J/ApJ/738/122 ScoCen debris disks Around F- and G-type stars (Chen+, 2011)
A Magellan MIKE and Spitzer MIPS study of 1.5-1.0M☉ stars in
Scorpius-Centaurus.
Chen C.H., Mamajek E.E., Bitner M.A., Pecaut M., Su K.Y.L., Weinberger A.J.
<Astrophys. J., 738, 122 (2011)>
=2011ApJ...738..122C 2011ApJ...738..122C
ADC_Keywords: Associations, stellar ; Photometry, infrared ; Stars, F-type ;
Stars, G-type
Keywords: circumstellar matter - infrared, planetary systems -
planets and satellites: formation - protoplanetary disks -
stars: kinematics and dynamics - stars: solar type
Abstract:
We obtained Spitzer Space Telescope Multiband Imaging Photometer for
Spitzer (MIPS) 24 micron and 70 micron observations of 182 nearby,
Hipparcos F- and G-type common proper motion single and binary systems
in the nearest OB association, Scorpius-Centaurus. We also obtained
Magellan/MIKE R∼50,000 visual spectra at 3500-10500Å for 181
candidate ScoCen stars in single and binary systems. Combining our
MIPS observations with those of other ScoCen stars in the literature,
we estimate 24 micron F+G-type disk fractions of 9/27 (33%±11%),
21/67 (31%±7%), and 25/71 (35%±7%) for Upper Scorpius (∼10Myr),
Upper Centaurus Lupus (∼15Myr), and Lower Centaurus Crux (∼17Myr),
respectively. We confirm previous IRAS and MIPS excess detections and
present new discoveries of 41 protoplanetary and debris disk systems,
with fractional infrared luminosities ranging from LIR/L*=10-5 to
1.0-2 and grain temperatures ranging from Tgr=40-300K. We searched
for an increase in 24 micron excess at an age of 15-20Myr, consistent
with the onset of debris production predicted by coagulation N-body
simulations of outer planetary systems. We found such an increase
around 1.5M☉ stars but discovered a decrease in the 24 micron
excess around 1.0M☉ stars. We additionally discovered that the
24 micron excess around 1.0M☉ stars is larger than predicted by
self-stirred models. Finally, we found a weak anti-correlation between
fractional infrared luminosity (LIR/L*) and chromospheric activity
(R'_HK), that may be the result of differences in stellar HK
properties, such as mass, luminosity, and/or winds. We obtained
Spitzer Space Telescope Multiband Imaging Photometer for Spitzer
(MIPS) 24 micron and 70 micron observations of 182 nearby, Hipparcos
F- and G-type common proper motion single and binary systems in the
nearest OB association, Scorpius-Centaurus.
We also obtained Magellan/MIKE R∼50,000 visual spectra at
3500-10500Å for 181 candidate ScoCen stars in single and binary
systems. Combining our MIPS observations with those of other ScoCen
stars in the literature, we estimate 24 micron F+G-type disk fractions
of 9/27 (33%±11%), 21/67 (31%±7%), and 25/71 (35%±7%) for Upper
Scorpius (∼10Myr), Upper Centaurus Lupus (∼15Myr), and Lower Centaurus
Crux (∼17Myr), respectively. We confirm previous IRAS and MIPS excess
detections and present new discoveries of 41 protoplanetary and debris
disk systems, with fractional infrared luminosities ranging from
LIR/L* = 10-5 to 10-2 and grain temperatures ranging from
Tgr=40-300K. We searched for an increase in 24 micron excess at an
age of 15-20Myr, consistent with the onset of debris production
predicted by coagulation N-body simulations of outer planetary
systems. We found such an increase around 1.5M☉ stars but
discovered a decrease in the 24 micron excess around 1.0M☉
stars. We additionally discovered that the 24 micron excess around
1.0M☉ stars is larger than predicted by self-stirred models.
