J/AJ/153/25 Near-infrared observations of 84 KOI systems (Atkinson+, 2017)
Probability of the physical association of 104 blended companions to Kepler
Objects of Interest using visible and near-infrared adaptive optics photometry.
Atkinson D., Baranec C., Ziegler C., Law N., Riddle R., Morton T.
<Astron. J., 153, 25-25 (2017)>
=2017AJ....153...25A 2017AJ....153...25A (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Stars, double and multiple ; Photometry, infrared ;
Effective temperatures ; Spectral types ; Stars, diameters ;
Stars, distances
Keywords: binaries: close - planetary systems -
planets and satellites: detection -
planets and satellites: fundamental parameters
Abstract:
We determine probabilities of physical association for stars in
blended Kepler Objects of Interest (KOIs), and find that
14.5%-3.4%+3.8% of companions within ∼4'' are consistent with
being physically unassociated with their primary. This produces a
better understanding of potential false positives in the Kepler
catalog and will guide models of planet formation in binary systems.
Physical association is determined through two methods of calculating
multi-band photometric parallax using visible and near-infrared
adaptive optics observations of 84 KOI systems with 104 contaminating
companions within ∼4''. We find no evidence that KOI companions with
separations of less than 1'' are more likely to be physically
associated than KOI companions generally. We also reinterpret transit
depths for 94 planet candidates, and calculate that 2.6%±0.4% of
transits have R>15R⊕, which is consistent with prior modeling
work.
Description:
The initial observations identifying companion candidates are from
multiple Robo-AO observing runs on the Palomar Observatory 1.5m
telescope, spanning 2012 July to September, 2013 April to October,
2014 June to September, and 2015 June. Observations were in either
Sloan-i or a long-pass 600nm (LP600) filter, the latter being similar
to the Kepler-bandpass when combined with the EMCCD's quantum
efficiency curve for red/cool stars.
The near-infrared observations are from the Near-InfraRed Camera 2
(NIRC2) instrument on the 10m Keck II telescope, conducted on 2013
June 24, August 24 and 25, 2014 August 17, 2015 July 25, and August 4
in the J, H, K, and/or Kp filters in the narrow mode of NIRC2
(9.952mas/pixel).
The relative positions and raw contrast measurements of imaged
companions are presented in Table4. The reduced apparent magnitudes,
which use both measured contrasts and canonical apparent magnitudes of
combined systems in Kepler literature, are presented in Table5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 180 Fitted stellar parameters
table2.dat 143 89 Adjusted transit depth and candidate sizes
table3.dat 34 38 Probability of R>15R⊕ for each planet
candidate
table4.dat 64 104 *Measured JHK contrasts
table5.dat 75 186 *Apparent magnitudes of resolved KOI components
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Note on table4.dat: Relative locations and near-infrared contrast measurements
of observed Kepler Objects of Interest (KOI).
Note on table5.dat: Apparent magnitudes of individual stars from contrast
measurements and literature values of blended system.
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJS/224/12 : Kepler planetary candidates. VII. 48-month (Coughlin+, 2016)
J/AJ/152/18 : Robo-AO Kepler planetary candidate survey. II. (Baranec+, 2016)
J/AJ/147/119 : Catalog of sources in the Kepler FOV (Coughlin+, 2014)
J/ApJS/211/2 : Revised stellar prop. of Q1-16 Kepler targets (Huber+, 2014)
J/ApJ/791/35 : Detection of Kepler planet candidates host stars (Law+, 2014)
J/ApJ/783/4 : Kepler multi-planet candidate systems (Wang+, 2014)
J/ApJ/753/90 : Parameters of K5 and later type Kepler stars (Mann+, 2012)
J/AJ/144/42 : Infrared photometry of 90 KOIs (Adams+, 2012)
J/A+A/546/A10 : Multiplicity in transiting planet-host stars (Lillo-Box+, 2012)
J/ApJ/738/170 : False positive Kepler planet candidates (Morton+, 2011)
J/AJ/142/160 : Kepler Mission. II. Eclipsing binaries in DR2 (Slawson+, 2011)
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/ApJ/725/331 : Astrometry in the Galactic Center (Yelda+, 2010)
J/AJ/134/2340 : Membership of Praesepe and Coma Berenices (Kraus+, 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- KOI Kepler Object of Interest identifier
5 A1 --- m_KOI Component of the KOI system (A, B, C, or D)
