J/A+A/267/515 Very cold C-rich circumstellar envelopes (Omont+ 1993)
Characterization and proportion of very cold C-rich circumstellar envelopes
Omont A., Loup C., Forveille T., te Lintel Hekkert P.,
Habing H., Sivagnanam P.
<Astron. Astrophys. 267, 515, (1993)>
=1993A&A...267..515O 1993A&A...267..515O
ADC_Keywords: Infrared sources ; Radio lines ; Stars, carbon
Keywords: infrared radiation - radiolines: molecular - stars: carbon -
stars: circumstellar matter - stars: late-type - stars: OH/IR
Abstract:
The paper develops a method for identification of very cold C-rich
circumstellar envelopes (CSEs) in IR regions colder than region VII
(i.e., larger value of IRAS flux ratio S25/S12), by reviewing the
different criteria and by identifying C-rich CSEs in a sample of 228
bright IRAS sources. By using the results of OH surveys and catalogs
together with the results of additional HCN/CO millimeter observations
performed on critical classes of objects, a C/O classification is
proposed for 94 percent of the sources with a good probability. It is
shown that the low-resolution spectra by themselves are a reasonable
and easy way to identify C-rich late AGB CSEs. For post-AGB object
with cold CSEs, HCN and OH observations or visible/near IR
spectroscopy are necessary.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 58 19 Supergiants
table2.dat 120 57 Sources with CO(2-1) or HCN(1-0) emission
table3.dat 116 27 Non-detected sources
table4.dat 77 28 CO/HCN line ratios
table5.dat 80 24 Estimates of mass-loss rates
tablea1.dat 113 228 Master list of the main sample
tablea2.dat 98 18 Additional sources
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See also:
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
III/197 : IRAS Low Resolution Spectra (IRAS team, 1987)
Table6 : Number and proportion of C- and O-rich sources in the different
regions of the IRAS color-color diagram (Fig. 1) from tablea1.
The last column indicates the rate of OH detections among the
sources classified as O-rich where OH was searched
Region Total O-rich C-rich ? OH/O
-----------------------------------------
IIIa2 61 59 0 2 52%
IIIa1 88 52 31 5 67%
(59%) (35%) (6%)
IIIb2 38 27 9 2 77%
(71%) (24%) (5%)
IIIb1+IV 17 17 0 0 100%
V 17 7 4 6 (100%)
VIb 7 6 0 1 ( 25%)
-----------------------------------------
Total 228 168 44 16 68%
(74%) (19%) (7%)
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Byte-per-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- No Identification number in tablea1 and tablea2
7- 16 A10 --- Name Usual name
20 A1 --- Sp Spectral type
26- 30 A5 --- Region Region in the IRAS color-color diagram (G1)
34- 36 A3 --- LRS LRS spectral class
41- 45 I5 solLum FIRAS IRAS total flux expressed in solar
luminosity at 1kpc
58 A1 --- n [+?] A + indicates the post-AGB nature of
the star
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Byte-per-byte Description of file: table2.dat table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- No Identification number in tablea1 and tablea2
5- 14 A10 --- Name Usual name
16- 17 I2 h RAh ? Right ascension 1950
19- 20 I2 min RAm ? Right ascension 1950
22- 25 F4.1 s RAs ? Right ascension 1950
27 A1 --- DE- ? Declination sign
28- 29 I2 deg DEd ? Declination 1950
31- 32 I2 arcmin DEm ? Declination 1950
34- 35 I2 arcsec DEs ? Declination 1950
37 A1 --- Chem [COS] Chemical type (C, O or S)
38 A1 --- n_Chem [*#] (1)
39 A1 --- u_Chem [?] uncertainty flag on chemical type
41- 45 A5 --- Region Region in the IRAS color-color diagram (G1)
47- 55 A9 --- Trans Observed transitions
57- 59 I3 km/s Vlsr ? Star Local Standard of Rest velocity
61- 64 F4.1 km/s Ve ? Expansion velocity as the half width at
zero power
66- 70 F5.3 K TMB ? Main-beam brightness temperature measured
at the peak of the line
72- 76 F5.3 K e_TMB ? rms noise of T_MB
78- 82 F5.1 K.km/s I ? Integrated area
83 A1 --- u_I [?] uncertainty flag on I
84 A1 --- l_CO2 limit flag on ICO/IHCN
85- 88 F4.1 --- CO2 ? Intensity ratio CO(2-1)/HCN(1-0)
90- 94 F5.2 --- S60/CO ? Ratio 60µm to CO(2-1) emissions
97-120 A24 --- Rem Remarks and references (3)
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Note (1):
* indicates that the determination of the chemical type comes from this
paper,
# indicates that the chemical type was confirmed in this paper
Note (3):
Obervation date, mapping, interstellar contamination,
numbers in brackets indicate references of previous detections
(1) Zuckerman & Dyck 1986ApJ...304..394Z 1986ApJ...304..394Z
(2) Zuckerman et al. 1986ApJ...304..401Z 1986ApJ...304..401Z
(3) Zuckerman & Dyck 1986ApJ...311..345Z 1986ApJ...311..345Z
