GREAT followup of SN 2019cca/ZTF19aajwogx: a superluminous supernova at redshift 0.42
ATel #12604; T.-W. Chen (MPE), T. Schweyer (MPE), C. Inserra (Cardiff), G. Leloudas (DTU), M. Nicholl (Edinburgh), D. Perley (Liverpool), L. Tartaglia (Stockholm Univ.), V. Brinnel (HU Berlin), A. S. Carracedo, C. Barbarino, J. Sollerman (Stockholm Univ.), R. Cartier (CTIO), J. Lyman (Warwick), E. Kankare (Turku), K. Maguire, S. J. Smartt, D. R. Young, K. W. Smith, O. McBrien (QUB), O. Yaron, I. Manulis (Weizmann)
on 21 Mar 2019; 20:41 UT
Credential Certification: Ting-Wan Chen (jchen@mpe.mpg.de)
Subjects: Infra-Red, Optical, Supernovae, Transient
We observed the field of SN 2019cca/ZTF19aajwogx (TNS #31124; target was supplied by the Zwicky Transient Facility: https://www.ztf.caltech.edu/; Kulkarni et al. 2018, ATel #11266) as part of the GREAT survey (Chen et al. 2018, ApJ, 867L, 31), simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted on the MPG 2.2m telescope at the ESO La Silla Observatory (Chile).
Observations started at 04:49 UT on 2019-03-21 (MJD = 58563.201). We derive the following magnitudes and 3-sigma detections limits (all in the AB system) :
g' = 19.48 +/- 0.02 mag,
r' = 19.50 +/- 0.02 mag,
i' = 19.73 +/- 0.05 mag,
z' = 19.79 +/- 0.05 mag,
J = 19.92 +/- 0.11 mag,
H = 20.33 +/- 0.24 mag, and
K > 19.55 mag.
Given magnitudes are calibrated against PanSTARRS1 field stars as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.05 mag in the direction of the transient (Schlafly & Finkbeiner 2011). Assuming the emission is a pure black body, we estimate a temperature of 11000 +/- 500 K using SED fitting.
We re-analyse the classification spectrum of SN 2019cca taken by ePESSTO (Smartt et al. 2015, A&A, 579, 40) on 2019-03-16 (Tartaglia et al. 2019, ATel#12588) obtained from http://www.pessto.org (via WISeREP) and the IAU Transient Name Server. The spectrum shows a typical Type I superluminous supernova UV Mg II absorption feature and shallow O II absorption features. We estimate the redshift to be 0.42 by cross-matching the spectrum with other superluminous supernovae (e.g. PTF10aagc, PTF09cwl, PTF13ajg and PTF12dam) around the peak phase using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Additionally, the ZTF light curve has been rising slowly for over a month, see the Lasair broker https://lasair.roe.ac.uk/object/ZTF19aajwogx/.
The host galaxy is faint - there is no detection in the PanSTARRS1 pre-explosion images.
We acknowledge excellent help in obtaining these GROND data from Sam Kim on La Silla.