J/MNRAS/445/2268 Bayesian method for detecting stellar flares (Pitkin+, 2014)
A Bayesian method for detecting stellar flares.
Pitkin M., Williams D., Fletcher L., Grant S.D.T.
<Mon. Not. R. Astron. Soc., 445, 2268-2284 (2014)>
=2014MNRAS.445.2268P 2014MNRAS.445.2268P
ADC_Keywords: Stars, flare ; Effective temperatures
Keywords: methods: data analysis - methods: statistical - stars: flare
Abstract:
We present a Bayesian-odds-ratio-based algorithm for detecting stellar
flares in light-curve data. We assume flares are described by a model
in which there is a rapid rise with a half-Gaussian profile, followed
by an exponential decay. Our signal model also contains a polynomial
background model required to fit underlying light-curve variations in
the data, which could otherwise partially mimic a flare. We
characterize the false alarm probability and efficiency of this method
under the assumption that any unmodelled noise in the data is
Gaussian, and compare it with a simpler thresholding method based on
that used in Walkowicz et al. We find our method has a significant
increase in detection efficiency for low signal-to-noise ratio (S/N)
flares. For a conservative false alarm probability our method can
detect 95 per cent of flares with S/N less than 20, as compared to S/N
of 25 for the simpler method. We also test how well the assumption of
Gaussian noise holds by applying the method to a selection of 'quiet'
Kepler stars. As an example we have applied our method to a
selection of stars in Kepler Quarter 1 data. The method finds
687 flaring stars with a total of 1873 flares after vetos have been
applied. For these flares we have made preliminary characterizations
of their durations and and S/N.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 50 687 A summary table of flare statistics
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- KIC Kepler ID
11- 12 I2 --- Nf [1/13] Number of flares on the star
14- 17 I4 K Teff [3232/5150] Effective temperature
19- 22 F4.2 [cm/s2] logg [4.2/4.99] log of the surface gravity
24- 28 F5.2 h Dur [0.9/20] Median flare duration
30- 35 F6.2 --- S/N [9/576] Median signal-to-noise ratio
37- 44 F8.2 s-1 Amp [32/27541] Median amplitude (Flux in electron/s)
46- 50 F5.1 s-1 e_Amp [3/268] Noise standard deviation estimate
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 19-May-2015