J/ApJ/810/95 Kepler pipeline S/N studies. II. 2011 data (Christiansen+, 2015)
Measuring transit signal recovery in the Kepler pipeline.
II. detection efficiency as calculated in one year of data.
Christiansen J.L., Clarke B.D., Burke C.J., Seader S., Jenkins J.M.,
Twicken J.D., Catanzarite J.D., Smith J.C., Batalha N.M., Haas M.R.,
Thompson S.E., Campbell J.R., Sabale A., Uddin A.K.
<Astrophys. J., 810, 95 (2015)>
=2015ApJ...810...95C 2015ApJ...810...95C (SIMBAD/NED BibCode)
ADC_Keywords: Planets
Keywords: methods: data analysis; techniques: photometric
Abstract:
The Kepler planet sample can only be used to reconstruct the
underlying planet occurrence rate if the detection efficiency of the
Kepler pipeline is known; here we present the results of a second
experiment aimed at characterizing this detection efficiency. We
inject simulated transiting planet signals into the pixel data of
∼10000 targets, spanning one year of observations, and process the
pixels as normal. We compare the set of detections made by the
pipeline with the expectation from the set of simulated planets, and
construct a sensitivity curve of signal recovery as a function of the
signal-to-noise of the simulated transit signal train. The sensitivity
curve does not meet the hypothetical maximum detection efficiency;
however, it is not as pessimistic as some of the published estimates
of the detection efficiency. For the FGK stars in our sample, the
sensitivity curve is well fit by a gamma function with the
coefficients a=4.35 and b=1.05. We also find that the pipeline
algorithms recover the depths and periods of the injected signals with
very high fidelity, especially for periods longer than 10 days. We
perform a simplified occurrence rate calculation using the measured
detection efficiency compared to previous assumptions of the detection
efficiency found in the literature to demonstrate the systematic error
introduced into the resulting occurrence rates. The discrepancies in
the calculated occurrence rates may go some way toward reconciling
some of the inconsistencies found in the literature.
Description:
For computational reasons we limit this first multi-quarter transit
injection experiment to one year of data comprising Kepler Q9-Q12
(2011).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 80 10341 Parameters of the injected transiting planets
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/ApJS/217/18 : Potential transit signals in Kepler Q1-Q17 (Seader+, 2015)
J/ApJS/217/16 : Kepler planetary candidates. V. 3yr Q1-Q12 (Rowe+, 2015)
J/ApJS/211/2 : Revised properties of Q1-16 Kepler targets (Huber+, 2014)
J/ApJS/210/19 : Kepler planetary candidates. IV. 22 months (Burke+, 2014)
J/ApJS/207/35 : Kepler pipeline signal-to-noise studies (Christiansen+, 2013)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/PASP/124/1279 : Q3 Kepler's combined photometry (Christiansen+, 2012)
J/ApJS/199/24 : The first three quarters of Kepler mission (Tenenbaum+, 2012)
http://exoplanetarchive.ipac.caltech.edu/ : NASA exoplanet archive
http://archive.stsci.edu/kepler/ : MAST Kepler home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC [757099/12984422] Kepler identifier
10- 11 I2 --- Sky [4/84] Sky group identifier (1)
13- 20 F8.4 d Per [0.5/184.6] Orbital period
22- 27 F6.4 --- Rp/R* [0.004/0.2] Ratio of planet radius to stellar radius
29- 36 F8.4 --- d/R* [0.6/227] Ratio of planet separation to
stellar radius
38- 43 F6.4 --- b [0/1] Impact parameter
45- 53 F9.3 ppm Depth [23.7/24608.3] Transit depth
55- 60 F6.3 h Tdur [1/16] Transit duration
62- 70 F9.3 d Epoch [55641/55738.5] Transit epoch; BJD-2400000.5
72- 78 F7.3 --- MES [0.8/583] Expected Multiple Event Statistic (2)
80 I1 --- R [0/1] Recovered (1: successfull recovery) (3)
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Note (1): We selected 15 sky groups across the Kepler focal plane --a sky group
refers to the set of target stars that fall together on the same
CCD channel. Sky groups and corresponding Q9 CCD channels used
in the transit injection test, and a qualitative description of any
noted features of the channel (see table 1):
-------------------------------------------------------------------------
Sky group Channel Description
-------------------------------------------------------------------------
32 4 Edge of field/worst focus
70 10 Variable black/bias correction
71 11 Edge of field/worst focus
9 13 FGS crosstalk
25 17 Nominal/best focus
66 26 Rolling band artifacts/Moire pattern drift
84 32 Edge of field/worst focus
62 46 Variable black/bias correction
78 50 FGS crosstalk
4 56 Edge of field/worst focus
18 58 Rolling band artifacts/Moire pattern drift
19 59 Nominal/best focus
38 62 Rolling band artifacts/Moire pattern drift
74 70 FGS crosstalk
53 81 Start-of-line ringing
-------------------------------------------------------------------------
In the other quarters used in this test (Q10-Q12), the sky groups will
fall on other CCDS, typically with "average" behavior.
Note (2): The Multiple Event Statistic (MES) gives the significance of the
correlation between the data and a putative box-shaped transit
signal of a given orbital period, transit duration, and phase
in units of the uncertainty in the data (Jenkins et al.
2010SPIE.7740E..0DJ). See section 3.1 for further explanations.
Note (3): See section 3.2.
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History:
From electronic version of the journal
References:
Christiansen et al. Paper I. 2013ApJS..207...35C 2013ApJS..207...35C Cat. J/ApJS/207/35
Christiansen et al. Paper III. 2016ApJ...828...99C 2016ApJ...828...99C
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Dec-2015