The SDSS-II Supernova Survey: Parameterizing the Type Ia Supernova Rate as a Function of Host Galaxy Properties

Journal Article · Mon Aug 01 00:00:00 EDT 2011 · Astrophys.J.

DOI:https://doi.org/10.1088/0004-637X/755/1/61· OSTI ID:1967997

Smith, Mathew  ^[1]; Nichol, Robert C.  ^[2]; Dilday, Benjamin ^[3]; Marriner, John  ^[4]; Kessler, Richard  ^[5]; Bassett, Bruce  ^[6]; Cinabro, David  ^[7]; Frieman, Joshua  ^[8]; Garnavich, Peter  ^[9]; Jha, Saurabh W.  ^[10]; Lampeitl, Hubert ^[2]; Sako, Masao  ^[11]; Schneider, Donald P. ^[12]; Sollerman, Jesper  ^[13]

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1. Cape Town U.; Portsmouth U., ICG; African Inst. Math. Sci., Cape Town
2. Portsmouth U., ICG
3. Las Cumbres Observ.; UC, Santa Barbara
4. Fermilab
5. Chicago U.
6. African Inst. Math. Sci., Cape Town; South African Astron. Observ.; Cape Town U.
7. Wayne State U.
8. Fermilab; Chicago U.
9. Notre Dame U.
10. Rutgers U., Piscataway
11. Pennsylvania U.
12. Penn State U.
13. Stockholm U., OKC

Using data from the Sloan Digital Sky Supernova Survey-II, we measure the rate of Type Ia Supernovae (SNe Ia) as a function of galaxy properties at intermediate redshift. A sample of 342 SNe Ia with 0.05<0.25 is constructed. Using broad-band photometry we use the PEGASE spectral energy distributions (SEDs) to estimate host galaxy stellar masses and recent star-formation rates. We find that the rate of SNe Ia per unit stellar mass is significantly higher (by a factor of ~30) in highly star-forming galaxies compared to passive galaxies. When parameterizing the SN Ia rate (SNR_Ia) based on host galaxy properties, we find that the rate of SNe Ia in passive galaxies is not linearly proportional to the stellar mass, instead a SNR_Ia proportional to M^0.68 is favored. However, such a parameterization does not describe the observed SN Ia rate in star-forming galaxies. The SN Ia rate in star-forming galaxies is well fit by SNR_Ia = 1.05\pm0.16x10^{-10} M ^{0.68\pm0.01} + 1.01\pm0.09x10^{-3} SFR^{1.00\pm0.05} (statistical errors only), where M is the host galaxy mass and SFR is the star-formation rate. These results are insensitive to the selection criteria used, redshift limit considered and the inclusion of non-spectroscopically confirmed SNe Ia. We also show there is a dependence between the distribution of the MLCS light-curve decline rate parameter, \Delta, and host galaxy type. Passive galaxies host less luminous SNe Ia than seen in moderately and highly star-forming galaxies, although a population of luminous SNe is observed in passive galaxies, contradicting previous assertions that these SNe Ia are only observed in younger stellar systems. The MLCS extinction parameter, A_V, is similar in passive and moderately star-forming galaxies, but we find indications that it is smaller, on average, in highly star-forming galaxies. We confirm these results using the SALT2 light-curve fitter.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: SDSS
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1967997
• Report Number(s): FERMILAB-PUB-11-647-AE; arXiv:1108.4923; oai:inspirehep.net:924876
• Journal Information: Astrophys.J., Vol. 755
• Country of Publication: United States
• Language: English

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79 ASTRONOMY AND ASTROPHYSICS