spectroscopic diversity of SNe Ia in the near-infrared

Eric Y. HsiaoUniversity of Victoria

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SNe Ia in the near-infraredwhy?

less dust extinction

low redshift standard candles in JHK bands independent measure of Hubble constant

high redshift rest frame I band Hubble diagram independent evidence of dark energy

Eric Y. Hsiao

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SNe Ia in the near-infraredlow redshift

Eric Y. Hsiao

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SNe Ia in the near-infraredlow redshift

Krisciunas et al. 2004 ApJ, 602, 81Eric Y. Hsiao

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SNe Ia in the near-infraredhigh redshift

Eric Y. Hsiao

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SNe Ia in the near-infraredhigh redshift

Eric Y. Hsiao

Nobili et al. 2005 A&A, 437, 789

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SNe Ia in the near-infraredk-corrections

Eric Y. Hsiao

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near-infraredlibrary spectra

Eric Y. Hsiao

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near-infraredlibrary spectra

Eric Y. Hsiao

Hamuy et al. 2002 AJ, 124, 417 (1999ee) Krisciunas et al. 2007 AJ, 133, 58 (2004S) Marion et al. 2003 ApJ, 591, 316 Marion et al. 2009 AJ, submitted

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near-infraredlibrary spectra

Eric Y. Hsiao

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near-infraredlibrary spectra

Eric Y. Hsiao

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spectral templateprocedures

measure the feature strengths of the library spectra

determine the weighted mean feature strength at each epoch and wavelength

adjust the base spectral template to the weighted mean feature strengths

Eric Y. Hsiao

Hsiao et al. 2007 ApJ, 663, 1187

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spectral templatemeasurement of spectral features

measure the feature strengths of the library spectra

determine the weighted mean feature strength at each epoch and wavelength

adjust the base spectral template to the weighted mean feature strengths

Eric Y. Hsiao

Hsiao et al. 2007 ApJ, 663, 1187

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spectral templatemeasurement of spectral features

Eric Y. Hsiao

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spectral templateweighting functions

measure the feature strengths of the library spectra

determine the weighted mean feature strength at each epoch and wavelength

adjust the base spectral template to the weighted mean feature strengths

Eric Y. Hsiao

Hsiao et al. 2007 ApJ, 663, 1187

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spectral templateweighting functions

Eric Y. Hsiao

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spectral templateprocedures

measure the feature strengths of the library spectra

determine the weighted mean feature strength at each epoch and wavelength

adjust the base spectral template to the weighted mean feature strengths

Eric Y. Hsiao

Hsiao et al. 2007 ApJ, 663, 1187

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spectral templatemangling function

Eric Y. Hsiao

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spectral templatebase spectral template

Eric Y. Hsiao

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principal component analysis (PCA)

PCA reduces multi-dimensional data into principal components

first component is the vector pointing toward the direction of the highest variance in the multi-dimensional data space

rest of the components are orthogonal vectors ranked by their variances

Eric Y. Hsiao

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near-infraredtemporal evolution

Eric Y. Hsiao

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near-infraredtemporal evolution

Eric Y. Hsiao

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near-infraredtemporal evolution

Eric Y. Hsiao

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near-infraredspectral template

Eric Y. Hsiao

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near-infraredspectral template

Eric Y. Hsiao

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near-infraredspectral template

Eric Y. Hsiao

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near-infraredk-corrections

Eric Y. Hsiao

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near-infrareddependence on stretch

Eric Y. Hsiao

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near-infrareddependence on stretch (pre-maximum)

Eric Y. Hsiao

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I-bandlibrary spectra

Eric Y. Hsiao

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I-bandlibrary spectra

Eric Y. Hsiao

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I-bandspectral template

Eric Y. Hsiao

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I-bandk-corrections

Eric Y. Hsiao

CSP

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I-bandk-corrections

Eric Y. Hsiao

CSP

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I-bandtemporal evolution

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-bandstretch template epoch or not?

Eric Y. Hsiao

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I-banddependence on stretch

Eric Y. Hsiao

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

1991T

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

2000cx

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I-banddependence on stretch (primary maximum)

Eric Y. Hsiao

1999aa

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I-banddependence on stretch (secondary maximum)

Eric Y. Hsiao

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summary

low redshift/JHK band slow temporal evolution of spectral features

k-correction errors small around NIR maximum k-corrections using 1 SN can cause

significant systematic errorshigh redshift/I band epochs of the spectral template should be

stretch corrected there is an apparent spectroscopic sequence

in the I-band OI and CaII triplet features

Eric Y. Hsiao