Details

Autor(en) / Beteiligte

• Aleksic, J
• Alvarez, E A
• Antonelli, L A
• ANTORANZ, P
• Asensio, M
• Backes, M
• DE ALMEIDA, U BARRES
• Barrio, J A
• BASTIERI, D
• Gonzalez, J Becerra

Titel

DETECTION OF VHE γ-RAYS FROM HESS J0632+057 DURING THE 2011 FEBRUARY X-RAY OUTBURST WITH THE MAGIC TELESCOPES

Ist Teil von

• Astrophysical journal. Letters, 2012-07, Vol.754 (1), p.1-6

Erscheinungsjahr

2012

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The very high energy (VHE) gamma -ray source HESS J0632+057 has recently been confirmed to be a gamma -ray binary. The optical counterpart is the Be star MWC 148, and a compact object of unknown nature orbits it every ~321 days with a high eccentricity of ~0.8. We monitored HESS J0632+057 with the stereoscopic MAGIC telescopes from 2010 October to 2011 March and detected significant VHE gamma -ray emission during 2011 February, when the system exhibited an X-ray outburst. We find no gamma -ray signal in the other observation periods when the system did not show increased X-ray flux. Thus, HESS J0632+057 exhibits gamma -ray variability on timescales of the order of one to two months possibly linked to the X-ray outburst that takes place about 100 days after the periastron passage. Furthermore, our measurements provide for the first time the gamma -ray spectrum down to about 140 GeV and indicate no turnover of the spectrum at low energies. We compare the properties of HESS J0632+057 with the similar gamma -ray binary LS I +61[degrees]303 and discuss the possible origin of the multi-wavelength emission of the source.