On the Determination of Ejecta Structure and Explosion Asymmetry from the X-Ray Knots of Cassiopeia A
139 citations recorded by the source corpus.
We present a detailed analysis of Chandra X-ray spectra from individual ejecta knots in the supernova remnant Cassiopeia A. The spectra are fitted to give the electron temperature Te and (single) ionization age net. These quantities are compared with the predictions of self-similar hydrodynamic models incorporating time-dependent ionization and radiation losses and Coulomb electron-ion equilibration behind the reverse shock for a variety of different ejecta density profiles described by a uniform-density core and a power-law envelope. We find that the ejecta close to the "jet" region in the northeast, but not actually in the jet itself, have a systematically shallower outer envelope than ejecta elsewhere in the remnant, and we interpret this as being due to more energy of the initial explosion being directed in this polar direction as opposed to equatorially. The degree of asymmetry we infer is at the low end of that generally modeled in asymmetric core-collapse simulations and may possibly be used to rule out highly asymmetric explosion models.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/1e98ceb94672fe1b3825ef99f718f9ca08d88220
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
- FERMI-LAT DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE YOUNG SUPERNOVA REMNANT CASSIOPEIA A (2010, methodology): “Using Mejecta = 2M⊙ (Willingale et al. 2002; Laming & Hwang 2003) comprised of only oxygen, we obtain neff = nOZO(ZO + 1) ≃ 32 cm −3.”
- Observational Signatures of Particle Acceleration in Supernova Remnants (2012, methodology): “Laming and Hwang (2003) analyzed several knots of Cassiopeia A as observed with Chandra.”
- A Million Second Chandra View of Cassiopeia A (2004, background): “…the discovery of the compact stellar remnant (Tananbaum et al. 1999), identification of major types of nucleosynthesis products (Hughes et al. 2000; Laming & Hwang 2003; Hwang & Laming 2003), measurement of magnetic fields (Vink & Laming 2003), identification of the forward and reverse shocks…”