First-year spectroscopy for the Sloan Digital Sky Survey-II supernova survey
journal contribution
posted on 2023-06-08, 09:25authored byChen Zheng, Roger W Romani, Masao Sako, John Marriner, Bruce Bassett, Andrew Becker, Changsu Choi, David Cinabro, Fritz DeJongh, Darren L Depoy, Ben Dilday, Mamoru Doi, Joshua A Frieman, Peter M Garnavich, Craig J Hogan, Jon Holtzman, Myungshin Im, Saurabh Jha, Richard Kessler, Kohki Konishi, Hubert Lampeitl, Jennifer L Marshall, David McGinnis, Gajus Miknaitis, Robert C Nichol, Jose Luis Prieto, Adam G Riess, Michael W Richmond, Donald P Schneider, Mathew Smith, Naohiro Takanashi, Kouichi Tokita, Kurt van der Heyden, Naoki Yasuda, Kathy RomerKathy Romer, et al
This paper presents spectroscopy of supernovae (SNe) discovered in the first season of the Sloan Digital Sky Survey-II SN Survey. This program searches for and measures multi-band light curves of SNe in the redshift range z = 0.05-0.4, complementing existing surveys at lower and higher redshifts. Our goal is to better characterize the SN population, with a particular focus on SNe Ia, improving their utility as cosmological distance indicators and as probes of dark energy. Our SN spectroscopy program features rapid-response observations using telescopes of a range of apertures, and provides confirmation of the SN and host-galaxy types as well as precise redshifts. We describe here the target identification and prioritization, data reduction, redshift measurement, and classification of 129 SNe Ia, 16 spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first season. We also describe our efforts to measure and remove the substantial host-galaxy contamination existing in the majority of our SN spectra.