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

  • Decorations
  • Plot3D
  • Statistics
  • Projection


Remember, to create and manipulate regions, be sure you are in Edit -> Region mode.


This data has been heavily processed to remove the point sources embedded in the extended emission. The basic steps replicate the An image of Diffuse Emission thread.

The processing starts with cluster Abell401, OBS_ID 14024

download_chandra_obsid 14024
chandra_repro 14024 out=repro
fluximage "14024/repro/acisf14024_repro_evt2.fits[ccd_id=0:3]" out=a401 bin=1 \
    band="0.500:3.000:1.4" psfecf=0.9
wavdetect infile='a401_0.500-3.000_thresh.img' outfile='wav.out' \
  scellfile='wav.cell' imagefile='wav.recon' defnbkgfile='wav.nbkg' \
  expfile='a401_0.500-3.000_thresh.expmap' \
  psffile='a401_0.500-3.000_thresh.psfmap' \
  scales='1.4 2 4 8 12 16'
roi infile=wav.out outsrcfile="srcfill/srcs_%04d.fits" group=indi \
  radiusmode=mul bkgradius=3 bkgfactor=2 bkgfunction=add targetbkg=target
splitroi @srcfill/srcs.lis points
dmfilth a401_0.500-3.000_thresh.img a401.img method="POISSON" \
    srclist="@points.src.reg" bkglist="" 
aconvolve a401.img a401_sm.img lib:'gaus(2,5,1,2,2)' meth=slide clob+
aconvolve a401_0.500-3.000_thresh.expmap a401_sm.exp lib:'gaus(2,5,1,2,2)' \
    meth=slide clob+
dmimgcalc a401_sm.img a401_sm.exp a401_sm.flux div clob+ 
dmimgthresh a401_sm.flux a401_sm_thresh.flux cut=5% \
  exp=a401_0.500-3.000_thresh.expmap value=0 clob+
In [1]:
cd RegionDecoration;  
ds9 a401_sm_thresh.flux -block 4 -scale linear -pan to 4205.73 4357.09 physical &
[1] 27085
In [2]:
xpaset -p ds9 region load ds9.reg  

import -window "SAOImage ds9" ds9_04_regions_02.png 
display < ds9_04_regions_02.png

In [3]:
grep 'fill=1' ds9.reg
Ellipse(4205.73,4357.09,65.3328,47.5412,-69.2655) #  color=red fill=1
Ellipse(4206.72,4356.37,96.5828,69.6816,-67.0843) #  color=orange fill=1
Ellipse(4205.87,4355.63,121.583,88.7383,-65.0033) #  color=yellow fill=1
Ellipse(4205.41,4354.61,143.458,104.839,-65.6778) #  color=green fill=1
Ellipse(4205.12,4353.4,165.333,120.587,-65.4777) #   color=blue fill=1
Ellipse(4205.52,4351.85,185.645,134.127,-64.8471) #  color=purple fill=1
Ellipse(4206.81,4351.17,204.395,148.252,-63.8608) #  color=magenta fill=1
Ellipse(4208.95,4350.84,224.708,163.856,-62.6683) #  color=grey fill=1
In [4]:
grep 'darkgreen' --after-context=12 ds9.reg
Ellipse(4217.19,4352.56,388.77,280.943,-64.0236) #  color=darkgreen
Ellipse(4218.47,4353.69,412.208,298.867,-63.1396) #  color=darkolivegreen
Ellipse(4219.49,4355.47,434.083,317.69,-62.0701) #  color=darkseagreen
Ellipse(4220.27,4356.91,457.52,336.716,-61.5087) #  color=forestgreen
Ellipse(4221.08,4357.75,480.958,358.111,-60.6625) #  color=teal
Ellipse(4220.87,4359.08,505.958,380.527,-60.067) #  color=lawngreen
Ellipse(4220.9,4359.77,530.958,401.577,-59.6175) #  color=lightseagreen
Ellipse(4220.63,4360.33,559.083,425.075,-58.769) #  color=limegreen
Ellipse(4220.77,4360.28,587.208,448.562,-57.8081) # color=palegreen
Ellipse(4220.76,4359.89,615.333,474.052,-56.6615) # color=seagreen
Ellipse(4220.36,4359.74,646.583,500.295,-55.8772) # color=springgreen
Ellipse(4219.88,4359.3,680.958,526.823,-54.83) #  color=yellowgreen
Ellipse(4219.52,4357.85,715.333,556.473,-54.9205) #  text="Shades of Green"
In [5]:
grep 'width=.$' ds9.reg
Ellipse(4227.63,4322.95,971.583,806.68,-57.2076) #  width=2
Ellipse(4232.08,4308.8,1034.08,868.965,-58.151) #   width=3
Ellipse(4236.62,4293.31,1102.83,935.269,-59.6756) #  width=4
In [6]:
grep 'tag=' ds9.reg
Ellipse(4214.29,4351.05,345.802,247.916,-64.718) #  tag="Somewhere in the middle"
Ellipse(4215.82,4351.75,365.333,264.986,-63.849) #  tag="Somewhere in the middle" tag="Multiple Tags"
Ellipse(4269.46,4216.41,1715.33,1469.25,-61.3013) # tag="Outter Edge"
In [7]:
xpaset -p ds9 regions group "{Outter Edge}" color magenta
In [8]:
# Open Region -> Groups ...
sleep 3

import -window "Groups" ds9_04_regions_03.png 
display < ds9_04_regions_03.png

In [9]:
xpaset -p ds9 quit
[1]+  Done                    ds9 a401_sm_thresh.flux -block 4 -scale linear -pan to 4205.73 4357.09 physical
In [ ]: