J/A+A/551/A113 Spectrum of VY CMa in 220.65-224.25GHz range (Kaminski+, 2013)
Pure rotational spectra of TiO and TiO2 in VY Canis Majoris.
Kaminski T., Gottlieb C.A., Menten K.M., Patel N.A., Young K.H.,
Brunken S., Muller H.S.P., McCarthy M.C., Winters J.M., Decin L.
<Astron. Astrophys. 551, A113 (2013)>
=2013A&A...551A.113K 2013A&A...551A.113K
ADC_Keywords: Radio lines ; Stars, emission ; Stars, late-type
Keywords: astrochemistry - stars: winds, outflows - circumstellar matter -
stars: individual: VY Canis Majoris - line: identification
Abstract:
We report the first detection of pure rotational transitions of TiO
and TiO2 at (sub-)millimeter wavelengths towards the red supergiant
VYCMa. A rotational temperature, Trot, of about 250K was derived for
TiO2. Although Trot was not well constrained for TiO, it is likely
somewhat higher than that of TiO2. The detection of the Ti oxides
confirms that they are formed in the circumstellar envelopes of cool
oxygen-rich stars and may be the "seeds" of inorganic-dust formation,
but alternative explanations for our observation of TiO and TiO2 in
the cooler regions of the envelope cannot be ruled out at this time.
The observations suggest that a significant fraction of the oxides is
not converted to dust, but instead remains in the gas phase throughout
the outflow.
Description:
A spectrum of VY Canis Majoris obtained with the Plateau de Bure
Interferometer on 22 April and 13 October 2012 in the frequency range
220.65-224.25GHz. The interferometer was used in its D configuration
with six antennas and the synthesized beam was 4.9x2.2-arcsec. The
spectrum was extracted from the central pixel of the map obtained with
the gridding of 0.65-arcsec.
Objects:
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RA (2000) DE Designation(s)
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07 22 58.33 -25 46 03.2 VY CMa = HD 58061
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spec.dat 16 1800 The spectrum of VY CMa in 220.65-224.25GHz
spec.fit 2880 6 FITS file of the spectrum
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Byte-by-byte Description of file: spec.dat
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Bytes Format Units Label Explanations
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3- 8 I6 MHz Freq [220652/224250] Rest frequency
10- 16 F7.4 Jy Fnu Flux density (in Jy/beam)
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Acknowledgements:
Tomasz Kaminski, kaminski(at)mpifr.de
(End) Tomasz Kaminski [MPIfR, Bonn, Germany], Patricia Vannier [CDS] 01-Feb-2013