TY - JOUR
T1 - Spectroscopy of high-redshift supernovae from the essence project
T2 - The first 2 years
AU - Matheson, Thomas
AU - Blondin, Stéphane
AU - Foley, Ryan J.
AU - Chornock, Ryan
AU - Filippenko, Alexei V.
AU - Leibundgut, Bruno
AU - Smith, R. Chris
AU - Sollerman, Jesper
AU - Spyromilio, Jason
AU - Kirshner, Robert P.
AU - Clocchiatti, Alejandro
AU - Aguilera, Claudio
AU - Barris, Brian
AU - Becker, Andrew C.
AU - Challis, Peter
AU - Covarrubias, Ricardo
AU - Garnavich, Peter
AU - Hicken, Malcolm
AU - Jha, Saurabh
AU - Krisciunas, Kevin
AU - Li, Weidong
AU - Miceli, Anthony
AU - Miknaitis, Gajus
AU - Prieto, Jose Luis
AU - Rest, Armin
AU - Riess, Adam G.
AU - Salvo, Maria Elena
AU - Schmidt, Brian P.
AU - Stubbs, Christopher W.
AU - Suntzeff, Nicholas B.
AU - Tonry, John L.
PY - 2005/5
Y1 - 2005/5
N2 - We present the results of spectroscopic observations of targets discovered during the first 2 years of the ESSENCE project. The goal of ESSENCE is to use a sample of ∼200 Type Ia supernovae (SNe la) at moderate redshifts (0.2 ≲ z ≲ 0.8) to place constraints on the equation of state of the universe. Spectroscopy not only provides the redshifts of the objects but also confirms that some of the discoveries are indeed SNe Ia. This confirmation is critical to the project, as techniques developed to determine luminosity distances to SNe Ia depend on the knowledge that the objects at high redshift have the same properties as the ones at low redshift. We describe the methods of target selection and prioritization, the telescopes and detectors, and the software used to identify objects. The redshifts deduced from spectral matching of high-redshift SNe Ia with low-redshift SNe Ia are consistent with those determined from host-galaxy spectra. We show that the high-redshift SNe Ia match well with low-redshift templates. We include all spectra obtained by the ESSENCE project, including 52 SNe Ia, five corecollapse SNe, 12 active galactic nuclei, 19 galaxies, four possibly variable stars, and 16 objects with uncertain identifications.
AB - We present the results of spectroscopic observations of targets discovered during the first 2 years of the ESSENCE project. The goal of ESSENCE is to use a sample of ∼200 Type Ia supernovae (SNe la) at moderate redshifts (0.2 ≲ z ≲ 0.8) to place constraints on the equation of state of the universe. Spectroscopy not only provides the redshifts of the objects but also confirms that some of the discoveries are indeed SNe Ia. This confirmation is critical to the project, as techniques developed to determine luminosity distances to SNe Ia depend on the knowledge that the objects at high redshift have the same properties as the ones at low redshift. We describe the methods of target selection and prioritization, the telescopes and detectors, and the software used to identify objects. The redshifts deduced from spectral matching of high-redshift SNe Ia with low-redshift SNe Ia are consistent with those determined from host-galaxy spectra. We show that the high-redshift SNe Ia match well with low-redshift templates. We include all spectra obtained by the ESSENCE project, including 52 SNe Ia, five corecollapse SNe, 12 active galactic nuclei, 19 galaxies, four possibly variable stars, and 16 objects with uncertain identifications.
KW - Distance scale
KW - Galaxies: distances and redshifts
KW - Supernovae: general
UR - http://www.scopus.com/inward/record.url?scp=22144472993&partnerID=8YFLogxK
U2 - 10.1086/429679
DO - 10.1086/429679
M3 - Review article
SN - 0004-6256
VL - 129
SP - 2352
EP - 2375
JO - Astronomical Journal
JF - Astronomical Journal
IS - 5
ER -