DRAFT
2021-04-27 20:56:18
Type: Object/s-Data/Analysis
Bibcode: 2021TNSAN.139....1M
X-ray detection of the SLSN-I 2020tcw
Authors: D. Matthews, R. Margutti, D. Coppejans, G. Terreran, A. Hajela, A. Baldeschi, P. Blanchard, M. Stroh, R. Chornock, W. Jacobson-Galan (Northwestern U.), E. Berger, T. Eftekhari (Harvard U.), M. Nicholl (U. of Birmingham), D. Milisavljevic (Purdue U.), C. Guidorzi (U. degli Studi di Ferrara), B. Metzger (Columbia U.), L. Herzog (Ohio U.), B. Zauderer (NSF), A. MacFadyen (New York U.)
Keywords: Supernova, X-rays, Time-domain, Transient
Abstract:
We report the first X-ray detection of SN2020tcw with the Chandra X-ray Observatory (CXO) at 60 days post-discovery.

We report the first X-ray detection of SN2020tcw with the Chandra X-ray Observatory (CXO) at 60 days post-discovery (program #21500443, PI Margutti). SN2020tcw was discovered on September 12th 2020 (Tonry et al., TNS Astronomical Transient Report No. 81951) and classified as a hydrogen-poor super-luminous supernova (Perley et al., AstroNote 2020-192) at a redshift of z~0.0645 (d~291 Mpc).

 

We observed SN2020tcw on November 10th and 11th 2020 and detected significant X-ray emission at the location of the optical counterpart of the transient. A preliminary reduction yields a 0.3-10 keV absorbed flux of 5.1E-15 erg/s/cm^2 (1 sigma c.l. between 3.5E-15 - 6.9E-15 erg/s/cm^2) assuming a power law spectral model with a photon index of 2. This corresponds to a 0.3-10 keV luminosity of 5.2E+40 erg/s (1 sigma c.l. between 3.5E+40 - 7.0E+40 erg/s).  The Galactic neutral hydrogen column density along the line of sight of the transient is 1.57E+20 cm^-2 (Kalberla+ 2005).

 

SN2020tcw was also detected by the VLA on November 15th 2020 with a flux density of 0.2 mJy at 6 GHz (Coppejans et al., AstroNote 2021-73). Extrapolating this result with an optically-thin synchrotron spectrum (assuming a spectral index of beta=1, where Fnu ~ nu^-beta) predicts an X-ray synchrotron component of 4E-17 erg/s/cm^2 (0.3-10 keV). The X-ray emission detected by CXO is in significant excess of this prediction by a factor of ~100 and we thus suggest that, similar to other SNe, the X-ray emission might be powered by bremsstrahlung radiation.

 

Subsequent observations of SN2020tcw in December 2020 revealed no significant X-ray emission to a 0.3-10 keV luminosity upper limit of 1.5E+40 erg/s (3 sigma c.l.). This shows that the X-ray emission has faded, supporting a physical association of the detected X-ray emission with SN2020tcw. Further multi-wavelength observations are planned.

 

We thank the entire CXO team for making these observations possible.

 

Show current TNS values
Catalog Name Reported RA Reported DEC Reported Obj-Type Reported Redshift Host Name Host Redshift Remarks TNS RA TNS DEC TNS Obj-Type TNS Redshift
TNS 2020tcw 15:28:17.080 +39:56:50.53 SLSN-I 0.0645 15:28:17.080 +39:56:50.53 SLSN-I 0.0645
AstroNote Publication Timestamp Title Authors
2020-192 2020-10-14 16:20:05 ZTF Detection and Classification of Nearby Superluminous Supernova SN2020tcw Daniel Perley (LJMU), Jesper Sollerman (Stockholm), Christoffer Fremling (Caltech), Richard Walters (Caltech), Aishwarya Dahiwale (Caltech), Shri Kulkarni (Caltech)
2021-73 2021-02-22 17:12:14 Radio detection of the hydrogen-poor super-luminous supernova 2020tcw at 64 days post discovery Deanne L. Coppejans, David Matthews, Raffaella Margutti, Giacomo Terreran, Wynn Jacobson-Galan (Northwestern U.), Edo Berger, Tarraneh Eftekhari (Harvard U.), Michael Bietenholz (SARAO/Hartrao and York U.), Danny Milisavljevic (Purdue U.), Tanmoy Laskar (U. Bath), Conor Omand (U. Tokyo), Matt Nicholl (U. Birmingham)

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