J/ApJS/119/141 Oxygen-rich dust shells IR spectral classification (Sloan+ 1998)
The infrared spectral classification of oxygen-rich dust shells.
Sloan G.C., Price S.D.
<Astrophys. J. Suppl. Ser. 119, 141 (1998)>
=1998ApJS..119..141S 1998ApJS..119..141S
ADC_Keywords: Stars, variable ; MK spectral classification ;
Photometry, infrared
Keywords: stars: circumstellar matter - infrared: stars -
stars: AGB and post-AGB - stars: fundamental parameters -
stars: mass loss
Abstract:
This paper presents infrared spectral classifications for a
flux-limited sample of 635 optically identified oxygen-rich variables
including supergiants and sources on the asymptotic giant branch
(AGB). Several classes of spectra from oxygen-rich dust exist, and
these can be arranged in a smoothly varying sequence of spectral
shapes known as the silicate dust sequence. Classification based on
this sequence reveals several dependencies of the dust emission on the
properties of the central star. Nearly all S stars show broad emission
features from alumina dust, while most of the supergiants exhibit
classic features from amorphous silicate dust. Mira variables with
symmetric light curves generally show broad alumina emission, while
those with more asymmetric light curves show classic silicate
emission. These differences may arise from differences in the
photospheric C/O ratio.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 92 546 Infrared spectral classifications of the AGB sample
table5.dat 92 65 Infrared spectral classifications of the supergiants
table6.dat 91 24 Infrared spectral classifications of the optical
S stars
table9.dat 10 18 MS (oxygen-rich AGB or supergiant) stars
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See also:
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
Byte-by-byte Description of file: table4.dat table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRA-PSC (Cat. II/125) designation
11 A1 --- m_IRAS Multilicity index on IRAS
13- 24 A12 --- Name Name
26- 34 A9 -- Var Variability type (1)
36- 41 F6.2 d Per ? Period
43- 59 A17 --- SpType Spectral Type
61- 65 F5.2 mag 12um 12µm magnitude
67- 71 F5.2 mag [12]-[25] Colour index [12]-[25]
73- 75 I3 --- LRS ? LRS characterisations described in the LRS
Atlas
77- 81 F5.2 --- DEC Dust emission contrast (2)
83- 86 F4.2 --- F11/F12 Corrected flux ratio F11µm/F12µm
88- 92 A5 --- Dust Infrared emission class (3)
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Note (1): M: Mira Ceti-type variables
Lb: Slow irregular variable of late spectral type
SRa: Semiregular late-type giants displaying persistent periodicity
and usually small light amplitudes
SRb: Semiregular late-type giants with poorly defined periodicity, or
with alternating intervals of periodic and slow irregular changes,
and even with light constancy intervals
Note (2): Ratio of the summed emission from the dust to the summed emission from
the star over the interval 7.67-14.03µm.
Note (3): N: Naked (no dust)
SE: Silicate (and oxygen-rich dust) emission
SB: Silicate self-absorbed emission
SA: Silicate absorption
CE: Carbon-rich dust emission
H: Very red spectrum (possible H II region)
P: Peculiar (or noisy)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRAS-PSC designation
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History: From ApJS electronic version
(End) James Marcout, Patricia Bauer [CDS] 19-Jan-1999