The MAGIC collaboration has studied the high-frequency-peaked BL Lac object 1ES 1218 + 30.4, at a redshift z = 0.182, using the MAGIC imaging air Cerenkov telescope located on the Canary Island of La Palma. A gamma-ray signal was observed with 6.4 sigma significance. The differential energy spectrum for an energy threshold of 120 GeV can be fitted by a simple power law, yielding F-E = (8.1 +/- 2.1) x 10(-7)[E/(250 GeV)](-3.0 +/- 0.4) TeV-1 F (E) m(-2) s(-1). During the 6 days of observation in 2005 January, no time variability on timescales of days was found within the statistical errors. The observed integral flux above 350 GeV is nearly a factor of 2 below the upper limit reported by the Whipple collaboration in 2003.
Titolo: | Discovery of Very High Energy Gamma Rays from 1ES 1218+30.4 |
Autori: | |
Data di pubblicazione: | 2006 |
Rivista: | |
Abstract: | The MAGIC collaboration has studied the high-frequency-peaked BL Lac object 1ES 1218 + 30.4, at a redshift z = 0.182, using the MAGIC imaging air Cerenkov telescope located on the Canary Island of La Palma. A gamma-ray signal was observed with 6.4 sigma significance. The differential energy spectrum for an energy threshold of 120 GeV can be fitted by a simple power law, yielding F-E = (8.1 +/- 2.1) x 10(-7)[E/(250 GeV)](-3.0 +/- 0.4) TeV-1 F (E) m(-2) s(-1). During the 6 days of observation in 2005 January, no time variability on timescales of days was found within the statistical errors. The observed integral flux above 350 GeV is nearly a factor of 2 below the upper limit reported by the Whipple collaboration in 2003. |
Handle: | http://hdl.handle.net/11577/137283 |
Appare nelle tipologie: | 01.01 - Articolo in rivista |