Evidence for TeV gamma ray emission from Cassiopeia A

By H. C. Aharonian, et al. 2001

224 citations recorded by the source corpus.

232 hours of data were accumulated from 1997 to 1999, using the HEGRA Stereoscopic Cherenkov Telescope System to observe the supernova remnant Cassiopeia A. TeV γ -ray emission was detected at the $5 \sigma$ level, and a flux of $(5.8 \pm 1.2_{\mathrm{stat}} \pm 1.2_{\mathrm{syst}}) 10^{-9}\ {ph} {m}^{-2} {s}^{-1}$ above 1 TeV was derived. The spectral distribution is consistent with a power law with a differential spectral index of $-2.5 \pm 0.4_{\mathrm{stat}} \pm 0.1_{\mathrm{syst}}$ between 1 and 10 TeV. As this is the first report of the detection of a TeV γ -ray source on the "centi-Crab"scale, we present the analysis in some detail. Implications for the acceleration of cosmic rays depend on the details of the source modeling. We discuss some important aspects in this paper.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/8ba160a3ee752deb343d337c69f3c24bed335a68

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In Nuclear and High Energy Physics

1. J. Vink
2. F. Aharonian
3. V. Zirakashvili
4. L. Ksenofontov
5. H. Völk
6. E. Berezhko
7. E. Orlando
8. R. Yamazaki

Citations in the corpus

• Analytical solutions for energy spectra of electrons accelerated by nonrelativistic shock-waves in shell type supernova remnants (2006, background): “The discovery of TeV gamma-rays from young SNRs, in particular from Cas A (Aharonian et al. 2001), RX J1713.”
• On the Magnetic Fields and Particle Acceleration in Cassiopeia A (2002, methodology): “The detection of TeV emission by HEGRA is consistent with this interpretation, but pion decay associated with relativistic ions is an equally valid interpretation (Aharonian et al. 2001).”
• On the Determination of Ejecta Structure and Explosion Asymmetry from the X-Ray Knots of Cassiopeia A (2003, background): “…by astronomers at all wavelengths from the radio (it is the brightest source in the northern sky, Reber 1944; Ryle & Smith 1948) to TeV γ-rays (Aharonian et al. 2001), allowing determinations with a high degree of confidence of important parameters such as the expansion velocities of various…”
• Magnetic field amplification in Tycho and other shell-type supernova remnants (2004, background): “Finally, the predicted hadronic gamma-ray flux for Tycho’s SNR (Völk et al. 2002) is still below the upper limit measured by HEGRA (Aharonian et al. 2001b).”
• The Crab Nebula and Pulsar between 500 GeV and 80 TeV: Observations with the HEGRA Stereoscopic Air Cerenkov Telescopes (2004, background): “The overall relative operation efficiency of the HEGRA system of Cerenkov telescopes reached 85% of the total available darkness time, so that 5500 hr of data on more than 100 objects and various scans (Aharonian et al. 2001b, 2002c) were collected in 67 months of operation.”
• Study of Nonthermal Emission from SNR RX J1713.7–3946 with Suzaku (2008, background): “Further evidence for multi-TeV particles (electrons and/or protons) has been provided by discovery of TeV gamma rays from some SNRs, such as Cassiopeia A (Aharonian et al. 2001) or RX J1713.”
• Turbulent amplification of magnetic field and diffusive shock acceleration of cosmic rays (2004, background): “…evidence that electrons, and probably protons, are accelerated to energies of at least 1014 eV in supernova remnants (SNR) (Koyama et al. 1995; Allen et al. 1997; Tanimori et al. 1998; Aharonian 1999; Naito et al. 1999; Aharonian et al. 2001; Berezhko, Ksenofontov & Völk 2003; Vink & Laming 2003).”
• Is the Giant Radio Galaxy M 87 a TeV Gamma-Ray Emitter? (2003, background): “This ring segment background model is similar to the usage of a set of control regions (Aharonian et al. 2001), but provides a smaller ratio of ON- to OFF-source solid angle areas (α = ΩON/ΩOFF) and thus reduces the statistical error on the number of estimated background events.”
• FERMI-LAT DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE YOUNG SUPERNOVA REMNANT CASSIOPEIA A (2010, methodology): “Cas A was the first SNR detected in TeV gamma rays, first by HEGRA (Aharonian et al. 2001) and later confirmed by MAGIC (Albert et al. 2007) and VERITAS (Humensky 2008), firmly establishing the existence of multi-TeV particles.”