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Related papers: Precessing Black Hole Jets and Galactic Fossils

200 papers

We search for the gamma-ray counterparts of stellar-mass black holes using long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon, by applying the pulsar…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Lupin Chun-Che Lin , Hung-Yi Pu , Kouichi Hirotani , Albert K. H Kong , Satoki Matsushita , Hsiang-Kuang Chang , Makoto Inoue , Pak-Hin T. Tam

Recent observations of the diffuse Galactic \gr emission (DGE) by the {\it Fermi} Large Area Telescope ({\it Fermi}-LAT) have shown significant deviations, above a few GeV until about 100 GeV, from DGE models that use the GALPROP code for…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Heinrich J. Voelk , Evgeny G. Berezhko

The large number of isolated black holes (IBHs) in the Galaxy, estimated to be 10^8, implies a very high density of 10^-4 pc^-3 and an average distance between IBHs of 10 pc. Our study shows that the magnetic flux, accumulated on the…

High Energy Astrophysical Phenomena · Physics 2012-11-26 M. V. Barkov , D. V. Khangulyan , S. B. Popov

The Fermi-LAT data revealed giant bubbles of emission above and below the Galactic plane with an energy spectrum significantly harder than seen from other directions. How the bubbles connect to the Galactic plane is unclear. We find that…

High Energy Astrophysical Phenomena · Physics 2015-09-18 Wim de Boer , Iris Gebauer , Simon Kunz , Alexander Neumann

We compare the surface brightness profile and morphology of the Galactic Centre Excess (GCE) identified in wide-angle $\gamma$-ray maps from the Fermi-Large Area Telescope to dark matter annihilation predictions derived from high-resolution…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Robert J. J. Grand , Simon D. M. White

The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…

High Energy Astrophysical Phenomena · Physics 2010-04-23 LAT Collaboration

The Galactic Center Excess (GCE), one of the most remarkable discoveries by Fermi-LAT, has prompted extensive exploration over the past decade, often attributed to dark matter or millisecond pulsars. This work proposes a novel…

High Energy Astrophysical Phenomena · Physics 2023-12-25 Wei Zhu , Zi-Qing Xia , Yu-Chen Tang , Lei Feng

The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…

High Energy Astrophysical Phenomena · Physics 2019-08-13 T. A. Porter

We have investigated the linear X-ray filament, G359.944-0.052, previously identified as a likely X-ray counterpart of a parsec-scale jet from the Galactic Center super-massive black hole (SMBH), Sagittarius A* (Sgr A*), using a total of…

High Energy Astrophysical Phenomena · Physics 2019-04-17 Zhenlin Zhu , Zhiyuan Li , Mark R. Morris , Shuo Zhang , Siming Liu

Recent X-ray and gamma-ray observations of the Galactic center region by the ASCA and CGRO/EGRET instruments show evidence of 2--10 keV and $>1$ GeV continuum emission as well as 6.7 and 6.4 keV line emission from the inner $0.2^\circ$ of…

Astrophysics · Physics 2009-10-30 F. Yusef-Zadeh , W. Purcell , E. Gotthelf

The Fermi-LAT data appear to have an excess of gamma rays from the inner 150 pc of the Galactic Center. The main explanations proposed for this are: an unresolved population of millisecond pulsars (MSPs), dark matter (DM) annihilation, and…

High Energy Astrophysical Phenomena · Physics 2014-03-19 Oscar Macias , Chris Gordon

A spherical-symmetric gamma-ray emission from the central region of the Galaxy has been recently identified in Fermi-LAT data, and initially associated to dark matter particle annihilations. Guided by the evidence for a high gas density in…

High Energy Astrophysical Phenomena · Physics 2016-01-13 Daniele Gaggero , Marco Taoso , Alfredo Urbano , Mauro Valli , Piero Ullio

A central compact object (CCO, e.g. a black hole) with an accretion disk has been suggested as the common central engine of various astrophysical phenomena, such as gamma-ray bursts (GRBs), tidal disruption events (TDEs) and active galactic…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Mi-Xiang Lan , Rui Xue , Dingrong Xiong , Wei-Hua Lei , Xue-Feng Wu , Zi-Gao Dai

The Energetic Gamma-Ray Experiment Telescope (EGRET) experiment onboard the Compton Gamma-Ray Observatory (CGRO) has provided the most precise measurements of the gamma-ray sky to date. The EGRET measurements of the diffuse emission across…

Astrophysics · Physics 2007-06-05 B. M. Baughman , W. B. Atwood , R. P. Johnson , T. A. Porter , M. Ziegler

Analyses have found a "haze" of anomalous microwave emission surrounding the Galactic Center in the WMAP sky maps. A recent study using Fermi data detected a similar haze in the gamma-ray. Several studies have modeled these hazes as…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Matthew McQuinn , Matias Zaldarriaga

In this work, we revisit the all-sky Galactic diffuse $\gamma$-ray emission taking into account the new measurements of cosmic ray electron/positron spectrum by PAMELA, ATIC and Fermi, which show excesses of cosmic electrons/positrons…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Juan Zhang , Qiang Yuan , Xiao-Jun Bi

The diffuse Galactic $\gamma$-rays from EGRET observation shows excesses above 1 GeV in comparison with the expectations from conventional Galactic cosmic ray (CR) propagation model. In the work we try to solve the "GeV excess" problem by…

Astrophysics · Physics 2008-11-26 Xiao-Jun Bi , Juan Zhang , Qiang Yuan , Jian-Li Zhang , HongSheng Zhao

The Galactic Center Excess (GCE) remains an enduring mystery, with leading explanations being annihilating dark matter or an unresolved population of millisecond pulsars. Analyzing the morphology of the GCE provides critical clues to…

High Energy Astrophysical Phenomena · Physics 2024-06-13 Yi-Ming Zhong , Ilias Cholis

Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the…

High Energy Astrophysical Phenomena · Physics 2015-02-11 Francesca Calore , Ilias Cholis , Christoph Weniger

The possible short gamma-ray burst (GRB) observed by {\it Fermi}/GBM in coincidence with the first gravitational wave (GW) detection, offers new ways to test GRB prompt emission models. Gravitational wave observations provide previously…

High Energy Astrophysical Phenomena · Physics 2016-08-31 P. Veres , R. D. Preece , A. Goldstein , P. Mészáros , E. Burns , V. Connaughton