Chandra/CIAO Workshop, Virtual AAS 237

Chandra/CIAO AAS workshop

Members of the CXC hosted a 2 day Chandra/CIAO workshop as part of the Virtual AAS 237 meeting on 07-08 January 2021. Students registered for the workshop when they registered for the AAS meeting.

The workshop schedule is shown below. All times are shown in EST (UTC-5).

Date/Time	Topic	Presenter
Thursday, 07 January 2021
11:00-11:45	Introduction to X-ray Astronomy	Jonathan McDowell
11:45-12:30	Introduction to CIAO	Antonella Fruscione
12:30-13:00	Lunch
13:00-13:45	Using SAOImage ds9 and dax demo with sample files (~400Mb)	Kenny Glotfelty
13:45-15:00	From archive to source detection	Nick Lee
15:00-18:00	Hands on Session
Friday, 08 January 2021
11:00-11:45	Point Source Analysis (specextract and srcflux)	Antonella Fruscione
11:45-12:30	Radial Profile, Combining, Reprojecting, Smoothing	Doug Burke
12:30-13:00	Lunch
13:00-13:45	Sherpa: the CIAO modeling and fitting application	Aneta Siemiginowska
13:45-14:30	High-Resolution Spectroscopy and the TGCAT	Hans Moritz Günther
14:30-18:00	Hands-on Session

Students new to CIAO may want to go through the exercises in the Chandra/CIAO Workbook, 2019 AAS233 edition.

We also have the exercises in the form a Jupyter notebook. You can view and download the blank notebook (without the answers); or you can view and download the completed notebook with the answers supplied.

Workbook Addendum

In CIAO 4.13, the chandra_repro script was updated to run the new asp_offaxis_corr tool to update the aspect solution file. This has a few consequences for the current version of the workbook.

Due to a bug in chandra_repro, users will need to make some keyword edits to the header of the new aspect solution file. In Exercise 9, after running chandra_repro, users should run the following commands:

# After : chandra_repro 13858 out= clob+

asp_file=13858/repro/pcadf13858_repro_asol1.fits
cp ${asp_file} ${asp_file}.bak

for key in RA DEC ROLL
do
  val=`dmkeypar ${asp_file} ${key}_PNT echo+`
  dmhedit ${asp_file} file= op=add key=${key}_NOM 
done

Because running asp_offaxis_corr changes the sky coordinates (X and Y values), the coordinates used in the workbook examples are no longer correct. Starting in Exercise 11, the coordinates for the source, in physical coordinates, are shown as
```
physical;circle(4104.5,4115.5,10)
```
It should be obvious in the ds9 display that these coordinates do not correspond to any obvious source. The source we are actually interested in is now located at
```
physical;circle(4090.9,4077.6,10)
```
Similarly the background region should be moved to that same location as well as other references to that location in several of the later exercises.

Because chandra_repro has modified the aspect solution, when running ChaRT in Exercise 15, we need to upload the aspect solution file rather than using the one available in the Chandra archive. So, in the Pointing Information panel, select the Upload aspect solution file option, and then upload the aspect solution file, 13858/repro/pcadf13858_repro_asol1.fits

The equivalent curl command looks like:

# Replace email address with YOUR email address!

curl \
  -F email=${USER}@head.cfa.harvard.edu \
  -F coords=cel \
  -F ra=09:14:49.088  \
  -F dec=+08:53:21.16 \
  -F asol=upload_asol \
  -F asol_file=@13858/repro/pcadf13858_repro_asol1.fits \
  -F niter=10\
  -F randseed=32767 \
  -F energy=mono \
  -F mono=2.3 \
  -F flux=0.000221 \
https://saotrace.cfa.harvard.edu/cgi-bin/runwrapper