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Related papers: Millisecond pulsars and the gamma-ray excess in An…

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The $Fermi$-LAT has revealed that rotation powered millisecond pulsars (MSPs) are a major contributor to the Galactic $\gamma$-ray source population. We discuss the $\gamma$-ray emission process within the context of the outer gap…

High Energy Astrophysical Phenomena · Physics 2011-10-26 J. Takata , Y. Wang , K. S. Cheng

The Milky Way centre exhibits an intense flux in the gamma and X-ray bands, whose origin is partly ascribed to the possible presence of a large population of millisecond pulsars (MSPs) and cataclysmic variables (CVs), respectively. However,…

Astrophysics of Galaxies · Physics 2018-06-13 Manuel Arca-Sedda , Bence Kocsis , Timothy Brandt

We estimate the conventional astrophysical emission from dwarf spheroidal satellite galaxies (dSphs) of the Milky Way, focusing on millisecond pulsars (MSPs), and evaluate the potential for confusion with dark matter (DM) annihilation…

High Energy Astrophysical Phenomena · Physics 2016-11-15 Miles Winter , Gabrijela Zaharijas , Keith Bechtol , Justin Vandenbroucke

The observed correlation between the far-infrared and radio luminosities of galaxies illustrates the close connection between star formation and cosmic-ray production. Intriguingly, recent gamma-ray observations indicate that…

Astrophysics of Galaxies · Physics 2021-04-28 Takahiro Sudoh , Tim Linden , John F. Beacom

Observations by the Fermi-LAT have uncovered a bright, spherically symmetric excess surrounding the center of the Milky Way galaxy. The spectrum of the gamma-ray excess peaks sharply at an energy ~2 GeV, exhibiting a hard spectrum at lower…

High Energy Astrophysical Phenomena · Physics 2017-02-28 Tim Linden , Nicholas L. Rodd , Benjamin R. Safdi , Tracy R. Slatyer

2 years worth of archival FERMI-LAT data was used to search for the gamma-ray emission from the Andromeda galaxy. The data show no noticeable elliptical image. Subsequent on-off source aperture photometry analysis using a CO image template…

High Energy Astrophysical Phenomena · Physics 2015-05-19 H. Ögelman , N. Aksaker , S. Anılan , H. Dereli , N. Emrahoğlu , I. Yegingil

Gamma-ray haloes can exist around galaxies due to the interaction of escaping galactic cosmic rays with the surrounding gas. We have searched for such a halo around the nearby giant spiral Andromeda galaxy M31 using almost 7 years of Fermi…

High Energy Astrophysical Phenomena · Physics 2016-03-24 M. S. Pshirkov , V. V. Vasiliev , K. A. Postnov

Recent observations of gamma-rays with the Fermi Large Area Telescope (LAT) in the direction of the inner Galaxy revealed a mysterious GeV excess. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs)…

High Energy Astrophysical Phenomena · Physics 2021-08-10 Dmitry O. Chernyshov , Andrei E. Egorov , Vladimir A. Dogiel , Alexei V. Ivlev

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 present a summary of gamma-ray millisecond pulsar (MSP) observations with the Fermi Large Area Telescope. The radio and gamma-ray light curves of these MSPs have been modeled in the framework of the retarded vacuum dipole magnetic field.…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Tyrel J. Johnson , Christo Venter , Alice K. Harding , Lucas Guillemot

Past studies have identified a spatially extended excess of $\sim$1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from annihilating dark matter. We revisit and scrutinize this signal…

High Energy Astrophysical Phenomena · Physics 2016-02-24 Tansu Daylan , Douglas P. Finkbeiner , Dan Hooper , Tim Linden , Stephen K. N. Portillo , Nicholas L. Rodd , Tracy R. Slatyer

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

Millisecond pulsars are very likely the main source of gamma-ray emission from globular clusters. However, the relative contributions of two separate emission processes--curvature radiation from millisecond pulsar magnetospheres vs. inverse…

High Energy Astrophysical Phenomena · Physics 2021-10-13 Deheng Song , Oscar Macias , Shunsaku Horiuchi , Roland M. Crocker , David M. Nataf

We report the Fermi Large Area Telescope detection of gamma-ray (>100 megaelectronvolts) pulsations from pulsar J1823-3021A in the globular cluster NGC 6624 with high significance (~7 sigma). Its gamma-ray luminosity L_gamma = (8.4 +/- 1.6)…

Astrophysics of Galaxies · Physics 2015-06-03 The Fermi LAT Collaboration

Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly $\pm$20 degrees in latitude. The leading theory postulates that this GeV excess is…

High Energy Astrophysical Phenomena · Physics 2019-07-19 Deheng Song , Oscar Macias , Shunsaku Horiuchi

We present evidence for $\gamma$-ray emission from a stacked population of 39 high-latitude globular clusters (GCs) not detected in the Fermi Point Source Catalog, likely attributable to populations of millisecond pulsars within them. In…

High Energy Astrophysical Phenomena · Physics 2024-10-17 Owen K. Henry , Timothy A. D. Paglione , Yuzhe Song , Joshua Tan , David Zurek , Vanessa Pinto

In the third Fermi catalogue (3FGL) there are sixteen gamma-ray globular clusters. After analyzing the recent released Pass 8 data of Fermi Large Area Telescope (LAT), we report the discovery of significant gamma-ray emission from M 15 and…

High Energy Astrophysical Phenomena · Physics 2016-03-23 P. F. Zhang , Y. L. Xin , L. Fu , J. N. Zhou , J. Z. Yan , Q. Z. Liu , L. Zhang

We perform a composite likelihood analysis of subdivided regions within the central $26^\circ\times20^\circ$ of the Milky Way, with the aim of characterizing the spectrum of the gamma-ray galactic center excess in regions of varying…

High Energy Astrophysical Phenomena · Physics 2018-01-30 Shunsaku Horiuchi , Manoj Kaplinghat , Anna Kwa

The $Fermi$ gamma-ray telescope discovered a pair of bubbles at the Galactic center. These structures are spatially-correlated with the microwave emission detected by the WMAP and Planck satellites. These bubbles were likely inflated by a…

High Energy Astrophysical Phenomena · Physics 2015-06-18 M. Ruszkowski , H. -Y. K. Yang , E. Zweibel

The possible gamma-ray excess in the inner Galaxy and the Galactic center (GC) suggested by Fermi-LAT observations has triggered a large number of studies. It has been interpreted as a variety of different phenomena such as a signal from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Francesca Calore , Ilias Cholis , Christoph Weniger
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