Variable gamma-ray emission from the Be/X-ray transient A0535+26?

Citation
Ge. Romero et al., Variable gamma-ray emission from the Be/X-ray transient A0535+26?, ASTRON ASTR, 376(2), 2001, pp. 599-605
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS
ISSN journal
1432-0746 → ACNP
Volume
376
Issue
2
Year of publication
2001
Pages
599 - 605
Database
ISI
SICI code
1432-0746(200109)376:2<599:VGEFTB>2.0.ZU;2-D
Abstract
We present a study of the unidentified gamma-ray source 3EG J0542+2610. Thi s source is spatially superposed on the supernova remnant G180.0-1.7, but i ts time variability makes a physical link unlikely. We have searched in the EGRET location error box for compact radio sources that could be the low e nergy counterpart of the gamma-ray source. Although 29 point-like radio sou rces were detected and measured, none of them is strong enough to be consid ered the counterpart of a background gamma-ray emitting AGN. We suggest tha t the only object within the 95% error box capable of producing the require d gamma-ray flux is the X-ray transient A0535+26. We show that this Be/accr eting pulsar can produce variable hadronic gamma-ray emission through the m echanism originally proposed by Cheng & Ruderman (1989), where a proton bea m accelerated in a magnetospheric electrostatic gap impacts the transient a ccretion disk.