相关论文: Multi-wavelength astronomical searches for primord…
Primordial black holes (PBH) accretion in the late Universe can lead to significant mass growth. A larger mass further accelerates the accretion radiation output for PBHs with initial masses greater than one solar mass, potentially leading…
Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission.…
Overdense regions can collapse into primordial black holes (PBHs) in the early universe, which are a compelling candidate for dark matter. Current constraints leave the asteroid-mass window the only possible one for PBH to account for all…
Primordial black holes (PBHs) are expected to accrete particle dark matter around them to form ultracompact minihalos (UCMHs), if the PBHs themselves are not most of the dark matter. We show that if most dark matter is a thermal relic, then…
We use medium resolution optical spectra of 3CR radio galaxies to estimate their black hole masses and accretion rates. Black hole masses are found from central stellar velocity dispersions and accretion rates are derived from narrow…
In the absence of direct kinematic measurements, the mass of an accreting black hole is sometimes inferred from the X-ray spectral parameters of its accretion disk; specifically, from the temperature and normalization of a disk-blackbody…
Ultra-Luminous X-ray sources (ULXs) are accreting black holes for which their X-ray properties have been seen to be different to the case of stellar-mass black hole binaries. For most of the cases their intrinsic energy spectra are well…
Primordial black holes in the solar mass range are a possibly significant component of dark matter. We show how an argument relating the deflection of light by such black holes in the density spike likely to exist around the M87…
We investigate a new mechanism to create large curvature perturbations on small scales due to parameter resonance in a single-field inflationary model with a small periodic structure upon the potential. After reentering the horizon, the…
We explore the potential cumulative energy production of stellar mass black holes in early galaxies. Stellar mass black holes may accrete substantially from the higher density interstellar media of primordial galaxies, and their energy…
In this work, we study the luminosity that results from the conversion of QCD axion particles into photons in the magnetic field of the plasma accreting onto black holes (BHs). For the luminosities to be large two conditions need to be met:…
We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established…
Supermassive black holes in giant elliptical galaxies are remarkably faint given their expected accretion rates. This motivates models of radiatively inefficient accretion, due to either ion-electron thermal decoupling, generation of…
Within the mass range of $10^{16}-5\times 10^{18}$ g, primordial black holes (PBHs) persist as plausible candidates for dark matter. Our study involves a reassessment of the constraints on PBHs through a comparative analysis of the cosmic…
To understand the feedback of black holes on their environment or the acceleration of ultra-high energy cosmic rays in the present cosmic epoch, a systematic, all-sky inventory of radio galaxies in the local universe is needed. Here we…
We present a sample of nearby dwarf galaxies with radio-selected accreting massive black holes (BHs), the majority of which are non-nuclear. We observed 111 galaxies using sensitive, high-resolution observations from the Karl G. Jansky Very…
It is argued that the bulk of black holes (BH) in the universe are primordial (PBH). This assertion is strongly supported by the recent astronomical observations, which allow to conclude that supermassive BHs with $M= (10^6 - 10^9) M_\odot$…
As a promising dark matter candidate, primordial black holes (PBHs) lighter than $\sim10^{-18}M_{\odot}$ are supposed to have evaporated by today through Hawking radiation. This scenario is challenged by the memory burden effect, which…
Primordial black holes possibly formed in the early universe could provide a significant fraction of the dark matter and would be unique probes of inflation. A smoking gun for their discovery would be the detection of a subsolar mass…
Powerful radio-AGN are hosted by massive elliptical galaxies which are usually very poor in molecular gas. Nevertheless the central Black Hole (BH) needs molecular gas for the nuclear activity. Thus it is important to study the origin, the…