scholarly journals Microquasars: A Galactic-Extragalactic Connection?

2002 ◽  
Vol 19 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Kinwah Wu ◽  
Jason A. Stevens ◽  
Diana C. Hannikainen
Keyword(s):  
Radio Emission ◽  
Growth Phase ◽  
Radio Sources ◽  
Shock Model ◽  
Relativistic Jets ◽  
Spectral Evolution ◽  
X Ray ◽  
Radio Outburst ◽  
X Ray Binaries ◽  
Quasar 3C 273

AbstractMicroquasars are Galactic X-ray binaries which show radio emission from relativistic outflows. Here we argue that the origins of radio emission from microquasars and compact extragalactic radio sources are similar. In particular, both can be explained qualitatively by a model in which shocks are propagating in the relativistic jets. The microquasar GRO J1655–40 is used to illustrate that the spectral evolution of its 1994 radio outburst can be explained by the growth phase of the generalised-shock model, similar to the case of the quasar 3C 273.

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

2020 ◽  
Vol 640 ◽  
pp. A18
Author(s):  
G. Marcel ◽  
F. Cangemi ◽  
J. Rodriguez ◽  
J. Neilsen ◽  
J. Ferreira ◽  
...  
Keyword(s):  
Radio Emission ◽  
Low Frequency ◽  
Spectral Evolution ◽  
X Ray ◽  
Multi Wavelength ◽  
Normalisation Factor ◽  
Transition Radius ◽  
Type C ◽  
Activity Cycles ◽  
X Ray Binaries

Context. We proposed in paper I that the spectral evolution of transient X-ray binaries (XrB) is due to an interplay between two flows: a standard accretion disk (SAD) in the outer parts and a jet-emitting disk (JED) in the inner parts. We showed in papers II, III, and IV that the spectral evolution in X-ray and radio during the 2010–2011 outburst of GX 339-4 can be recovered. However, the observed variability in X-ray was never addressed in this framework. Aims. We investigate the presence of low frequency quasi-periodic oscillations (LFQPOs) during an X-ray outburst, and address the possible correlation between the frequencies of these LFQPOs and the transition radius between the two flows, rJ. Methods. We select X-ray and radio data that correspond to 3 outbursts of GX 339-4. We use the method detailed in Paper IV to obtain the best parameters rJ(t) and ṁin(t) for each outburst. We also independently search for X-ray QPOs in each selected spectra and compare the QPO frequency to the Kepler and epicyclic frequencies of the flow in rJ. Results. We successfully reproduce the correlated evolution of the X-ray spectra and the radio emission for 3 different activity cycles of GX 339-4. We use a unique normalisation factor for the radio emission, f∼R. We also report the detection of 7 new LFQPOs (3 Type B, and 4 Type C), to go along with the ones previously reported in the literature. We show that the frequency of Type C QPOs can be linked to the dynamical JED-SAD transition radius rJ, rather than to the optically thin-thick transition radius in the disk. The scaling factor q such that νQPO ≃ νK(rJ)/q is q ≃ 70 − 130, a factor consistent during the 4 cycles, and similar to previous studies. Conclusions. The JED-SAD hybrid disk configuration not only provides a successful paradigm allowing us to describe XrB cycles, but also matches the evolution of QPO frequencies. Type C QPOs provide an indirect way to probe the JED-SAD transition radius, where an undetermined process produces secular variability. The demonstrated relation between the transition radius links Type C QPOs to the transition between two different flows, effectively tying it to the inner magnetized structure, i.e., the jets. This direct connection between the jets’ (accretion-ejection) structure and the process responsible for Type C QPOs, if confirmed, could naturally explain their puzzling multi-wavelength behavior.

Radio emission of galactic X-ray binaries with relativistic jets

2000 ◽  
Vol 19 (3-4) ◽  
pp. 525-535 ◽  
Author(s):  
S. A. Trushkin
Keyword(s):  
Radio Emission ◽  
Relativistic Jets ◽  
X Ray ◽  
X Ray Binaries

The GLEAM 4-Jy Sample: The brightest radio-sources in the southern sky

2019 ◽  
Vol 15 (S356) ◽  
pp. 375-375
Author(s):  
Sarah White
Keyword(s):  
Radio Emission ◽  
Active Galactic Nuclei ◽  
Visual Inspection ◽  
Low Frequency ◽  
Galactic Nuclei ◽  
Radio Sources ◽  
Relativistic Jets ◽  
The Galaxy ◽  
Murchison Widefield Array ◽  
Past Activity

AbstractLow-frequency radio emission allows powerful active galactic nuclei (AGN) to be selected in a way that is unaffected by dust obscuration and orientation of the jet axis. It also reveals past activity (e.g. radio lobes) that may not be evident at higher frequencies. Currently, there are too few “radio-loud” galaxies for robust studies in terms of redshift-evolution and/or environment. Hence our use of new observations from the Murchison Widefield Array (the SKA-Low precursor), over the southern sky, to construct the GLEAM 4-Jy Sample (1,860 sources at S151MHz > 4 Jy). This sample is dominated by AGN and is 10 times larger than the heavily relied-upon 3CRR sample (173 sources at S178MHz > 10 Jy) of the northern hemisphere. In order to understand how AGN influence their surroundings and the way galaxies evolve, we first need to correctly identify the galaxy hosting the radio emission. This has now been completed for the GLEAM 4-Jy Sample – through repeated visual inspection and extensive checks against the literature – forming a valuable, legacy dataset for investigating relativistic jets and their interplay with the environment.

