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Abstract We present a detailed analysis of nearly two decades of optical/UV and X-ray data to study the multi-wavelength pre-explosion properties and post-explosion X-ray properties of nearby SN2023ixf located in M101. We find no evidence of precursor activity in the optical to UV down to a luminosity of$$\lesssim$$$$1.0\times10^{5}\, \textrm{L}_{\odot}$$, while X-ray observations covering nearly 18 yr prior to explosion show no evidence of luminous precursor X-ray emission down to an absorbed 0.3–10.0 keV X-ray luminosity of$$\sim$$$$6\times10^{36}$$erg s$$^{-1}$$. ExtensiveSwiftobservations taken post-explosion did not detect soft X-ray emission from SN2023ixf within the first$$\sim$$3.3 days after first light, which suggests a mass-loss rate for the progenitor of$$\lesssim$$$$5\times10^{-4}\,\textrm{M}_{\odot}$$yr$$^{-1}$$or a radius of$$\lesssim$$$$4\times10^{15}$$cm for the circumstellar material. Our analysis also suggests that if the progenitor underwent a mass-loss episode, this had to occur$$>$$0.5–1.5 yr prior to explosion, consistent with previous estimates.Swiftdetected soft X-rays from SN2023ixf$$\sim$$$$4.25$$days after first light, and it rose to a peak luminosity of$$\sim10^{39}$$erg s$$^{-1}$$after 10 days and has maintained this luminosity for nearly 50 days post first light. This peak luminosity is lower than expected, given the evidence that SN2023ixf is interacting with dense material. However, this might be a natural consequence of an asymmetric circumstellar medium. X-ray spectra derived from merging allSwiftobservations over the first 50 days are best described by a two-component bremsstrahlung model consisting of a heavily absorbed and hotter component similar to that found usingNuSTAR, and a less-absorbed, cooler component. We suggest that this soft component arises from cooling of the forward shock similar to that found in Type IIn SN2010jl.
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This content will become publicly available on January 1, 2026
The radio re-brightening of the Type IIb SN 2001ig
Abstract We study the late-time evolution of the compact Type IIb SN 2001ig in the spiral galaxy NGC 7424, with new and unpublished archival data from the Australia Telescope Compact Array and the Australian Square Kilometre Array Pathfinder. More than two decades after the SN explosion, its radio luminosity is showing a substantial re-brightening: it is now two orders of magnitude brighter than expected from the standard model of a shock expanding into a uniform circumstellar wind (i.e. with a density scaling as$$R^{-2}$$). This suggests that the SN ejecta have reached a denser shell, perhaps compressed by the fast wind of the Wolf–Rayet progenitor or expelled centuries before the final stellar collapse. We model the system parameters (circumstellar density profile, shock velocity, and mass loss rate), finding that the denser layer was encountered when the shock reached a distance of$$\approx 0.1$$pc; the mass-loss rate of the progenitor immediately before the explosion was$$\dot{M}/v_{w} \sim 10^{-7} {\rm M}_\odot {\mathrm {~yr}}^{-1} {\mathrm {km}}^{-1} {\mathrm {s}}$$. We compare SN 2001ig with other SNe that have shown late-time re-brightenings, and highlight the opposite behaviour of some extended Type IIb SNe which show instead a late-time flux cut-off.
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- Award ID(s):
- 2224255
- PAR ID:
- 10613945
- Publisher / Repository:
- PASP
- Date Published:
- Journal Name:
- Publications of the Astronomical Society of Australia
- Volume:
- 42
- ISSN:
- 1323-3580
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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