J/MNRAS/466/1963 Silicate crystallinities of O-rich evolved stars (Liu+, 2017)
On the silicate crystallinities of oxygen-rich evolved stars and
their mass-loss rates.
Liu J., Jiang B.W., Li A., Gao J.
<Mon. Not. R. Astron. Soc., 466, 1963-1986 (2017)>
=2017MNRAS.466.1963L 2017MNRAS.466.1963L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Mass loss ; Photometry, UBVRI ;
Photometry, infrared
Keywords: stars: AGB and post-AGB - circumstellar matter - stars: evolution -
stars: mass-loss - dust, extinction
Abstract:
For decades ever since the early detection in the 1990s of the
emission spectral features of crystalline silicates in oxygen-rich
evolved stars, there is a long-standing debate on whether the
crystallinity of the silicate dust correlates with the stellar
mass-loss rate. To investigate the relation between the silicate
crystallinities and the mass-loss rates of evolved stars, we carry out
a detailed analysis of 28 nearby oxygen-rich stars. We derive the
mass-loss rates of these sources by modelling their spectral energy
distributions from the optical to the far-infrared. Unlike previous
studies in which the silicate crystallinity was often measured in
terms of the crystalline-to-amorphous silicate mass ratio, we
characterize the silicate crystallinities of these sources with the
flux ratios of the emission features of crystalline silicates to that
of amorphous silicates. This does not require the knowledge of the
silicate dust temperatures, which are the major source of
uncertainties in estimating the crystalline-to-amorphous silicate mass
ratio. With a Pearson correlation coefficient of ~-0.24, we find
that the silicate crystallinities and the mass-loss rates of these
sources are not correlated. This supports the earlier findings that
the dust shells of low mass-loss rate stars can contain a significant
fraction of crystalline silicates without showing the characteristic
features in their emission spectra.
Description:
We select a sample of 28 O-rich evolved stars (see Table 1) based on
the following criteria: (i) the ISO/SWS spectra of most of these
sources exhibit prominent crystalline silicate emission features; (ii)
they exhibit distinguished 10 and 18µm amorphous silicate emission
features; (iii) they are relatively 'local' with a distance of less
than 5kpc to remove the influence of extinction and metallicity.
The ISO/SWS spectra are taken from the archive and the ∼2.4-45µm
wavelength range covers 6 out of 7 of the crystalline silicate feature
complexes summarized by Molster et al. (2002A&A...382..222M 2002A&A...382..222M), i.e. the
10, 18, 23, 28, 33.6 and 40µm complexes except the 69µm complex.
These archival data have already been processed by Sloan et al.
(2003ApJS..147..379S 2003ApJS..147..379S) in a uniform manner.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 142 28 Photometric data of our sample stars
table2.dat 70 28 Stellar and circumstellar parameters and the dust
mass-loss rates derived from 2-dust as well as
the silicate crystallinities ηcsi,f and
η'csi,f derived from pahfit
table3.dat 53 28 The visual extinction AV and the J-K colour index
of each object
tab5-13.dat 29 1098 The peak wavelength, FWHM and total emitted
fluxes of each silicate feature
(table4-table13 of the paper)
table14.dat 70 44 The mean wavelength and its range (variance) as
well as the mean FWHM and its range of each
crystalline silicate feature derived in this work
compared with that of Molster et al.
