The MAGIC collaboration has observed very high energy gamma-ray emission from the AGN 1ES 2344+514. A gamma-ray signal corresponding to an 11 sigma excess and an integral flux of ( 2.38 +/- 0.30(stat) +/- 0.70(syst)) x 10(-11) cm(-2) s(-1) above 200 GeV has been obtained from 23.1 hr of data taking between 2005 August 3 and 2006 January 1. The data confirm the previously detected gamma-ray emission from this object during a flare seen by the Whipple collaboration in 1995 and the evidence ( below 5 sigma significance level) from long-term observations conducted by the Whipple and HEGRA groups. The MAGIC observations show a relatively steep differential photon spectrum that can be described by a power law with a photon index of alpha = -2.95 +/- 0.12(stat) +/- 0.2(syst) between 140 GeV and 5.4 TeV. The observations reveal a low-flux state, about 6 times below the 1995 flare seen by Whipple and comparable with the previous Whipple and HEGRA long-term measurements. During the MAGIC observations no significant time variability was observed.
Titolo: | Observation of Very High Energy γ‐Rays from the AGN 1ES 2344+514 in a Low Emission State with the MAGIC Telescope |
Autori: | |
Data di pubblicazione: | 2007 |
Rivista: | |
Abstract: | The MAGIC collaboration has observed very high energy gamma-ray emission from the AGN 1ES 2344+514. A gamma-ray signal corresponding to an 11 sigma excess and an integral flux of ( 2.38 +/- 0.30(stat) +/- 0.70(syst)) x 10(-11) cm(-2) s(-1) above 200 GeV has been obtained from 23.1 hr of data taking between 2005 August 3 and 2006 January 1. The data confirm the previously detected gamma-ray emission from this object during a flare seen by the Whipple collaboration in 1995 and the evidence ( below 5 sigma significance level) from long-term observations conducted by the Whipple and HEGRA groups. The MAGIC observations show a relatively steep differential photon spectrum that can be described by a power law with a photon index of alpha = -2.95 +/- 0.12(stat) +/- 0.2(syst) between 140 GeV and 5.4 TeV. The observations reveal a low-flux state, about 6 times below the 1995 flare seen by Whipple and comparable with the previous Whipple and HEGRA long-term measurements. During the MAGIC observations no significant time variability was observed. |
Handle: | http://hdl.handle.net/11577/2530260 |
Appare nelle tipologie: | 01.01 - Articolo in rivista |