Related papers: Quiescent black hole X-ray binaries as multi-messe…
For over a century, the identification of high-energy cosmic ray (CR) sources remains an open question. For Galactic CRs with energy up to $10^{15}$ eV, supernova remnants (SNRs) have traditionally been thought the main candidate source.…
Since the discovery of cosmic rays (CRs) over a century ago, their origin remains an open question. Galactic CRs with energy up to the knee ($10^{15}$ eV) are considered to originate from supernova remnants, but this scenario has recently…
We use the Very Long Baseline Array to conduct high precision astrometry of a sample of 33 compact, flat spectrum, variable radio sources in the direction of the Galactic plane (Becker et al. 2010). Although Becker et al. (2010) ruled out a…
The radiative mechanism of the black hole X-ray transients (BHXTs) in their quiescent states (defined as the 2-10 keV X-ray luminosity $\le 10^{34}{\rm \,erg\,s^{-1}}$) remains unclear. In this work, we investigate the quasi-simultaneous…
Black holes of stellar mass and neutron stars in binary systems are first detected as hard X-ray sources using high-energy space telescopes. Relativistic jets in some of these compact sources are found by means of multiwavelength…
In 2018, we reported our discovery of a dozen quiescent X-ray binaries in the central parsec (pc) of the Galaxy (Hailey et al. 2018). In a recent follow-up paper (Mori et al. 2021), we published an extended analysis of these sources and…
Black hole X-ray binaries (BHXBs) are observed in various wavelengths from radio to GeV gamma-ray. Several BHXBs, including MAXI J1820+070 and Cygnus X-1, are also found to emit ultrahigh-energy (UHE; photon energy $>$100 TeV) gamma rays.…
We present an investigation of the quiescent and transient X-ray binaries (XRBs) of the Galactic Center (GC). We extended our Chandra analysis of the non-thermal X-ray sources, located in the central parsec, from Hailey et al. (2018), using…
Relativistic jets powered by stellar mass black holes in X-ray binaries appear to come in two types: steady outflows associated with hard X-ray states and large scale discrete ejections associated with transient outbursts. We show that the…
Weakly accreting black hole X-ray binaries launch compact radio jets that persist even in the quiescent spectral state, at X-ray luminosities <1e-5 of the Eddington luminosity. However, radio continuum emission has been detected from only a…
We summarize the quiescent X-ray observations of transient low-mass X-ray binaries. These observations show that, in quiescence, binaries containing black holes are fainter than those containing neutron stars. This has triggered a number of…
The observed relation between the X-ray and radio properties of low-luminosity accreting black holes has enabled the identification of multiple candidate black hole X-ray binaries (BHXBs) in globular clusters. Here we report an…
The nature of black hole jets at the lowest detectable luminosities remains an open question, largely due to a dearth of observational constraints. Here, we present a new, nearly-simultaneous broadband spectrum of the black hole X-ray…
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…
A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the galactic sources GRS 1915+105 and GRO J1655-40. Both of these objects have given us a broader view of black holes and the…
The first high-energy neutrino source identified by IceCube was a blazar -- an active galactic nucleus driving a relativistic jet towards Earth. Jets driven by accreting black holes are commonly assumed to be needed for high-energy neutrino…
(Abridged) Among the various issues that remain open in the field of accretion onto black hole X-ray binaries (BHBs) is the way the gas accretes at very low Eddington ratios, in the so-called quiescent regime. While there is general…
Theoretical models and observations suggest that primordial Stellar Black Holes (Pop-III-BHs) were prolifically formed in HMXBs, which are powerful relativistic jet sources of synchrotron radiation called Microquasars (MQs). Large…
As smaller analogs of Active Galactic Nuclei (AGN), X-ray Binaries (XRBs) are also capable of launching jets that accelerate particles to high energies. In this work, we reexamine XRB jets as potential sources of high-energy cosmic rays…
The most luminous X-ray sources in nearby elliptical galaxies are likely black hole low-mass X-ray binaries (BHLMXBs). In the Milky Way, such systems are always transient, and with the exception of GRS1915+105 have burst durations on the…