Browsing by Author "Lampeitl, Hubert"

Now showing 1 - 6 of 6
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    A more general model for the intrinsic scatter in type Ia supernova distance moduli
    (2011) Marriner, John; Bernstein, J P; Kessler, Richard; Lampeitl, Hubert; Miquel, Ramon; Mosher, Jennifer; Nichol, Robert C; Sako, Masao; Schneider, Donald P; Smith, Mathew
    We describe a new formalism to fit the parameters {alpha} and {beta} that are used in the SALT2 model to determine the standard magnitudes of Type Ia supernovae (SNe Ia). The new formalism describes the intrinsic scatter in SNe Ia by a covariance matrix in place of the single parameter normally used. We have applied this formalism to the Sloan Digital Sky Survey Supernova Survey (SDSS-II) data and conclude that the data are best described by {alpha} = 0.135{sup +.033} - .017 and {beta} = 3.19{sup +0.14} - 0.24, where the error is dominated by the uncertainty in the form of the intrinsic scatter matrix. Our result depends on the introduction of a more general form for the intrinsic scatter of the distance moduli of SNe Ia than is conventional, resulting in a larger value of {beta} and a larger uncertainty than the conventional approach. Although this analysis results in a larger value of {beta} and a larger error, the SDSS data differ (at a 98% confidence level) from {beta} = 4.1, the value expected for extinction by the type of dust found in the Milky Way. We have modeled the distribution of SNe Ia in terms of their colormore » and conclude that there is strong evidence that variation in color is a significant contributor to the scatter of SNe Ia around their standard candle magnitude.« less
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    Improved constraints on type Ia supernova host galaxy properties using multi-wavelength photometry and their correlations with supernova properties
    (2011) Gupta, Ravi R; D’Andrea, Chris B; Sako, Masao; Conroy, Charlie; Smith, Mathew; Bassett, Bruce; Frieman, Joshua A; Garnavich, Peter M; Jha, Saurabh W; Kessler, Richard; Lampeitl, Hubert; Marriner, John; Nichol, Robert C; Schneider, Donald P
    We improve estimates of the stellar mass and mass-weighted average age of Type Ia supernova (SN Ia) host galaxies by combining UV and near-IR photometry with optical photometry in our analysis. Using 206 SNe Ia drawn from the full three-year Sloan Digital Sky Survey (SDSS-II) Supernova Survey (median redshift of z 0.2) and multi-wavelength host-galaxy photometry from SDSS, the Galaxy Evolution Explorer, and the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we present evidence of a correlation (1.9σ confidence level) between the residuals of SNe Ia about the best-fit Hubble relation and the mass-weighted average age of their host galaxies. The trend is such that older galaxies host SNe Ia that are brighter than average after standard light-curve corrections are made. We also confirm, at the 3.0σ level, the trend seen by previous studies that more massive galaxies often host brighter SNe Ia after light-curve correction.
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    PHOTOMETRIC TYPE Ia SUPERNOVA CANDIDATES FROM THE THREE-YEAR SDSS-II SN SURVEY DATA
    (2011) Sako, Masao; Bassett, Bruce; Connolly, Brian; Dilday, Benjamin; Cambell, Heather; Frieman, Joshua A; Gladney, Larry; Kessler, Richard; Lampeitl, Hubert; Marriner, John; Miquel, Ramon; Nichol, Robert C; Schneider, Donald P; Smith, Mathew; Sollerman, Jesper
    We analyze the three-year Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey data and identify a sample of 1070 photometric Type Ia supernova (SN Ia) candidates based on their multiband li ...
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    Spectroscopic properties of star-forming host galaxies and type Ia supernova hubble residuals in a nearly unbiased sample
    (2011) D\'Andrea, Chris B; Gupta, Ravi R; Sako, Masao; Morris, Matt; Nichol, Robert C; Brown, Peter J; Campbell, Heather; Olmstead, Matthew D; Frieman, Joshua A; Garnavich, Peter; Jha, Saurabh W; Kessler, Richard; Lampeitl, Hubert; Marriner, John; Schneider, Donald P; Smith, Mathew
    We examine the correlation between supernova (SN) host-galaxy properties and their residuals in the Hubble diagram. We use SNe discovered during the Sloan Digital Sky Survey-II Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova (SN Ia) sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M{sub r} < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star formation rates (SFRs) from host galaxies with active star formation. From a final sample of {approx}40 emission-line galaxies, we find that light-curve-corrected SNe Ia are {approx}0.1 mag brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (>3{sigma}) correlation between the Hubble Residuals of SNe Ia and the specific SFR of the host galaxy. We comment on the importance of SN/host-galaxy correlations as a source of systematic bias in future deep SN surveys.
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    THE SDSS-II SUPERNOVA SURVEY: PARAMETERIZING THE TYPE Ia SUPERNOVA RATE AS A FUNCTION OF HOST GALAXY PROPERTIES
    (2012) Smith, Mathew; Nichol, Robert C; Dilday, Benjamin; Marriner, John; Kessler, Richard; Bassett, Bruce; Cinabro, David; Frieman, Joshua; Garnavich, Peter; Jha, Saurabh W; Lampeitl, Hubert; Sako, Masao; Schneider, Donald P; Sollerman, Jesper
    Using data from the Sloan Digital Sky Supernova Survey-II (SDSS-II SN Survey), we measure the rate of Type Ia supernovae (SNe Ia) as a function of galaxy properties at intermediate redshift. A samp ...
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    Type II-P supernovae from the SDSS-II supernova survey and the standardized candle method
    (2010) D’Andrea, Chris B; Sako, Masao; Dilday, Benjamin; Frieman, Joshua A; Holtzman, Jon; Kessler, Richard; Konishi, Kohki; Schneider, D P; Sollerman, Jesper; Wheeler, J Craig; Yasuda, Naoki; Cinabro, David; Jha, Saurabh; Nichol, Robert C; Lampeitl, Hubert; Smith, Mathew; Atlee, David W; Bassett, Bruce; Castander, Francisco J; Goobar, Ariel; Miquel, Ramon; Nordin, Jakob; Östman, Linda; Prieto, José L; Quimby, Robert; Riess, Adam G; Stritzinger, Maximilian
    We apply the Standardized Candle Method (SCM) for Type II Plateau supernovae (SNe II-P), which relates the velocity of the ejecta of a SN to its luminosity during the plateau, to 15 SNe II-P discov ...