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Related papers: Millisecond Pulsars and Black Holes in Globular Cl…

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Abridged) We model the X-ray properties of millisecond pulsars (MSPs) by considering hot spot emission from a weakly magnetized rotating neutron star (NS) covered by an optically-thick hydrogen atmosphere. We investigate the limitations of…

Astrophysics · Physics 2009-11-13 Slavko Bogdanov , Jonathan E. Grindlay , George B. Rybicki

We present a comparison between the average radio pulse profiles of millisecond pulsars (MSPs) in the field and in globular clusters. Our sample consists of 20 field MSPs and 25 cluster MSPs for which observations exist at 400-600 MHz.

Astrophysics · Physics 2007-05-23 Ray Jayawardhana , Jonathan E. Grindlay

The X-ray and $\gamma$-ray emission of globular clusters (GCs) is attributed to their large fraction of compact binary systems, especially those with millisecond pulsars (MSPs). We analyze a population of 124 Galactic GCs to investigate how…

High Energy Astrophysical Phenomena · Physics 2023-06-14 Raniere de Menezes , Federico Di Pierro , Andrea Chiavassa

This paper describes the new Globular Clusters GMRT Pulsar Search (GCGPS) survey. This survey aims to find MSPs in the globular clusters (GCs) of the Milky Way using uGMRT. The observations use the uGMRT's Band-4 (550$-$750 MHz) and Band-3…

Globular clusters (GCs) display much lower binary fractions than found among main-sequence stars in the solar neighborhood. The physical cause of this difference is debatable: does it reflect different star formation outcomes at low…

Astrophysics of Galaxies · Physics 2026-04-06 Christopher E. O'Connor , Kyle Kremer , Frederic A. Rasio

We examine the growing data set of binary millisecond pulsars that are thought to have a helium white dwarf companion. These systems are believed to form when a low- to intermediate-mass companion to a neutron star fills its Roche lobe…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sarah L. Smedley , Christopher A. Tout , Lilia Ferrario , Dayal T. Wickramasinghe

The presence of Multiple Stellar Populations (MSPs) in Galactic Globular Clusters (GCs) is a poorly understood phenomenon. By probing different spectral ranges that are affected by different absorption lines using the multi-band photometric…

We report Chandra observations of the complete sample of millisecond pulsars (MSPs) with precise radio positions in the globular clusters 47Tuc (NGC104) and NGC6397. The 47Tuc MSPs are predominantly soft sources suggestive of thermal…

Astrophysics · Physics 2009-11-07 J. E. Grindlay , F. Camilo , C. O. Heinke , P. D. Edmonds , H. Cohn , P. Lugger

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…

Star clusters can interact and merge in galactic discs, halos, or centers. We present direct N-body simulations of binary mergers of star clusters with $M_{\star} = 2.7 \times 10^4 \: \mathrm{M_{\odot}}$ each, using the N-body code BIFROST…

Astrophysics of Galaxies · Physics 2025-03-18 Lazaros Souvaitzis , Antti Rantala , Thorsten Naab

The growing population of binary black holes (BBHs) observed by gravitational wave detectors is a potential Rosetta stone for understanding their formation channels. Here, we use an upgraded version of our semi-analytic codes {\sc…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Michela Mapelli , Yann Bouffanais , Filippo Santoliquido , Manuel Arca Sedda , M. Celeste Artale

Black holes (BHs) play a major role in the structural and dynamical evolutions of Globular Clusters (GCs). Several recent works searched for BHs in Galactic GCs using scaling relations derived from numerical simulations. However, the…

Astrophysics of Galaxies · Physics 2025-10-20 Alessandro Della Croce

Stellar mass black holes are formed in the field, and are observed in binaries. Population synthesis estimates for the formation of BH-PSR binaries suggest these may be observed, but with very large formal uncertainties in the formation…

Astrophysics · Physics 2007-05-23 Steinn Sigurdsson

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

Two generations of stars, G1 and G2, typically populate Galactic globular clusters (GCs). The origin of G2 stars is unclear. We uncover two empirical dependencies between GC characteristics, which can be explained by the formation of G2…

Astrophysics of Galaxies · Physics 2022-09-23 Valery Kravtsov , Sami Dib , Francisco A. Calderon , Jose A. Belinchon

We investigate the structural, kinematical, and chemical properties of globular cluster systems (GCSs) in galaxies of different Hubble types in a self-consistent manner based on high-resolution cosmological N-body simulations combined with…

Astrophysics · Physics 2009-11-13 K. Bekki , H. Yahagi , M. Nagashima , D. A. Forbes

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

The importance of stellar encounters in producing stellar exotica in dense stellar clusters is reviewed. We discuss how collisions between main-sequence stars may be responsible for the production of blue stragglers in globular clusters. We…

Astrophysics · Physics 2007-05-23 Melvyn B. Davies

Nuclear stellar cluster (NSCs) are known to exist around massive black holes (MBHs) in galactic nuclei. Two formation scenarios were suggested for their origin: (1) Build-up of NSCs from consecutive infall of stellar cluster and (2)…

Astrophysics of Galaxies · Physics 2015-06-22 Danor Aharon , Hagai B. Perets

While chemical composition spreads are now believed to be a universal characteristic of globular clusters (GCs), not all of them present multiple populations in their color-magnitude diagrams (CMDs). Here we present a new scenario for the…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. A. R. Valcarce , M. Catelan