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Related papers: Gamma-ray emission from globular clusters

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We report our analysis of the Fermi Large Area Telescope data for 39 millisecond pulsars (MSPs) listed in the second $\gamma$-ray pulsar catalog. Spectra of the pulsars are obtained. We fit the spectra with a function of a power law with…

High Energy Astrophysical Phenomena · Physics 2016-11-09 Yi Xing , Zhongxiang Wang

The LAT instrument on the Fermi Gamma-Ray Space Telescope is performing an all-sky survey from 20 MeV to 300 GeV with unprecedented statistics and angular resolution. This is providing a wealth of new information on the non-thermal emission…

High Energy Astrophysical Phenomena · Physics 2019-08-14 A. W. Strong

Galaxy clusters can be sources of high-energy (HE) $\gamma$-ray radiation, due to the efficient acceleration of particles exceeding EeV energies. At present, though, the only candidate for emitting HE $\gamma$-rays is the Coma cluster,…

High Energy Astrophysical Phenomena · Physics 2022-08-24 Vardan Baghmanyan , Davit Zargaryan , Felix Aharonian , Ruizhi Yang , Sabrina Casanova , Jonathan Mackey

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

Pulsars are powerful sources of radiation across the electromagnetic spectrum. This paper highlights some theoretical insights into non-thermal, magnetospheric pulsar gamma-ray radiation. These advances have been driven by NASA's Fermi…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Matthew G. Baring

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 searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsars (MSPs) from…

Using archival {\it Fermi}-LAT data with a time span of $\sim12$ years, we study the population of Millisecond Pulsars (MSPs) in Globular Clusters (GlCs) and investigate their dependence on cluster dynamical evolution in the Milky Way…

Astrophysics of Galaxies · Physics 2024-01-30 Li Feng , Zhongqun Cheng , Wei Wang , Zhiyuan Li , Yang Chen

More than 100 millisecond pulsars (MSPs) have been discovered in radio observations of gamma-ray sources detected by the Fermi Large Area Telescope (LAT), but hundreds of pulsar-like sources remain unidentified. Here we present the first…

The wealth of high-energy (E > 50 MeV) and very-high-energy (E > 100 GeV) data accumulated over the past few years have provided unprecedented opportunities to probe pulsar emission models. The Fermi Large Area Telescope (LAT) has now…

High Energy Astrophysical Phenomena · Physics 2017-02-03 Christo Venter

A cluster of galaxies is a huge system bounded by gravitation, and cosmic rays are thought to be confined in the system, thus it should contain much non-thermal components. Many theories predict significant gamma-ray emission that could be…

High Energy Astrophysical Phenomena · Physics 2009-12-18 Masaki Mori

The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and…

High Energy Astrophysical Phenomena · Physics 2023-11-06 Rui Zhang , Xiaoyuan Huang , Zhi-Hui Xu , Shiping Zhao , Qiang Yuan

We have monitored a sample of 27 nearby globular clusters in the hard X-ray band (20-120 keV) for approximately 1400 days using the BATSE instrument on board the Compton Gamma-Ray Observatory. Globular clusters may contain a large number of…

Astrophysics · Physics 2009-10-28 E. Ford , P. Kaaret , B. A. Harmon , M. Tavani , S. N. Zhang

In three years of observations since the beginning of nominal science operations in August 2008, the Large Area Telescope (LAT) on board the Fermi Gamma Ray Space Telescope has observed high-energy (>20 MeV) \gamma-ray emission from 35…

High Energy Astrophysical Phenomena · Physics 2015-06-15 LAT Collaboration

The Fermi satellite has recently detected gamma ray emission from the central regions of our Galaxy. This may be evidence for dark matter particles, a major component of the standard cosmological model, annihilating to produce high-energy…

High Energy Astrophysical Phenomena · Physics 2015-10-07 Timothy D. Brandt , Bence Kocsis

Globular clusters (GCs) are the oldest stellar system in the Galaxy, in which the millisecond pulsars are widely believed to be the only steady {\gamma}-ray emitters. So far 9 {\gamma}-ray GCs have been identified and a few candidates such…

High Energy Astrophysical Phenomena · Physics 2015-06-23 J. N. Zhou , P. F. Zhang , X. Y. Huang , X. Li , Y. F. Liang , L. Fu , J. Z. Yan , Q. Z. Liu

In this study, we investigate the contribution of millisecond pulsars (MSPs) to the gamma-ray excess observed in the Galactic Center by analyzing data from high-resolution direct N-body simulations of six globular clusters (GCs) that…

High Energy Astrophysical Phenomena · Physics 2024-10-22 Dana Kuvatova , Taras Panamarev , Maryna Ishchenko , Anton Gluchshenko , Peter Berczik

The Fermi Large Area Telescope, in collaboration with several groups from the radio community, have had marvellous success at uncovering new gamma-ray millisecond pulsars (MSPs). In fact, MSPs now make up a sizable fraction of the total…

High Energy Astrophysical Phenomena · Physics 2015-05-19 C. Venter , A. K. Harding , T. J. Johnson

Millisecond pulsars occur abundantly in globular clusters. They are expected to be responsible for several spectral components in the radio through gamma-ray waveband (e.g., involving synchrotron and inverse Compton emission), as have been…

High Energy Astrophysical Phenomena · Physics 2015-04-21 C. Venter , A. Kopp

Using the data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope, we have searched for the gamma-ray pulsations from the direction of globular cluster M28 (NGC 6626). We report the discovery of a signal with the…

High Energy Astrophysical Phenomena · Physics 2015-06-12 J. H. K. Wu , C. Y. Hui , E. M. H. Wu , A. K. H. Kong , R. H. H. Huang , P. H. T. Tam , J. Takata , K. S. Cheng
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