A Spatial and Spectral Study of Nonthermal Filaments in Historical Supernova Remnants: Observational Results with Chandra

By A. Bamba, R. Yamazaki, T. Yoshida, T. Terasawa, K. Koyama. 2004

227 citations recorded by the source corpus.

The outer shells of young supernova remnants (SNRs) are the most plausible acceleration sites of high-energy electrons with the diffusive shock acceleration (DSA) mechanism. We studied spatial and spectral properties close to the shock fronts in four historical SNRs (Cas A, Kepler's remnant, Tycho's remnant, and RCW 86) with excellent spatial resolution of Chandra. In all of the SNRs, hard X-ray emissions were found on the rims of the SNRs, which concentrate in very narrow regions (so-called filaments); apparent scale widths on the upstream side are below or on the order of the point-spread function of Chandra, while they are 0.″5-40'' (0.01-0.4 pc) on the downstream side with most reliable distances. The spectra of these filaments can be fitted with both thermal and nonthermal (power law and SRCUT) models. The former requires unrealistic high temperature (≳2 keV) and low abundances (≲1 solar) for emission from young SNRs and may be thus unlikely. The latter reproduces the spectra with best-fit photon indices of 2.1-3.8, or roll-off frequencies of (0.1-28) × 1017 Hz, which reminds us of the synchrotron emission from electrons accelerated via DSA. We consider various physical parameters as functions of the SNR age, including the previous results on SN 1006; the filament width on the downstream side increases with the SNR age, and the spectrum becomes softer, keeping a nonthermal feature. It was also found that a function, that is, the roll-off frequency divided by the square of the scale width on the downstream side, shows negative correlation with the age, which might provide us some information on the DSA theory.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/08ac6381112fc45e432cd983cb3a7e969a192437

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. E. Orlando
2. J. Vink
3. Y. Fukui
4. Tsuyoshi Inoue
5. Troy A. Porter
6. D. Caprioli
7. C. McKee
8. R. Yamazaki

In Nuclear and High Energy Physics

1. E. Orlando
2. J. Vink
3. Troy A. Porter
4. Tsuyoshi Inoue
5. D. Caprioli
6. Y. Fukui
7. I. Grenier
8. S. Inutsuka

Citations in the corpus

• TURBULENCE AND MAGNETIC FIELD AMPLIFICATION IN SUPERNOVA REMNANTS: INTERACTIONS BETWEEN A STRONG SHOCK WAVE AND MULTIPHASE INTERSTELLAR MEDIUM (2009, background): “The evidence for magnetic field amplification in SNR has been also obtained from the thickness of X-ray filaments that shows typicallyB ∼ 100 microGauss (Bamba et al. 2003, 2005a, 2005b; Vink & Laming 2003).”
• Observational Signatures of Particle Acceleration in Supernova Remnants (2012, background): “This has been taken as evidence that some form of magnetic field amplification is operating in the vicinity of shocks of young supernova remnants (Vink and Laming, 2003; Berezhko et al., 2003b; Bamba et al., 2005; Ballet, 2006).”
• DISCOVERY OF TeV GAMMA-RAY EMISSION FROM TYCHO’S SUPERNOVA REMNANT (2011, background): “X-ray images reveal strong non-thermal emission concentrated in the SNR rim (Hwang et al. 2002; Bamba et al. 2005; Warren et al. 2005; Katsuda et al. 2010).”
• Cosmic-Ray Acceleration at the Forward Shock in Tycho’s Supernova Remnant: Evidence from Chandra X-Ray Observations (2005, background): “The widths of the rim as seen here in projection are quite narrow, of order only a few arcseconds, as previously noted by Hwang et al. (2002) and Bamba et al. (2005).”
• Strong evidence for hadron acceleration in Tycho’s supernova remnant (2011, background): “High-resolution X-ray maps reveal strong non-thermal emission concentrated in thin filaments (Hwang et al., 2002; Bamba et al., 2005; Warren et al., 2005; Katsuda et al., 2010; Eriksen et al., 2011).”
• TOWARD UNDERSTANDING THE COSMIC-RAY ACCELERATION AT YOUNG SUPERNOVA REMNANTS INTERACTING WITH INTERSTELLAR CLOUDS: POSSIBLE APPLICATIONS TO RX J1713.7−3946 (2011, background): “…the magnetic field strength can be as large as B∼ 1 mG, and the thickness of the X-ray filaments indicates B∼ 100 µG around the shock front (Ballet 2006, Uchiyama et al. 2007, Tanaka et al. 2008, Acero et al. 2009), which is similar to other young SNRs (Vink & Laming 2003, Bamba et al. 2003, 2005).”
• FERMI-LAT DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE YOUNG SUPERNOVA REMNANT CASSIOPEIA A (2010, background): “…field at supernova shocks can be amplified way beyond the factor of ∼ 4 that is expected for standard compression of interstellar magnetic fields in the absence of CR modification of the shock’s hydrodynamic structure (Uchiyama et al. 2007; Völk et al. 2005; Bamba et al. 2005; Vink & Laming 2003).”