Related papers: Berkeley Supernova Ia Program II: Initial Analysis…

Velocity Evolution and the Intrinsic Color of Type Ia Supernovae

To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ryan J. Foley , Nathan E. Sanders , Robert P. Kirshner

The Type Ia Supernova Rate at z$\sim 0.4 $

We present the first measurement of the rate of Type Ia supernovae at high redshift. The result is derived using a large subset of data from the Supernova Cosmology Project. Three supernovae were discovered in a surveyed area of 1.7 square…

Astrophysics · Physics 2011-03-10 R. Pain , I. M. Hook , S. Deustua , S. Gabi , G. Goldhaber , A. Goobar , D. Groom , A. G. Kim , M. Y. Kim , J. C. Lee , C. R. Pennypacker , S. Perlmutter , I. A. Small , R. S. Ellis , R. G. McMahon , K. Glazebrook , B. J. Boyle , P. S. Bunclark , D. Carter , M. J. Irwin

The Mean Type Ia Supernova Spectrum Over the Past 9 Gigayears

We examine the possibility of evolution with redshift in the mean rest-frame ultraviolet (UV; <4500A) spectrum of Type Ia Supernovae (SNe Ia) sampling the redshift range 0<z<1.3. We find new evidence for a decrease with redshift in the…

Solar and Stellar Astrophysics · Physics 2011-02-11 M. Sullivan , R. S. Ellis , D. A. Howell , A. Riess , P. E. Nugent , A. Gal-Yam

Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts

Using archival data of low-redshift (z < 0.01) Type Ia supernovae (SN Ia) and recent observations of high-redshift (0.16 < z <0.64; Matheson et al. 2005) SN Ia, we study the "uniformity'' of the spectroscopic properties of nearby and…

Astrophysics · Physics 2010-11-11 S. Blondin , L. Dessart , B. Leibundgut , D. Branch , P. Hoeflich , J. L. Tonry , T. Matheson , R. J. Foley , R. Chornock , A. V. Filippenko , J. Sollerman , J. Spyromilio , R. P. Kirshner , W. M. Wood-Vasey , A. Clocchiatti , C. Aguilera , B. Barris , A. C. Becker , P. Challis , R. Covarrubias , T. Davis , P. Garnavich , M. Hicken , S. Jha , K. Krisciunas , W. Li , A. Miceli , G. Miknaitis , G. Pignata , J. L. Prieto , A. Rest , A. G. Riess , M. E. Salvo , B. P. Schmidt , R. C. Smith , C. W. Stubbs , N. B. Suntzeff

Measuring Ejecta Velocity Improves Type Ia Supernova Distances

We use a sample of 121 spectroscopically normal Type Ia supernovae (SNe Ia) to show that their intrinsic color is correlated with their ejecta velocity, as measured from the blueshift of the Si II 6355 feature near maximum brightness, v_Si.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Ryan J. Foley , Daniel Kasen

A Novel Color Parameter As A Luminosity Calibrator for Type Ia Supernovae

Type Ia supernovae (SNe Ia) provide us with a unique tool for measuring extragalactic distances and determining cosmological parameters. As a result, the precise and effective calibration for peak luminosities of SNe Ia becomes extremely…

Astrophysics · Physics 2016-08-30 Xiaofeng Wang , Lifan Wang , Xu Zhou , Yuqing Lou , Zongwei Li

Breaking the color-reddening degeneracy in type Ia supernovae

A new method to study the intrinsic color and luminosity of type Ia supernovae (SNe Ia) is presented. A metric space built using principal component analysis (PCA) on spectral series SNe Ia between -12.5 and +17.5 days from B maximum is…

Solar and Stellar Astrophysics · Physics 2016-04-27 M. Sasdelli , E. E. O. Ishida , W. Hillebrandt , C. Ashall , P. A. Mazzali , S. Prentice

Spectra of High-Redshift Type Ia Supernovae and a Comparison with their Low-Redshift Counterparts

We present spectra for 14 high-redshift (0.17 < z < 0.83) supernovae, which were discovered by the Supernova Cosmology Project as part of a campaign to measure cosmological parameters. The spectra are used to determine the redshift and…

Astrophysics · Physics 2008-11-26 I. M. Hook , D. A. Howell , G. Aldering , R. Amanullah , M. S. Burns , A. Conley , S. E. Deustua , R. Ellis , S. Fabbro , V. Fadeyev , G. Folatelli , G. Garavini , R. Gibbons , G. Goldhaber , A. Goobar , D. E. Groom , A. G. Kim , R. A. Knop , M. Kowalski , C. Lidman , S. Nobili , P. E. Nugent , R. Pain , C. R. Pennypacker , S. Perlmutter , P. Ruiz-Lapuente , G. Sainton , B. E. Schaefer , E. Smith , A. L. Spadafora , V. Stanishev , R. C. Thomas , N. A. Walton , L. Wang , W. M. Wood-Vasey

