J/MNRAS/355/1196 MS bands of SiC2 in LMC carbon stars (Morgan+, 2004)
Merrill-Sanford bands in Large Magellanic Cloud carbon stars.
Morgan D.H., Hatzidimitriou D., Cannon R.D.
<Mon. Not. R. Astron. Soc., 355, 1196-1206 (2004)>
=2004MNRAS.355.1196M 2004MNRAS.355.1196M
ADC_Keywords: Magellanic Clouds ; Stars, carbon ; Spectroscopy
Keywords: stars: carbon - Magellanic Clouds
Abstract:
From a sample of 304 carbon stars in the central parts of the Large
Magellanic Cloud (LMC), ∼27 per cent have Merrill-Sanford (MS) bands
of the SiC2 molecule. The data are based on a uniform set of spectra
taken with 2dF on the Anglo-Australian Telescope, and give useful
statistics on the incidence of MS bands and on their correlation (or
otherwise) with other properties. All of these are red stars, cooler
than 3100 K. The proportion of stars showing the bands is highest
amongst the coolest stars, but not all very cool stars show the bands.
There is no evidence that MS bands are more common in J-type stars
(carbon stars with a high 13C/12C ratio) than in N-type carbon
stars, at least within this sample of LMC stars. There is no apparent
correlation with stellar variability, or between the photospheric
temperature [as measured by (J-K)] and the occurrence of the 'hot'
MS bands from excited molecular states.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 22 285 MS band strengths
table2.dat 13 63 MS hot band strengths
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See also:
J/A+A/369/932 : RI photometry of LMC carbon stars (Kontizas+, 2001)
II/247 : Variable Stars in the Large Magellanic Clouds (MACHO, 2001)
J/AJ/114/326 : MACHO Variables V. (Alcock+ 1997)
J/AJ/124/2039 : LMC Blue variable stars from MACHO (Keller+, 2002)
J/AJ/127/334 : MACHO LMC first-overtone RR Lyrae variables (Alcock+, 2004)
J/ApJ/542/257 : MACHO LMC first-overtone RR Lyrae (Alcock+, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [KDM2001] KDM (J/A+A/369/932) number
5 A1 --- VClass [bcde] Variability class from MACHO
database (1)
6 A1 --- f_[KDM2001] [*] *: J-type stars (high 13C/12C)
8 I1 --- MSC [0/3] MSC code (G1)
9 A1 --- u_MSC Uncertainty flag on MSC
11- 15 F5.2 mag Kmag K magnitude
17- 20 F4.2 mag J-K J-K colour index
22 A1 --- n_[KDM2001] [*] Individal note (2)
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Note (1): Variability class as follows:
b = Long Period Variable Wood-B (semi-regular)
c = Long Period Variable Wood-C (Mira)
d = LPV WoodD : Long Period Variable Wood-D (long secondary period)
e = Eclipsing Binary (all kinds including Wood-E)
Note (2): KDM 2382 and 2383 have the same coordinates in the [KDM2001]
catalogue (Kontizas et al., 2001A&A...369..932K 2001A&A...369..932K) because they are
very close and blended; they are resolved in 2-MASS to
05:10:32.4+69:50:42.8 with JHK as quoted above and
05:10:31.7+69:50:43.3 with JHK= 12.49, 11.35, 10.73;
2dF probably observed the blend.
The RCB star KDM2373 (not listed above) has an MSC code of 0.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [KDM2001] KDM (J/A+A/369/932) number
6 I1 --- MSC [0/3] MSC code (G1)_
7 A1 --- u_MSC Uncertainty flag on MSC
9- 11 A3 --- H1 ? Ratio of the 311λ4906 band to the
110 210λ4867 band (1)
13 I1 --- H2 [0/2] Level of the strength classes (2)
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Note (1): The ratios are expressed in a scale of 1-4, with a value of 4
indicating that the two bands are of equal strength.
'-' indicates measurement prevented by noise.
Note (2): Three levels are assigned to the strength of the λ5192 band
as follows:
0 = d3<0.1
1 = 0.1<d3<0.2
2 = d3>0.2
where d3 is the intensity ratio, (I0-I)/I0
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Global notes:
Note (G1): A three-level Merrill-Sanford Code (MSC) based on the depth
of the origin band at 4977Å is defined as:
1 = weak,
2 = moderate,
3 = strong
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 20-Jun-2005