Regions in ds9
serve multiple purposes. Some are purely decorative such as the Text
and Compass
. Some are functional such as Projection
, and some represent multiple analysis regions such as Annulus
and Panda
Panda
=Pie
AND
Annulus
In this section we demonstrate a few of these
Basic regions (circle, box, polygon, ellipse) in ds9
are also functional.
This is a special dataset. Before the iconic Chandra CasA first light, we had to be sure that the instruments were still in focus. The isolated point source PKS0637-752 was selected as the calibration target. When the data were processed, there was something to the East of the source. Soon thoughts of Hubble's blurry mirrors sprang to mind along with potential of software bugs. Luckily, we found out that the smudge was coincident with a Radio jet -- and what we thought was a problem, was in fact Chandra's first scientific discovery of an unresolved X-ray jet.
download_chandra_obsid 62554 evt2
cd RegionFunctionality
ds9 acisf62554N003_evt2.fits -scale log -zoom 8 -pan to 3893 4038 physical &
[1] 27616
xpaset -p ds9 regions command "circle(3893,4038,10)"
import -window "SAOImage ds9" ds9_04_regions_03.png
display < ds9_04_regions_03.png
# Region -> Get Information
# Analysis -> Statistics
# Close Circle info box
sleep 5
import -window "Circle" ds9_04_regions_04.png
display < ds9_04_regions_04.png
xpaset -p ds9 regions delete all
xpaset -p ds9 regions load ds9.reg
import -window "SAOImage ds9" ds9_04_regions_05.png
display < ds9_04_regions_05.png
# Double Click Region, Analysis -> Plot2D
# close Projection info window
sleep 5
import -window "Projection" ds9_04_regions_06.png
display < ds9_04_regions_06.png
xpaset -p ds9 quit
[1]+ Done ds9 acisf62554N003_evt2.fits -scale log -zoom 8 -pan to 3893 4038 physical