J/ApJ/798/87 Spitzer/IRS debris disk catalog. II. (Mittal+, 2015)
The Spitzer infrared spectrograph debris disk catalog.
II. Silicate feature analysis of unresolved targets.
Mittal T., Chen C.H., Jang-Condell H., Manoj P., Sargent B.A., Watson D.M.,
Lisse C.M.
<Astrophys. J., 798, 87 (2015)>
=2015ApJ...798...87M 2015ApJ...798...87M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, masses ; Spectral types ; Stars, ages ;
Stars, distances ; Effective temperatures ; Photometry, infrared
Keywords: circumstellar matter - infrared: planetary systems - infrared: stars -
zodiacal dust
Abstract:
During the Spitzer Space Telescope cryogenic mission, astronomers
obtained Infrared Spectrograph (IRS) observations of hundreds of
debris disk candidates that have been compiled in the Spitzer IRS
Debris Disk Catalog (Chen et al. 2014, J/ApJS/211/25). We have
discovered 10 and/or 20 µm silicate emission features toward 120
targets in the catalog and modeled the IRS spectra of these sources,
consistent with MIPS 70 µm observations, assuming that the grains
are composed of silicates (olivine, pyroxene, forsterite, and
enstatite) and are located either in a continuous disk with power-law
size and surface density distributions or thin rings that are
well-characterized using two separate dust grain temperatures. For
systems better fit by the continuous disk model, we find that (1) the
dust size distribution power-law index is consistent with that
expected from a collisional cascade, q=3.5-4.0, with a large number of
values outside this range, and (2) the minimum grain size, amin,
increases with stellar luminosity, L*, but the dependence of amin
on L* is weaker than expected from radiation pressure alone. In
addition, we also find that (3) the crystalline fraction of dust in
debris disks evolves as a function of time with a large dispersion in
crystalline fractions for stars of any particular stellar age or mass,
(4) the disk inner edge is correlated with host star mass, and (5)
there exists substantial variation in the properties of coeval disks
in Sco-Cen, indicating that the observed variation is probably due to
stochasticity and diversity in planet formation.
Description:
During our blackbody spectral energy distribution (SED) analysis of
sources in the Spitzer IRS Debris Disk Catalog (Chen et al. 2014,
J/ApJS/211/25), we discovered solid-state emission features toward a
substantial fraction of the sources in our sample, including 10 and
20 µm silicate emission features. More accurate modeling of the
spectra for these objects requires the use of grain emissivities and
provides refinements in the estimated dust properties (e.g.,
composition and grain temperature). Therefore, we have carried out a
second analysis, quantitatively searching all of the sources in the
catalog for silicate emission at 5-14 and 14-36 µm and modeling
their Spitzer IRS spectra using silicate emissivities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 139 120 Stellar Properties
refs.dat 74 72 References
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See also:
J/ApJ/697/1578 : A debris disk study of Praesepe (Gaspar+, 2009)
J/ApJ/705/1646 : Debris disks in Upper Sco (Carpenter+, 2009)
J/ApJS/188/242 : Variations on debris disks. II. (Kenyon+, 2010)
J/ApJ/738/122 : ScoCen debris disks Around F- and G-type stars (Chen+, 2011)
J/ApJ/745/147 : Binaries among debris disk stars (Rodriguez+, 2012)
J/ApJ/756/133 : ScoCen debris disks around B- and A-type stars (Chen+, 2012)
J/ApJ/768/25 : Spitzer and Herschel observations of debris disks
(Gaspar+, 2013)
J/ApJS/211/25 : Spitzer/IRS debris disk catalog. I. (Chen+, 2014)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Star's name
10 A1 --- n_Name [bce] Note on Name (1)
12- 15 F4.2 Msun M* Stellar mass
16 A1 --- n_M* [a] Note on M* (2)
18- 25 A8 --- SpType Spectral type
27- 32 F6.2 pc Dist ? Distance
34- 38 I5 K Teff [4000/16000] Effective temperature
40- 45 F6.2 Lsun L* ? Stellar luminosity
47- 54 E8.3 --- LIR/L* ? Ratio of IR to total luminosities
56- 59 I4 Myr Age [3/5670]? Stellar age
61- 70 A10 --- Assoc Association identifier
72 A1 --- n_Assoc [d] Note on Assoc (3)
74- 81 A8 --- r_Assoc Reference(s) on Assoc (see refs.dat file)
83- 84 A2 --- Binary [Y N MB] Binary system ?
86- 96 F11.5 AU Sep ? Binary separation
98-108 A11 --- r_Binary Reference(s) on Binary (see refs.dat file)
110-117 E8.3 mW/m2 F10 ? 10 µm band flux
119-124 F6.2 --- S/N10 ? Signal-to-noise ratio of 10 µm flux
126-133 E8.3 mW/m2 F20 20 µm band flux
135-139 F5.2 --- S/N20 ? Signal-to-noise ratio of 20 µm flux
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Note (1): Note as follows:
b = 1RXS=1RXSJ051111.1+281353;
c = Cl NGC=Cl* NGC 2422 PMS 1121;
e = ID8=2MASSJ08090250-4858172.
Note (2): Note as follows:
a = Stellar mass estimated using the V-band mass-luminosity relationship
(Fang & Yan-Ning 2010ChA&A..34..277X 2010ChA&A..34..277X).
Note (3): Note as follows:
d = M47=NGC 2422 Open Cluster.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Num [5/130] Reference number
5- 30 A26 --- Aut Author's name(s)
34- 52 A19 --- Bibcode Reference bibcode
54- 74 A21 --- Comm Comment on reference
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History:
From electronic version of the journal
References:
Chen et al., Paper I, 2014ApJS..211...25C 2014ApJS..211...25C, Cat. J/ApJS/211/25
(End) Prepared by Tiphaine Pouvreau [CDS] 24-Aug-2017