Chandra X-Ray Observatory
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Last modified: 16 Dec 2014

URL: http://cxc.harvard.edu/ciao/threads/csccli/

Simple Command Line Access to the Chandra Source Catalog

CIAO 4.9 Science Threads


Overview

Synopsis:

The Chandra Source Catalog (CSC) , version 1, contains properties for nearly 100,000 point like sources observed by Chandra during its first 8 years. This includes source positions, fluxes, count rates, hardness ratios (colors), extent, and measures of variability in multiple energy bands; all of which are reported for each individual observation as well as merged properties for overlapping datasets.

The primary interface to query the source catalog is CSCView a Java-based graphical user interface (GUI). There is also a web based command line interface (CLI) that is available for users who experience problems running the Java application.

The CIAO contributed scripts search_csc and obsid_search_csc provide simple wrappers around the CLI interface for the two most common and simple searches: a radius search around a position and a search by a Chandra OBS_ID

They also provide access to the catalog data products and can optionally query the CSC Limiting Sensitivity service for upper limits when a source is not detected.

Purpose:

To show how to perform a simple search of the CSC catalog using either a Chandra OBS_ID or a position with radius.

Users who require more filtering and sorting capabilities should use the CSCView application.

Related Links:

Last Update: 16 Dec 2014 - Review for CIAo 4.7. No changes.


Contents


Getting Started

To get started will assume that a user knows the position or name of a source of interest. As an example we will use the source

SDSS J1004+4112

from the Sload Digitial Sky Survey catalog.


Search by Position

We begin our search by simply using the search_csc script and providing the name of the object and a search radius (in the default units of arc-minutes). Since the name has a space it needs to be quoted.

unix% search_csc "SDSS J1004+4112"
Search radius [default: arcmin] (0:60) (0): 1
Output file TSV format file name (): none
search_csc
             pos = SDSS J1004+4112
          radius = 1
         outfile = none
         radunit = arcmin
         columns = INDEF
     sensitivity = no
        download = none
            root = ./
           bands = broad,wide
       filetypes = regevt,pha,arf,rmf,lc,psf,regexp
         catalog = csc1
         verbose = 1
         clobber = no
            mode = ql


8 rows returned by query
8 Different Master Source(s).
1 Different Observation(s).

name                	ra          	dec         	sepn	obsid	
CXO J100433.6+411307	151.14038   	 41.21862   	0.47'	 5794	
CXO J100433.8+411234	151.14101   	 41.20962   	0.25'	 5794	
CXO J100434.0+411248	151.14199   	 41.21356   	0.19'	 5794	
CXO J100434.2+411220	151.14285   	 41.20560   	0.39'	 5794	
CXO J100434.2+411243	151.14249   	 41.21205   	0.14'	 5794	
CXO J100434.8+411239	151.14509   	 41.21087   	0.063'	 5794	
CXO J100434.9+411242	151.14557   	 41.21185   	0.00018'	 5794	
CXO J100437.1+411231	151.15491   	 41.20887   	0.46'	 5794	

If you use this data, please cite Evans et al 2010, ApJS 189, 37

The results are printed to the screen. There are 8 sources in the CSC within 1 arcmin of the location SDSS J1004+4112. The script uses the NED name resolver to translate the name into a position. Setting the verbose level to 2 or higher displays the position.

unix% search_csc "SDSS J1004+4112" verbose=2
Search radius [default: arcmin] (0:60) (1): 
Output file TSV format file name (none): 
...

Resolved SDSS J1004+4112 to ra=151.14557 dec=41.21185

The separation between the detected sources and the input coordinates are provided in the sepn (separation) column in the same units at the radius (default is arcmin).

