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Title: Revisiting SNR Puppis A with Seven Years of Fermi Large Area Telescope Observations

Abstract

Puppis A is a very famous and extensively studied supernova remnant that shows strong evidence of shock-cloud interaction. We reanalyze its GeV γ -ray emission using seven years of Pass 8 data recorded by the Fermi Large Area Telescope. The morphology of the γ -ray emission is more compatible with that of the thermal X-ray and IR emissions than the radio image, which suggests a possible correlation between the gamma-ray-emitting region and dense clouds. The γ -ray spectrum in the energy range of 1–500 GeV shows a break at 7.92 ± 1.91 GeV, with photon indices of 1.81 ± 0.08 below the break and 2.53 ± 0.12 above the break, which can naturally explain the lack of TeV γ -ray emission from Puppis A. The multi-wavelength observations favor a hadronic origin for the γ -ray emission.

Authors:
; ; ; ; ;  [1]
  1. Key laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)
Publication Date:
OSTI Identifier:
22663426
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 843; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRELATIONS; COSMIC GAMMA SOURCES; EMISSION; GAMMA RADIATION; GAMMA SPECTRA; GEV RANGE; HADRONS; PHOTONS; SUPERNOVA REMNANTS; TELESCOPES; TEV RANGE; X RADIATION

Citation Formats

Xin, Yu-Liang, Guo, Xiao-Lei, Liao, Neng-Hui, Yuan, Qiang, Liu, Si-Ming, and Wei, Da-Ming, E-mail: yuanq@pmo.ac.cn, E-mail: liusm@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn. Revisiting SNR Puppis A with Seven Years of Fermi Large Area Telescope Observations. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA74BB.
Xin, Yu-Liang, Guo, Xiao-Lei, Liao, Neng-Hui, Yuan, Qiang, Liu, Si-Ming, & Wei, Da-Ming, E-mail: yuanq@pmo.ac.cn, E-mail: liusm@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn. Revisiting SNR Puppis A with Seven Years of Fermi Large Area Telescope Observations. United States. doi:10.3847/1538-4357/AA74BB.
Xin, Yu-Liang, Guo, Xiao-Lei, Liao, Neng-Hui, Yuan, Qiang, Liu, Si-Ming, and Wei, Da-Ming, E-mail: yuanq@pmo.ac.cn, E-mail: liusm@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn. Mon . "Revisiting SNR Puppis A with Seven Years of Fermi Large Area Telescope Observations". United States. doi:10.3847/1538-4357/AA74BB.
@article{osti_22663426,
title = {Revisiting SNR Puppis A with Seven Years of Fermi Large Area Telescope Observations},
author = {Xin, Yu-Liang and Guo, Xiao-Lei and Liao, Neng-Hui and Yuan, Qiang and Liu, Si-Ming and Wei, Da-Ming, E-mail: yuanq@pmo.ac.cn, E-mail: liusm@pmo.ac.cn, E-mail: dmwei@pmo.ac.cn},
abstractNote = {Puppis A is a very famous and extensively studied supernova remnant that shows strong evidence of shock-cloud interaction. We reanalyze its GeV γ -ray emission using seven years of Pass 8 data recorded by the Fermi Large Area Telescope. The morphology of the γ -ray emission is more compatible with that of the thermal X-ray and IR emissions than the radio image, which suggests a possible correlation between the gamma-ray-emitting region and dense clouds. The γ -ray spectrum in the energy range of 1–500 GeV shows a break at 7.92 ± 1.91 GeV, with photon indices of 1.81 ± 0.08 below the break and 2.53 ± 0.12 above the break, which can naturally explain the lack of TeV γ -ray emission from Puppis A. The multi-wavelength observations favor a hadronic origin for the γ -ray emission.},
doi = {10.3847/1538-4357/AA74BB},
journal = {Astrophysical Journal},
number = 2,
volume = 843,
place = {United States},
year = {Mon Jul 10 00:00:00 EDT 2017},
month = {Mon Jul 10 00:00:00 EDT 2017}
}
  • Based on more than seven years of Fermi Large Area Telescope Pass 8 data, we report on a detailed analysis of the bright gamma-ray pulsar (PSR) J0007+7303. We confirm that PSR J0007+7303 is significantly detected as a point source also during the off-peak phases with a test statistic value of 262 (∼16 σ ). In the description of the off-peak spectrum of PSR J0007+7303, a power law with an exponential cutoff at 2.7 ± 1.2 ± 1.3 GeV (the first/second uncertainties correspond to statistical/systematic errors) is preferred over a single power law at a level of 3.5 σ . Themore » possible existence of a cutoff hints at a magnetospheric origin of the emission. In addition, no extended gamma-ray emission is detected that is compatible with either the supernova remnant (CTA 1) or the very high-energy (>100 GeV) pulsar wind nebula. A flux upper limit of 6.5 × 10{sup −12} erg cm{sup −2} s{sup −1} in the energy range 10–300 GeV is reported, for an extended source assuming the morphology of the VERITAS detection. During on-peak phases, a sub-exponential cutoff is significantly preferred (∼11 σ ) for representing the spectral energy distribution, in both the phase-averaged and phase-resolved spectra. Three glitches are detected during the observation period and we found no flux variability at the time of the glitches or in the long-term behavior. We also report the discovery of a previously unknown gamma-ray source in the vicinity of PSR J0007+7303, Fermi J0020+7328, which we associate with the z = 1.781 quasar S5 0016+73. A concurrent analysis of this source is needed to correctly characterize the behavior of CTA 1 and it is also presented in the paper.« less
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