scholarly journals The hard X-ray spectral evolution in X-ray binaries and ULXs

2009 ◽  
Author(s):  
Qingwen Wu ◽  
Minfeng Gu
Keyword(s):  
Spectral Evolution ◽  
X Ray ◽  
X Ray Binaries

Recollimation shocks in relativistic jets

2018 ◽  
Vol 27 (10) ◽  
pp. 1844011 ◽  
Author(s):  
José M. Martí ◽  
Manel Perucho ◽  
José L. Gómez ◽  
Antonio Fuentes
Keyword(s):  
Magnetic Fields ◽  
Numerical Simulations ◽  
Theoretical Background ◽  
Synchrotron Emission ◽  
Relativistic Jets ◽  
Dominant Type ◽  
X Ray ◽  
Extragalactic Jets ◽  
X Ray Binaries ◽  
Selection Of

Recollimation shocks (RS) appear associated with relativistic flows propagating through pressure mismatched atmospheres. Astrophysical scenarios invoking the presence of such shocks include jets from AGNs and X-ray binaries and GRBs. We shall start reviewing the theoretical background behind the structure of RS in overpressured jets. Next, basing on numerical simulations, we will focus on the properties of RS in relativistic steady jets threaded by helical magnetic fields depending on the dominant type of energy. Synthetic radio maps from the simulation of the synchrotron emission for a selection of models in the context of parsec-scale extragalactic jets will also be discussed.

scholarly journals Radio Emitting X-Ray Binary Stars

1996 ◽  
Vol 158 ◽  
pp. 371-374
Author(s):  
R. E. Spencer
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Radio Emission ◽  
Binary Stars ◽  
X Ray ◽  
Ss 433 ◽  
Normal Star ◽  
Large Numbers ◽  
X Ray Binaries

Some of the most astrophysically interesting objects are found among the radio-emitting X-ray binary stars (REXRB). The class includes the well-studied objects such as SS 433, Cyg X-3 and Sco X-1. The recent discoveries of relativistic ejection of radio knots in the X-ray transients 1915+105 (Mirabel & Rodriguez 1994) and 1655–40 (Hjellming & Rupen 1995) well illustrate the extreme nature of some of these objects.X-ray binaries are semi-detached binary stars in which matter is transfered from a more or less normal star onto a neutron star or black hole. X-ray satellites have detected large numbers of these objects (193 in a recent catalogue by van Paradijs 1995). However only a small fraction of these are known to have radio emission (e.g. Hjellming 1988).

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 Revealing the Physical Changes Taking Place in Z-Track Motion in Low Mass X-Ray Binaries

2004 ◽  
Vol 194 ◽  
pp. 206-206
Author(s):  
M. Bałucińska-Church ◽  
M. J. Church ◽  
G. Halai ◽  
A. Szostek
Keyword(s):  
Neutron Star ◽  
Emission Model ◽  
Spectral Evolution ◽  
X Ray ◽  
Astrophysical Problem ◽  
Low Mass ◽  
Physical Changes ◽  
First Time ◽  
X Ray Binaries

The explanation of the strong physical changes clearly taking place in the Z-track class of Low Mass X-ray Binaries has so far not been obtained, and this remains a significant astrophysical problem, without which we cannot claim to understand accretion in LMXB. We have for the first time applied the Birmingham emission model (2,3) to this problem to attempt to obtain a solution from the spectral evolution along the Z-track in the source GX 340+0 observed with Rossi- ХTE. In this model, X-ray emission consists of blackbody from the neutron star, plus Comptonized emission from an extended ADC.

scholarly journals The Intergalactic Medium

1982 ◽  
Vol 97 ◽  
pp. 453-459
Author(s):  
A. C. Fabian ◽  
A. K. Kembhavi
Keyword(s):  
Radio Emission ◽  
Intergalactic Medium ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Intergalactic Gas ◽  
X Ray ◽  
Extended Radio ◽  
X Ray Background ◽  
Ngc 1275 ◽  
Intracluster Gas

The density of intergalactic gas may be an important parameter in the formation of extended radio sources. It may range from ∼ 0.1 particle cm−3 in the centres of some rich clusters of galaxies down to 10−8cm−3 or less in intercluster space. The possible influence of the intracluster gas surrounding NGC 1275 on its radio emission is discussed, and the possibility that a significant fraction of the X-ray background is due to a hot intergalactic medium is explored in some detail.

scholarly journals The Jets in Micro-Quasars and Quasars: A Comparison

2005 ◽  
Vol 13 ◽  
pp. 709-713
Author(s):  
Ralph Spencer
Keyword(s):  
Radio Galaxies ◽  
Relativistic Jets ◽  
X Ray ◽  
Physical Conditions ◽  
Similarities And Differences ◽  
X Ray Binaries ◽  
Quasars And Radio Galaxies

AbstractThe discovery of relativistic jets in radio emitting X-ray binaries in our own galaxy has led to the term ‘microquasar’ being coined for these objects. In this paper the properties of microquasars are compared with those of quasars and radio galaxies, with the aim of trying to see how the similarities and differences can inform us about the physical conditions and evolution of jets. GRS1915+105 and SS433 are also discussed in more detail.

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