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The recent Fermi detection of the globular cluster (GC) 47 Tucanae highlighted the importance of modeling collective gamma-ray emission of millisecond pulsars (MSPs) in GCs. Steady flux from such populations is also expected in the very…

High Energy Astrophysical Phenomena · Physics 2011-02-11 C. Venter , O. C. de Jager , A. -C. Clapson

Although only 22 millisecond pulsars (MSPs) are currently known to exist in the globular cluster (GC) 47 Tucanae, this cluster may harbor 30-60 MSPs, or even up to ~200. In this Letter, we model the pulsed curvature radiation (CR) gamma-ray…

Astrophysics · Physics 2009-11-30 C. Venter , O. C. de Jager

We present spectral and long-timescale variability analyses of \textit{Chandra} ACIS-S observations of the 19 millisecond pulsars (MSPs) with precisely known positions in the globular cluster 47 Tucanae. The X-ray emission of the majority…

MeerKAT imaging of the globular cluster 47 Tucanae (47 Tuc) reveals 1.28 GHz continuum emission at the locations of 20 known millisecond pulsars (MSPs). We use time series and spectral imaging to investigate the image-domain characteristics…

High Energy Astrophysical Phenomena · Physics 2023-07-19 Ian Heywood

We present results from our 830 ksec observation of the globular cluster 47 Tucanae with the Chandra X-ray Observatory's High Resolution Camera-S. We limit our analysis here to the 19 previously known, localized millisecond pulsars (MSPs)…

Astrophysics · Physics 2011-02-11 P. B. Cameron , R. E. Rutledge , F. Camilo , L. Bildsten , S. M. Ransom , S. R. Kulkarni

Over a hundred millisecond radio pulsars (MSPs) have been observed in globular clusters (GCs), motivating theoretical studies of the formation and evolution of these sources through stellar evolution coupled to stellar dynamics. Here we…

High Energy Astrophysical Phenomena · Physics 2019-06-12 Claire S. Ye , Kyle Kremer , Sourav Chatterjee , Carl L. Rodriguez , Frederic A. Rasio

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

Globular clusters with their large populations of millisecond pulsars (MSPs) are believed to be potential emitters of high-energy gamma-ray emission. Our goal is to constrain the millisecond pulsar populations in globular clusters from…

Astrophysics of Galaxies · Physics 2015-05-18 The Fermi LAT collaboration

Millisecond pulsars (MSPs) are abundant in globular clusters (GCs), which offer favorable environments for their creation. While the advent of recent, powerful facilities led to a rapid increase in MSP discoveries in GCs through pulsation…

High Energy Astrophysical Phenomena · Physics 2024-05-27 Joanna Berteaud , Christopher Eckner , Francesca Calore , Maïca Clavel , Daryl Haggard

Globular clusters (GCs) are evolved stellar systems containing entire populations of millisecond pulsars (MSPs), which are efficient gamma-ray emitters. Observations of this emission can be used as a powerful tool to explore the dynamical…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Raniere de Menezes , Fabio Cafardo , Rodrigo Nemmen

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

Recent observations by the Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) have revealed globular clusters (GC) to be sources of high-energy (HE) and very-high-energy (VHE) gamma-rays. It has been…

High Energy Astrophysical Phenomena · Physics 2014-12-15 P L Prinsloo , C Venter , I Büsching , A Kopp

We study the gamma-ray spectra of 30 globular clusters (GCs) thus far detected with the Fermi Gamma-ray Space Telescope. Presuming that gamma-ray emission of a GC comes from millisecond pulsars (MSPs) contained in, a model that generates…

High Energy Astrophysical Phenomena · Physics 2022-03-14 Wei Wu , Zhongxiang Wang , Yi Xing , Pengfei Zhang

The high resolution X-ray imaging and broad-band moderate resolution spectra enabled by the ACIS cameras on the Chandra X-ray Observatory have opened a new window in our study of millisecond pulsars (MSPs). Given the large excess of MSPs in…

Astrophysics · Physics 2007-05-23 Jonathan E. Grindlay

The Fermi Large Area Telescope (LAT) has recently detected a population of globular clusters (GCs) in high-energy (HE) gamma-rays. Their spectral properties and energetics are consistent with cumulative emission from a population of…

High Energy Astrophysical Phenomena · Physics 2011-11-08 C. Venter , O. C. de Jager , A. Kopp , I. Büsching

We present results from an emission code that assumes millisecond pulsars (MSPs) to be sources of relativistic particles in globular clusters (GCs) and models the resulting spectral energy distribution (SED) of Galactic GCs due to these…

High Energy Astrophysical Phenomena · Physics 2017-11-08 Hambeleleni Ndiyavala , Petrus Paulus Kruger , Christo Venter

We have obtained high resolution (<1") deep x-ray images of the globular cluster 47Tucanae (NGC 104) with the Chandra X-ray Observatory to study the population of compact binaries in the high stellar density core. A 70 kilosec exposure of…

Astrophysics · Physics 2019-08-17 Jonathan E. Grindlay , Craig Heinke , Peter D. Edmonds , Stephen S. Murray

Globular clusters (GCs) are established emitters of high-energy (HE, 100 MeV<E<100 GeV) \gamma-ray radiation which could originate from the cumulative emission of the numerous millisecond pulsars (msPSRs) in the clusters' cores or from…

High Energy Astrophysical Phenomena · Physics 2019-08-14 P. Eger , C. van Eldik

Over the last few years, the data obtained using the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope has provided new insights on high-energy processes in globular clusters, particularly those involving compact objects…

High Energy Astrophysical Phenomena · Physics 2017-02-22 P. H. Thomas Tam , C. Y. Hui , Albert K H. Kong

Chandra observations of globular clusters provide insight into the formation, evolution, and X-ray emission mechanisms of X-ray binary populations. Our recent (2002) deep observations of 47 Tuc allow detailed study of its populations of…

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