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

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<z<0.25 is constructed. Using…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mathew Smith , Robert C Nichol , Benjamin Dilday , John Marriner , Richard Kessler , Bruce Bassett , David Cinabro , Joshua Frieman , Peter Garnavich , Saurabh W Jha , Hubert Lampeitl , Masao Sako , Donald P Schneider , Jesper Sollerman

Evidence for a correlation between the Si II 4000 width and Type Ia supernova color

We study the pseudo equivalent width of the Si II 4000 feature of Type Ia supernovae in the redshift range 0.0024 < z < 0.634. We find that this spectral indicator correlates with the lightcurve color excess (SALT2 c) as well as previously…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 J. Nordin , L. Ostman , A. Goobar , C. Balland , H. Lampeitl , R. C. Nichol , M. Sako , D. P. Schneider , M. Smith , J. Sollerman , J. C. Wheeler

First Cosmology Results Using Type Ia Supernovae From the Dark Energy Survey: Analysis, Systematic Uncertainties, and Validation

We present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified type Ia supernovae (SNe Ia) from the first three years of the Dark Energy Survey Supernova Program (DES-SN), spanning a…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-04 D. Brout , D. Scolnic , R. Kessler , C. B. D'Andrea , T. M. Davis , R. R. Gupta , S. R. Hinton , A. G. Kim , J. Lasker , C. Lidman , E. Macaulay , A. Möller , R. C. Nichol , M. Sako , M. Smith , M. Sullivan , B. Zhang , P. Andersen , J. Asorey , A. Avelino , B. A. Bassett , P. Brown , J. Calcino , D. Carollo , P. Challis , M. Childress , A. Clocchiatti , A. V. Filippenko , R. J. Foley , L. Galbany , K. Glazebrook , J. K. Hoormann , E. Kasai , R. P. Kirshner , K. Kuehn , S. Kuhlmann , G. F. Lewis , K. S. Mandel , M. March , V. Miranda , E. Morganson , D. Muthukrishna , P. Nugent , A. Palmese , Y. -C. Pan , R. Sharp , N. E. Sommer , E. Swann , R. C. Thomas , B. E. Tucker , S. A. Uddin , W. Wester , T. M. C. Abbott , S. Allam , J. Annis , S. Avila , K. Bechtol , G. M. Bernstein , E. Bertin , D. Brooks , D. L. Burke , A. Carnero Rosell , M. Carrasco Kind , J. Carretero , F. J. Castander , C. E. Cunha , L. N. da Costa , C. Davis , J. De Vicente , D. L. DePoy , S. Desai , H. T. Diehl , P. Doel , A. Drlica-Wagner , T. F. Eifler , J. Estrada , E. Fernandez , B. Flaugher , P. Fosalba , J. Frieman , J. García-Bellido , D. Gruen , R. A. Gruendl , G. Gutierrez , W. G. Hartley , D. L. Hollowood , K. Honscheid , B. Hoyle , D. J. James , M. Jarvis , T. Jeltema , E. Krause , O. Lahav , T. S. Li , M. Lima , M. A. G. Maia , J. Marriner , J. L. Marshall , P. Martini , F. Menanteau , C. J. Miller , R. Miquel , R. L. C. Ogando , A. A. Plazas , A. K. Romer , A. Roodman , E. S. Rykoff , E. Sanchez , B. Santiago , V. Scarpine , M. Schubnell , S. Serrano , I. Sevilla-Noarbe , R. C. Smith , M. Soares-Santos , F. Sobreira , E. Suchyta , M. E. C. Swanson , G. Tarle , D. Thomas , M. A. Troxel , D. L. Tucker , V. Vikram , A. R. Walker , Y. Zhang

On the Spectroscopic Diversity of Type Ia Supernovae

A comparison of the ratio of the depths of two absorption features in the spectra of TypeIa supernovae (SNe Ia) near the time of maximum brightness with the blueshift of the deep red Si II absorption feature 10 days after maximum shows that…

Astrophysics · Physics 2009-10-31 Kazuhito Hatano , David Branch , Eric J. Lentz , E. Baron , Alexei V. Filippenko , Peter M. Garnavich

Seeing the Outer Edge of the Infant Type Ia Supernova 2024epr in the Optical and Near Infrared

We present optical-to-near-infrared (NIR) photometry and spectroscopy of the Type Ia supernova (SN Ia) 2024epr, including NIR spectra observed within two days of first light. The early-time optical spectra show strong, high-velocity Ca and…

High Energy Astrophysical Phenomena · Physics 2025-08-21 W. B. Hoogendam , D. O. Jones , C. Ashall , B. J. Shappee , R. J. Foley , M. A. Tucker , M. E. Huber , K. Auchettl , D. D. Desai , A. Do , J. T. Hinkle , S. Romagnoli , J. Shi , A. Syncatto , C. R. Angus , K. C. Chambers , D. A. Coulter , K. W. Davis , T. de Boer , A. Gagliano , M. Kong , C. -C. Lin , T. B. Lowe , E. A. Magnier , P. Minguez , Y. -C. Pan , K. C. Patra , S. A. Severson , K. Taggart , A. R. Wasserman , S. K. Yadavalli , P. Chen , R. S. Post

