相关论文: Models for microquasars

We compute the X-ray spectra produced by non-static coronae atop accretion discs around black holes and neutron stars. The hot corona is radiatively coupled to the underlying disc (the reflector) and generates an X-ray spectrum which is…

In this paper, we summarize key observational constraints of the accretion flow on the black hole X-ray binary Cygnus X-1 (Cyg X-1). The discussion highlights the flows of energy close to the black hole and the importance of the distance…

The observed correlation between the radio and X-ray fluxes in the hard state of black-hole X-ray binaries (BHXRBs) has been around for more than two decades. It is currently accepted that the hard X-rays in BHXRBs come from Comptonization…

We have recently put forward a 'unified' semi-empirical model for the coupling between accretion and jet production in galactic black hole X-ray binaries (published in MNRAS, 2004). In this paper we summarise this model and briefly discuss…

Several physical and astrophysical problems related to accretion onto black holes and neutron stars are shortly reviewed. I discuss the observed differences between these two types of compact objects in quiescent Soft X-ray Transients. Then…

We investigated the relation between compact jet emission and X-ray variability properties of all black hole transients with multiwavelength coverage during their outburst decays. We studied the evolution of all power spectral components…

Context. Many low-redshift active galactic nuclei harbor a supermassive black hole accreting matter at low or medium rates. At such rates, the accretion flow usually consists of a cold optically thick disk, plus a hot, low density,…

In all the microquasars with two hHz QPOs, the ratio of the frequencies is 3:2, supporting our suggestion that a non-linear resonance between two modes of oscillation in the accretion disk plays a role in exciting the observed modulations…

In the last decade, high-resolution X-ray spectroscopy has revolutionized our understanding of the role of accretion disk winds in black hole X-ray binaries. Here I present a brief review of the state of wind studies in black hole X-ray…

In the last decade multi-wavelength observations have demonstrated the importance of jets in the energy output of accreting black hole binaries. The observed correlations between the presence of a jet and the state of the accretion flow…

The power spectra of black hole binaries have been well studied for decades, giving a detailed phenomenological picture of the variability properties and their correlation with the energy spectrum (spectral state) of the source. Here we…

I briefly outline the state-paradigm that has emerged from the study of black-hole binaries with RossiXTE. This is the starting point of a number of studies that address the connection between accretion and jet ejection and the physical…

An empirical relation between `canonical' X-ray states in black hole X-ray binaries and radio emission is presented. In the Low/Hard state a quasi-continuous radio-emitting jet is produced. In the the High/Soft state the jet is not…

This paper summarises our current understanding of the spectral continuum components observed in black hole X-ray binaries. The consequences for theoretical models are discussed with an emphasis on the constraints set by observations on the…

We propose a jet model for the low/hard state of Galactic black-hole X-ray sources that can explain the energy spectra from radio to X-rays. The model assumes that i) there is a magnetic field along the axis of the jet; ii) the electron…

The accretion/ejection coupling in accreting black hole binaries has been described by empirical relations between the X-ray/radio and X-ray/optical-infrared luminosities. These correlations were initially thought to be universal. However,…

Two component X-ray spectra (soft multicolor black body plus harder power law) are frequently observed from accreting black holes. These components are presumably associated with the different parts of the accretion flow (optically thick…

To understand the origin of hard X-ray emissions from black hole X-ray binaries during their low/hard states, we calculate the X-ray spectra of black-hole accretion flow for the following three configurations of hot and cool media: (a) an…

Black holes and weakly-magnetic accreting neutron stars show strong quasi-periodic variability over timescales that span a very wide range. This property offer us a unique opportunity to improve our understanding of basic physical processes…

We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and…