MEASUREMENTS OF THE RATE OF TYPE Ia SUPERNOVAE AT REDSHIFT less than or similar to 0.3 FROM THE SLOAN DIGITAL SKY SURVEY II SUPERNOVA SURVEY

作者：Dilday Benjamin^*; Smith Mathew; Bassett Bruce; Becker Andrew; Bender Ralf; Castander Francisco; Cinabro David; Filippenko Alexei V; Frieman Joshua A; Galbany Lluis; Garnavich Peter M; Goobar Ariel; Hopp Ulrich; Ihara Yutaka; Jha Saurabh W; Kessler Richard; Lampeitl Hubert; Marriner John; Miquel Ramon; Molla Mercedes; Nichol Robert C; Nordin Jakob; Riess Adam G; Sako Masao; Schneider Donald P; Sollerman Jesper; Wheeler J Craig; Ostman Linda; Bizyaev Dmitry

来源：Astrophysical Journal, 2010, 713(2): 1026-1036.

DOI：10.1088/0004-637X/713/2/1026

• supernovae: general

We present ameasurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z less than or similar to 0.3, of which 270(52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04+(1.61%)(-0.95) -0.95% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey. If we assume an SN Ia rate that is constant at low redshift (z < 0.15), then the SN observations can be used to infer a value of the SN rate of rV = (2.69(-0.30-0.01)(+ 0.34+ 0.21)) x 10(-5) SNe yr(-1) Mpc(-3) (H(0)/(70 km s(-1) Mpc(-1)))(3) at a mean redshift of similar to 0.12, based on 79 SNe Ia of which 72 are spectroscopically confirmed. However, the large sample of SNe Ia included in this study allows us to place constraints on the redshift dependence of the SN Ia rate based on the SDSS-II Supernova Survey data alone. Fitting a power-law model of the SN rate evolution, rV (z) = A(p) x((1 + z)/(1 + z(0)))(nu), over the redshift range 0.0 < z < 0.3 with z0 = 0.21, results in A(p) = (3.43+(+0.15)(-.015) SNe yr-1 Mpc-3 (H(0)/(70 km s(-1) Mpc(-1)))(3) and nu = 2.04(-0.89)(+0.89).

• 出版日期2010-4-20