Additional source properties can be requested by adding them to the columns parameter.

unix% search_csc "SDSS J1004+4112" radius=1 outfile= columns=m.significance,m.flux_aper_b,o.theta,o.cnts_aper_b
...
name                	ra          	dec         	sepn	obsid	significance	flux_aper_b	theta	cnts_aper_b	
CXO J100433.6+411307	151.14038   	 41.21862   	0.47'	 5794	   5.11	3.577e-15	    0.842	         32	
CXO J100433.8+411234	151.14101   	 41.20962   	0.25'	 5794	  35.73	9.788e-14	    1.382	       1314	
CXO J100434.0+411248	151.14199   	 41.21356   	0.19'	 5794	  26.72	6.189e-14	    1.149	        762	
CXO J100434.2+411220	151.14285   	 41.20560   	0.39'	 5794	  29.86	1.060e-13	    1.629	        910	
CXO J100434.2+411243	151.14249   	 41.21205   	0.14'	 5794	   7.47	5.309e-15	    1.241	        109	
CXO J100434.8+411239	151.14509   	 41.21087   	0.063'	 5794	  34.48	1.011e-13	    1.329	       1234	
CXO J100434.9+411242	151.14557   	 41.21185   	0.00018'	 5794	  38.90	1.195e-13	    1.276	       1554	
CXO J100437.1+411231	151.15491   	 41.20887   	0.46'	 5794	  12.79	1.190e-14	    1.584	        168	

Here we ask, for example, for the source significance [m.significance], the broad band (0.5-7.0 keV) flux [m.flux_aper_b], the location of the source relative to the optical axis [o.theta], and the number of broad band counts [o.cnts_aper_b]. The list of columns is quite extensive and includes all the columns discussed in the CSC pages. The o denotes an "observation" source property, computed from a single OBS_ID and m denotes a "master" source property which is computed from data from all the OBS_IDs a source was detected.

We can change the units of the search radius and it will change the units of the sepn values

unix% search_csc "SDSS J1004+4112" radius=10 radunit=arcsec out=
search_csc
             pos = SDSS J1004+4112
          radius = 10
         outfile = 
         radunit = arcsec
         columns = INDEF
     sensitivity = no
        download = none
            root = ./
           bands = broad,wide
       filetypes = regevt,pha,arf,rmf,lc,psf,regexp
         catalog = csc1
         verbose = 1
         clobber = no
            mode = ql


3 rows returned by query
3 Different Master Source(s).
1 Different Observation(s).

name                	ra          	dec         	sepn	obsid	
CXO J100434.2+411243	151.14249   	 41.21205   	8.4"	 5794	
CXO J100434.8+411239	151.14509   	 41.21087   	3.8"	 5794	
CXO J100434.9+411242	151.14557   	 41.21185   	0.011"	 5794	

If you use this data, please cite Evans et al 2010, ApJS 189, 37

When the output file is "none" or left blank, the source properties are only printed to the screen (with verbose >0). We can set the output file and it will save the Tab Separated Value (TSV) format results.

