Related papers: Probing Strong Gravitational Fields in X-ray Novae
We discuss new observations of X-ray novae which provide strong evidence that black holes have event horizons. Optical observations of 13 X-ray novae indicate that these binary stars contain collapsed objects too heavy to be stable neutron…
Neutron stars and black holes are the astrophysical systems with the strongest gravitational fields in the universe. In this article, I review the prospect of probing with observations of such compact objects some of the most intriguing…
General relativity is one of the pillars of modern physics. For decades, the theory has been mainly tested in the weak field regime with experiments in the Solar System and radio observations of binary pulsars. Until 2015, the strong field…
The case for collapsed objects in some X-ray binary systems continues to strengthen. But there is now even firmer evidence for supermassive black holes in galactic centres. Gravitational collapse seems to have occurred in the centres of…
We discuss new observations of X-ray novae with Chandra which provide strong evidence that black holes have event horizons. The evidence is based on the finding that black hole X-ray novae in quiescence are approximately 100 times fainter…
The observations and theory of the exciting new class of galactic black hole X-ray transients is reviewed. Seven of these systems have measured mass functions or mass estimates in excess of stable neutron stars, making them excellent black…
Gravitational wave observations will be excellent tools for making precise measurements of processes that occur in very strong-field regions of spacetime. Extreme mass ratio systems, formed by the capture of a stellar mass body compact by a…
The analysis of the properties of the X-ray radiation emitted from geometrically thin accretion disks around black holes can be a powerful tool to test General Relativity in the strong field regime. This chapter reviews the state-of-the-art…
Accreting black holes often show iron line emission in their X-ray spectra. When this line emission is very broad or variable then it is likely to originate from close to the black hole. The theory and observations of such broad and…
Fast variability studies of accreting black holes in the Galaxy offer us a unique opportunity to measure the spins of black holes and test the strong-field behavior of general relativity. In this review, I summarize the arguments often used…
We review the properties and behavior X-ray binaries that contain an accreting black hole. The larger majority of such systems are X-ray transients, and many of them were observed in daily pointings with RXTE throughout the course of their…
Neutrinos do oscillate, which up to our best knowledge implies that they are massive particles. As such, neutrinos should interact with gravitational fields. As their masses are tiny, the gravitational fields must be extremely strong. In…
Fluid discs and tori around black holes are discussed within different approaches and with the emphasis on the role of disc gravity. First reviewed are the prospects of investigating the gravitational field of a black hole--disc system by…
Proof that black holes exist will likely require confirmation of the existence of event horizons. The common assumption that the mere existence of large compact masses proves the case for black holes is an unwarranted extrapolation of…
Accretion disks around black holes radiate a significant fraction of the rest mass of the accreting material in the form of thermal radiation from within a few gravitational radii of the black hole ($ r \lesssim 20 G M / c^{2}$). In…
In the past decades, the phenomenology of fast time variations of high-energy flux from black-hole binaries has increased, thanks to the availability of more and more sophisticated space observatories, and a complex picture has emerged.…
There is strong evidence for the existence of black holes(BHs) in some X-ray binaries and most galatic nuclei, based on different measuremental approaches, but black holes aren't finally identified for the lack of very firm observational…
The spectrum of the hard X-ray background records the history of accretion processes integrated over the cosmic time. Several observational and theoretical evidences indicate that a significant fraction of the energy density is obscured by…
General relativity has passed all solar system experiments and neutron star based tests, such as binary pulsar observations, with flying colors. A more exotic arena for testing general relativity is in systems that contain one or more black…
The recent LIGO detection of gravitational waves from black-hole binaries offers the exciting possibility of testing gravitational theories in the previously inaccessible strong-field, highly relativistic regime. While the LIGO detections…