J/MNRAS/427/3209 Galactic and MC O-AGBs and RSGs stars (Jones+, 2012)
On the metallicity dependence of crystalline silicates in oxygen-rich
asymptotic giant branch stars and red supergiants.
Jones O.C., Kemper F., Sargent B.A., McDonald I., Gielen C., Woods P.M.,
Sloan G.C., Boyer M.L., Zijlstra A.A., Clayton G.C., Kraemer K.E.,
Srinivasan S., Ruffle P.M.E.
<Mon. Not. R. Astron. Soc., 427, 3209-3229 (2012)>
=2012MNRAS.427.3209J 2012MNRAS.427.3209J (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Milky Way ; Stars, giant ; Stars, supergiant ;
Infrared sources
Keywords: radiative transfer - stars: AGB and post-AGB - circumstellar matter -
dust, extinction - Magellanic Clouds - infrared: stars
Abstract:
We investigate the occurrence of crystalline silicates in oxygen-rich
evolved stars across a range of metallicities and mass-loss rates. It
has been suggested that the crystalline silicate feature strength
increases with increasing mass-loss rate, implying a correlation
between lattice structure and wind density. To test this, we analyse
Spitzer Infrared Spectrograph and Infrared Space Observatory Short
Wavelength Spectrometer spectra of 217 oxygen-rich asymptotic giant
branch and 98 red supergiants in the Milky Way, the Large and Small
Magellanic Clouds, and Galactic globular clusters. These encompass a
range of spectral morphologies from the spectrally rich which exhibit
a wealth of crystalline and amorphous silicate features to 'naked'
(dust-free) stars. We combine spectroscopic and photometric
observations with the GRAMS grid of radiative transfer models to
derive (dust) mass-loss rates and temperature. We then measure the
strength of the crystalline silicate bands at 23, 28 and 33µm. We
detect crystalline silicates in stars with dust mass-loss rates which
span over 3dex, down to rates of ∼10-9M☉/yr. Detections of
crystalline silicates are more prevalent in higher mass-loss rate
objects, though the highest mass-loss rate objects do not show the
23-µm feature, possibly due to the low temperature of the
forsterite grains or it may indicate that the 23-µm band is going
into absorption due to high column density. Furthermore, we detect a
change in the crystalline silicate mineralogy with metallicity, with
enstatite seen increasingly at low metallicity.
Description:
Our sample contains 69 oxygen-rich AGB stars (O-AGB) and 76 RSG stars
in the Magellanic Clouds which were observed spectroscopically with
Spitzer, and 131 Galactic field O-AGBs and RSGs observed with either
Spitzer or ISO. The Spitzer spectra cover a wavelength range of
5.2-37.2um, while ISO spectra cover the 2.38-45.2um part
of the spectrum. We combine this sample with 39 spectra from 14 GGCs
to extend the low end of the metallicity range.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 98 114 Details of the sources in the LMC sample
table3.dat 98 31 Details of the sources in the SMC sample
table4.dat 77 110 Details of the sources in the Galatic ISO/SWS
sample
table5.dat 98 21 Details of the sources in the Galactic Spitzer
IRS sample
table6.dat 87 39 Details of the sources in the globular cluster
sample
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Byte-by-byte Description of file: table2.dat table3.dat table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- SSID ? SAGE-Spec identification number
(only in table 2)
6- 34 A29 --- Name Name
36- 37 I2 h RAh Right ascension (J2000)
39- 40 I2 min RAm Right ascension (J2000)
42- 46 F5.2 s RAs Right ascension (J2000)
48 A1 --- DE- Declination sign (J2000)
49- 50 I2 deg DEd Declination (J2000)
52- 53 I2 arcmin DEm Declination (J2000)
55- 59 F5.2 arcsec DEs Declination (J2000)
61- 68 I8 --- AOR AOR number
70- 74 A5 --- Class Classification (1)
76- 80 F5.2 mag Mbol ? Bolometric magnitude
(only in tables 2 and 3)
82- 87 F6.1 d Per ?=- Period
89 A1 --- r_Per [bcdeg] Reference for Per (2)
91- 98 E8.3 Msun/yr dMdust/dt Dust production rate
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Note (1): The available data were insufficient for determining whether some
sources were an O-AGB or RSG; these sources are not assigned a classification.