The Peculiar Type Ia Supernova 1999by: Spectroscopy at Early Epochs

We present medium resolution (lambda/Delta lambda = 2500) optical spectroscopy of SN 1999by in NGC 2841 made around its light maximum. The depth ratio of the two Si II features at 5800 AA and 6150 AA being R(SiII) approx. 0.63 at maximum…

Astrophysics · Physics 2009-11-06 J. Vinko , L. L. Kiss , B. Csak , G. Furesz , R. Szabo , J. R. Thomson , S. W. Mochnacki

Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation

We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including high signal-to-noise HST data, and spectra of six SNe Ia that were discovered during 2001 are presented.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-15 R. Amanullah , C. Lidman , D. Rubin , G. Aldering , P. Astier , K. Barbary , M. S. Burns , A. Conley , K. S. Dawson , S. E. Deustua , M. Doi , S. Fabbro , L. Faccioli , H. K. Fakhouri , G. Folatelli , A. S. Fruchter , H. Furusawa , G. Garavini , G. Goldhaber , A. Goobar , D. E. Groom , I. Hook , D. A. Howell , N. Kashikawa , A. G. Kim , R. A. Knop , M. Kowalski , E. Linder , J. Meyers , T. Morokuma , S. Nobili , J. Nordin , P. E. Nugent , L. Ostman , R. Pain , N. Panagia , S. Perlmutter , J. Raux , P. Ruiz-Lapuente , A. L. Spadafora , M. Strovink , N. Suzuki , L. Wang , W. M. Wood-Vasey , N. Yasuda

Tests of the Accelerating Universe with Near-Infrared Observations of a High-Redshift Type Ia Supernova

We have measured the rest-frame B,V, and I-band light curves of a high-redshift type Ia supernova (SN Ia), SN 1999Q (z=0.46), using HST and ground-based near-infrared detectors. A goal of this study is the measurement of the color excess,…

Astrophysics · Physics 2019-08-17 Adam G. Riess , Alexei V. Filippenko , Michael C. Liu , Peter Challis , Alejandro Clocchiatti , Alan Diercks , Peter M. Garnavich , Craig J. Hogan , Saurabh Jha , Robert P. Kirshner , B. Leibundgut , M. M. Phillips , David Reiss , Brian P. Schmidt , Robert A. Schommer , R. Chris Smith , J. Spyromilio , Christopher Stubbs , Nicholas B. Suntzeff , John Tonry , Patrick Woudt , Robert J. Brunner , Arjun Dey , Roy Gal , James Graham , James Larkin , Steve C. Odewah n , Ben Oppenheimer

Statistical Analysis of Early Spectra in Type II and IIb Supernovae

We present a comprehensive analysis of the early spectra of type II and type IIb supernovae (SNe) to explore their diversity and distinguishable characteristics. Using 866 publicly available spectra from 393 SNe, 407 from type IIb SNe (SNe…

High Energy Astrophysical Phenomena · Physics 2025-07-14 Maider González-Bañuelos , Claudia P. Gutiérrez , Lluís Galbany , Santiago González-Gaitán

Evidence for a Spectroscopic Sequence Among SNe Ia

In this Letter we present evidence for a spectral sequence among Type Ia supernovae (SNe Ia). The sequence is based on the systematic variation of several features seen in the near-maximum light spectrum. This sequence is analogous to the…

Astrophysics · Physics 2009-07-28 Peter Nugent , Mark Phillips , E. Baron , David Branch , Peter Hauschildt

Using Spectral Flux Ratios to Standardize SN Ia Luminosities

We present a new method to standardize Type Ia supernova (SN Ia) luminosities to ~<0.13 magnitudes using flux ratios from a single flux-calibrated spectrum per SN. Using Nearby Supernova Factory spectrophotomery of 58 SNe Ia, we performed…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Bailey , G. Aldering , P. Antilogus , C. Aragon , C. Baltay , S. Bongard , C. Buton , M. Childress , N. Chotard , Y. Copin , E. Gangler , S. Loken , P. Nugent , R. Pain , E. Pecontal , R. Pereira , S. Perlmutter , D. Rabinowitz , G. Rigaudier , K. Runge , R. Scalzo , G. Smadja , H. Swift , C. Tao , R. C. Thomas , C. Wu

A Mismatch in the Ultraviolet Spectra between Low-Redshift and Intermediate-Redshift Type Ia Supernovae as a Possible Systematic Uncertainty for Supernova Cosmology

We present Keck high-quality rest-frame ultraviolet (UV) through optical spectra of 21 Type Ia supernovae (SNe Ia) in the redshift range 0.11 < z < 0.37 and a mean redshift of 0.22 that were discovered during the Sloan Digital Sky Survey-II…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-20 Ryan J. Foley , Alexei V. Filippenko , Richard Kessler , Bruce Bassett , Joshua A. Frieman , Peter M. Garnavich , Saurabh W. Jha , Kohki Konishi , Hubert Lampeitl , Adam G. Riess , Masao Sako , Donald P. Schneider , Jesper Sollerman , Mathew Smith