J/ApJ/690/837 CN and CO observations toward AGB stars (Milam+, 2009)
Circumstellar 12c/13c isotope ratios from millimeter observations of CN and
CO: mixing in carbon- and oxygen-rich stars.
Milam S.N., Woolf N.J., Ziurys L.M.
<Astrophys. J., 690, 837-849 (2009)>
=2009ApJ...690..837M 2009ApJ...690..837M
ADC_Keywords: Stars, carbon ; Stars, giant ; Spectra, millimetric/submm ;
Radio lines ; Line Profiles
Keywords: astrobiology - astrochemistry - line: profiles - nuclear reactions,
nucleosynthesis, abundances - radio lines: stars - stars: AGB and
post-AGB
Abstract:
A survey of the 12C/13C ratio toward circumstellar envelopes has
been conducted at millimeter wavelengths using the facilities of the
Arizona Radio Observatory (ARO). The ratios were obtained for a sample
of 18 local C- and O-rich asymptotic giant branch and supergiant stars
from observations of the 12C and 13C isotopologues of CO and CN,
respectively. The J=1->0 transitions of both molecules were observed
at λ=3mm using the ARO 12m telescope, while the J=2->1 lines of
the two species were measured using the ARO Sub-Millimeter Telescope
(SMT) at λ=1mm. The 12C/13C ratios were determined from the
CO data by modeling both transitions simultaneously with a
circumstellar radiative transfer code, which can account for the high
opacities present in the emission from this species. In the case of
CN, the hyperfine structure was used to evaluate opacity effects.
Ratios obtained independently from CO and CN are in good agreement.
Description:
The measurements were conducted during the period 2003 October through
2007 June at λ=1 and 3mm using the facilities of the Arizona
Radio Observatory (ARO): the Kitt Peak 12m and Sub-Millimeter
Telescope (SMT) on Mt. Graham, AZ.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 23 Source parameters
table4.dat 67 344 Observed line parameters for CN
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See also:
J/A+A/390/501 : Millimetre observations of carbon stars. I. (Groenewegen+,
2002)
J/A+A/390/511 : Millimetre observations of carbon stars. II. (Groenewegen+,
2002)
J/A+AS/107/445 : Envelopes of oxygen-rich AGB stars (Hashimoto, 1994)
J/A+A/275/163 : Luminous Carbon stars in Galactic Plane (Kastner+ 1993)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Source Source designation
13 A1 --- El [CO=] Overabundant element, or = if C ≃ O
15- 26 A12 --- Class Class of star (AGB, supergiant, or proto-PN)
29- 30 I2 h RAh Hour of right ascension (B1950)
32- 33 I2 min RAm Minute of right ascension (B1950)
35- 38 F4.1 s RAs Second of right ascension (B1950)
40 A1 --- DE- Declination sign (B1950)
41- 42 I2 deg DEd Degree of declination (B1950)
44- 45 I2 arcmin DEm Arcminute of declination (B1950)
47- 48 I2 arcsec DEs Arcsecond of declination (B1950)
50- 53 F4.2 --- C/O Carbon to Oxygen ratio
55 A1 --- r_C/O [cd] Origin of value (1)
57- 60 I4 pc Dist Heliocentric distance
62- 67 I6 Lsun Lum Luminosity of star
69- 73 I5 K Teff Effective temperature
74 A1 --- n_Teff [b] indicates an assumed Teff
76- 81 E6.2 cm Rad Radius of star
83- 88 E6.2 Msun/yr Mdot Mass loss
90- 99 A10 --- Ref References (2)
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Note (1):
c = from Bergeat & Chevallier (2005A&A...429..235B 2005A&A...429..235B)
d = from Duari & Hatchell (2000A&A...358L..25D 2000A&A...358L..25D)
Note (2): references are numbered as follows:
1 = Ivezic & Elitzur (1995ApJ...445..415I 1995ApJ...445..415I)
2 = Fong et al. (2006ApJ...652.1626F 2006ApJ...652.1626F)
3 = Teyssier et al. (2006A&A...450..167T 2006A&A...450..167T)
4 = Skinner et al. (1997A&A...328..290S 1997A&A...328..290S)
5 = Truong-Bach et al. (1990A&A...230..431T 1990A&A...230..431T)
6 = Jaminet et al. (1992ApJ...400..535J 1992ApJ...400..535J)
7 = Bergeat & Chevallier (2005A&A...429..235B 2005A&A...429..235B)
8 = Agundez & Cernicharo (2006ApJ...650..374A 2006ApJ...650..374A)
9 = Bujarrabal et al. (1989A&A...219..256B 1989A&A...219..256B)
10 = van Loon et al. (2005A&A...438..273V 2005A&A...438..273V)
11 = Bujarrabal et al. (1994A&A...285..247B 1994A&A...285..247B)
12 = Levesque et al. (2005ApJ...628..973L 2005ApJ...628..973L)
13 = Humphreys et al. (2007AJ....133.2716H 2007AJ....133.2716H)
14 = Greaves & Holland (1997A&A...327..342G 1997A&A...327..342G)
15 = Olofsson et al. (1991A&A...245..611O 1991A&A...245..611O)
16 = Cherchneff (2006A&A...456.1001C 2006A&A...456.1001C)
17 = Zubko & Elitzur (2000ApJ...544L.137Z 2000ApJ...544L.137Z)
18 = Zubko et al. (2004ApJ...610..427Z 2004ApJ...610..427Z)
19 = Duari et al. (1999A&A...341L..47D 1999A&A...341L..47D)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Source Source designation
12 A1 --- Res [ef] Note when resolution differs from 1MHz (1)
14- 17 A4 --- Iso Isotopologue
19- 20 A2 --- QN Quantum number label (F, F1, F2, J or N)
22- 24 A3 --- Qu Upper state quantum number
26- 28 A3 --- Ql Lower state quantum number
30 A1 --- bl [bc] blended (b) or partially blended (c)
32 A1 --- l_Int [≲ ] Limit or approximate flag on Int
33- 38 F6.4 K Int ? Intensity (2)
40- 44 F5.3 K e_Int ? Error in Int
46 A1 --- u_delV [∼ ] Approximate flag on delV
47- 50 F4.1 km/s delV ? Linewidth ΔV
52- 54 F3.1 km/s e_delV ? Error in delV
56 A1 --- u_VLSR [∼ ] Approximate flag on VLSR
57- 61 F5.1 km/s VLSR ? Local Standard of Rest velocity
63 A1 --- f_VLSR [d] d = Assumed value.
65- 67 F3.1 km/s e_VLSR ? Error in VLSR
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Note (1): All values measured from 1MHz resolution unless:
e = 2MHz resolution;
f = N=2-1 data from 12m, with resolution of 0.782MHz.
Note (2): TR* for 12m data (N=1-0) and TA* for SMT (N=2-1)
unless otherwise noted.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Feb-2011