unix% search_csc "SDSS J1004+4112" radius=1 outfile=sdss_j1004+4112.tsv  columns=m.significance,m.flux_aper_b,o.theta,o.cnts_aper_b verbose=0
unix% cat sdss_j1004+4112.tsv 
#Column	sepn	(E9.6)		(.sepn)	[""]	[]
#Column	name	(A20)	Source name in the format 'CXO Jhhmmss.s +/- ddmmss'	(master_source.name)	[""]	[meta.id;meta.main]
#Column	ra	(F9.5)	Source position, ICRS right ascension	(master_source.ra)	["deg"]	[pos.eq.ra;meta.main]
#Column	dec	(F9.5)	Source position, ICRS declination	(master_source.dec)	["deg"]	[pos.eq.dec;meta.main]
#Column	instrument	(A4)	Instrument used for the observation; 'ACIS' or 'HRC'	(obi_source.instrument)	[""]	[meta.id;instr]
#Column	obsid	(I5)	Observation identifier	(obi_source.obsid)	[""]	[meta.id;obs.param]
#Column	obi	(I3)	Observation interval number	(obi_source.obi)	[""]	[meta.id;obs.param]
#Column	region_id	(I4)	Source region identifier	(obi_source.region_id)	[""]	[meta.id;instr.fov]
#Column	match_type	(A1)	A Source Observation association with a single Master Source is unique ('u'), with more than one is ambiguous ('a').	(master_obi_assoc.match_type)	[""]	[meta.code]
#Column	significance	(F7.2)	Highest source flux significance across all observations	(master_source.significance)	[""]	[stat.snr]
#Column	flux_aper_b	(E9.3)	Aperture-corrected net energy flux inferred from the source region aperture, calculated by counting X-ray events; ACIS broad energy band	(master_source.flux_aper_b)	["erg/s/cm^2"]	[phot.flux;src.net;em.X-ray]
#Column	theta	(F9.3)	Source aperture position, off-axis angle	(obi_source.theta)	["arcmin"]	[instr.offset]
#Column	cnts_aper_b	(I11)	Total counts observed in the modified source region aperture; ACIS broad energy band	(obi_source.cnts_aper_b)	["counts"]	[phot.count;em.X-ray]
sepn	name	ra	dec	instrument	obsid	obi	region_id	match_type	significance	flux_aper_b	theta	cnts_aper_b
2.812644e+01	CXO J100433.6+411307	151.14038	 41.21862	ACIS	 5794	  0	  18	u	   5.11	3.577e-15	    0.842	         32
1.472472e+01	CXO J100433.8+411234	151.14101	 41.20962	ACIS	 5794	  0	  13	u	  35.73	9.788e-14	    1.382	       1314
1.149939e+01	CXO J100434.0+411248	151.14199	 41.21356	ACIS	 5794	  0	  17	u	  26.72	6.189e-14	    1.149	        762
2.368759e+01	CXO J100434.2+411220	151.14285	 41.20560	ACIS	 5794	  0	  11	u	  29.86	1.060e-13	    1.629	        910
8.382573e+00	CXO J100434.2+411243	151.14249	 41.21205	ACIS	 5794	  0	  16	u	   7.47	5.309e-15	    1.241	        109
3.758912e+00	CXO J100434.8+411239	151.14509	 41.21087	ACIS	 5794	  0	  14	u	  34.48	1.011e-13	    1.329	       1234
1.064721e-02	CXO J100434.9+411242	151.14557	 41.21185	ACIS	 5794	  0	  15	u	  38.90	1.195e-13	    1.276	       1554
2.747748e+01	CXO J100437.1+411231	151.15491	 41.20887	ACIS	 5794	  0	  12	u	  12.79	1.190e-14	    1.584	        168

Users will notice that some additional columns are also included: obi, region_id, match_type, and instrument. These columns are required by the script and are always included in the results. Also users should be aware that - contrary to what happens when the results are just printed to the screen - the sepn value is always saved in units of arcsec regardless of the radunit value.

When the default columns=INDEF is set, many of the most common columns are retrieved and saved to the output file; however, only a few are printed to the screen.


Search by OBS_ID

After reviewing the above results, we notice that all the sources belong to the same Chandra obsid: 5794. Let us now widen our search and see which other sources were also detected in this observation. To do this we switch to use the obsid_search_csc tool

unix% obsid_search_csc 5794 out="" column=o.theta,o.cnts_aper_b,o.ks_prob_b,o.flux_significance_b
obsid_search_csc
           obsid = 5794
         outfile = 
         columns = o.theta,o.cnts_aper_b,o.ks_prob_b,o.flux_significance_b
        download = none
            root = ./
           bands = broad,wide
       filetypes = regevt,pha,arf,rmf,lc,psf,regexp
         catalog = csc1
         verbose = 1
         clobber = no
            mode = ql


35 rows returned by query
35 Different Master Source(s).
1 Different Observation(s).

