Year: 2020
Type: article
Abstract: During a search for X-ray transients in the XMM–Newton archive within the EXTraS project, we discovered a new X-ray source that is detected only during an ∼5 min interval of an ∼21 hr-long observation performed on 2011 June 21 ( EXMM 023135.0–603743 , probability of a random Poissonian fluctuation: ∼1.4 × 10 −27 ). With dedicated follow-up observations, we found that its position is consistent with a star-forming galaxy (SFR = 1–2 M ⊙ yr −1 ) at redshift z = 0.092 ± 0.003 ( d = 435 ± 15 Mpc). At this redshift, the energy released during the transient event was 2.8 × 10 46 erg in the 0.3–10 keV energy band (in the source rest frame). The luminosity of the transient, together with its spectral and timing properties, make EXMM 023135.0–603743 a gripping analog to the X-ray transient associated to SN 2008D, which was discovered during a Swift/XRT observation of the nearby ( d = 27 Mpc) supernova-rich galaxy NGC 2770. We interpret the XMM–Newton event as a supernova shock break-out or an early cocoon, and show that our serendipitous discovery is broadly compatible with the rate of core-collapse supernovae derived from optical observations and much higher than that of tidal disruption events.
Source: The Astrophysical Journal
Authors: Giovanni Novara, Paolo Esposito, Andrea Tiengo, Giacomo Vianello, Ruben Salvaterra, Andrea Belfiore, Andrea De Luca, Paolo D’Avanzo, Jochen Greiner, Marco Scodeggio, Simon Rosen, Corentin Delvaux, Elena Pian, Sergio Campana, Gianni Lisini, Sandro Mereghetti, G. L. Israel
Institutions: Istituto Universitario di Studi Superiori di Pavia, Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Stanford University, Brera Astronomical Observatory, National Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, University of Leicester, European Space Astronomy Centre, Osservatorio di Astrofisica e Scienza dello Spazio, Astronomical Observatory of Rome
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W3028768919