J/ApJ/864/L20 SN 2017eaw NIR spectroscopy (Rho+, 2018)
Near-infrared spectroscopy of Supernova 2017eaw in 2017:
carbon monoxide and dust formation in a Type II-P supernova.
Rho J., Geballe T.R., Banerjee D.P.K., Dessart L., Evans A., Joshi V.
<Astrophys. J., 864, L20 (2018)>
=2018ApJ...864L..20R 2018ApJ...864L..20R (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Spectra, infrared
Keywords: dust, extinction - ISM: molecules - molecular processes -
supernovae: individual: SN 2017eaw
Abstract:
The origin of dust in the early universe has been the subject of
considerable debate. Core-collapse supernovae (ccSNe), which occur
several million years after their massive progenitors form, could be a
major source of that dust, as in the local universe several ccSNe have
been observed to be copious dust producers. Here we report nine
near-infrared (0.8-2.5µm) spectra, obtained with GNIRS on Gemini
North, of the Type II-P supernova (SN) 2017eaw in NGC 6946, spanning
the time interval 22-205 days after discovery. The spectra show the
onset of CO formation and continuum emission at wavelengths greater
than 2.1µm from newly formed hot dust, in addition to numerous
lines of hydrogen and metals, which reveal the change in ionization as
the density of much of the ejecta decreases. The observed CO masses
estimated from a local thermodynamic equilibrium (LTE) model are
typically 10-4M☉ during days 124-205, but could be an order
of magnitude larger if non-LTE conditions are present in the emitting
region. The timing of the appearance of CO is remarkably consistent
with the chemically controlled dust models of Sarangi & Cherchneff.
Description:
We obtained 0.81-2.52um spectra of SN 2017eaw using the Gemini
Near-Infrared Spectrograph (GNIRS) on the 8.1m Frederick C. Gillett
Gemini-North telescope, for programs GN-2017A-DD-8 and GN-2017B-DD-11.
Objects:
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RA (2000) DE Designation(s)
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20 34 44.23 +60 11 36.0 SN 2017eaw = AT 2017eaw
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 83 9 List of spectra
sp/* . 9 Individual spectra
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 46 A46 --- Title Title of the spectrum
48- 83 A36 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 9 F9.7 um lambda Wavelength
16- 28 E13.7 W/m2/um Flux Flux
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History:
From Aravind P. Ravi, aravind.pazhayathravi(at)mavs.uta.edu,
University of Texas at Arlington, USA
Acknowledgements:
This paper is based on observations obtained at the Gemini
Observatory, which is operated by the Association of Universities for
Research in Astronomy, Inc., under a cooperative agreement with the
NSF on behalf of the Gemini partnership: the National Science
Foundation (United States), the National Research Council (Canada),
CONICYT (Chile), Ministerio de Ciencia, Tecnologa e Innovacin
Productiva (Argentina), and Ministrio da Cincia, Tecnologia e Inovao
(Brazil). J.R. acknowledges support in part for this work from NASA
ADAP grant (NNX12AG97G). Research at the Physical Research Laboratory
is funded by the Department of Space, Government of India. We thank
Dr. Arka Sarangi for providing his models, and the anonymous referee
for insightful comments.
(End) Aravind P. Ravi [Univ. Texas, Arlington], P. Vannier [CDS] 04-Apr-2023