J/A+A/574/A56 IRC +10216 17.8GHz-26.3GHz spectrum (Gong+, 2015)
A 1.3 cm line survey toward IRC +10216.
Gong Y., Henkel C., Spezzano S., Thorwirth S., Menten K.M., Wyrowski F.,
Mao R.Q., Klein B.
<Astron. Astrophys. 574, A56 (2015)>
=2015A&A...574A..56G 2015A&A...574A..56G
ADC_Keywords: Stars, variable ; Stars, carbon ; Spectroscopy
Keywords: astrochemistry - ISM: molecules - stars: individual: IRC +10216 -
radio lines: stars
Abstract:
IRC +10216 is the prototypical carbon star exhibiting an extended
molecular circumstellar envelope. Its spectral properties are
therefore the template for an entire class of objects. The main goal is
to systematically study the 1.3cm spectral line characteristics of
IRC +10216. We carried out a spectral line survey with the
Effelsberg-100m telescope toward IRC +10216. It covers the frequency
range between 17.8GHz and 26.3GHz (K-band). In the circumstellar shell
of IRC +10216, we find 78 spectral lines, among which 12 remain
unidentified. The identified lines are assigned to 18 different
molecules and radicals. A total of 23 lines from species known to
exist in this envelope are detected for the first time outside the
Solar System and there are additional 20 lines firstly detected in
IRC +10216. The potential orgin of U lines is also discussed. Assuming
local thermodynamic equilibrium (LTE), we determine rotational
temperatures and column densities of 17 detected molecules. Molecular
abundances relative to H2 are also estimated. A non-LTE analysis of
NH3 shows that the bulk of its emission arises from the inner
envelope with a kinetic temperature of 70±20K. Evidence for NH3
emitting gas with higher kinetic temperature is also obtained, and
potential abundance differences between various 13C-bearing
isotopologues of HC5N are evaluated. Overall, the isotopic
12C/13C ratio is estimated to be 49±9. Finally, a comparison of
detected molecules in the 1.3cm range with the dark cloud TMC-1
indicates that silicate bearing molecules are more predominant in
IRC +10216.
Description:
The observations of the 1.3cm line survey toward IRC +10216 were
observed with the Effelsberg 100-m telescope. The intensity of the
spectra is in units of Jy for this fits file. The spectra have 140001
channels and a channel spacing of 61kHz, covering the entire 1.3cm
K-band wavelength range. The rest frequency at the 70001st channel is
22000MHz.
Objects:
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RA (2000) DE Designation(s)
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09 47 57.41 +13 16 43.6 IRC +10216 = V* CW Leo
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 151 1 Spectrum information
irc10216.fit 2880 197 FITS spectrum for the 1.3cm wavelength range
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See also:
J/A+A/330/676 : IRC+10216 Silicon and sulfur chemistry (Willacy+ 1998)
J/A+A/545/A12 : Chemistry of IRC+10216 inner wind modelled (Cherchneff, 2012)
J/ApJ/688/L83 : Detection of C5N- in IRC +10216 (Cernicharo+, 2008)
J/ApJS/177/275 : 1.3 and 2mm survey of IRC+10216 (He+, 2008)
J/ApJS/190/348 : 1mm spectral survey of IRC+10216 + VY CMa (Tenenbaum+, 2010)
J/ApJS/193/17 : Spectral-line survey of IRC+10216 at 293-355GHz (Patel+, 2011)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (B1950)
10- 18 F9.5 deg DEdeg Declination of center (B1950)
26- 31 I6 --- Nx [140001] Number of channels
33- 51 A19 "datime" ObsDate Observation date (YYYY-MM-DDThh:mm:ss.sss)
57- 64 F8.5 GHz Dfreq0 [-4.27246] Lower value of frequency interval
relative to restfrequency (22GHz)
69- 76 F8.5 GHz Dfreq1 [4.27246] Upper value of frequency interval
82- 88 F7.1 Hz dFreq [61035.2] Channel width
90- 92 I3 Kibyte size [557] Size of FITS file
94-105 A12 --- FileName Name of FITS file
107-151 A45 --- Title Title of the file
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Acknowledgements:
Yan Gong, ygong(at)pmo.ac.cn
(End) Patricia Vannier [CDS] 24-Nov-2014