J/A+A/634/L6 NIR spectrum of interstellar object 2I/Borisov (Yang+, 2020)
Searching for water ice in the coma of interstellar object 2I/Borisov.
Yang B., Kelley M.S.P., Meech K.J., Keane J.V., Protopapa S., Bus S.J.
<Astron. Astrophys. 634, L6 (2020)>
=2020A&A...634L...6Y 2020A&A...634L...6Y (SIMBAD/NED BibCode)
ADC_Keywords: Comets ; Spectra, infrared
Keywords: techniques: spectroscopic - comets: individual: 2I/Borisov
Abstract:
Interstellar objects (ISOs) passing through our Solar System offer a
rare opportunity to probe the physical and chemical processes involved
in solid body and planet formation in extrasolar systems. The main
objective of our study is to search for diagnostic absorption features
of water ice in the near-infrared (NIR) spectrum of the second
interstellar object 2I/2019 Q4 (Borisov) and compare its ice features
to those of the Solar System icy objects. We observed 2I in the NIR on
three separate occasions. The first observation was made on 2019
September 19 UT using the SpeX spectrograph at the 3m IRTF and again
on September 24 UT with the GNIRS spectrograph at the 8m GEMINI
telescope; the last observation was made on October 09 UT with IRTF.
The spectra obtained from all three nights appear featureless. No
absorption features associated with water ice are detected. Spectral
modeling suggests that water grains, if present, comprise no more than
10% of the coma cross section. The comet consistently exhibits a red
D-type like spectrum with a spectral slope of about 6% per 1000~Å,
which is similar to that of 1I/'Oumuamua and is comparable to Solar
System comets.
Description:
Near infrared spectrum for the interstellar object 2I/Borisov from
0.82 to 2.4 micron, taken with GEMINI-N. Note that the spectrum is
re-sampled to a resolution of 170 and binned by a factor of 10.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 59 1 Information of fits spectrum
fits/* . 1 fits spectrum
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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- 3 I3 --- Nx Number of pixels along X-axis
5 I1 --- Ny Number of pixels along Y-axis
7- 16 A10 "date" Obs.date Observation date
18 I1 Kibyte size Size of FITS file
20- 39 A20 --- FileName Name of FITS file, in subdirectory fits
41- 59 A19 --- Title Title of the FITS file
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Acknowledgements:
Bin Yang, byang(at)eso.org
(End) Patricia Vannier [CDS] 28-Jan-2020