(4) Arquilla et al. 1986MNRAS.220..125A 1986MNRAS.220..125A
(5) Likkel et al. 1987A&A...173L..11L 1987A&A...173L..11L
(6) Lucas et al. 1988A&A...194..230L 1988A&A...194..230L
(7) Lindqvist et al 1988A&A...205L..15L 1988A&A...205L..15L
(8) Knapp et al. 1989ApJ...336..822K 1989ApJ...336..822K
(9) Zuckerman & Dyck 1989A&A...209..119Z 1989A&A...209..119Z
(10) Woodsworth et al. 1990A&A...228..503W 1990A&A...228..503W
(11) Likkel et al. 1991A&A...246..153L 1991A&A...246..153L
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Byte-per-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- No Identification number in tablea1 & tablea2
5- 14 A10 --- Name Usual name
16- 20 A5 --- Region Region in the IRAS color-color diagram (G1)
23- 28 A6 --- LRS LRS spectral class
31 A1 --- Chem [COS] Chemical type
32 A1 --- u_Chem [?] uncertainty flag on chemical type
36 A1 --- l_CO1 [~] limit flag on CO(1-0)/HCN
37- 40 F4.1 --- CO1 ? CO(1-0)/HCN line ratio
45- 48 F4.1 --- CO2 ? CO(2-1)/HCN line ratio
54- 58 A5 --- Ref References (2)
63- 77 A15 --- Com Comments
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Note (2):
(0) present paper (Table 2)
(13) Nguyen-Q-Rieu et al. 1987A&A...180..117N 1987A&A...180..117N
(14) Sopka et al. 1989A&A...210...78S 1989A&A...210...78S
(15) Knapp & Morris 1985ApJ...292..640K 1985ApJ...292..640K
(16) Nercessian et al. 1989A&A...210..225N 1989A&A...210..225N
(17) Bujarrabal et al. 1988A&A...204..242B 1988A&A...204..242B
(18) Morris et al. 1987ApJ...321..888M 1987ApJ...321..888M
(19) Bachiller et al. 1988A&A...196L...5B 1988A&A...196L...5B
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Byte-per-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- No Identification number in tablea1 & tablea2
5- 14 A10 --- Name Usual name
16- 20 A5 --- Region Region in the IRAS color-color diagram (G1)
23- 28 A6 --- LRS LRS spectral class
30 A1 --- Chem [COS] Chemical type
31 A1 --- u_Chem [?] uncertainty flag on chemical type
35- 38 F4.2 --- BC Bolometric correction Ftot/F(IRAS)
41 A1 --- r_BC references for Ftot (2)
45- 48 F4.2 kpc D Distance
49 A1 --- n_D note for D (3)
53- 56 F4.2 10-5Msun/yr dM1/dt ? mass-loss rate from CO(1-0) (4)
60- 62 A3 --- r_dM1/dt references for J=1-0 CO observations
66- 71 F6.4 10-5Msun/yr dM2/dt ? mass-loss rate from CO(2-1) (4)
72 A1 --- f_dM2/dt [pq] problematic dMCO(2-1)/dt (3)
76- 80 F5.2 --- dMIR/dt ? mass-loss rates deduced from infrared
observations following Jura & Kleinmann
(1989ApJ...341..359J 1989ApJ...341..359J)
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Note (2): References as follows:
a = van der Veen & Breukers (1989A&A...213..133V 1989A&A...213..133V)
from actual 1-60µm photometry
b = applying to S12 the bolometric corrections proposed by
van der Veen & Breukers (1989A&A...213..133V 1989A&A...213..133V)
c = assuming the following values for Ftot/Firas:
2 for region IIIa1, 1.2 for region IIIb2,
1.0 for region V without visible star,
2.5 for region V where a visible star is reported
d = Kwok et al. 1989.
Note (3):
'p' inappropriate if the source is a supergiant
'q' extended CO(2-1) source, dM2/dt should be multiplied by ∼2
Note (4):
mass-loss rate are deduced from Eqs (3) and (4) assuming the abundance
of CO relative to H2 f(CO): f(CO)=10-3 for C-rich sources and
f(CO)=5.10-4 for other sources
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Byte-per-byte Description of file: tablea1.dat tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1 A1 --- n_No [*] A "*" preceding the number indicates that
the source was observed in the millimeter
lines in the present study
2- 4 A3 --- No Classification number
7- 16 A10 --- IRAS IRAS-PSC (Cat. II/125) name
19- 23 F5.2 --- C21 25/12µm index, C21=log(12F25/25F12)
24 A1 --- u_C21 [)] uncertainty flag on C21
26- 30 F5.2 --- C32 60/25µm index, C32=log(25F60/12F25)
31 A1 --- u_C32 [)] uncertainty flag on C32
33- 37 E5.2 solLum FIRAS ? IRAS total flux expressed in solar
luminosity at 1kpc
41- 42 I2 --- Var. ? variability index from the IRAS-PSC
catalogue (Cat. II/125)
46- 52 A7 --- Region Region of the IRAS color-color diagram (G1)
54 A1 --- OH [-+.] OH maser detection (2)
58- 61 A4 --- r_OH References for OH maser observations (3)
64- 69 A6 --- LRS LRS spectral class (4)
70 A1 --- u_LRS [?] uncertainty flag on LRS
72 A1 --- Chem [COS] Proposed chemical type (C, O or S)
73 A1 --- u_Chem [?] uncertainty flag on chemical type
77 A1 --- CO CO detections (2)
78 A1 --- HCN [-+.*] HCN detections (2)
82 A1 --- H2O [-+.] H2O detections (+) or non-detections (-)
from the catalogue of Comoretto et al.
