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ABSTRACT We report on Chandra X-ray observations of ASASSN-18tb/SN 2018fhw, a low luminosity Type Ia supernova (SN) that showed a H line in its optical spectrum. No X-ray emission was detected at the location of the SN. Upper limits to the luminosity of up to 3 × 1039 erg s−1 are calculated, depending on the assumed spectral model, temperature, and column density. These are compared to Type Ia-CSM SNe, SN 2005gj, and SN 2002ic that have been observed with Chandra in the past. The upper limits are lower than the X-ray luminosity found for the Type Ia-CSM SN 2012ca, the only Type Ia SN to have been detected in X-rays. Consideration of various scenarios for the Hα line suggests that the density of the surrounding medium at the time of Hα line detection could have been as high as 108 cm−3, but must have decreased below 5 $$\times \, 10^6$$ cm−3 at the time of X-ray observation. Continual X-ray observations of SNe which show a H line in their spectrum are necessary in order to establish Type Ia SNe as an X-ray emitting class.
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X-ray observations of two Type Ia supernovae with an Hα line in their optical spectrum
ABSTRACT We report on Chandra X-ray observations of SN 2016jae and SN 2018cqj, both low-luminosity Type Ia supernova (SN) that showed the presence of an H line in their early optical spectrum. No X-ray emission is detected at the location of either SN. Upper limits to the luminosity of up to 2 $$\times 10^{40}$$ erg s$$^{-1}$$ are calculated for each SN, depending on the assumed spectral model, temperature, and column density. This luminosity is comparable to that of another low-luminosity Type Ia SN, SN 2018fhw, that was observed with Chandra. It is generally lower than upper limits calculated for Type Ia-CSM SNe observed in X-rays, and also below that of SN 2012ca, the only Type Ia-CSM SN to have been detected in X-rays. Comparisons are made to other Type Ia SN with an H line observed in X-rays. The observations suggest that while the density into which the SN is expanding may have been high at the time the H$$\alpha$$ line was detected, it had decreased considerably by the time of X-ray observations.
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- Award ID(s):
- 1911061
- PAR ID:
- 10531957
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 533
- Issue:
- 1
- ISSN:
- 0035-8711
- Format(s):
- Medium: X Size: p. 27-35
- Size(s):
- p. 27-35
- Sponsoring Org:
- National Science Foundation
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