J/ApJ/736/89 Search for companions around nearby massive stars (Janson+, 2011)
High-contrast imaging search for planets and brown dwarfs around the most
massive stars in the solar neighborhood.
Janson M., Bonavita M., Klahr H., Lafreniere D., Jayawardhana R.,
Zinnecker H.
<Astrophys. J., 736, 89 (2011)>
=2011ApJ...736...89J 2011ApJ...736...89J
ADC_Keywords: Stars, nearby ; Photometry, infrared ; Stars, double and multiple
Keywords: brown dwarfs - planetary systems - stars: massive
Abstract:
In this study, we present high-contrast imaging of 18 nearby massive
stars of which 15 are in the B2-A0 spectral-type range and provide
excellent sensitivity to wide companions. By comparing our
sensitivities to model predictions of disk instability based on
physical criteria for fragmentation and cooling, and using Monte Carlo
simulations for orbital distributions, we find that ∼85% of such
companions should have been detected in our images on average. Given
this high degree of completeness, stringent statistical limits can be
set from the null-detection result, even with the limited sample size.
We find that <30% of massive stars form and retain disk instability
planets, brown dwarfs, and very low mass stars of <100Mjup within
300AU, at 99% confidence. These results, combined with previous
findings in the literature, lead to the conclusion that core accretion
is likely the dominant mode of planet formation.
Description:
The observations presented in this paper were taken with adaptive
optics using primarily NIRI (Near InfraRed Imager and Spectrometer)
at Gemini North (filter H:1.65um, CH4(short):1.58um,
K-continuum:2.0975um, Brα:4.052um), and additionally IRCS at
Subaru (Brα:4.052um) and NIRC2 (H:1.633um) at Keck.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 62 40 Summary of observations (18 targets)
table2.dat 104 18 Target stars properties
table4.dat 56 203 Properties of all point sources
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/352/555 : Fundamental parameters of stars (Allende Prieto+, 1999)
J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)
J/ApJS/152/251 : Indo-US library of coude feed stellar spectra (Valdes+, 2004)
J/ApJ/670/1367 : Gemini Deep Planet Survey (Lafreniere+, 2007)
J/A+A/506/501 : Eclipsing binaries in CoRoT-LRc01 field (Cabrera+, 2009)
J/A+A/509/A52 : Search for companions with VLT/NACO (Chauvin+, 2010)
J/A+A/525/A71 : Atmospheric parameters for 1273 stars (Wu+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Target name
13- 17 I5 --- HIP [677/97649] HIP number
19- 23 A5 --- Inst Instrument (IRCS, NIRC2, NIRI) (1)
25- 33 A9 --- Filt Filter (Brα, CH4S, H, Kc)
35- 45 A11 "YYYY/MMM/DD" Date Observation date
47- 50 F4.1 s DIT [0.5/30] Detector Integration Time
52- 53 I2 --- Coadd [1/60] Number of coadded images
55- 57 I3 --- NF [45/317] Frame number
59- 62 F4.1 deg Rot [18.2/93] Rotation angle
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Note (1): Instruments are:
NIRI = Near-Infrared Imager at Gemini North
IRCS = Infrared Camera and Spectrograph at the Subaru Telescope
NIRC2 = Near-Infrared camera at Keck
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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- 11 A11 --- Name Target name
13- 17 I5 --- HIP [677/97649] HIP number
19- 20 I2 h RAh Hour of right ascension (J2000)
22- 23 I2 min RAm Minute of right ascension (J2000)
25- 29 F5.2 s RAs Second of right ascension (J2000)
31 A1 --- DE- Second of right ascension (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of declination (J2000)
43- 47 A5 --- SpT MK spectral type
49- 53 F5.2 mag Hmag [-0.03/13.11] 2MASS H-band magnitude (typical
uncertainties are ±0.2mag)
55- 58 F4.1 pc Dist [5.1/74.5] Distance from Hipparcos (1)
60- 66 F7.2 mas/yr pmRA [-249.4/536.87] Proper motion in RA
68- 74 F7.2 mas/yr pmDE [-935.45/385.57] Proper motion in DEC
76- 78 I3 Myr Age [20/700] Estimated age
80- 82 I3 Myr E_Age Positive error on Age
84- 86 I3 Myr e_Age Negative error on Age
88- 90 F3.1 Msun Mass [1.7/8.4] Mass of the primary in the case of
binaries, primordial mass for white dwarfs
92- 94 F3.1 Msun E_Mass Positive error on Mass
96- 98 F3.1 Msun e_Mass Negative error on Mass
100-104 F5.2 [Sun] [Fe/H] [-0.44/0.4]? Metal abundance [Fe/H] (2)
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Note (1): Distances from Hipparcos (Perryman et al. 1997, Cat. I/239). Typical
uncertainties are 1%-5% in distance and 0.5-1mas/yr in proper motion.
Note (2): From Gray et al. (2003, Cat. J/AJ/126/2048), Valdes et al. (2004,
Cat. J/ApJS/152/251), and Wu et al. (2011, Cat. J/A+A/525/A71).
Typical uncertainties are 0.1dex when quoted in the literature.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- HIP [677/93805] HIP number
7- 9 I3 --- Seq [1/105] ID source number
11- 16 F6.3 arcsec Sep [0.572/14.679] Separation
18- 22 F5.3 arcsec e_Sep Sep uncertainty
24- 29 F6.2 deg PA [0.63/359.63] Position angle
31- 34 F4.2 deg e_PA PA uncertainty
36- 40 F5.2 mag Dmag [5.1/18.76] Magnitude difference with HIP
42- 45 F4.2 mag e_Dmag Dmag uncertainty
46 A1 --- f_Dmag [bc] which contrast band (1)
48- 54 F7.2 yr Epoch [2008.65/2010.91] Epoch of observation
56 A1 --- S [BCU] Status of detection (C=confirmed) (2)
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Note (1): Flag as follows:
b = Contrast in H band
c = Contrast in Kc band
Note (2): Status flag as follows:
B = background source,
C = confirmed companion,
U = unconfirmed
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 14-Dec-2012