(2002A&A...382..222M 2002A&A...382..222M)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Star Star name
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- declination sign (J2000)
22- 23 I2 deg DEd declination (J2000)
25- 26 I2 arcmin DEm declination (J2000)
28- 32 F5.2 arcsec DEs declination (J2000)
34- 36 A3 --- Type Type
38- 41 I4 pc Dist Distance to Earth
42 A1 --- n_Dist Distance reference (1)
44- 48 F5.2 mag Umag ? Johnson U magnitude
50- 54 F5.2 mag Bmag Johnson B magnitude
56- 60 F5.2 mag Vmag Johnson V magnitude
62- 66 F5.2 mag Rmag ? Johnson R magnitude
68- 71 F4.2 mag Imag ? Johnson I magnitude
73- 77 F5.2 mag Jmag 2MASS J magnitude
79- 83 F5.2 mag Hmag 2MASS H magnitude
85- 89 F5.2 mag Kmag 2MASS K magnitude
91- 94 F4.2 mag W1mag WISE W1 magnitude
96- 99 F4.2 mag W2mag WISE W2 magnitude
101-105 F5.2 mag W3mag WISE W3 magnitude
107-111 F5.2 mag W4mag WISE W4 magnitude
113-118 F6.1 Jy F12 IRAS 12um flux
120-125 F6.1 Jy F25 IRAS 25um flux
128-133 F6.2 Jy F60 IRAS 60um flux
134 A1 --- l_F60 [L] L for upper limit in F60
136-140 F5.2 Jy F100 IRAS 100um flux
141 A1 --- u_F100 Unvertaity flag on F100
142 A1 --- l_F100 [U] U for upper limit in F100
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Note (1): References as follows:
b = Engels (1979A&AS...36..337E 1979A&AS...36..337E, Cat. V/18)
c = Jones et al. (2012, Cat. J/MNRAS/427/3209)
d = Ammons et al. (2006ApJ...638.1004A 2006ApJ...638.1004A, Cat. V/136)
e = Pickles & Depagne (2010PASP..122.1437P 2010PASP..122.1437P, Cat. VI/135)
f = Frinchaboy & Majewski (2008, Cat. J/AJ/136/118)
g = McDonald, Zijlstra & Boyer (2012, Cat. J/MNRAS/427/343)
h = Famaey et al. (2005, Cat. J/A+A/430/165)
i = Richards et al. (2012, Cat. J/A+A/546/A16)
j = Kim, Cho & Kim (2014, Cat. J/AJ/147/22)
k = Palagi et al. (1993, Cat. J/A+AS/101/153)
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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- 7 A7 --- Star Star name
9- 12 I4 K T* Stellar temperature
14- 20 E7.3 Lsun L* Steallar luminosity
22- 28 E7.3 cm R* Stellar radius
30- 33 F4.1 --- rmin Minimum radius in R* unit
35- 41 F7.1 --- rmax Maximum radius in R* unit
43- 50 E8.3 g/cm3 rhomin Minimum density
52- 58 E7.3 Msun/yr dM/dtdust Dust mass loss rate
60- 64 F5.3 --- eta Silicate crystallinity, ηcsi,f (1)
66- 70 F5.3 --- etap Silicate crystallinity, η'csi,f (2)
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Note (1): ηcsi,f ≅ Pcsi/(Pcsi+Pasi+Pcon)
Note (2): η'csi,f_ ≅ Pcsi/(Pcsi+Pasi)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Star Star name
9- 13 F5.2 mag Jmag Observed J magnitude
17- 21 F5.2 mag Kmag Observed K magnitude
25- 28 F4.2 mag J-K ? Observed J-K colour index
33- 36 F4.2 mag (J-K)int ? Intrinsic J-K colour index
41- 45 F5.3 mag AV Visual extinction
49- 53 A5 --- Ref Source of measurements
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Byte-by-byte Description of file: tab5-13.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Star Star name
9- 13 F5.2 um lambda Peak wavelength
14 A1 --- n_lambda [*] * for amorphous silicate
16- 20 F5.2 um FWHM FWHM (γλ)
22- 29 E8.4 W/m2 P ? Total emitted flux (1)
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Note (1): The total emitted flux (P) is only tabulated for those features
with P exceeding 10-21W/m2.
P ≅ {Int}{DELTA}F_νdν
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Byte-by-byte Description of file: table14.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 um Mean wavelength (this work)
6 A1 --- n_ [*] Note on (this work)
8- 12 F5.2 um b_lambda Minimum wavelength value (this work)
14- 18 F5.2 um B_lambda Maximum wavelength value (this work)
20- 24 F5.2 um Mean FWHM value (this work)
26- 30 F5.2 um b_ Minimum FWHM value (this work)
32- 36 F5.2 um B_ Maximum FWHM value (this work)
38- 42 F5.2 um M Mean wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
43 A1 --- n_M [*] Note on M
45- 49 F5.2 um b_lambdaM Minimum wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
51- 55 F5.2 um B_lambdaM Maximum wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
57- 60 F4.2 um M Mean wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
62- 65 F4.2 um b_M Minimum wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
67- 70 F4.2 um B_M Maximum wavelength
(Molster et al., 2002A&A...382..222M 2002A&A...382..222M)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Mar-2020