Reducing a single observation with makee.

Reducing an entire observing run (multiple reductions) using esipipe.

Before running makee you must select your four input images: (1) object , (2) trace star , (3) flat field , and (4) arc lamp . The arclamp is optional (you just won't get a wavelength scale.) You can also use two arclamps for ESI (CuAr and HgNe) although only one is required for wavelength calibration. A short dark (or bias image) may be included using the "bias=", but is not required (a default pattern for ESI will be used).

Select your input files by referring to your logsheets and/or a listing of your ESI Exposures (you can use rhh to get a quick listing of your data). Below is an example listing using rhh :

  58  esi0058  23Oct00 15:46  Ec:IntF+qtz1  0.75  1x1     6s  IntFlat 
  65  esi0065  24Oct00 04:26  Ec:Obje       0.75  1x1   100s  BD+28 4211  
  76  esi0076  24Oct00 13:28  Ec:Obje       0.75  1x1  3000s  SDSSp0324-0457 
  77  esi0077  24Oct00 14:30  Ec:Obje       0.75  1x1  3000s  HS1818+1037 
  83  esi0083  24Oct00 15:46  Ec:Line+cu1   0.75  1x1   300s  CuAr              
  84  esi0084  24Oct00 15:56  Ec:Line+ne1   0.75  1x1     4s  Hg+Xe       

This listing shows the observation number, filename (.fits is assumed), the UT date and time, "Ec:" for echellette., observation type, slit width, binning, exposure time, and object name.

In this example, we want to reduce observation #76, a 3000 second exposure of "SDSSp0324-0457". We will use the UV bright standard star BD+28 4211 to define the echelle trace curve.

The MAKEE command for this would be:

makee esi0076 esi0065 esi0058 esi0083 esi0084  log=esi0076.log

Here we used a single quartz flat, although a sum of flats is usually recommended. We also used two arclamps, although only one was required. We have included the option "log=" to send the output to a log file, alternatively we could have had the output sent to screen (default).

First, look at the log file for this reduction, esi0076.log . Look for error and warning messages or excessive cosmic ray rejections (more than 1000 in the object, or 5000 in the sky background).

Next, look at the trace PostScript file, trace-065.ps . The residuals should be less than about 0.5 pixels with larger residuals of a pixel or more at the edges of some orders.

Then look at the profiles PostScript file, profiles-076.ps . The dotted lines show which regions were extracted as object and background. If the automatically selected regions are inadequate, you can manually select the object and background regions (see Controlling the Object Extraction Boundaries ).

Then we look at the wavelength calibration PostScript file, Arc-083-fr.ps . The top plot shows the first iteration correlation shift which usually has residuals of about 0.2 pixels. The bottom plot shows the fit to arcline centroids which usually has residuals of about 0.2 pixels. For more information on how the ESI wavelength calibrations are done see ESI Wavelength Calibrations .

If those plots look ok, we can view the Flux-076.fits and Err-076.fits with spim0 or xplot .

The program esipipe can be used to create a script of "makee" commands. The following steps may be used:

1. Create a tabular listing of all ESI raw image files using rhh :

        rhh esi*.fits > rhh.list
   

2. Create a simple listing of all ESI raw image files within the directory containing the raw ESI exposures.

        ls esi*.fits > raw.list
   

3. By looking at "rhh.list", select which exposures may be used for tracing the echelle pattern (trace stars). Create a new file which contains the observation numbers of these exposures. One observation number per line in the file. For example, this file could be called "star.list".

        vi star.list
   

4. In your working directory, run the esipipe command. For example, if your raw image directory is a sub-directory called "myrawdata" below your working directory:

        esipipe raw.list star.list raw=myrawdata
   

5. Look at the file "makee.script" to see if the makee commands are appropriate for your data set.

        vi makee.script
   

6. Run the script "makee.script" in the background:

        source makee.script &
   

7. By default, a ".log" file will be created for each reduction. You can check the size of the ".log" files for unusual reductions, and also search for errors and warnings:

        egrep -i error *.log
        egrep -i warning *.log
   

8. For each observation, check the PostScript plot output as described above. Note that the "trace-###.ps" and "Arc-###-fr.ps" files are labelled using the observation numbers of the trace stars and arclamps. In particular, if any of the ranges shown in "profiles-###.ps" files look bad, you may need to re-run makee and manually control the object and background ranges (see Controlling the Object Extraction Boundaries ).

9. Run logsum to create a tabular and PostScript summary of cosmic ray rejections given in the ".log" files:

        logsum all