Deep morphological and spectral study of the SNR RCW 86 with Fermi-LAT

Journal Article · Thu Mar 10 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/819/2/98· OSTI ID:22886956

Ajello, M. ^[1]; Baldini, L. ^[2]; Barbiellini, G. ^[3]; Bastieri, D. ^[4]; Bellazzini, R. ^[5]; Bissaldi, E.; Caragiulo, M. ^[6]; Bloom, E. D.; Bottacini, E.; Caliandro, G. A.; Cameron, R. A.; Charles, E. ^[7]; Bonino, R. ^[8]; Brandt, T. J. ^[9]; Bregeon, J. ^[10]; Bruel, P. ^[11]; Buehler, R. ^[12]; Cavazzuti, E.; Ciprini, S. ^[13]; others, and

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1. Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States)
2. Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy)
3. Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy)
4. Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy)
5. Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy)
6. Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy)
7. W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)
8. Istituto Nazionale di Fisica Nucleare, Sezione di Torino, I-10125 Torino (Italy)
9. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
10. Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3, Montpellier (France)
11. Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France)
12. Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany)
13. Agenzia Spaziale Italiana (ASI) Science Data Center, I-00133 Roma (Italy)

RCW 86 is a young supernova remnant (SNR) showing a shell-type structure at several wavelengths and is thought to be an efficient cosmic-ray (CR) accelerator. Earlier Fermi Large Area Telescope results reported the detection of γ-ray emission coincident with the position of RCW 86 but its origin (leptonic or hadronic) remained unclear due to the poor statistics. Thanks to 6.5 years of data acquired by the Fermi-LAT and the new event reconstruction Pass 8, we report the significant detection of spatially extended emission coming from RCW 86. The spectrum is described by a power-law function with a very hard photon index (Γ=1.42±0.1{sub stat}±0.06{sub syst}) in the 0.1–500 GeV range and an energy flux above 100 MeV of (2.91±0.8{sub stat}±0.12{sub syst}) × 10{sup −11} erg cm{sup −2} s{sup −1}. Gathering all the available multiwavelength (MWL) data, we perform a broadband modeling of the nonthermal emission of RCW 86 to constrain parameters of the nearby medium and bring new hints about the origin of the γ-ray emission. For the whole SNR, the modeling favors a leptonic scenario in the framework of a two-zone model with an average magnetic field of 10.2 ± 0.7 μG and a limit on the maximum energy injected into protons of 2 × 10{sup 49} erg for a density of 1 cm{sup −3}. In addition, parameter values are derived for the north–east and south–west (SW) regions of RCW 86, providing the first indication of a higher magnetic field in the SW region.

• OSTI ID: 22886956
• Journal Information: Astrophysical Journal, Vol. 819, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COMPUTERIZED SIMULATION
COSMIC RADIATION
EMISSION
GEV RANGE
MAGNETIC FIELDS
MEV RANGE 100-1000
SPECTRA
STATISTICS
SUPERNOVA REMNANTS
TELESCOPES