OSU Photometric Reduction Pipeline

Quick Reference Guide

Updated: 2014 April 3 [rwp]

For details refer to the full reduction guide.

If not interested in details at all, see the Quick Quick Guide...

Create/configure a directory for a new microlensing event

Create a new directory with newfield:
   newfield CT13 OB140123
where CT13 is the observatory code for the CTIO 1.3m telescope and ANDICAM, and OB140123 is the short form of microlensing event OGLE-2014-BLG-0123. A list of MicroFUN observatory site codes can be viewed by typing
   microsites
newfield gets the RA and Dec coordinates of the target from the most recent OGLE and MOA event catalogs, and all the site information from the current MicroFUN site table.

If more than one instrument configuration is availble at a given observing site, you will be shown a list of possible setups to choose from. If only one configuration is available, it will choose this automatically.

Note:
Starting in 2011 OGLE event names use a 4-digit event numbers (e.g., OGLE-2014-BLG-0123), while MOA is still using 3-digit event numbers (e.g., MOA-2014-BLG-123). Be aware of this when working with data from before 2011.

Create a DoPhot Reduction Template

  1. Choose an image with good seeing and the event near peak (if possible) to use as the template image.

  2. Run mktemplate on the image:
       mktemplate I 12
    
    In this example we have chosen the image CT13_OB140123I0012.fits as the template.

The mktemplate script creates all of the template files needed by the DoPhot pipeline, and creates the ".template" file with the name of the template field. In this example, .template will contain the string "CT13_OB140123I0012".


Process images through the DoPhot pipeline

You have two options:

(1) process all unprocessed FITS images in the Raw/ directory:

   photproc all
(2) process only those images listed in a file
   photproc imlist
where "imlist" is the name of the file listing the FITS files in Raw/ to process, one image per line.

After photproc runs, you should investigate any processing errors reported and take corrective action as required, or at least note the failures for future attention. The photproc script should tell you which files to inspect if there have been any failures.

After processing, it is a good idea to clean out any delinquent files from the Work directory:

   cleanup

At this step, there will be a number of DoPhot .dop files in the Dop/ directory, and copies of the DoPhot runtime parameter (.par) files in the Par/ directory.


Archive Photometry Data

Create a new photometry archive

The command
   archive I 1 10 C
creates (C) an I-band archive file named Archive/CT13_OB140123I, and enters data for I-band images 1-10. Any existing archive file of this name will be over-written. Note that the rootname of the archive, here "CT13_OB140123", is stored in the .fieldname file.

Append data to an existing photometry archive

To add new data to an existing archive, use this command:
   cd CT13_OB140123
   archive I 11 20 A
This adds (A) the records for frames 11-20 to the existing archive file named "Archive/CT13_OB140123I". As above, the rootname of the archive, here "CT13_OB140123", is stored in the .fieldname file.

Processing data taken with more than one filter

ANDICAM CCD data are usually taken in I and V, with fewer images being taken in V. While V and I band photometry are done in parallel with the DoPHOT parts of the pipeline, they must be separately archived.

To create the initial V archive, you would type:

   archive V 1 5 C
This is done the first time, or anytime you change the template or choice of reference stars and need to regenerate the photometry archive from the start.

To add photometry to an existing V archive, you use

   archive V 6 10 A
to append.

Each time you process I and V photometry, you must run the archive script twice, once for each filter.


Identify the Lens and some reference stars using tvphot

  1. Run archive with the current set of parameters on data for several images that have been already been processed once through photproc to create an initial archive for searching purposes.

  2. Go into the Archive directory
       cd Archive
    
    start up ds9 and run tvphot over the archive and the template image:
       ds9 &
       tvphot CT13_OB140123I
    
    This presumes that the archive is named CT13_OB01013I and a template image named CT13_OB140123I.fits; if the template image has a different name, it is entered as a second argument on the command line. The interactive cursor (the blinking donut) is used to select stars. Hitting the "f" key will search the archive records and print the info about this star and any within 5 pixels of it.

  3. Find the microlensing event and get its ID number.

  4. For a start, select 3-5 reasonably bright and uncrowded stars near the target as reference stars. When tvphot prints the photometry info, choose only stars with Typ=11 (the DoPhot code that means bright and unblended). Avoid all other types.

  5. Edit the archive script and update the entries for the template number (if different), event ID, comparison stars and their IDs.

  6. Re-run the archive script using the C option to create a new photometry archive with the updated parameters.

    NOTE: If you have I and V data, you need to run the archive script separately for I and V to regenerate the archive after changing the reference star photometry


Extract the light curve data

   exphot CT13_OB140123I I.pho
This extracts the microlens and reference star light curves into an ASCII text file suitable for plotting with SM, mongo, etc.
Return to [ OSU Pipeline how-to page | OSU Microlensing Software Page ]
Updated: 2014 April 3 [rwp]