The Galactic Center

(crowded field and faint sources)


JEM-X

2. Data selection.

Browse the INTEGRAL archive to create the list of Science Windows  of Revolution 49 in which an X-ray binary GX 339-4 is seen by JEMX. Save the Science Window list into a file rev49_jmx2.txt

Using the list of ScWs  create an observation group named rev49_jmx2

2.Search for sources in the FOV.

Create the JEM_X ScW and mosaic images of the region around GX 339-4.

Determine  sources which were found  during the image analysis. The information about the sources can be found either by running jemx_science_analysis till IMA2 level  or collecting the sources found in individual science windows with the help of command

src_collect og_jmx2.fits+1 DEFAULT jmx2_obs_res.fits
 

3. Spectral analysis: comparison of different methods.

Determine the flux and spectrum  of an X-ray binary GX 340+0 using different methods of spectral extraction: (a) the analysis of SPE -level, (b) the analysis of SPE level with position of the source fixed to the catalog position (c) spectral extraction from mosaic images.  Compare the three results.

4.Search for an X-ray-flare.

Run the science analysis for detector lightcurve level (BIN_T).  As long as you have not run this before, one can just run: jemx_science_analysis  from BIN_T BIN_T with timeStep=10

Study the results visually with the help of fplot

 > foreach dlc ( scw/*/jmx2/res/jmx2_dete_lcr.fits )
foreach? fplot $dlc'[3]' TIME RATE - /XW 'r y 0 80; plot'
foreach? end
 
This will loop over all pointings and for each plot the  detector lightcurve in an XWindow corrected for GTI,  deadtime and grey filter. By typing "quit" at the prompt, the current instance of fplot is stopped and the next window shown.  The first and last bin of each curve may be wrong and should be ignored (known problem).

FInd the science windows in which you can susspect (from the appearence of the lightcurves) that there can be a flare of one of the sources.

3. Follow up analysis of flares

For the science windows in which you have found the flares in the lightcurves in which you  find the lightcurves of individual sources and compare them with detector lightcurves.
Decide whether the found flares are due to activity of a source or due to change of the  background.

For more detailed study you can create a separate observation group which includes only interesting  science windows and repeat the science analysis trying different settings (e.g.  changing LCR_timeStep, or build your own GTIs around flares).