English
Related papers

Related papers: Estimates for Very High Energy Gamma Rays from Glo…

200 papers

Pair cascades from millisecond pulsars (MSPs) may be a primary source of Galactic electrons and positrons that contribute to the increase in positron flux above 10 GeV as observed by PAMELA and AMS-02. The Fermi Large Area Telescope (LAT)…

High Energy Astrophysical Phenomena · Physics 2015-08-20 Christo Venter , Andreas Kopp , Alice K Harding , Peter L Gonthier , Ingo Buesching

It has been proposed that a large population of unresolved millisecond pulsars (MSPs) could potentially account for the excess of GeV-scale gamma-rays observed from the region surrounding the Galactic Center. The viability of this scenario…

High Energy Astrophysical Phenomena · Physics 2016-04-13 Dan Hooper , Gopolang Mohlabeng

The discovery of a binary comprising a black hole (BH) and a millisecond pulsar (MSP) would yield insights into stellar evolution and facilitate exquisitely sensitive tests of general relativity. Globular clusters (GCs) are known to harbor…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Drew Clausen , Steinn Sigurdsson , David F. Chernoff

We report the discovery of a new 5.78 ms-period millisecond pulsar (MSP), PSR J1740-5340B (NGC 6397B), in an eclipsing binary system discovered with the Parkes radio telescope (now also known as Murriyang), Australia, and confirmed with the…

We know from observations that globular clusters are very efficient catalysts in forming unusual short-period binary systems or their offspring, such as low-mass X-ray binaries (LMXBs; neutron stars accreting matter from low-mass stellar…

It has been postulated that globular clusters could be sources of Very-High Energy (VHE) gamma rays, powered by milli-second pulsars. This could be due to cumulative direct emission or to plerion-type emission driven by colliding winds. In…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Michael McCutcheon

The Fermi Large Area Telescope has provided the most detailed view toward the Galactic Centre (GC) in high-energy gamma rays. Besides the interstellar emission and point-source contributions, the data suggest a residual diffuse gamma-ray…

Astrophysics of Galaxies · Physics 2018-02-07 Giacomo Fragione , Fabio Antonini , Oleg Y. Gnedin

We suggest the possibility of including millisecond pulsars inside the core of globular clusters in pulsar timing array experiments. Since they are very close to each other, their gravitational wave induced timing residuals are expected to…

Astrophysics of Galaxies · Physics 2021-10-22 Michele Maiorano , Francesco de Paolis , Achille Nucita

CFHT Megacam data in (g',r',i') are used to obtain deep, wide-field photometry of the globular cluster system (GCS) around M87. A total of 6200 GCs brighter than M_I = -8.5 are included in the study, essentially containing almost the entire…

Astrophysics of Galaxies · Physics 2015-05-13 William E. Harris

The study of binary millisecond pulsars (MSPs) in globular clusters (GCs) is a key ingredient to study binary and stellar evolution under extreme conditions. In this context, an accurate analysis of the optical emission, which is mostly…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Greta Ettorre , Emanuele Dalessandro , Mario Cadelano , Cristina Pallanca , Paulo C. C. Freire , Alessandro Ridolfi

Globular clusters host large populations of millisecond pulsars (MSPs) due to their high gravitational encounter rates, producing many binary systems and thus MSPs via the recycling process. Seven pulsars with spin periods ranging from 3 ms…

High Energy Astrophysical Phenomena · Physics 2024-12-17 Justine Singleton , Megan DeCesar , Shi Dai , Deven Bhakta , Scott Ransom , Jay Strader , Laura Chomiuk , James Miller-Jones

We present the discovery of six millisecond pulsars (MSPs) in the High Time Resolution Universe (HTRU) survey for pulsars and fast transients carried out with the Parkes radio telescope. All six are in binary systems with approximately…

Using the Hubble Ultraviolet Globular Cluster Survey (HUGS) and additional HST archival data, we have carried out a search for optical counterparts to the low-luminosity Chandra X-ray sources in the globular cluster M4 (NGC 6121). We have…

High Energy Astrophysical Phenomena · Physics 2023-06-28 Phyllis M. Lugger , Haldan N. Cohn , Craig O. Heinke , Jiaqi Zhao , Yue Zhao , Jay Anderson

Millisecond pulsars (MSPs) are a growing class of gamma-ray emitters. Pulsed gamma-ray signals have been detected from more than 40 MSPs with the Fermi Large Area Telescope (LAT). The wider radio beams and more compact magnetospheres of…

High Energy Astrophysical Phenomena · Physics 2014-06-24 T. J. Johnson , C. Venter , A. K. Harding , L. Guillemot , D. A. Smith , M. Kramer , O. Celik , P. R. den Hartog , E. C. Ferrara , X. Hou , J. Lande , P. S. Ray

For pulsars in globular clusters, we suggest using observations of the relativistic time delay of their radiation in the gravitational eld of a massive body (the Shapiro effect) located close to the line of sight to detect and identify…

Astrophysics · Physics 2009-11-16 T. I. Larchenkova , A. A. Lutovinov

Observations by HAWC indicate that many young pulsars (including Geminga and Monogem) are surrounded by spatially extended, multi-TeV emitting regions. It is not currently known, however, whether TeV emission is also produced by recycled,…

High Energy Astrophysical Phenomena · Physics 2018-08-15 Dan Hooper , Tim Linden

We identify through their X-ray spectra one certain (W37) and two probable (W17 and X4) quiescent low-mass X-ray binaries (qLMXBs) containing neutron stars in a long Chandra X-ray exposure of the globular cluster 47 Tucanae, in addition to…

Astrophysics · Physics 2009-11-10 C. O. Heinke , J. E. Grindlay , P. D. Edmonds

We analyzed the globular cluster M5 (NGC 5904) using 15 years of gamma-ray data from the Fermi Large Area Telescope (LAT). Using rotation ephemerides generated from Arecibo and FAST radio telescope observations, we searched for gamma-ray…

High Energy Astrophysical Phenomena · Physics 2024-03-26 X. Hou , W. Zhang , P. C. C. Freire , D. F. Torres , J. Ballet , D. A. Smith , T. J. Johnson , M. Kerr , C. C. Cheung , L. Guillemot , J. Li , L. Zhang , A. Ridolfi , P. Wang , D. Li , J. Yuan , N. Wang

Pulsars (PSRs) orbiting intermediate or supermassive black holes at the centre of galaxies and globular clusters are known as Extreme Mass Ratio Binaries (EMRBs) and have been identified as precision probes of strong-field GR. For…

High Energy Astrophysical Phenomena · Physics 2020-05-13 Tom Kimpson , Kinwah Wu , Silvia Zane

Pulsars, if existing and detectable in the immediate vicinity of the massive black hole (MBH) in the Galactic center (GC), may be used as a superb tool to probe both the environment and the metric of the central MBH. The recent discovery of…

Astrophysics of Galaxies · Physics 2015-06-18 Fupeng Zhang , Youjun Lu , Qingjuan Yu