Date: Tue, 28 Jun 2016 08:52:10 GMT
Subject: RGS spectrum with multiple source regions defined by xdspregions
Full_Name: Junjie Mao
Submission from: (NULL) (220.127.116.11)
Dear XMM-SAS help desk,
I am working on the RGS data for extended source, groups/clusters of galaxies,
and I am
trying to extract spectra from two rectangular source regions, say,
xdspregions="-1.7 -0.3 0.3 1.7.. The aim is to exclude the central brightest
region, which suffers from contamination of non thermal component from BCG/AGN.
However, I am encountering the following problem. It turns out the spectrum I
got was only counts from one source region (i.e. the first half [-1.7, -0.3] of
the expression in xdspregions), the counts from the second source region was not
included. I looked into the source list file and found that there was an
extension of RGS1_SRC3_SPATIAL (the first source region) and another one for
RGS1_SRC4_SPATIAL (the second source region, verified by extracting the region
via tool cxctods9 and plot it with ds9 in dispersion - cross dispersion space).
Note that in the SRCLIST extension I had 3 rows (PROPOSAL, ONAXIS and USER, the
3rd is introduce by myself), as expected. This also prevents me to use parameter
like procsrcsexpr=.INDEX==3 & INDEX==4. since the source with index=4 is not
So what went wrong and how do I get the a spectrum with counts from both source
regions I defined?
ObsID: 0114120101 of M87
SAS version: sas (gui-1.52.9) [xmmsas_20160201_1833-15.0.0]
The routine I've runned is the following:
rgsproc withsrc=yes srclabel=USER srcra=187.704 srcdec=12.393 xpsfincl=99
xpsfexcl=99 xdspregions=.-1.7 0.0 0.0 1.7. xdspbackground=.-2.5 -2.0.
The GTI filter is left out, since it does not affect the results here. The
xdspregions is slightly different from the one I mentioned at the beginning of
this letter, so that I can compare the results with another run of rgsproc with
Thank you very much in advance,
All the best,