J/ApJ/948/27 Carnegie Supernova Project. II. NIR sp. of SNIa (Lu+, 2023)
Carnegie Supernova Project.
II. Near-infrared Spectral Diversity and Template of Type Ia Supernovae.
Lu J., Hsiao E.Y., Phillips M.M., Burns C.R., Ashall C., Morrell N.,
Ng L., Kumar S., Shahbandeh M., Hoeflich P., Baron E., Uddin S.,
Stritzinger M.D., Suntzeff N.B., Baltay C., Davis S., Diamond T.R.,
Folatelli G., Forster F., Gagne J., Galbany L., Gall C.,
Gonzalez-Gaitan S., Holmbo S., Kirshner R.P., Krisciunas K., Marion G.H.,
Perlmutter S., Pessi P.J., Piro A.L., Rabinowitz D., Ryder S.D.,
Sand D.J.
<Astrophys. J., 948, 27 (2023)>
=2023ApJ...948...27L 2023ApJ...948...27L
ADC_Keywords: Supernovae; Surveys; Spectra, infrared; Redshifts
Keywords: High energy astrophysics ; Time domain astronomy ;
Infrared spectroscopy ; Type Ia supernovae
Abstract:
We present the largest and most homogeneous collection of
near-infrared (NIR) spectra of Type Ia supernovae (SNe Ia):
339 spectra of 98 individual SNe obtained as part of the Carnegie
Supernova Project-II. These spectra, obtained with the FIRE
spectrograph on the 6.5m Magellan Baade telescope, have a spectral
range of 0.8-2.5µm. Using this sample, we explore the NIR spectral
diversity of SNe Ia and construct a template of spectral time series
as a function of the light-curve-shape parameter, color stretch sBV.
Principal component analysis is applied to characterize the diversity
of the spectral features and reduce data dimensionality to a smaller
subspace. Gaussian process regression is then used to model the
subspace dependence on phase and light-curve shape and the associated
uncertainty. Our template is able to predict spectral variations that
are correlated with sBV, such as the hallmark NIR features: MgII at
early times and the H-band break after peak. Using this template
reduces the systematic uncertainties in K-corrections by ∼90% compared
to those from the Hsiao template. These uncertainties, defined as the
mean K-correction differences computed with the color-matched template
and observed spectra, are on the level of 4x10-4mag on average. This
template can serve as the baseline spectral energy distribution for
light-curve fitters and can identify peculiar spectral features that
might point to compelling physics. The results presented here will
substantially improve future SN Ia cosmological experiments, for both
nearby and distant samples.
Description:
The sample of NIR spectra comes entirely from the second stage of the
Carnegie Supernova Project (CSP-II; Hsiao+ 2019, J/PASP/131/A4002 &
Phillips+ 2019PASP..131a4001P 2019PASP..131a4001P). Approximately three-quarters of SN Ia
spectra were obtained using FIRE mounted on the Magellan Baade
telescope in the high-throughput prism mode. The spectra observed in
FIRE prism mode have an approximate wavelength coverage from
0.8-2.5um, and resolutions of R∼500, 450, and 300 in the J, H, and K
bands, respectively.
All spectra that passed through the selection described in Section 2.1,
339 spectra of 98 SNe, are available in the CSP website
(https://csp.obs.carnegiescience.edu/data).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 122 339 Summary of SNe Ia and spectra used in this work
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See also:
J/ApJ/689/377 : SNIa as NIR standard candles from PAIRITEL (Wood-Vasey+, 2008)
J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/ApJ/731/120 : Intrinsic SN Ia light curves (Mandel+, 2011)
J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)
J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)
J/A+A/578/A9 : Optical and NIR spectra of SN iPTF13ebh (Hsiao+, 2015)
J/AJ/154/211 : The CSP (DR3): photometry of low-z SNe Ia (Krisciunas+, 2017)
J/ApJ/848/56 : Relationships between SNe Ia & the host galaxies (Uddin+, 2017)
J/ApJ/869/56 : Updated calibration of the CSP-I SNe Ia sample (Burns+, 2018)
J/ApJ/859/101 : The supernovae Ia Pantheon sample (Scolnic+, 2018)
J/A+A/615/A45 : NIR K-corrections (Stanishev+, 2018)
J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)
J/ApJ/882/120 : CfA, CSP, BSP and LOSS spec. & phot. of SNe Ia (Wang+, 2019)
J/ApJ/905/94 : Classif. for PS1-MDS SNe with SuperRAENN (Villar+, 2020)
J/ApJ/923/237 : Opt and NIR phot. follow-up of iPTF SNIa (Johansson+, 2021)
J/ApJ/914/57 : Follow-up Opt. and NIR obs. of the SNIa SN2015bp (Wyatt+, 2021)
J/ApJ/938/110 : The Pantheon+ analysis: cosmological constraints (Brout+, 2022)
J/ApJ/928/103 : Phot. and sp. obs. of type Ia SN 2015bo (Hoogendam+, 2022)
J/ApJ/933/172 : NIR HST phot. of SNIa from the RAISIN survey (Jones+, 2022)
J/ApJ/927/142 : Type Ia SN 2012ij opt. & NIR spectra (Li+, 2022)
J/ApJ/938/83 : Multiepoch opt. obs. of 91T/99aa-like SNe Ia (Yang+, 2022)
http://csp.obs.carnegiescience.edu/data : CSP data homepage
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 29 A29 --- Name Supernova name
31- 40 A10 --- Target Targeted or untargeted?
42- 47 F6.4 --- zhelio [0.0036/0.1] Heliocentric redshift
49- 56 F8.2 d Tbmax [55893.24/57151.6] Time of B-band maximum,
Modified Julian date
58- 61 F4.2 d e_Tbmax [0.02/1.01] Uncertainty in Tbmax
63- 67 F5.3 --- sBV [0.48/1.3] Color-stretch parameter, B-V;
obtained by fitting multi-band CSP light
curves with SNooPy
69- 73 F5.3 --- e_sBV [0.04/0.06] Uncertainty in sBV
75- 76 I2 --- Nsp [1/26] Spectra counts
78- 87 A10 --- Date UT Date, YYYY-MM-DD
89- 96 F8.2 d MJD-sp [55911/57175.3] Modified Julian Date of
spectral observation
98-103 F6.2 d Phase [-13.4/96.4] Epoch (phase, days since Tbmax)
of spectral observation
105-112 F8.3 s ExpTime [42.4/3804] Total on-target exposure time
excluding overhead
114-118 F5.1 --- SNR-H [1.6/280] H-band signal-to-noise of spectrum
120-122 A3 --- Cont Whether the spectrum is contaminated by
host galaxy
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History:
From electronic version of the journal
References:
Hsiao et al. 2019PASP..131a4002H 2019PASP..131a4002H Cat. J/PASP/131/A4002
Phillips et al. 2019PASP..131a4001P 2019PASP..131a4001P
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Apr-2025