Detection of PTF10cwr/CSS100313 on PS1 sky survey images and host galaxy identification

ATel #2504; A. Pastorello, S. J. Smartt, D. Young (Queen's University Belfast) E. Kankare (QUB/NOT), K. Smith, M. T. Botticella, S. Mattila, R. Kotak, S. Valenti (QUB), N. Metcalfe (Durham University), W. E. Sweeney, P. A. Price, E. Magnier, J. Tonry, F. Bresolin, R. P. Kudritzki, K. Chambers (University of Hawaii), C. Stubbs, A. Rest, G. Narayan (Harvard), A. Riess, M. Huber (JHU), W. M. Wood-Vasey (Pittsburgh).
on 24 Mar 2010; 11:40 UT
Credential Certification: Stephen Smartt (s.smartt@qub.ac.uk)

Tweet

We report that the transient PTF10cwr (Quimby et al. ATEL #2492), a.k.a. CSS100313:112547-084941 (Mahabal et al. ATel #2490), was also recovered on images from the Pan-STARRS Telescope #1 (PS1) as part of the PS1 3Pi survey (PS1-1000037). Magnitudes of i=18.96 and r=18.65 where measured with respect to SDSS sequence stars on March 12.45 and 13.49 UT respectively. Further photometry was gathered at the Liverpool Telescope on March 20.92 and March 23.00 UT. A spectrum taken at the Nordic Optical Telescope on March 21.20 UT shows the broad absorption features identified by Quimby et al. as OII and a blue continuum. We favour the redshift of z=0.23 reported by Quimby et al. (ATEL #2492), rather than that of Mahabal et al (ATel #2490) of z=0.17. The galaxy emission lines at [OII] 3727, [OIII] 4959/5006 and H-alpha are faint and marginally detected. Taking into account a Galactic extinction of E(B-V) = 0.04 mag, this implies a rest frame absolute magnitude of M_u ~ -22.0 and M_g ~ -21.9 (from the LT g- and r-band magnitudes). A rise of ~ 0.2 mags, in 9 days indicates that the transient has not yet reached maximum, its rise time may be significant, and it could peak at r~16 mag if it behaves like SCP 06F6 (Barbary et al. 2009 ApJ 690 1358) There is a faint host galaxy detection in the SDSS images (SDSS J112546.72-084942.0) at g=22.7 and g-r=0.3. It is not detected in the other bands. This suggests a dwarf galaxy host at rest frame g-band absolute magnitude of ~ -18, similar to the LMC. A deep spectrum from Gemini should confirm the narrow emission lines and provide a measurement of host galaxy metallicity. The PS1 3Pi survey also observed the position of 2010ay (Drake et al. ; Filippenko et al. ; Prieto et al. CBET 2244) on several epochs before discovery, the latest being Feb 25. No obvious transient is observed, setting limits on any optical afterglow and SN explosion epoch. This announcement was enabled using the PS1 System operated by the PS1 Science Consortium (PS1SC) and its member institutions, and made possible through the PS1 Builders : http://www.ps1sc.org/PS1_System_ATel.htm