Note (2): References as follows:
b = Soszynski et al. (2011AcA....61..217S 2011AcA....61..217S, Cat. J/AcA/61/217)
c = Fraser et al. (2005AJ....129..768F 2005AJ....129..768F),
Fraser, Hawley & Cook (2008, Cat. J/AJ/136/1242)
d = Groenewegen et al. (2009A&A...506.1277G 2009A&A...506.1277G, Cat. J/A+A/506/1277)
e = Pojmanski (2002AcA....52..397P 2002AcA....52..397P, Cat. II/264)
g = GCVS (Kholopov et al. (Cat. II/214); Samus et al. (Cat. II/250))
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Name
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 39 F4.1 arcsec DEs Declination (J2000)
42- 49 I8 --- TDT Target Dedicated Time number
51- 55 A5 --- Class Classification
57- 60 I4 pc Dist ?=- Distance to the source
62- 63 I2 --- r_Dist [1/18]? Reference for the distance (2)
65- 68 I4 d Per ?=- Period
70- 77 E8.3 Msun/yr dMdust/dt Dust production rate
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Note (2): References as follows:
1 = van Leeuwen (2007, Cat. I/311)
2 = Chen & Shen (2008ApJ...681.1574C 2008ApJ...681.1574C)
3 = De Beck et al. (2010A&A...523A..18D 2010A&A...523A..18D)
4 = Decin et al. (2007A&A...475..233D 2007A&A...475..233D)
5 = Herman, Burger & Penninx (1986A&A...167..247H 1986A&A...167..247H)
6 = Humphreys (1978ApJS...38..309H 1978ApJS...38..309H)
7 = Justtanont et al. (2006A&A...450.1051J 2006A&A...450.1051J)
8 = Knapp & Bowers (1988ApJ...331..974K 1988ApJ...331..974K)
9 = Le Sidaner & Le Bertre (1996, Cat. J/A+A/314/896)
10 = Levesque et al. (2005ApJ...628..973L 2005ApJ...628..973L)
11 = Loup et al. (1993, Cat. J/A+AS/99/291)
12 = Massey & Thompson (1991, Cat. J/AJ/101/1408)
13 = Olivier, Whitelock & Marang (2001MNRAS.326..490O 2001MNRAS.326..490O)
14 = Olofsson et al. (2002A&A...391.1053O 2002A&A...391.1053O)
15 = van Langevelde, van der Heiden & van Schooneveld (1990A&A...239..193V 1990A&A...239..193V)
16 = Whitelock, Feast & van Leeuwen (Cat. J/MNRAS/386/313)
17 = Xiong, Chen & Gao (1994A&AS..108..661X 1994A&AS..108..661X)
18 = Young (1995ApJ...445..872Y 1995ApJ...445..872Y)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Cluster Cluster name
12- 21 A10 --- Star Star name
23- 24 I2 h RAh Right ascension (J2000)
26- 27 I2 min RAm Right ascension (J2000)
29- 33 F5.2 s RAs Right ascension (J2000)
35 A1 --- DE- Declination sign (J2000)
36- 37 I2 deg DEd Declination (J2000)
39- 40 I2 arcmin DEm Declination (J2000)
42- 45 F4.1 arcsec DEs Declination (J2000)
47- 54 I8 --- AOR AOR number
56- 60 F5.2 kpc Dist Distance (1)
62- 66 F5.2 [-] [Fe/H] Metallicity (1)
68- 72 F5.1 d Per ?=- Period (1)
74- 78 F5.2 mag Mbol Bolometric magnitude (1)
80- 87 E8.3 Msun/yr dMdust/dt Dust mass-loss rate
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Note (1): Distances, [Fe/H] values, periods and bolometric magnitudes for
NGC 5139 (omega Cen) were taken from McDonald et al. (2011MNRAS.417...20M 2011MNRAS.417...20M),
values for these parameters for all other clusters are from Sloan et al.
(2010ApJ...719.1274S 2010ApJ...719.1274S).
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Acknowledgements:
Olivia C. Jones, ojones(at)stsci.edu
(End) Olivia Charlotte Jones [STScI], Patricia Vannier [CDS] 19-Nov-2015