Cosmic-Ray Acceleration at the Forward Shock in Tycho’s Supernova Remnant: Evidence from Chandra X-Ray Observations

By Jessica S. Warren, J. Hughes, C. Badenes, P. Ghavamian, C. McKee, D. Moffett, P. Plucinsky, C. Rakowski, E. Reynoso, P. Slane. 2005

276 citations recorded by the source corpus.

We present evidence for cosmic-ray acceleration at the forward shock in Tycho's supernova remnant (SNR) from three X-ray observables: (1) the proximity of the contact discontinuity to the forward shock, or blast wave, (2) the morphology of the emission from the rim of Tycho, and (3) the spectral nature of the rim emission. We determine the locations of the blast wave (BW), contact discontinuity (CD), and reverse shock (RS) around the rim of Tycho's supernova remnant using a principal component analysis and other methods applied to new Chandra data. The azimuthal-angle-averaged radius of the BW is 251''. For the CD and RS we find average radii of 241'' and 183'', respectively. Taking account of projection effects, we find ratios of 1 : 0.93 : 0.70 (BW : CD : RS). We show these values to be inconsistent with adiabatic hydrodynamic models of SNR evolution. The CD : BW ratio can be explained if cosmic-ray acceleration of ions is occurring at the forward shock. The RS : BW ratio, as well as the strong Fe Kα emission from the Tycho ejecta, imply that the RS is not accelerating cosmic rays. We also extract radial profiles from ~34% of the rim of Tycho and compare them to models of surface brightness profiles behind the BW for a purely thermal plasma with an adiabatic shock. The observed morphology of the rim is much more strongly peaked than predicted by the model, indicating that such thermal emission is implausible here. Spectral analysis also implies that the rim emission is nonthermal in nature, lending further support to the idea that Tycho's forward shock is accelerating cosmic rays.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/b114258fb4351c58f889c75b7eef34881917241a

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

In Nuclear and High Energy Physics

Citations in the corpus

Are the Models for Type Ia Supernova Progenitors Consistent with the Properties of Supernova Remnants? (2007, background): “This process is known to take part in many young SNRs, and recent theoretical (Ellison et al. 2004) and observational (Decourchelle et al. 2000; Warren et al. 2005) works have shown that it can have a noticeable impact on the internal structure and X-ray emission of the SNR, specially in the…”
Observational Signatures of Particle Acceleration in Supernova Remnants (2012, methodology): “This was done for the first time by Warren et al. (2005) for the Tycho supernova remnant using a principal component analysis to determine the location of the forward shock, contact discontinuity and reverse shock.”
THE PHYSICS OF THE FAR-INFRARED–RADIO CORRELATION. I. CALORIMETRY, CONSPIRACY, AND IMPLICATIONS (2009, background): “This value is also inferred from SN remnants, which are believed to accelerate CRs (Warren et al. 2005).”
THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY X-RAY MISSION (2013, background): “X-ray synchrotron emission is known to extend to high energies in several young remnants (see Reynolds 2008 and Vink 2012 for reviews) and possibly in others; its characterization addresses questions of particle acceleration and the origin of cosmic rays (e.g., Reynolds 1998; Warren et al. 2005).”
A Physical Relationship between Electron-Proton Temperature Equilibration and Mach Number in Fast Collisionless Shocks (2006, result): “2 from Hα IB/IN measurements, the electron temperatures from RCW 86 (Vink et al. 2006), the Cygnus Loop (Levenson et al. 2002), SN 1006 (Laming et al. 1996, Vink et al. 2003) and Tycho (Hwang et al. 2002; Warren et al. 2005) have been independently corroborated by measurements in other wavebands.”
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).”
Circumstellar Emission from Type Ib and Ic Supernovae (2006, background): “In the case of Tycho’s supernova remnant, Warren et al. (2005) have argued on the basis of X-ray observations that the particle acceleration is primarily at the forward shock and not at the reverse shock.”
Constraints on the Physics of Type Ia Supernovae from the X-Ray Spectrum of the Tycho Supernova Remnant (2005, methodology): “The data are from the 150 ks observation described in Warren et al. (2005) and were extracted from the same region B whose spatially integrated spectrum we have used throughout the present work.”
The origin of galactic cosmic rays (2013, unknown): “7-3946 (left panel, from Aharonian et al. 2007) and Tycho (right panel, from Warren et al. 2005).”
Simulating cosmic rays in clusters of galaxies – II. A unified scheme for radio haloes and relics with predictions of the γ-ray emission (2007, background): “…CR protons at galactic supernova remnants suggest a range ofxinj ≃ 3.3 to 3.6, implying a particle injection efficiency ofηlin ≃ 10−4 to 10−3 (Drury et al. 1989; Jones & Kang 1993; Berezhko et al. 1994; Kang & Jones 1995; Malkov & Völk 1995; Ellison 2000; Hughes et al. 2000; Warren et al. 2005).”
EFFICIENT COSMIC RAY ACCELERATION, HYDRODYNAMICS, AND SELF-CONSISTENT THERMAL X-RAY EMISSION APPLIED TO SUPERNOVA REMNANT RX J1713.7–3946 (2010, unknown): “Indirect evidence, based on particular models, suggests that the efficiency in some young SNRs, at least in some regions of the FS, can be 50% or more (e.g., Völk, Berezhko & Ksenofontov 2003; Warren et al. 2005; Helder et al. 2009).”
Strong evidence for hadron acceleration in Tycho’s supernova remnant (2011, background): “On the other hand, Warren et al. (2005) showed that the inferred distance between the CD and RS is compatible with hydrodynamical model excluding efficient CR acceleration at the RS.”