J/A+A/578/A9 Optical and NIR spectra of SN iPTF13ebh (Hsiao+, 2015) ================================================================================ Strong near-infrared carbon in the Type Ia supernova iPTF13ebh. Hsiao E.Y., Burns C.R., Contreras C., Hoeflich P., Sand D., Marion G.H., Phillips M.M., Stritzinger M., Gonzalez-Gaitan S., Mason R.E., Folatelli G., Parent E., Gall C., Amanullah R., Anupama G.C., Arcavi I., Banerjee D.P.K., Beletsky Y., Blanc G.A., Bloom J.S., Brown P.J., Campillay A., Cao Y., De Cia A., Diamond T., Freedman W.L., Gonzalez C., Goobar A., Holmbo S., Howell D.A., Johansson J., Kasliwal M.M., Kirshner R.P., Krisciunas K., Kulkarni S.R., Maguire K., Milne P.A., Morrell N., Nugent P.E., Ofek E.O., Osip D., Palunas P., Perley D.A., Persson S.E., Piro A.L., Rabus M., Roth M., Schiefelbein J.M., Srivastav S., Sullivan M., Suntzeff N.B., Surace J., Wozniak P.R., Yaron O. =2015A&A...578A...9H ================================================================================ ADC_Keywords: Supernovae ; Spectra, infrared Keywords: infrared: general - supernovae: general - supernovae: individual: iPTF13ebh Abstract: We present near-infrared (NIR) time-series spectroscopy, as well as complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from the estimated time of explosion. The first NIR spectrum was taken merely 2.3 days after explosion and may be the earliest NIR spectrum yet obtained of a SN Ia. The most striking features in the spectrum are several NIR CI lines, and the CI {lambda}1.0693um line is the strongest ever observed in a SN Ia. Interestingly, no strong optical CII counterparts were found, even though the optical spectroscopic time series began early and is densely-cadenced. Except at the very early epochs, within a few days from the time of explosion, we show that the strong NIR CI compared to the weaker optical CII appears to be general in SNe Ia. iPTF13ebh is a fast decliner with {Delta}m15(B)=1.79+/-0.01, and its absolute magnitude obeys the linear part of the width-luminosity relation. It is therefore categorized as a "transitional" event, on the fast-declining end of normal SNe Ia as opposed to subluminous/91bg-like objects. iPTF13ebh shows NIR spectroscopic properties that are distinct from both the normal and subluminous/91bg-like classes, bridging the observed characteristics of the two classes. These NIR observations suggest composition and density of the inner core similar to that of 91bg-like events, and a deep reaching carbon burning layer not observed in slower declining SNe Ia. There is also a substantial difference between the explosion times inferred from the early-time light curve and the velocity evolution of the SiII {lambda}0.6355um line, implying a long dark phase of ~4 days. Description: The data contained here are the optical and near-infrared spectroscopic data of iPTF13ebh. The spectra are as observed, without any redshift or extinction corrections. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 02 21 59.98 +33 16 13.7 SN iPTF13ebh ----------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file list.dat 76 24 List of spectra sp/* . 24 Individual optical and NIR spectra -------------------------------------------------------------------------------- Byte-by-byte Description of file: list.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 10 A10 "date" Date Observation date 12- 19 A8 --- Tel Telescope name (1) 21- 26 A6 --- Inst Instrument name 28- 32 I5 0.1nm lam.min [3055/8395] Wavelength range (lower value) 34- 38 I5 0.1nm lam.max [8998/27636] Wavelength range (upper value) 40- 76 A37 --- FileName Name of the spectrum file in subdirectory sp -------------------------------------------------------------------------------- Note (1): Telescope and instruments as follows: APO = ARC 3.5-m telescope with Dual Imaging Spectrograph (DIS) FTN = Faulkes Telescope North with cross-dispersed spectrograph (FLOYDS ) Gemini = Gemini North Telescope with GNIRS infrared spectrograph HCT = Himalayan Chandra Telescope with Himalaya Faint Object Spectrograph Camera (HFOSC) IRTF = NASA Infrared Telescope Facility with SpeX Keck = Keck II telescope with Deep Imaging Multi-Object Spectrograph DEIMOS and Keck I telescope with Low Resolution Imaging Spectrometer LRIS Magellan = Magellan telescope with FIRE and Inamori Magellan Areal Camera and Spectrograph (IMACS) NOT = Nordic Optical telescope with Andalucia Faint Object Spectrograph and Camera (ALFOSC) P200 = Palomar 200-inch telescope with double Beam Spectrograph (DBSP) WHT = William Herschel Telescope with Intermediate dispersion Spectrograph and Imaging System (ISIS) -------------------------------------------------------------------------------- Byte-by-byte Description of file: sp/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 F9.1 0.1nm lambda Observed wavelength in Angstrom 10- 24 E15.1 --- Flux ?=- Observed flux F_lambda_ in arbitrary units -------------------------------------------------------------------------------- Acknowledgements: Eric Y. Hsiao, yichi.hsiao(at)gmail.com ================================================================================ (End) Eric Hsiao [Aarhus University], Patricia Vannier [CDS] 27-Mar-2015