Photometry Reference

Below is a list of all functions that are part of the photometry module.

• autoredux - automated photometry script
  • Runs photom and plotphotom.
• photom - main photometry script
  • Finds sources with sextractor, and calculates magnitudes and corrected magnitude errors of each source.
• plotphotom - plotting script
  • Plots overlay of all filters, images of each filter with annotated sources, and HTML report with all information.
• printhtml - HTML report script

##photom <> photom([prefchar='coadd'])

1. Creates a stacked image with all filters (saved to multicolor.fits and multicolor.weight.fits).
2. Crops all of the filter images and combined image to the same size and coordinates (file).ref.multi.fits.
3. Then finds sources using the master combined image, and calculates the magnitude based on just the filtered images (with weight file using sextractor. Saves new sextractor values to fluxes_(FILTER).txt.
4. Calculates absolute magnitude errors based on fluxes_(FILTER).txt and keyword in file for absolute zeropoint RMS. Saves final magnitudes to finalphot(FILTER).am.

####Params

• prefchar {string}: Filename prefix of output files from reduction module.

####Output

• multicolor.[weights.]fits - files with all filter images stacked.
• (file).ref.[weights.]fits - files resampled from swarp using all files.
• (file).ref.multi.[weights.]fits - files cropped so that they include all filters.
• coords(FILTER) - RA and DEC coordinates from sextractor from cropped images.
• fluxes_(FILTER).txt - sextractor output from cropped images.
• finalphot(FILTER).am - file containing pixel and coordinate location, mag and corrected mag error of sextractor sources found (fluxes_(FILTER).txt)

##plotphotom <> plotphotom([prefchar='coadd'])

1. Reads in prefchar*(FILTER).multi.ref.fits and finalphot(FILTER).am.
2. Finds number of unique stars and saves each filter's magnitude and error to the same star. Saves this to finalmags.txt.
3. Creates color plot with all of the images overlaid (red = J/H, green = z/y, blue = r/i) and creates plot of each filter field with green circles around each object. Saves as coadd*(FILTER).png.
4. Calls printhtml which create HTML to view all information.

Supports multiple filters.

####Params

• prefchar {string}: Filename prefix of output files from reduction module.

####Output

• finalmags.txt - text file with all the magnitudes for each filter of each source.
• color.png - overlay of all filters (red = J/H, green = z/y, blue = r/i).
• coadd*(FILTER).png - images of each filter field with green circles over source.
• ratir.html- html showing all information.

###Dependencies printhtml.py

##printhtml <> printhtml(filters, colnames)

Create photcomp.png comparing magnitude and errors as well as create HTML page that has all of the data easily displayed for up to 9 filters.

####Params

• filters {list of str}: List of filter types (e.g. ['r','i','z','y','J','H']).
• colnames {list of str}: List columns names to use in table header.

####Output

• photcomp.png - shows magnitude vs. error for each filter
• photom.html - html page showing information about sources

####Dependencies Images and finalmags.txt file created from plotphotom.