J/AJ/141/11 Spitzer observations of planet-host stars (Dodson-Robinson+, 2011)
A Spitzer infrared spectrograph study of debris disks around planet-host stars.
Dodson-Robinson S.E., Beichman C.A., Carpenter J.M., Bryden G.
<Astron. J., 141, 11 (2011)>
=2011AJ....141...11D 2011AJ....141...11D
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, infrared
Keywords: circumstellar matter - infrared: stars - Kuiper belt: general -
planetary systems - planets and satellites: formation
Abstract:
Since giant planets scatter planetesimals within a few tidal radii of
their orbits, the locations of existing planetesimal belts indicate
regions where giant planet formation failed in bygone protostellar
disks. Infrared observations of circumstellar dust produced by
colliding planetesimals are therefore powerful probes of the formation
histories of known planets. Here we present new Spitzer infrared
spectrograph (IRS) spectrophotometry of 111 solar-type stars,
including 105 planet hosts. Our observations reveal 11 debris disks,
including two previously undetected debris disks orbiting HD 108874
and HD 130322. Combining the 32um spectrophotometry with previously
published MIPS photometry, we find that the majority of debris disks
around solar-type stars have temperatures in the range
60≲Tdust≲100K. Assuming a dust temperature Tdust=70K, which is
representative of the nine debris disks detected by both IRS and MIPS,
debris rings surrounding Sun-like stars orbit between 15 and 240AU
depending on the mean particle size. Our observations imply that the
planets detected by radial-velocity searches formed within 240AU of
their parent stars. If any of the debris disks studied here have
mostly large, blackbody emitting grains, their companion giant planets
must have formed in a narrow region between the ice line and 15AU.
Description:
The main sample of extrasolar planetary systems was selected for
Spitzer program 40096 (PI: J. Carpenter) from the compilation reported
in the Extrasolar Planets Encyclopaedia (http://exoplanet.eu) as of
2007 February 16.
We also present observations of nine solar-type stars with previously
unpublished data from other IRS programs. From IRS program 41 (PI: G.
Rieke), we included the planet hosts HD 50554, HD 52265, HD 117176 (70
Vir), and HD 134987, bringing the total number of planet hosts in our
sample to 105. Finally, we included the stars without planets HD 166,
HD 33262, and HD 33636 from program 41, and HD 105211 and HD 219482
from program 2343 (PI: C. Beichman). Our final sample includes 111
stars, six of which have no detected planets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 112 Observed stellar sample
table2.dat 68 111 IRS 30-34um spectrophotometric results
refs.dat 101 31 References
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See also:
J/ApJ/705/1226 : Planet-bearing stars in Spitzer (Bryden+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD ? HD number of star
8- 18 A11 --- Name Other name of star
20- 31 A12 --- SpType MK spectral type
33- 36 I4 K Teff Effective temperature
37 A1 --- n_Teff [c] c: based on tabulated values for Teff
versus V-K
39- 42 A4 --- r_Teff Reference for Teff, in refs.dat file
46- 50 F5.2 mag Vmag V magnitude
52- 55 F4.1 pc Dist Heliocentric distance
57 I1 --- Pl Number of planets
58 A1 --- u_Pl [d] planet existence under debate (1)
60 A1 --- l_Ld*70 Limit flag on Ld*70
61- 65 F5.2 10-5 Ld*70 ?=- Dust luminosity (Ldust/L*) at 70um
67- 71 A5 --- r_Ld*70 Reference for Ld*70, in refs.dat file
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Note (1): Planet's existence under debate; see Eggenberger et al.
(2007A&A...466.1179E 2007A&A...466.1179E).
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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- 6 I6 --- HD ?=- HD number of star
8- 18 A11 --- Name Other name of star
20- 26 F7.2 mJy F* ? 30-34um flux for a perfect photosphere
28- 34 F7.2 mJy Fobs ? Frequency-weighted average observed flux
36- 39 F4.2 --- Sigma ? Dispersion of N=(Fobs-F*)/σ
41- 46 F6.3 --- Fd/F* ? Dust flux to stellar flux ratio (1)
47 A1 --- l_Ld/L* Limit flag on Ld
48- 51 F4.1 10-5 Ld/L* ? Dust luminosity (relative to star luminosity=
53 A1 --- l_Td Limit flag on Ld
54- 56 I3 K Td ? Dust temperature (2)
58- 59 I2 K e_Td ? rms uncertainty on Td
60 A1 --- n_Td [c] Note on Td for HD 219482 (3)
61- 68 A8 --- Tlim Dust temperature interval
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Note (1): Upper limits to the dust luminosity are calculated assuming a
single-temperature blackbody with Tdust=115K. For cold dust undetected by
both MIPS and IRS, the true luminosity ratio may be higher than the value
quoted here. See Section 5 for further discussion of the relationship between
observed 30-34µm fluxes and grain luminosity.
Note (2): Grain temperature estimates are based on the blackbody approximation.
For a discussion of temperature as a function of grain size, see Section 6.
Note (3): c: Our temperature measurement for the circumstellar dust of HD 219482
agrees with that of Beichman et al. (2006ApJ...652.1674B 2006ApJ...652.1674B), who calculated
Tdust = 82±3K based on 24 and 70um photometry.
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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- 5 A5 --- Ref Reference code
7- 25 A19 --- BibCode BibCode
27- 47 A21 --- Aut Author's name
49-101 A53 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Jul-2012