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تسجيل مستخدم جديدMAGIC observations of the giant radio galaxy M87 in a low-emission state between 2005 and 2007
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We present the results of a long M87 monitoring campaign in very high energy $gamma$-rays with the MAGIC-I Cherenkov telescope. We aim to model the persistent non-thermal jet emission by monitoring and characterizing the very high energy $gamma$-ray emission of M87 during a low state. A total of 150,h of data were taken between 2005 and 2007 with the single MAGIC-I telescope, out of which 128.6,h survived the data quality selection. We also collected data in the X-ray and textit{Fermi}--LAT bands from the literature (partially contemporaneous). No flaring activity was found during the campaign. The source was found to be in a persistent low-emission state, which was at a confidence level of $7sigma$. We present the spectrum between 100,GeV and 2,TeV, which is consistent with a simple power law with a photon index $Gamma=2.21pm0.21$ and a flux normalization at 300,GeV of $(7.7pm1.3) times 10^{-8}$ TeV$^{-1}$ s$^{-1}$ m$^{-2}$. The extrapolation of the MAGIC spectrum into the GeV energy range matches the previously published textit{Fermi}--LAT spectrum well, covering a combined energy range of four orders of magnitude with the same spectral index. We model the broad band energy spectrum with a spine layer model, which can satisfactorily describe our data.
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We present the results of a long M87 monitoring campaign in very high energy $gamma$-rays with the MAGIC-I Cherenkov telescope. A total of 150 hours of data was gathered between 2005 and 2007. No flaring activity was found during that time. Neverthel
ess, we have found an apparently steady and weak signal at the level of $7sigma$. We present the spectrum between 100 GeV and 2 TeV, which is consistent with a simple power law with a spectral index $-2.21pm0.21$ and a flux normalization (at 300 GeV) of $5.4pm1.1 times 10^{-8} frac{1}{mathrm{TeV s m}^{2}}$. It complements well with the previously published Fermi spectrum, covering an energy range of four orders of magnitude without apparent change in the spectral index.
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