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

Abstract

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 \textit{Fermi} Large Area Telescope results reported the detection of $\gamma$-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 \textit{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 ($\Gamma =1.42\pm 0.1_{\mathrm{stat}}\pm 0.06_{\mathrm{syst}}$) in the 0.1--500 GeV range and an energy flux above 100 MeV of ($2.91$ $\pm$ $0.8_{\mathrm{stat}}$ $\pm$ $0.12_{\mathrm{syst}}$) $\times$ $10^{-11}$ erg cm${}^{-2}$ s${}^{-1}$. 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 $\gamma$-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 $\pm$ 0.7 $\mu$G and a limit on the maximum energy injected into protons of 2 $\times$ 10${}^{49}$ erg for a density of 1 cm${}^{-3}$. In addition, parameter values are derived for the North-East (NE) and South-West (SW) regions of RCW 86, providing the first indication of a higher magnetic field in the SW region.

arXiv comment13 pages, 10 figures, accepted for publication in ApJ; Corresponding authors : Benjamin Condon, Marianne Lemoine-Goumard, Micaela Caragiulo

References in corpus (25)

• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• Design Concepts for the Cherenkov Telescope Array
• The Fermi Large Area Telescope On Orbit: Event Classification, Instrument Response Functions, and Calibration
• Supernova remnants: the X-ray perspective
• Broad-band nonthermal emission from molecular clouds illuminated by cosmic rays from nearby supernova remnants
• The Molonglo Galactic Plane Survey (MGPS-2): Compact Source Catalogue
• Balmer-Dominated Spectra of Nonradiative Shocks in the Cygnus Loop, RCW 86 and Tycho Supernova Remnants
• Non linear particle acceleration at non-relativistic shock waves in the presence of self-generated turbulence
• Measuring the cosmic ray acceleration efficiency of a supernova remnant
• The X-ray synchrotron emission of RCW 86 and the implications for its age
• RCW 86: A Type Ia Supernova in a Wind-Blown Bubble
• Discovery of gamma-ray emission from the shell-type supernova remnant RCW 86 with H.E.S.S
• High Resolution Spectroscopy of Balmer-Dominated Shocks in the RCW 86, Kepler and SN 1006 Supernova Remnants
• X-ray synchrotron emission from supernova remnants
• X-Ray Synchrotron Emitting Fe-Rich Ejecta in SNR RCW 86
• Dynamical effects of self-generated magnetic fields in cosmic ray modified shocks
• The many sides of RCW 86: a type Ia supernova remnant evolving in its progenitor's wind bubble
• Proper Motions of H-alpha filaments in the Supernova Remnant RCW 86
• The ASTRO-H X-ray Astronomy Satellite
• Hi Shells and Supershells in the I-GALFA Hi 21-cm Line Survey: I. Fast-Expanding Hi Shells Associated with Supernova Remnants
• Constraints on cosmic-ray efficiency in the supernova remnant RCW 86 using multi-wavelength observations
• Suzaku View of the Supernova Remnant RCW 86: X-Ray Studies of Newly-Discovered Fe-Rich Ejecta
• Fermi Large Area Telescope Detection of Supernova Remnant RCW 86
• The Radio Structure of the Supernova Remnant MSH14-63
• Suzaku Observation of the RCW86 Northeastern Shell

Cited by in corpus (19)

• Fermi Large Area Telescope Fourth Source Catalog
• 3FHL: The Third Catalog of Hard Fermi-LAT Sources
• The origin of Galactic cosmic rays: challenges to the standard paradigm
• Search for extended sources in the Galactic Plane using 6 years of Fermi-Large Area Telescope Pass 8 data above 10 GeV
• Evolution of high-energy particle distribution in Supernova Remnants
• Detection of two TeV shell-type remnants at GeV energies with Fermi-LAT: HESS J1731-347 and SN 1006
• TeV cosmic ray nuclei acceleration in shell-type supernova remnants with hard $\gamma$-ray spectra
• Possible Evidence for Cosmic-Ray Acceleration in the Type Ia SNR RCW 86: Spatial Correlation between TeV Gamma rays and Interstellar Atomic Protons
• High-energy gamma-ray study of the dynamically young SNR G150.3+4.5
• GeV emission in the region of HESS J1809-193 and HESS J1813-178: is HESS J1809-193 a proton pevatron?
• The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and $\gamma$-rays
• HESS J1640-465 -- a Gamma-ray emitting pulsar wind nebula ?
• Angular correlation between IceCube high-energy starting events and starburst sources
• Detection of GeV Gamma-rays from HESS J1534-571 and Multiwavelength Implications for the Origin of the Non-thermal Emission
• Electron Acceleration in Middle-age Shell-type $\gamma$-Ray Supernova Remnants
• G17.8+16.7: A New Supernova Remnant
• Pulsar+escape: the recipe for LHAASO sources ?
• A new wideband radio polarization observation of the Supernova Remnant G315.4$-$2.3
• Prospects for PWNe and SNRs science with the ASTRI mini-array of pre-production small-sized telescopes of the Cherenkov Telescope Array