Description:
We present (1) stellar radial velocities, Lithium equivalent widths,
rotation velocities, and Ca II R'_HK indices measured from Magellan
MIKE spectra and used to exclude non-members (Table 1), (2) 24 and 70
micron photometry measured from Spitzer MIPS images and used to
identify members with dusty disks (Table 2), and (3) debris disk
properties estimated from our estimated stellar properties and
far-infrared excesses (Table 4).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 127 192 Stellar properties (from Magellan/MIKE)
table2.dat 85 183 Spitzer MIPS 24 and 70 micron Fluxes
table4.dat 103 53 Single temperature blackbody model parameters
refs.dat 94 14 References
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- HIP Hipparcos star number number
6 A1 --- m_HIP [AB] Multiplicity index on HIP
8 A1 --- Bin [Y/N] Binary Flag
10 A1 --- LowV [Y/N] ΔV<0.06mag Flag
12 A1 --- HiV [Y/N] 0.06mag<ΔV<0.6mag Flag
14- 26 A13 --- SpType Spectral Type
29- 30 I2 --- r_SpType Reference for Spectral Type in refs.dat
32- 34 I3 pc Dist ? Hipparcos Distance
36- 38 I3 pc E_Dist ? 1-σ error on Distance (upper value)
40- 42 I3 pc e_Dist ? 1-σ error on Distance (lower value)
45- 48 F4.2 mag AV ? V-band Extinction
51- 54 F4.2 mag e_AV ? 1-σ error on A(V)
56- 57 A2 --- fLi [Y/N? ] Lithium Flag
59- 60 A2 --- fL* [Y/N? ] Luminosity Flag
62- 63 A2 --- fRV [Y/N? ] Radial Velocity Flag
65- 66 A2 --- fPM [Y/N? ] Proper Motion Flag
68- 69 A2 --- Mmb [Y/N? ] ScoCen Final Membership Flag
71- 73 A3 --- grp ScoCen Subgroup (G1)
75- 79 F5.1 km/s RV ? Stellar Radial Velocity
83- 85 F3.1 km/s e_RV ? 1-σ rms error on RV
87- 91 F5.3 ct/s ROSAT ? ROSAT Flux (count rate)
93 A1 --- l_FX Limit Flag on Surface X-ray Flux
95-101 E7.2 mW/m2 FX ? Stellar Surface X-ray Flux
103 A1 --- l_W(Li) Limit Flag on W(Li)
105-107 I3 0.1nm W(Li) ? Lithium Equivalent Width
110-111 I2 0.1nm e_W(Li) ? 1-σ rms error on W(Li)
113-115 I3 km/s vsini ? Projected Rotational Velocity
118-119 I2 km/s e_vsini ? 1-σ rms error on vsini
121-125 F5.2 [-] logR'HK ? CaII log(Rhk) Activity Index
127 A1 --- f_logR'HK CaII H and K Core Emission Flag
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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- 5 I5 --- HIP Hipparcos number
7 A1 --- f_F24 [Y/N] Source suffers from contamination at 24um
9- 21 A13 --- Name Star Name
23- 30 I8 --- AOR Astronomical Observing Request
32- 38 F7.2 mJy F24 MIPS 24um (Not Color-Corrected) Flux
41- 44 F4.2 mJy e_F24 1-σ rms error on F24 (1)
46- 52 F7.2 mJy F24p Predicted Photospheric MIPS 24um Flux
54- 57 F4.1 --- chi24 MIPS 24um Excess Significance
58 A1 --- --- [0]
60 A1 --- l_F70 Limit Flag on MIPS 70um Flux
62- 67 F6.1 mJy F70 MIPS 70um (Not Color-Corrected) Flux
68 A1 --- --- [0]
70- 71 I2 mJy e_F70 ? 1-σ rms error on F70um (1)
74- 78 F5.1 mJy P70 Predicted Photospheric MIPS 70um Flux
79 A1 --- --- [0]
82- 85 F4.1 --- chi70 ? MIPS 70-um Excess Significance
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Note (1): e_F24 and e_F70um are the statistical uncertainties in F24
and F70um photometry. The total uncertainty can be calculated by
adding the systematic, repeatability, and calibration uncertainties
in quadrature (see Section 2.1, 2011ApJ...738..122C 2011ApJ...738..122C).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- HIP Hipparcos number
6 A1 --- n_HIP [b] b: spectrum contains silicate emission
features
8- 19 A12 --- Name Star Name
21- 24 I4 --- Teff Stellar Effective Temperature
27- 30 F4.1 Lsun L* Stellar Luminosity
34- 36 F3.1 Lsun E_L* 1-σ error on L* (upper value)
40- 42 F3.1 Lsun e_L* 1-σ error on L* (lower value)
46- 48 F3.1 Msun M* Stellar Mass (1)
49 A1 --- f_M* [c] Flag on M* (2)
51- 52 I2 Myr Age Stellar Age
54 A1 --- l_Tgr Limit Flag on Tgr
56- 58 I3 K Tgr Grain Temperature
62- 68 E7.2 --- LIR/L* Fractional Infrared Luminosity
70- 72 F3.1 um amin Minimum Grain Size
74 A1 --- l_Dist limit on Dist
76- 78 I3 AU Dist Grain Distance
81- 88 F8.6 0.0123Mgeo Mdust Dust Mass, in Moon mass (M⊕/81.3)
90 A1 --- l_MPB limit on MPB
93- 98 F6.3 0.0123Mgeo MPB Parent Body Mass in Moon mass
101-103 A3 --- grp ScoCen Subgroup (G1)
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Note (1): Masses estimated using HR diagram fitting with D'Antona & Mazzitelli
(1997, 1997ApJ...477..519D 1997ApJ...477..519D) isochrones may be systematically
underestimated by 25% (Hillenbrand & White 2004, 2004ApJ...707..705H 2004ApJ...707..705H)
Note (2): The masses for HIP 79977, HIP 67497, HIP 67970, HIP 69720,
HIP 74499, HIP 75683, HIP 77432, HIP 79673, HIP 80921, HIP 57950,
HIP 58220, HIP 60348, HIP 62134, HIP 64184, and HIP 67068 were
estimated assuming age rather than isochrone fitting
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 3 I2 --- Ref Reference Code
5- 23 A19 --- BibCode BibCode
25- 48 A24 --- Aut Author's name
50- 94 A45 --- Com Comments
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Global notes:
Note (G1): Star-forming region name as follows:
US = Upper Scorpius
UCL = Upper Centaurus Lupus
LCC = Lower Centaurus Crux
N/A = not analysed
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Acknowledgements:
Christine Chen, cchen(at)stsci.edu
(End) Christine Chen [STScI, USA], Patricia Vannier [CDS] 02-Jan-2013