Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Revisiting the Supernova Engines in the 3C 397 and W49B Supernova Remnants

Cole Treyturik, Chelsea Braun, Samar Safi-Harb, Christopher L. Fryer, Gilles Ferrand

Abstract

The nature of the supernova remnants (SNRs) 3C 397 and W49B has long been a subject of debate, with prior studies offering conflicting interpretations between thermonuclear and core-collapse scenarios. To help settle this debate, we present a systematic, spatially resolved, spectroscopic analysis of both remnants using XMM-Newton. By applying multi-component thermal models, we derive key physical properties including elemental abundances, ejecta temperatures, ambient densities, and explosion energetics. We compare the inferred metal abundance ratios to a wide range of core-collapse and thermonuclear nucleosynthesis models, including new models whose explosion energies differ from the canonical value of $10^{51}$ ergs. We find that the observed Fe/Si and Ca/Si ratios in both SNRs are best matched by certain thermonuclear models. However, no model fully reproduces the complete set of observed abundance patterns. In 3C 397, high Fe enrichment and spatial abundance variations suggest interaction with a dense progenitor environment, and W49B's composition is overall consistent with a thermonuclear origin; however both require a low energy ($\sim 10^{50}$ erg) supernova explosion. We additionally map the Fe K$α$ line centroid energies and find a spread, with W49B falling within the core-collapse region -- highlighting both environmental complexity and the limitations of this diagnostic for supernova classification. Our results highlight the need for caution in relying on any single diagnostic or nucleosynthesis model for supernova typing, underscore the need for improved nucleosynthesis models, and motivate future high-resolution, high-throughput observations.

Revisiting the Supernova Engines in the 3C 397 and W49B Supernova Remnants

Abstract

The nature of the supernova remnants (SNRs) 3C 397 and W49B has long been a subject of debate, with prior studies offering conflicting interpretations between thermonuclear and core-collapse scenarios. To help settle this debate, we present a systematic, spatially resolved, spectroscopic analysis of both remnants using XMM-Newton. By applying multi-component thermal models, we derive key physical properties including elemental abundances, ejecta temperatures, ambient densities, and explosion energetics. We compare the inferred metal abundance ratios to a wide range of core-collapse and thermonuclear nucleosynthesis models, including new models whose explosion energies differ from the canonical value of ergs. We find that the observed Fe/Si and Ca/Si ratios in both SNRs are best matched by certain thermonuclear models. However, no model fully reproduces the complete set of observed abundance patterns. In 3C 397, high Fe enrichment and spatial abundance variations suggest interaction with a dense progenitor environment, and W49B's composition is overall consistent with a thermonuclear origin; however both require a low energy ( erg) supernova explosion. We additionally map the Fe K line centroid energies and find a spread, with W49B falling within the core-collapse region -- highlighting both environmental complexity and the limitations of this diagnostic for supernova classification. Our results highlight the need for caution in relying on any single diagnostic or nucleosynthesis model for supernova typing, underscore the need for improved nucleosynthesis models, and motivate future high-resolution, high-throughput observations.

Paper Structure

This paper contains 19 sections, 2 equations, 32 figures, 7 tables.

Table of Contents

  1. Introduction
  2. Observations and Data Preparation
  3. Observations of 3C 397
  4. Observations of W49B
  5. Spectroscopy
  6. Spectroscopy of 3C 397
  7. Spectroscopy of W49B
  8. Results
  9. X-ray Properties
  10. Nucleosynthesis Models and Progenitor Mass
  11. 3C 397
  12. W49B
  13. Fe K-Alpha Line Centroids
  14. Discussion
  15. Thermonuclear Supernovae
  16. ...and 4 more sections

Figures (32)

  • Figure 1: Selected regions for 3C 397 (left) and W49B (right), as generated by the contbin algorithm. Every color represents a different region. Regions are labeled in order of decreasing flux of their highest-flux pixel.
  • Figure 2: Sample fit spectra for both 3C 397 (left) and W49B (right). Both spectra were taken from the Region 00 of the respective SNR, and both show only the data for the longest observation used in each object (OBS ID 0830450101 and OBS ID 0724270101 for 3C 397 and W49B, respectively). In both figures, black represents MOS1 data, red represents MOS2 data, and green represents pn data.
  • Figure 3: 3C 397: Distribution maps for the given parameters. All maps are in a linear scale. N$_{H}$ is in units of $10^{22}$ cm$^{-2}$, kT$_{h}$ and kT$_{c}$ are in units of keV, and all other elements are in terms of solar abundances. The hue of each map is arbitrary.
  • Figure 4: W49B: Distribution maps for the given parameters. All maps are in a linear scale. N$_{H}$ is in units of $10^{22}$ cm$^{-2}$, kT$_{h}$ and kT$_{c}$ are in units of keV, and all other elements are in terms of solar abundances. The hue of each map is arbitrary.
  • Figure 5: Best-fit nucleosynthesis models for 3C 397, comparing to both Ia and CC supernova nucleosynthesis yields. See text for details of the models.
  • ...and 27 more figures