7- 8 A2 --- SpT Spectral type via Kraus & Hillenbrand 2007
(Cat. J/AJ/134/2340) (1)
10- 13 A4 --- f_KHRad [{=>}] Limit flag on KHRad
16- 19 F4.2 Rsun KHRad [0.2/1.5]? Radius via Kraus & Hillenbrand 2007
(Cat. J/AJ/134/2340) (R/RSun) (1)
21- 24 F4.2 Rsun E_KHRad [0.01/0.4]? Upper uncertainty in KHRad
26- 29 F4.2 Rsun e_KHRad [0.01/0.5]? Lower uncertainty in KHRad
31- 34 A4 --- f_KHDist [{=>}] Limit flag on KHDist
36- 39 I4 pc KHDist [77/5591]? Distance via Kraus & Hillenbrand 2007
(Cat. J/AJ/134/2340) (dist) (1)
41- 44 I4 pc E_KHDist [3/6446]? Upper uncertainty in KHDist
46- 49 I4 pc e_KHDist [6/1596]? Lower uncertainty in KHDist
51- 54 F4.2 --- KHsigma [0.01/10]? Standard deviation via Kraus &
Hillenbrand 2007 (Cat. J/AJ/134/2340)
(σunassoc) (1)
56- 59 I4 K BTeff [4398/6229]? Effective temperature via Brown
2011 (Cat. J/AJ/142/112) (Teff) (1)
61- 64 I4 K E_BTeff [57/1280]? Upper uncertainty in BTeff
66- 68 I3 K e_BTeff [83/835]? Lower uncertainty in BTeff
70- 73 F4.2 Rsun BRad [0.7/1.1]? Stellar radius via Brown 2011
(Cat. J/AJ/142/112) (R/RSun) (1)
75- 78 F4.2 Rsun E_BRad [0.02/0.48]? Upper uncertainty in BRad
80- 83 F4.2 Rsun e_BRad [0.02/0.22]? Lower uncertainty in BRad
85- 88 I4 pc BDist [230/8742]? Distance via Brown 2011
(Cat. J/AJ/142/112) (dist) (1)
90- 93 I4 pc E_BDist [16/5561]? Upper uncertainty in BDist
95- 98 I4 pc e_BDist [12/2760]? Lower uncertainty in BDist
100-104 F5.2 --- Bsigma [0.03/12]? Standard deviation via Brown 2011
(Cat. J/AJ/142/112) (σunassoc) (1)
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Note (1): Stellar parameters as a result of two different fitting techniques.
σunassoc is the certainty (in standard deviations) that each
companion is physically unassociated with its host due to their respective
distances. The Kraus & Hillenbrand fit yields a stellar type and
corresponding radius (Kraus & Hillenbrand 2007, Cat. J/AJ/134/2340). Values
are interpolated between the table items in the source for improved
precision. The fit to the KIC primary standards from Brown yields effective
temperature and stellar radius for all stars with sufficient photometry, as
produced by comparison to stars with similar color-color measurements among
the 279 entries in the KIC Primary Standard catalog (Brown et al. 2011,
Cat. J/AJ/142/112). As noted, photometric type-fitting of Kepler targets
has been found to have a limiting accuracy of ±200K and ∼0.2dex
respectively, which is largely a function of age/composition and is not
taken into account here. For each primary/companion pair a distance
measurement was produced from the measured apparent and fitted absolute
magnitudes, and used to generate a confidence of non-association between
the two objects.
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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 F7.2 --- KOI Kepler Object of Interest identifier
9- 15 F7.3 mmag ADepth [0.02/228.6] Candidate A transit depth (1)
17- 21 F5.3 mmag e_ADepth [0.003/0.35] Uncertainty in ADepth
23- 27 F5.2 Rgeo ARad [0.7/69] Candidate A radius (1)
29- 32 F4.2 Rgeo E_ARad [0.01/1.9] Upper uncertainty in ARad
34- 37 F4.2 Rgeo e_ARad [0.01/1.5] Lower uncertainty in ARad
39- 46 F8.3 mmag BDepth [0.1/1261]?=-999 Candidate B transit depth (1)
48- 52 F5.3 mmag e_BDepth [0.01/4.7]? Uncertainty in BDepth
54- 57 A4 --- f_BRad [{=>}] Limit flag on BRad (2)
59- 64 F6.2 Rgeo BRad [1.1/97.1] Candidate B radius (1)
66- 69 F4.2 Rgeo E_BRad [0.01/8.7]? Upper uncertainty in BRad
71- 74 F4.2 Rgeo e_BRad [0/9.8]? Lower uncertainty in BRad
76- 82 F7.2 mmag CDepth ? Candidate C transit depth (1)
84- 88 F5.3 mmag e_CDepth [1.2/9.5]? Uncertainty in CDepth
90- 93 A4 --- f_CRad [{=>}] Limit flag on CRad (2)
95-102 F8.2 Rgeo CRad [4.8/100.3]? Candidate C radius (1)
104-108 F5.2 Rgeo E_CRad [2.6/15.8]? Upper uncertainty in CRad
110-113 F4.2 Rgeo e_CRad [0.8/9.7]? Lower uncertainty in CRad
115-120 F6.2 mmag DDepth [60.4/356.4]? Candidate D transit depth (1)
122-126 F5.3 mmag e_DDepth [3.8/5.6]? Uncertainty in DDepth
128-132 F5.2 Rgeo DRad [10.1/23.1]? Candidate D radius (1)
134-138 F5.2 Rgeo E_DRad [4.8/10.4]? Upper uncertainty in DRad
140-143 F4.2 Rgeo e_DRad [2.6/5.8]? Lower uncertainty in DRad
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Note (1): The transit depth and radius relative to potential host for all
transit candidates, evaluated for association with all possible host stars.