(1990A&AS...84..179C 1990A&AS...84..179C)
85-113 A29 --- Rem Remarks (5)
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Note (2): code has the following meaning:
+ = detected with circumstellar characteristics;
- = undetected or interstellar characteristics;
. = not searched
* = new detection of the present paper
Note (3): the symbols refer to:
t = catalogue of OH/IR stars by te Lintel Hekkert et al.
(1989A&AS...78..399T 1989A&AS...78..399T)
D,B,P = observations at Dwingeloo, Bonn-Effelsberg, and Parkes,
respectively, in te Lintel Hekkert et al. (1991A&AS...90..327T 1991A&AS...90..327T)
n,N,N'= observations at Nancay:
n = Sivagnanam et al. (1990A&A...233..112S 1990A&A...233..112S)
N = Le Squeren et al. (1992A&A...254..133L 1992A&A...254..133L)
N' = te Lintel Hekkert et al. (1991, in preparation)
L = Likkel (1989ApJ...344..350L 1989ApJ...344..350L)
a = observations at Arecibo
W = catalogue of observations of stellar masers by Benson et al.
(1990ApJS...74..911B 1990ApJS...74..911B)
Note (4): LRS spectral class, from the IRAS-LRS atlas (1986, Cat. III/197)
when available; otherwise, from the IRAS-LRS database, without
determination of the subclass n (Appendix).
* Most sources classified 5n would have appeared as 50 or 05 in the
LRS atlas.
* Spectra quoted as 4no are 4n spectra with 18 micrometer silicate
emission (Fig.2, rows II and III).
* "kvh" indicates the presence of the 21 micrometer emission
(Kwok et al., 1989ApJ...345L..51K 1989ApJ...345L..51K, Fig.5, row II).
* "int" denotes intermediate spectra with a maximum in the middle
of the LRS range (Fig.5, row I), probably characteristics of the
very early stages of the detachment of PPN envelopes (Loup, 1991, thesis).
Note (5): The notes include:
* Most usual name(s):
T = IRC from the Two Micron Sky Survey (Neugebauer and Leighton, 1969,
see catalog II/2)
GL = RAFGL catalogue (Price and Murdock, 1983; see catalog II/94)
SAO = SAO catalogue (Cat. I/131)
V = General Catalogue of Variables Stars (Kholopov 1985-1987, Cat. II/139)
DO = Deaborn catalogue (Cat. II/68)
* visible spectral types mostly from the IRAS PSC catalogue (Cat. II/125)
* zeta44 autoclass from the auto-classification of LRS spectra by
Cheeseman et al. (1989, NASA Ref. Publ. 1217) for objects of
autoclass zeta44
* Sources marked with a * present a special interest and deserve further
peculiar studies. They include (objects xa belong to Table A2):
a = double-shell envelopes of region VIb, Nos 29, 57, 74, 89, 124, 130,
141, 16a
b = 21µm sources (kvh spectra), Nos 33, 216, 4a, 17a, possibly 13a
c = "int" spectra, Nos 85, 136, 159, 179 (Fig.5), 10a
d = 4n OH emitters without 18 micrometer feature (Le Squeren et al.,
1992A&A...254..133L 1992A&A...254..133L), Nos 67, 142;
e = No. 8a with a very strong silicate absorption and no OH emission
f = OH+HCN emitter, No.208
g = The peculiar OH spectrum 17376-3021 (No. 68) (te Lintel Hekkert et
al. 991A&AS...90..327T)
h = Sources associated with visible stars: Be (Nos. 24b, 26, 30, 102,
109, 195) or others (Nos. 36, 38, 5a, 11a, 15a)
i = Peculiar objects of region V:17441-2411 (GL 2385, No.72), which
displays extended CO emission; 18095+2704 (No.95) with a very
strong silicate absorption and a very strong 25 micrometer excess
(Volg & Kwok 1988ApJ...331..435V 1988ApJ...331..435V)
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Global Notes:
Note (G1): Regions in the IRAS color-color diagram according to the
definitions of van der Veen & Habing (1988A&A...194..125V 1988A&A...194..125V),
and this paper
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History:
* 22-Apr-1994: Keypunched at CDS
* 19-Feb-2014: ReadMe revised (Francois Ochsenbein)
(End) Patricia Bauer [CDS] 22-Apr-1994