Study of X-ray emission from the S147 nebula with SRG/eROSITA: X-ray imaging, spectral characterization, and a multiwavelength picture

Michailidis M, Pühlhofer G, Becker W, Freyberg M, Merloni A, Santangelo A, Sasaki M, Bykov A, Chugai N, Churazov E, Khabibullin I, Sunyaev R, Utrobin V, Zinchenko I (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Astronomy & Astrophysics EDP Sciences

Book Volume: 689

Article Number: A277

DOI: 10.1051/0004-6361/202449424

Abstract

Simeis 147 (S147, G180.0-01.7, “Spaghetti nebula”) is a supernova remnant (SNR) extensively studied across the entire electromagnetic spectrum, from radio to giga-electronvolt γ-rays, except in X-rays. Here, we report the first detection of significant X-ray emission from the entire SNR using data of the extended ROentgen Survey Imaging Telescope Array (eROSITA) onboard the Russian-German Spektrum Roentgen Gamma (SRG). The object is located at the Galactic anticenter, and its 3◦ size classifies it among the largest SNRs ever detected in X-rays. By employing ∼15 years of Fermi-LAT data, our study confirms the association of the remnant with a spatially coincident diffuse giga-electronvolt excess, namely 4FGL J0540.3+2756e or FGES J0537.6+2751. The X-ray emission is purely thermal, exhibiting strong O, Ne, and Mg lines; whereas it lacks heavier-Z elements. The emission is mainly confined to the 0.5–1.0 keV band; no significant emission is detected above 2.0 keV. Both a collisional plasma model in equilibrium and a model of nonequilibrium collisional plasma can fit the total spectrum. While the equilibrium model – though statistically disfavored – cannot be excluded by X-ray fitting, only the absorption column of the nonequilibrium model is consistent with expectations derived from optical extinction data. Adopting an expansion in a homogeneous medium of typical interstellar medium (ISM) density, the general SNR properties are broadly consistent with an expansion model that yields an estimated age of ∼0.66−2 × 105 yr, that is a rather old age. The preference for an X-ray-emitting plasma in nonequilibrium, however, adds to the observational evidence that favors a substantially younger age. In a companion paper, we explore an SNR-in-cavity scenario, resulting in a much younger age that alleviates some of the inconsistencies of the old-age scenario.

Authors with CRIS profile

Manami Sasaki Professur für Multiwellenlängenastronomie

Involved external institutions

Russian Space Research Institute / Институт космических исследований Российской академии наук (IKI RAN) RU Russian Federation (RU) Institute of Astronomy (INASAN) / Federal State Institution of Science Institute of Astronomy of the Russian Academy of Sciences RU Russian Federation (RU) Eberhard Karls Universität Tübingen DE Germany (DE) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics DE Germany (DE) Ioffe Physical-Technical Institute / Физико-технический институт имени А. Ф. Иоффе РАН RU Russian Federation (RU) Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) / Институт прикладной физики Российской академии наук RU Russian Federation (RU)

How to cite

APA:

Michailidis, M., Pühlhofer, G., Becker, W., Freyberg, M., Merloni, A., Santangelo, A.,... Zinchenko, I. (2024). Study of X-ray emission from the S147 nebula with SRG/eROSITA: X-ray imaging, spectral characterization, and a multiwavelength picture. Astronomy & Astrophysics, 689. https://doi.org/10.1051/0004-6361/202449424

MLA:

Michailidis, Miltiadis, et al. "Study of X-ray emission from the S147 nebula with SRG/eROSITA: X-ray imaging, spectral characterization, and a multiwavelength picture." Astronomy & Astrophysics 689 (2024).

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