X-Ray emission from SN1885A

Prucker M, Sasaki M, Schlegel E, Knies J, Weber P, Kreykenbohm I, Wilms J (2025)

Publication Language: English

Publication Type: Journal article

Publication year: 2025

Journal

Book Volume: 693

Article Number: A110

DOI: 10.1051/0004-6361/202450152

Abstract

The historical supernova (SN) S Andromedae (S And or SN1885A) in the Andromeda Galaxy (M31) was discovered in August 1885 and since then has been studied extensively in multi-wavelength observations. Although the remnant of S And could be detected in optical images, so far no X-ray source has been reported at the position of S And. In this work we report the first detection of X-ray emission from the remnant of SN1885A with a significance of Ï = 3.43 using Chandra High-Resolution Camera (HRC) data taken in the imaging (I) mode. A total of 45 Chandra HRC-I observations were analysed, which corresponds to 940 ks of exposure time. A faint X-ray source could be detected at the reported position of the supernova remnant (SNR) 1885 and the corresponding X-ray luminosity in the 0.1 10 keV band was obtained. The resulting value from merging all 45 observations amounts to L0.110keV = (63⁺⁴) A- 10³³ erg s¹. To contextualise the results, the luminosity was compared to the X-ray luminosities of four of the oldest known X-ray SNe, some younger Galactic remnants, some SNRs in M31, and to theoretical predictions. The X-ray luminosity of SNR1885 is three to four orders of magnitude lower compared to the other examined remnants. A comparison to theoretical models shows that such low X-ray luminosities can only be produced if the ejecta is still expanding freely into a low-density interstellar medium (ISM). On the other hand, strong absorption by a high-density medium surrounding the freely expanding ejecta could also account for the lack of X-ray emission. Furthermore, the extremely low emission in X-rays could be an indication that the X-ray luminosity decreases faster towards the end of the ejecta-dominated (ED) phase in the evolution of SNRs than in the beginning.

Authors with CRIS profile

Involved external institutions

University of Texas at San Antonio United States (USA) (US)

How to cite

APA:

Prucker, M., Sasaki, M., Schlegel, E., Knies, J., Weber, P., Kreykenbohm, I., & Wilms, J. (2025). X-Ray emission from SN1885A. Astronomy & Astrophysics, 693. https://doi.org/10.1051/0004-6361/202450152

MLA:

Prucker, Marie, et al. "X-Ray emission from SN1885A." Astronomy & Astrophysics 693 (2025).

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