The Hydrogen-Poor Superluminous Supernovae from the Zwicky Transient Facility Phase-I Survey: I. Data

Abstract

During the Zwicky Transient Facility (ZTF) Phase-I operation, 78 hydrogen-poor superluminous supernovae (SLSNe-I) were discovered in less than three years, making up the largest sample from a single survey. This paper (Paper I) presents the data, including the optical/ultraviolet light curves and classification spectra, while Paper II in this series will focus on the detailed analysis of the light curves and modeling. Our photometry is primarily taken by the ZTF in the g,r,i bands, and with additional data from other ground-based facilities and Swift. The events of our sample cover a redshift range of z = 0.06−0.67, with a median and 1σ error (16% and 84% percentiles) z_(med) = 0.265^(+0.143)_(−0.135). The peak luminosity covers −22.9 mag ≤ M_(g,peak) ≤ −19.9 mag, with a median value of −21.54^(+1.12)_(−0.61) mag. Their light curves evolve slowly with the mean rest-frame rise time of t_(rise) = 42.0 ± 17.8days. The luminosity and time scale distributions suggest that low luminosity SLSNe-I with peak luminosity ∼−20mag or extremely fast rising events (<10−15 days) exist but are rare. We confirm previous findings that slowly rising SLSNe-I also tend to fade slowly. The rest-frame color and temperature evolution show large scatters, suggesting that the SLSN-I population may have diverse spectral energy distributions. The peak rest-frame color shows a moderate correlation with the peak absolute magnitude, i.e. brighter SLSNe-I tend to have bluer colors. With optical and ultraviolet photometry, we construct bolometric luminosity and derive a bolometric correction relation generally applicable for converting g,r-band photometry to bolometric luminosity for SLSNe-I.