Gamma-ray emission from globular clusters 2MS-GC01, IC 1257, FSR 1735, NGC 5904 and 6656
Abstract
Globular clusters (GCs) are the oldest stellar systems in the Galaxy, in which millisecond pulsars are widely believed to be the only steady γ-ray emitters. So far, nine γ-ray GCs have been identified and a few candidates, such as 2MS-GC01 and IC 1257, have been suggested. In this work, after analysing the publicly available Fermi Large Area Telescope data, we confirm the significant γ-ray emission from 2MS-GC01 and IC 1257 and report the discovery of γ-ray emission from NGC 5904 and 6656 within their tidal radii. Also, strong evidence of significant γ-ray emission is found from FSR 1735. From the observed γ-ray luminosities, we estimate the numbers of millisecond pulsars that are expected to be present in these GCs.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2015
- DOI:
- 10.1093/mnras/stv185
- arXiv:
- arXiv:1501.06341
- Bibcode:
- 2015MNRAS.448.3215Z
- Keywords:
-
- gamma-rays: general;
- globular clusters: individual: NGC 5904;
- globular clusters: individual: NGC 6656;
- globular clusters: individual: FSR 1735;
- globular clusters: individual: 2MS-GC01;
- globular clusters: individual: IC 1257;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 3 figures, accepted for publication in MNRAS