English
Related papers

Related papers: Gamma-Rays from Dark Matter Mini-Spikes in M31

200 papers

The NSF's Karl G.\ Jansky Very Large Array (VLA) was used at 3~cm to search for accretion signatures from intermediate-mass black holes (IMBHs) in 19 globular star clusters (GCs) in NGC\,3115, an early-type galaxy at a distance of 9.4 Mpc.…

Astrophysics of Galaxies · Physics 2020-07-24 J. M. Wrobel , K. E. Nyland

The H.E.S.S. array of Cherenkov telescopes has performed, from 2004 to 2007, a survey of the inner Galactic plane at photon energies above 100 GeV. About 400 hours of data have been accumulated in the region between -30 and +60 degrees in…

Astrophysics · Physics 2009-09-29 HESS Collaboration , F Aharonian , G. Bertone

Black holes (BHs) with masses between 100 to 100,000 times the mass of the Sun ($\rm{M}_{\odot}$) are classified as intermediate-mass black holes (IMBHs), potentially representing a crucial link between stellar-mass and supermassive BHs.…

Astrophysics of Galaxies · Physics 2024-02-29 Abbas Askar , Vivienne F. Baldassare , Mar Mezcua

Gamma-ray is a good probe of dark matter (DM) particles in the Universe. We search for the DM annihilation signals in the direction of the Andromeda galaxy (M31) using 7.5 year Fermi-LAT pass 8 data. Similar to Pshirkov et al. (2016), we…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Zhengwei Li , Xiaoyuan Huang , Qiang Yuan , Yupeng Xu

The formation of supermassive black holes at high redshift still remains a puzzle to astronomers. Their growth becomes reasonable only when starting from a massive seed black hole with mass of the order of 10^2 - 10^5 M_SUN.…

The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the…

Astrophysics · Physics 2009-11-10 Edward A. Baltz

Events like inflation or phase transitions can produce large density perturbations on very small scales in the early Universe. Probes of small scales are therefore useful for e.g. discriminating between inflationary models. Until recently,…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-13 Pat Scott , Torsten Bringmann , Yashar Akrami

Dark Matter (DM) halos with masses below $\sim10^{8}$ $M_{\odot}$, which would help to discriminate between DM models, may be detected through their gravitational effect on distant sources. The same applies to primordial black holes,…

Between the groundbreaking detections of stellar-mass black holes by LIGO/Virgo/KAGRA and JWST's revelation of a surprisingly abundant population of supermassive black holes, one crucial missing link remains: the elusive intermediate-mass…

High Energy Astrophysical Phenomena · Physics 2026-01-21 Colin J. Burke , Priyamvada Natarajan

The Andromeda (M31) and Triangulum (M33) galaxies are the closest Local Group galaxies to the Milky Way, being only 785 and 870 kpc away. These two galaxies provide an independent view of high-energy processes that are often obscured in our…

High Energy Astrophysical Phenomena · Physics 2019-07-03 Mattia Di Mauro , Xian Hou , Christopher Eckner , Gabrijela Zaharijas , Eric Charles

Despite their potential role as massive seeds for quasars, in dwarf galaxy feedback, and in tidal disruption events, the observational evidence for intermediate-mass black holes (IMBHs) is scarce. LISA may observe stellar-mass black hole…

High Energy Astrophysical Phenomena · Physics 2022-07-13 Vladimir Strokov , Giacomo Fragione , Kaze W. K. Wong , Thomas Helfer , Emanuele Berti

Gravitational waves (GWs) offer an unprecedented opportunity to survey the sky and detect mergers of compact objects. While intermediate-mass black holes (IMBHs) have not been detected beyond any reasonable doubt with either dynamical or…

High Energy Astrophysical Phenomena · Physics 2022-11-16 Giacomo Fragione

The POINT-AGAPE collaboration is carrying out a search for gravitational microlensing toward M31 to reveal galactic dark matter in the form of MACHOs (Massive Astrophysical Compact Halo Objects) in the halos of the Milky Way and M31. A…

Using the HEGRA system of imaging atmospheric Cherenkov telescopes, the Andromeda galaxy (M31) was surveyed for TeV gamma ray emission. Given the large field of view of the HEGRA telescopes, three pointings were sufficient to cover all of…

Astrophysics · Physics 2008-11-26 the HEGRA Collaboration , F. Aharonian

Globular clusters have been alternatively predicted to host intermediate-mass black holes (IMBHs) or nearly impossible to form and retain them in their centres. Over the last decade enough theoretical and observational evidence have…

Astrophysics · Physics 2015-06-24 Margarita Safonova , C. S. Stalin

Intermediate mass black holes (IMBHs) with expected masses M_BH ~ 10^4 M_sun are thought to bridge the gap between stellar mass black holes (M_BH ~ 3 - 100 M_sun) and supermassive black holes found at the centre of galaxies (M_BH > 10^6…

Astrophysics of Galaxies · Physics 2015-06-04 F. Kirsten , W. H. T. Vlemmings

In order to constrain the density of intermediate-mass black holes (IMBHs) in galaxies, we run smoothed particle hydrodynamics (SPH) simulations of a gas-rich disc dwarf galaxy, where different halo and disc populations of IMBHs are…

Astrophysics · Physics 2008-11-26 M. Mapelli

We investigate the evolution of star clusters containing intermediate-mass black hole (IMBH) of $300$ to $5000\ \mathrm{M}_\odot$, focusing on the formation and evolution of IMBH-stellar mass black holes (SBHs; $M_{\rm BH} \lesssim 10^2\…

Astrophysics of Galaxies · Physics 2025-03-31 Seungjae Lee , Hyung Mok Lee , Ji-hoon Kim , Rainer Spurzem , Jongsuk Hong , Eunwoo Chung

Decades after the first predictions of intermediate-mass black holes (IMBHs) in globular clusters (GCs) there is still no unambiguous observational evidence for their existence. The most promising signatures for IMBHs are found in the cores…

Astrophysics of Galaxies · Physics 2015-06-05 Stefan Umbreit , Frederic A. Rasio

Cosmic rays, along with stellar radiation and magnetic fields, are known to make up a significant fraction of the energy density of galaxies such as the Milky Way. When cosmic rays interact in the interstellar medium, they produce gamma-ray…

‹ Prev 1 3 4 5 6 7 10 Next ›