THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

Journal Article · Mon Apr 01 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/766/2/72· OSTI ID:22167535

Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M. ^[1]; Marion, G. H.; Kirshner, R. P. ^[2]; Burns, C. R.; Freedman, W. L.; Persson, S. E. ^[3]; Winge, C. ^[4]; Kromer, M.; Gall, E. E. E. ^[5]; Gerardy, C. L.; Hoeflich, P. ^[6]; Im, M.; Jeon, Y. ^[7]; Nugent, P. E. ^[8]; Pignata, G. ^[9]; others, and

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1. Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile)
2. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
3. Carnegie Observatories, 813 Santa Barbara St, Pasadena, CA 91101 (United States)
4. Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile)
5. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching bei Muenchen (Germany)
6. Department of Physics, Florida State University, Tallahassee, FL 32306 (United States)
7. CEOU/Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)
8. Computational Cosmology Center, Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road MS 50B-4206, Berkeley, CA 94611 (United States)
9. Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile)

We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

• OSTI ID: 22167535
• Journal Information: Astrophysical Journal, Vol. 766, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CARBON BURNING
COSMOLOGY
INFRARED SPECTRA
NEAR INFRARED RADIATION
RESOLUTION
SIGNAL-TO-NOISE RATIO
SPECTROSCOPY
SUPERNOVAE
TELESCOPES
VELOCITY
VISIBLE RADIATION