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

pyke.keppixseries.keppixseries(infile, outfile=None, plotfile=None, plottype='global', filterlc=False, function='boxcar', cutoff=1.0, overwrite=False, verbose=False, logfile='keppixseries.log')

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

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.

Parameters:

infile : str

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

outfile : str

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 : str

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 : str

keppixseries can plot light curves of three types. The choice is made using this argument. The options are:

  • local - All individual pixel light curves are scaled separately to provide the most dynamic range for each pixel.
  • 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.
  • 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.

filterlc : bool

If True, 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 : str

The functional form of the high pass-band filter:

  • boxcar
  • gauss
  • sinc

cutoff : float

The frequency of the high pass-band cutoff in units of \(days^{-1}\).

overwrite : bool

Overwrite the output file?

verbose : bool

Print informative messages and warnings to the shell and logfile?

logfile = str

Name of the logfile containing error and warning messages.

Examples

$ keppixseries kplr008256049-2010174085026_lpd-targ.fits.gz
../_images/keppixseries.png