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Kepler Guest Observer Program

Contributed Software - KEPPIXSERIES

Software: PyKE
Version: 1.0.4
Contributor:

Figure 1: The PDC light curve at the top of the figure is an object observed during quarter 2 that apparently reveals coherent pulsation or rotation on a period of a few days. The series of light curves below this are the individual time series photometry for each individual pixel in the mask. The pixels with gray backgrounds are those that are included in the photometric aperture used to construct the upper light curve. This pixel-level presentation show that the oscillating object is not the target but a near neighbor off to the right, causing confusing within the photometric aperture. This diagnostic was created using the 'full' range plotting option and using a high-pass boxcar filter with a frequency cutoff of 0.1 days-1.

NAME
keppixseries -- individual time series photometry for all pixels within a target mask

USAGE
keppixseries infile outfile plotfile plottype filter function cutoff clobber verbose logfile status

PARAMETERS
infile = string
The name of a MAST standard format FITS file containing Kepler Target Pixel data within the first data extension.

outfile = string
The name of the output FITS file. This file has two data extensions. The first called 'PIXELSERIES' contains a table with columns of barycenter-corrected time, barycenter time correction, cadence number, cadence quality flag and a series of photometric light curves, one for each pixel within the target mask. Each pixel is labeled 'COLx_ROWy', where x is the pixel column number and y is the pixel row number on the CCD module/output. The second extension contains the mask definition map copied directly from the input target pixel file.

plotfile = string
Name of an optional diagnostic output plot file containing the results of keppixseries. An example is provided in Figure 1. Typically this is a PNG format file. If no diagnostic file is required, plotfile can be 'None'. The plot will be generated regardless of the value of this field, but the plot will not be saved to a file if plotfile='None'.

plottype = String
keppixseries can plot light curves of three types. The choice is made using this argument. The Options are: local | global | full

  1. local - All individual pixel light curves are scaled separately to provide the most dynamic range for each pixel.
  2. global - All pixel light curves are scaled between zero and the maximum flux attained by the brightest pixel in the mask. This option provides the relative contribution to the archived light curve by each pixel.
  3. full - All pixels light curves are scaled between zero and the maximum flux attained by that pixel. This provides the fraction of variability within each individual pixel.

filter = boolean
If filter=yes, the light curve for each pixel will be treated by a high band-pass filter to remove long-term trends from e.g. differential velocity aberration.

function = string
The functional form of the high pass-band filter. The Options:
boxcar | gauss | sinc

cutoff = float
The frequency of the high pass-band cutoff in units of days-1.

clobber = boolean (optional)
Overwrite the output file? if clobber = no and an existing file has the same name as outfile then the task will stop with an error.

verbose = boolean (optional)
Print informative messages and warnings to the shell and logfile?

logfile = string (optional)
Name of the logfile containing error and warning messages.

status = integer
Exit status of the script. It will be non-zero if the task halted with an error. This parameter is set by the task and should not be modified by the user.

DESCRIPTION
keppixseries plots a light curve for each individual pixel in a target mask. Light curves are extracted from a target pixel file obtained from the Kepler data archive at MAST. If required, the data can be fed through a boxcar, gaussian or sinc function high bandpass filter in order to remove low frequency signal from the data. keppixseries is a diagnostic tool for identifying source contaminants in the background or foreground of the target. It can be employed to identify pixels for inclusion or exclusion when re-extracting a Kepler light curve from target pixel files.

EXAMPLE

  • keppixseries infile=kplr002449074-2009350155506_lpd-targ.fits outfile=keppixseries.fits plotfile=keppixseries.png plottype=local filter=yes function=boxcar cutoff=1.0 clobber=yes

TIME REQUIREMENTS
Completion upon one target pixel file using a 2.66 GHz Intel Core 2 i7 Mac running OS 10.6.7, takes a few seconds in addition to the manual input required by the tool.

BUGS AND LIMITATIONS
The Kepler PyRAF package is privately-developed software made available to the community through the contributed software page of the Kepler astrophysics program at http://keplergo.arc.nasa.gov/ContributedSoftware.shtml. It is not an official software product of the Kepler mission or NASA. Bugs and errors are not the responsibility of the Kepler Team or NASA. Please send bug reports and suggestions to keplergo@mail.arc.nasa.gov.

HISTORY

Date
Version
Description
2011-05-31
1.0.0
Initial software release (MS)
2011-06-30
1.0.1
Trapped error where time=NaN is not flagged in the quality column (MS)
2011-06-30
1.0.2
Trapped error where flux array is all NaN is not flagged in the quality column (MS)
2011-08-30
1.0.3
Trapped new behavior of STSCI_PYTHON 2.12 in reading multi-dimension FITS columns (MS)
2014-03-25
1.0.4
Recognises Kepler quarters and K2 campaigns. Output file is not written if target mask contains > 999 pixels in order to avoid FITS storage errors (MS)

SEE ALSO
kepmask, kepextract, kepdiffim


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Last Updated: Jan 11, 2013
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