![]() Maxima, where there is a bright source in the field as is the case This particular scale helps to accentuate faint -scale sqrt - Tells ds9 to scale the colormap using the square root of the counts in.This isĬompletely optional and the choice of map "b" represents the personal -cmap b - Tells ds9 to use the " b" color map to display the image.So if you leave this off the command line you will get 1 degree bins Since we will be binning on the coordinates ( RA, DEC), -bin factor 0.1 0.1 - Tells ds9 that the x and y bin sizes are to be 0.1 units in eachĭirection.Prompt> ds9 -bin factor 0.1 0.1 -cmap b -scale sqrt "3C279_region_filtered_gti.fits"Ī ds9 window will open up and an image similar to the one shown below will be displayed.īreaking the command line into its parts, we find that: To see the data, use ds9 to create a quick counts maps of the events in the file.įor example, to look at the 3C279 data file, enter the following command: First, we'll look at making quick counts maps with ds9 then we'll perform a more in depthĮxploration of the data using fv. Ways to explore the data and make quick and dirty plots and graphs of In this section we look at several different There is no need to select event classes for bursts, as you will need all three event classes to gain statistics. This generates a data file from 500s before to 1500 seconds after the trigger time of the burst. Note: The grb_events.fits and grb_spacecraft.fits files were selected from the FSSC's LAT data server using the following criteria: grb_spacecraft.fits (52 kB) - the spacecraft data file for GRB 080916C.grb_events.fits (130 kB) - a 40 degree region around GRB080916C (trigger time = 243216766 MET).spacecraft.fits (62 MB) - the spacecraft data file for 3C279.3C279_region_filtered_gti_fits (9 MB) - a 20 degree region around the blazar 3C279 with appropriate selection cuts applied.Tip: If you are running on SLAC Central Linux and experience problems with either ds9 or fv when using the astrotools environment variable (/afs//g/glast/applications/astroTools) try changing to a bash shell and sourcing kipac's profile.xray script (source /afs/slac/g/ki/software/etc/profile.xray).Ĭlick on the links below to download the files used in this tutorial See: Example: Setup (when running Science Tools on SLAC Central Linux). Note: You may wish to perform these exercises on SLAC Central Linux. It is assumed that: you are working either in a Unix style terminal window, or inĪ Windows Command shell window and that the following are installed on your system and are in your path: Download and install from NASA's HEASARC: Software -> Fv: The Interactive FITS File Editor page. fv (view images and tables can also make plotsĪnd histograms.ds9 (image viewer) download and install from Harvard's: SAOImage DS9: Astronomical Data Visualization.You will be using the following FITS File This tutorial demonstrates various ways of examining and manipulating the LAT data, but it is a simple approach useful for quickly exploring the data. SciTools Reference pages to open in a popup window, click on: Open Popup Reference Window.
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