal Radio Emission

The suggestion that the shocks of supernova remnants (SNR's) are cosmic ray acceleration sites dates back more than 40 years. While observations of nonthermal radio emission from SNR shells indicate the ubiquity of GeV cosmic ray production, there is still theoretical debate about whether SNR shocks accelerate particles up to the well-known “knee” in the primary cosmic ray spectrum at ~3,000 TeV. Recent X-ray observations of SN1006 and other SNR's may have provided the missing observational link between SNR shocks and high energy cosmic ray acceleration. We discuss these observations and their interpretation, and summarize our ongoing efforts to find evidence from X-ray observations of cosmic ray acceleration in the shells of other SNR's.

scholarly journals On radio emission and related X-rays in solar-like stellar coronae

1996 ◽  
Vol 176 ◽  
pp. 485-492
Author(s):  
M. Güdel
Keyword(s):  
Particle Acceleration ◽  
Radio Emission ◽  
Coronal Heating ◽  
Emission Sources ◽  
X Rays ◽  
Direct Information ◽  
X Ray ◽  
Nonthermal Radio ◽  
Rotational Modulation ◽  
Magnetically Confined

Selected results relevant to coronal structuring in solar-like single stars based on combined radio and X-ray information are presented. Nonthermal radio and thermal soft X-ray emissions from coronal solar-like stars provide direct information on particle acceleration and coronal heating in the magnetically confined outer atmospheres. The structural relationship between the emission sources is mostly inferred from indirect arguments such as rotational modulation or gyroresonance emission. Direct VLBI provides evidence of resolved, extended coronae on solar-like stars.

scholarly journals Cygnus A ? John Bolton?s First Cosmic Source

1994 ◽  
Vol 47 (5) ◽  
pp. 615 ◽  
Author(s):  
DE Harris
Keyword(s):  
Radio Galaxy ◽  
Discrete Source ◽  
X Rays ◽  
Powerful Radio ◽  
X Ray ◽  
Cygnus A ◽  
Cosmic Source ◽  
Powerful Radio Galaxy

Using a sea interferometer, Bolton and Stanley isolated Cygnus A as a discrete source in 1948. It is a prime example� of a powerful radio galaxy and, in the last decade, has also been studied extensively in X-rays. In this paper I summarise the results from a ROSAT X-ray image.

scholarly journals AU-scale radio imaging of the wind collision region in the brightest and most luminous non-thermal colliding wind binary Apep

2020 ◽  
Vol 501 (2) ◽  
pp. 2478-2486
Author(s):  
B Marcote ◽  
J R Callingham ◽  
M De Becker ◽  
P G Edwards ◽  
Y Han ◽  
...  
Keyword(s):  
Radio Emission ◽  
Infrared Imaging ◽  
Opening Angle ◽  
X Rays ◽  
Mid Infrared ◽  
Long Baseline ◽  
Collision Region ◽  
Radio Imaging ◽  
Unique System ◽  
Order Of Magnitude

ABSTRACT The recently discovered colliding-wind binary (CWB) Apep has been shown to emit luminously from radio to X-rays, with the emission driven by a binary composed of two Wolf–Rayet (WR) stars of one carbon-sequence (WC8) and one nitrogen-sequence (WN4–6b). Mid-infrared imaging revealed a giant spiral dust plume that is reminiscent of a pinwheel nebula but with additional features that suggest Apep is a unique system. We have conducted observations with the Australian Long Baseline Array to resolve Apep’s radio emission on milliarcsecond scales, allowing us to relate the geometry of the wind-collision region to that of the spiral plume. The observed radio emission shows a bow-shaped structure, confirming its origin as a wind-collision region. The shape and orientation of this region is consistent with being originated by the two stars and with being likely dominated by the stronger wind of the WN4–6b star. This shape allowed us to provide a rough estimation of the opening angle of ∼150○ assuming ideal conditions. The orientation and opening angle of the emission also confirms it as the basis for the spiral dust plume. We also provide estimations for the two stars in the system to milliarcsecond precision. The observed radio emission, one order of magnitude brighter and more luminous than any other known non-thermal radio-emitting CWB, confirms it is produced by an extremely powerful wind collision. Such a powerful wind-collision region is consistent with Apep being a binary composed of two WR stars, so far the first unambiguously confirmed system of its kind.

Sign in / Sign up

Export Citation Format

Share Document