J/A+A/390/511 Millimetre observations of carbon stars. II. (Groenewegen+, 2002)
Millimetre observations of infrared carbon stars.
II. Mass loss rates and expansion velocities.
Groenewegen M.A.T., Sevenster M., Spoon H.W.W., Perez I.
<Astron. Astrophys. 390, 511 (2002)>
=2002A&A...390..511G 2002A&A...390..511G
ADC_Keywords: Stars, carbon ; Infrared sources ; Mass loss ; Radial velocities
Keywords: circumstellar matter - stars: mass loss - stars: AGB and post-AGB -
radio lines: stars
Abstract:
Dust- and gas mass loss rates and distances are determined for a
sample of about 330 infra-red carbon stars that probe a distance up to
about 5.5kpc. The dependence of the dust- and gas mass loss rates,
and the expansion velocity upon galactic longitude (l) are studied. It
is found that the expansion velocity significantly depends on l, but
that the absolute bolometric magnitude, the dust mass loss rate and
the gas-to-dust ratio depend on l marginally, if at all, and the gas
mass loss rate does not depend on l. Beyond the solar circle, the
expansion velocity (as well as the luminosity, dust-to-gas ratio, dust
mass loss rate) is lower than inside the solar circle, as expected
from the overall gradient in metallicity content of the Galaxy.
Combining the average expansion velocity inside and beyond the solar
circle with the theoretically predicted relation between expansion
velocity and gas-to-dust ratio, we find that the metallicity gradient
in the solar neighbourhood is about -0.034dex/kpc, well within the
quoted range of values in the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 331 Data on the stars used in this study
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See also:
J/A+A/390/501 : Millimetre observations of carbon stars. I (Groenewegen+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRAS name
12- 16 F5.1 deg GLON Galactic longitude
18- 22 F5.1 deg GLAT Galactic latitude
24- 27 F4.1 km/s Vexp ? Expansion velocity
29- 33 F5.1 km/s Vlsr Radial velocity, with respect to the LSR
35- 38 F4.2 mag mbol Apparent bolometric magnitude
40- 44 F5.2 mag Mbol Absolute bolometric magnitude
46- 49 F4.2 kpc Dist Distance
51- 59 E9.3 solMass/yr dMgas/dt ? Gas mass-loss rate
61- 69 E9.3 solMass/yr dMdust/dt ? Dust mass-loss rate
71- 74 I4 --- Gas/Dust ? Gas-to-dust ratio, (dMg/dt)/(dMd/dt)
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History:
From electronic version of the journal
* 23-Aug-2002: 27 IRAS names were in error and have been corrected,
following a mail exchange with the main author (Martin Groenewegen)
(End) Patricia Bauer [CDS] 16-Jul-2002