Evaluated only for KOIs with Kepler-band contrast observations.
Note (2): Candidates with radii lower limits indicate the depth of the eclipse
is equal to or greater than the star's full light.
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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 F7.2 --- KOI Kepler Object of Interest identifier
9 A1 --- f_KOI [abc] Disposition flag on KOI (a,c=identified
elsewhere as false positive, b=confirmed
elsewhere) (1)
11- 14 F4.2 --- AProb [0/1] Candidate A probability (PA) (2)
16- 19 F4.2 --- BProb [0/1] Candidate B probability (PB) (2)
21- 24 F4.2 --- CProb [0/1]? Candidate C probability (PC) (2)
26- 29 F4.2 --- DProb [0/1]? Candidate D probability (PD) (2)
31- 34 F4.2 --- TProb [0/1] Total probability
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Note (1): Flags are fully explained as follows:
a = Disposition is FALSE POSITIVE in the Exoplanet Archive
(http://exoplanetarchive.ipac.caltech.edu) as of 2015 September;
b = Disposition is CONFIRMED in the Exoplanet Archive
(http://exoplanetarchive.ipac.caltech.edu) as of 2015 September 18;
c = Other literature indicates that the candidate is false positive. See
Section 3.5 for more details.
Note (2): Estimated probabilities that each KOI planet candidate has a radius
R>15R⊕, for each potential host and summed across all. Only
candidates with P(R>15R⊕)≥0.01 are listed. For full transit depth
and planet size estimates, see Table2.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- KOI Kepler Object of Interest identifier
5 A1 --- m_KOI Component of the KOI system (B, C, or D)
7- 11 F5.3 arcsec Sep [0.1/4.2] Separation (sep)
13- 17 F5.3 arcsec e_Sep [0.001/0.4] Uncertainty in Sep (1)
19- 23 F5.1 deg PA [4/357.3] Position angle (ang)
25- 28 F4.1 deg e_PA [0.1/10.7] Uncertainty in PA (1)
30- 34 F5.3 mag DJmag [0.06/8]? Measured J band contrast (ΔmJ)
36- 40 F5.3 mag e_DJmag [0.05/0.5]? Uncertainty in DJmag (2)
42- 46 F5.3 mag DHmag [0.05/4.9]? Measured H band contrast
(ΔmH)
48- 52 F5.3 mag e_DHmag [0.007/0.8]? Uncertainty in DHmag (2)
54- 58 F5.3 mag DKmag [0.05/6.6] Measured K band contrast (ΔmK)
60- 64 F5.3 mag e_DKmag [0.008/0.4] Uncertainty in DKmag (2)
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Note (1): Use of co-added images reduces separation/angle measurement
uncertainties to the single-pixel level.
Note (2): Contrast uncertainties are systematically measured by varying the
photometric aperture size.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- KOI Kepler Object of Interest identifier
5 A1 --- m_KOI Component of the KOI system (A, B, C, or D)
7- 12 F6.3 mag Jmag [9.7/19.5]? Apparent J band magnitude (mJ) (1)
14- 18 F5.3 mag e_Jmag [0.02/0.5]? Uncertainty in Jmag
20- 25 F6.3 mag Hmag [9.6/17.9]? Apparent H band magnitude (mH) (1)
27- 31 F5.3 mag e_Hmag [0.01/0.7]? Uncertainty in Hmag
33- 39 F7.4 mag Kmag [9.5/18.4] Apparent K band magnitude (mK) (1)
41- 45 F5.3 mag e_Kmag [0.01/0.35] Uncertainty in Kmag
47- 52 F6.3 mag imag [12.1/19]? Apparent i band magnitude (mi) (1)
54- 58 F5.3 mag e_imag [0.02/0.63]? Uncertainty in imag
60 A1 --- f_imag [*d] Flag for imag not determined (*=not all
companions were detected, d=no blended
measurement) (2)
62- 67 F6.3 mag Kpmag [10.5/22.1]? Apparent Kepler band magnitude
(mKep) (1)
69- 73 F5.3 mag e_Kpmag [0.02/1.9]? Uncertainty in Kpmag
75 A1 --- f_Kpmag [*] Flag for Kpmag not determined (*=not all
companions were detected) (2)
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Note (1): The great majority of JHK values are from the 2MASS catalog (Liebert
et al. 1995AAS...187.7502L 1995AAS...187.7502L), while sources for i and Kepler are more
varied. All values are as reported in the Exoplanet Archive
(http://exoplanetarchive.ipac.caltech.edu), except JHK for KOI0268, which
is linked to a spurious 2MASS entry.
Note (2): The flag codes are defined as follows:
* = Not all companions were detected by Robo-AO. Without contrast
measurements for all objects we can not accurately determine
the apparent magnitudes;
d = Although a contrast measurement has been made, there is no blended
measurement, and we can not determine the apparent magnitude.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 19-Jun-2017