No X-ray detection of SN2016cok by Swift XRT
ATel #9189; Firoza Sutaria (Indian Institute of Astrophysics, Bangalore), Alak Ray (Tata Institute of Fundamental Research, Mumbai, India)
on 24 Jun 2016; 18:31 UT
Credential Certification: Alak Ray (akr@tifr.res.in)
Subjects: X-ray, Supernovae
We report on the X-ray observations of the field of type IIP Supernova SN2016cok (= ASASSN-16fq, see ATEL #9091,#9093) in NGC3627 (Messier 66) by Swift XRT telescope over 12 epochs, from MJD 57538.01127 (2016-05-30 00:16:13.728 UTC) to MJD 57553.55 (2016-06-14 13:12:00.000 UTC), yielding a total of 23025s exposure time in the stacked image (Swift target ID 84371). Presupernova Swift archival observation of NGC3627(Swift target ID 36578) appropriately scaled in exposure time and aligned with the SN exposures was used as a template to subtract the contribution of the host galaxy to the total flux at the position of the SN. This subtraction method completely eliminated the object seen $\simeq$ 12" from position of the SN in archival Chandra images (see ATEL #9094, by A.K.H. Kong). The resulting subtracted image was examined for sources. No source was detected at the position of the SN (RA = 11h20m19.10s, Dec = +12d 58min 56s), implying a limiting, unabsorbed flux of $1.6\times 10^{-15}$ erg/cm/cm/s in the 0.3-10 keV band, for a soft spectrum with a photon index $\Gamma = 2$ and a column density of $2.4 \times 10^{20}$ cm^{-2} (Dickey and Lockman, 1990, ARAA, 28, 215). Assuming a distance of 9.7 Mpc, this implies a limiting luminosity of $1.8 \times 10^{37}$ erg/s (0.3-10.0 keV) for this supernova, assuming constant X-ray emission over these epochs.
We thank Dr. Neil Gehrels for Swift observation of this target.
