The DESI Transients Survey: Legacy Classifications and Methodology
astro-ph.HE
/ Authors
Xander J. Hall, Antonella Palmese, Segev BenZvi, John Banovetz, Brendan O'Connor, Lei Hu, Erica Hammerstein, Ariel Amsellem, Jessica Nicole Aguilar, Steven Ahlen
and 49 more authors
Steven Bailey, Davide Bianchi, David Brooks, Todd Claybaugh, Andrei Cuceu, Kyle Dawson, Axel de la Macorra, John Della Costa, Arjun Dey, Peter Doel, Simone Ferraro, Andreu Font-Ribera, Jaime E. Forero-Romero, Enrique Gaztanaga, Satya Gontcho A Gontcho, Alma Xochitl Gonzalez-Morales, Or Graur, Gaston Gutierrez, Mustapha Ishak, Jorge Jimenez, Dick Joyce, Stephanie Juneau,
/ Abstract
We present the first systematic spectroscopic observations of extragalactic transients from the Dark Energy Spectroscopic Instrument (DESI), as part of the DESI Transients Survey program. With 5,000 fibers and an ${\sim} 8$ deg$^2$ field of view, we exploit DESI as a machine for the discovery and classification of transients. We present transient classifications from archival DESI data in Data Releases 1 and 2, relying on a combination of a secondary target program and serendipitous observations. We also present observations from the first 6 months of the DESI spare fiber program dedicated to transients. The program is run in coordination with a dedicated DECam time-domain survey, serving as a pathfinder for what we will be able to achieve in conjunction with the Rubin Observatory Legacy Survey of Space and Time (LSST). We classify over 250 transients, of which the majority were previously unclassified. The sample comprises thermonuclear and core-collapse supernovae and tidal disruption events (TDEs), including a TDE observed before its discovery in imaging. We demonstrate DESI's ability to classify a population of faint transients down to $r\sim 22.5$ mag during main survey operations, with negligible impacts on DESI's main observations.