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New Technology Telescope

[NTT Web]

General :

Observations :

PyQuick : the quicklook for EMMI echelle and long-slit.

Table of contents:

  1. Generalities (how, why, what for?)
  2. How to use PyQuick (click on start button...)
  3. How to display a reduced spectrum (the best of PyQuick)
  4. Menus (little and no-so-little things that makes life easier)
  5. Additional notes (e.g. about the command-line version... )



PyQuick is the name of the new quicklook-tool for EMMI echelle and long-slit in the red and the blue sides. Any observers that use EMMI for which PyQuick calibrations are available (see below) are encouraged to use PyQuick and to send feedback (Cédric Foellmi - cfoellmi@eso.org).

PyQuick allows to reduce in a few seconds any EMMI spectrum. It also provides various means to display the reduced spectrum.

Note, however, that PyQuick is a quicklook tool and does not provide science-quality spectra! And will never do...

PyQuick is written entirely in Python/PyRAF. It uses a database of calibration to reduce the spectra. It is available for download here:


Note that as of today (2006-03-17), not all calibrations are available. But it should cover about 90% of the requests.
The setups for which PyQuick is ready are:

--- Echelle 9 ---



--- Echelle 10 ---



--- Echelle 14 ---



--- REMD long-slit ---



--- RILD long-slit ---




--- BLMD long-slit ---


How to use PyQuick:

1. PyQuick is installed in the wg5off machine at the NTT.

2. To launch PyQuick, type: pyquick from anywhere. A "GUI" appears. It contains menus, large buttons for the reduction, various lines of status monitoring and information, and a large space for a complete log. The bottom contains a "counter" of the numbers of files to be reduced.




3. Use the button "Open" to choose a spectrum to reduce. You can choose only one spectrum at a time. However, you can open an unlimited number of spectra before starting the reduction itself, even if the spectra have different setups. By default, the open directory is /data/raw.



4. If the spectrum is recognized as a science or standard star spectrum, it is then ingested into PyQuick. For instance:



5. Once all the wanted spectra are entered into PyQuick, just click "START REDUCTION". PyQuick starts the reduction of each file individually, whatever their individual setups. The tasks performed are bias substraction, spectrum extraction and wavelength calibration, for all spectra. Optionally, one may want to make an (automatic) continuum fit



6.If the spectrum is a long-slit spectrum, PyQuick, by default, the position of the spectrum on the image is found interactively . PyQuick will make an horizontal and vertical central slices of the image and ask the user to choose the good peak. (Echelle spectra are reduced with no questions whatsoever).



7.Before continuing the user is asked to confirm that the peak found is the good one. If not, the loop is restarted. Plots can be reploted with the corresponding button. If "cancel" is pressed, then PyQuick will use the trace as defined in the database, blindly.



8.Once the spectrum/spectra are reduced, the "Show Spectra", and "Open" buttons will be enabled again, to allow the user to either add new spectra to reduce or display the currently reduced ones.


How to display a reduced spectrum

Once the spectra are reduced, they can be displayed in 2 different ways, depending on the "Use Pyraf" button. If "Use Pyraf" is NOT checked, then PyQuick will makes simple plots. If it does, the spectra will be displayed on an PyRAF "splot" window.




1. When not using PyRAF, a window pops up, with one reduced spectrum per line. Each button is a menu, with as many orders as there are in the reduced spectrum. Clicking on a entry will create the plot. Wavelength ranges (in Ansgtroem) of each individual order is indicated. When an echelle spectrum has too many orders for the menu to be correctly displayed, it is split into two menus.



2. The plot limits can be controled with the little entries "xmin", "xmax", "ymin" and "ymax". If "Print" is checked, the next created plot will be sent to the local printer using lpr.



4. If "Use Pyraf" is checked, PyQuick will use PyRAF to display the spectra. A window appears, whith again one line per reduced spectrum. Each button will open an IRAF "splot" window. The spectrum displayed order by order (i.e. non-merged spectrum). To navigate between one order to the next, use the parenthesis: ")" for the next order, and "(" for the previous one. See PyQuick built-in help for more infos about the "splot" possibilities (gaussian fit, equivalent widths measurments and so on).




1. The "File" menu is for various general things. (1) " Show Help " opens a window and display built-in help. (2) " Save Log " allows to save the content of the log window into a text file. (A filename is requested the first time) (3) " Show Log " opens a window with the whole content of the log. (A filename is asked the first time). Manuals can be opened from the menu as well. " Exit PyQuick " opens a wind ow asking for confirmation to exit.


2. The "Actions" menu has 2 entries. (1) "Redo reduction..." will opens a window with the list of reduced file. The user can select the ones he wants to re-reduce. This is particulraly useful when one wants to check/uncheck the continuum fit task (see main window). (2) "Show available calibrations..." opens a window (not shown) listing all the EMMI setups for which PyQuick has calibrations in the database.


3. The "Trace" menu allow the user to choose between the interactive or blind lookup of spectrum position (for long-slit spectra only).


4. The "Options" menu allows the user to select the possibility of including all PyRAF task information into the log file. By default, PyQuick shows only the most relevant informaton (input, output, etc).


5. The "About" menu is a cool menu. It opens a "About" window...


Additional notes:


1. There is a command-line version of PyQuick, using the -x flag. Simply specify the path of your spectra.

pyquick -x /data/raw/2005-03-05/EMMI.YYYY-MM-DDTHH:MM:SS.MMM.fits ...

2. The public webpage of PyQuick can be found here: http://www.sc.eso.org/~cfoellmi/pyquick.html

It allows to download individual sets of calibrations, as well as the source code and the documentation.

3. The reduced spectra can be found beside the raw file (i.e. in the same directory). Original filenames are kept throughout the reduction process to allow an easier identification of the file.


Send comments to: ls-emmi at eso dot org
Last Update: 17 March 2006 (cf)