name                	ra          	dec         	obsid	theta	cnts_aper_b	ks_prob_b	flux_significance_b	
CXO J100414.3+411259	151.05970   	 41.21640   	 5794	    3.734	         94	    0.706	     9.07	
CXO J100415.2+411155	151.06340   	 41.19878   	 5794	    3.994	        155	    0.891	    11.94	
CXO J100416.7+410813	151.06969   	 41.13700   	 5794	    6.549	         54	    0.985	     5.92	
CXO J100416.8+411203	151.07000   	 41.20109   	 5794	    3.667	         27	    0.172	     3.27	
CXO J100419.0+411029	151.07921   	 41.17494   	 5794	    4.406	         41	    0.309	     5.61	
CXO J100419.4+411024	151.08110   	 41.17341   	 5794	    4.427	         73	    0.903	     7.60	
CXO J100420.3+411414	151.08464   	 41.23730   	 5794	    2.495	        103	    0.483	     9.84	
CXO J100425.2+411159	151.10539   	 41.19974   	 5794	    2.505	         49	    0.284	     6.64	
CXO J100428.3+411128	151.11827   	 41.19136   	 5794	    2.656	         20	    0.489	     4.02	
CXO J100430.1+410944	151.12573   	 41.16223   	 5794	    4.270	         78	    0.695	     7.68	
CXO J100430.4+411414	151.12668   	 41.23737   	 5794	    0.648	         21	    0.032	     4.25	
CXO J100430.5+411405	151.12748   	 41.23491   	 5794	    0.564	         31	    0.684	     5.12	
CXO J100431.6+410936	151.13183   	 41.16016   	 5794	    4.362	        457	    0.485	    21.01	
CXO J100433.6+411307	151.14038   	 41.21862   	 5794	    0.842	         32	    1.000	     5.11	
CXO J100433.8+411018	151.14096   	 41.17185   	 5794	    3.648	         71	    0.482	     8.04	
CXO J100433.8+411234	151.14101   	 41.20962   	 5794	    1.382	       1314	    0.464	    35.73	
CXO J100434.0+411248	151.14199   	 41.21356   	 5794	    1.149	        762	    0.245	    26.72	
CXO J100434.2+411220	151.14285   	 41.20560   	 5794	    1.629	        910	    0.089	    29.86	
CXO J100434.2+411243	151.14249   	 41.21205   	 5794	    1.241	        109	    0.944	     7.47	
CXO J100434.8+411239	151.14509   	 41.21087   	 5794	    1.329	       1234	    0.015	    34.48	
CXO J100434.9+411242	151.14557   	 41.21185   	 5794	    1.276	       1554	    0.620	    38.90	
CXO J100436.3+410947	151.15141   	 41.16307   	 5794	    4.208	         39	    0.664	     5.16	
CXO J100437.0+411109	151.15442   	 41.18597   	 5794	    2.878	         13	    0.000	     3.02	
CXO J100437.0+411532	151.15433   	 41.25894   	 5794	    1.713	         19	    0.016	     3.72	
CXO J100437.1+411231	151.15491   	 41.20887   	 5794	    1.584	        168	    0.801	    12.79	
CXO J100437.2+411444	151.15525   	 41.24583   	 5794	    1.061	        170	    0.614	    12.89	
CXO J100441.0+410943	151.17087   	 41.16220   	 5794	    4.455	        506	    0.282	    22.03	
CXO J100441.3+411110	151.17221   	 41.18620   	 5794	    3.151	         19	    0.396	     4.05	
CXO J100442.0+411059	151.17525   	 41.18323   	 5794	    3.373	         83	    0.379	     8.66	
CXO J100444.9+411348	151.18731   	 41.23013   	 5794	    2.158	        100	    0.730	     9.82	
CXO J100446.0+411215	151.19191   	 41.20430   	 5794	    2.909	         29	    0.286	     4.94	
CXO J100446.4+411447	151.19346   	 41.24664   	 5794	    2.572	        115	    0.706	    10.50	
CXO J100451.6+410831	151.21536   	 41.14202   	 5794	    6.423	        148	    0.746	     6.94	
CXO J100452.2+411616	151.21764   	 41.27133   	 5794	    4.217	         46	    0.123	     5.20	
CXO J100459.0+411059	151.24596   	 41.18332   	 5794	    5.640	         17	    0.175	     3.43	

If you use this data, please cite Evans et al 2010, ApJS 189, 37

We see that there were a total of 35 sources detected in this observation. The columns parameter accepts the same inputs as the search_csc script and the screen and file outputs behave the same. The only difference is that there is no sepn column returned: since we are searching by observation there is no distance to compute.

Other Observations?

One might wonder if the original position was observed multiple times? We can try the find_chandra_obsid tool

unix% find_chandra_obsid "SDSS J1004+4112"
# obsid  sepn   inst grat   time    obsdate   piname            target
5794      0.2 ACIS-S NONE   81.1 2005-01-01    Inada "SDSS J1004+4112"
11546     0.1 ACIS-S NONE    6.0 2010-03-08 Kochanek     SDSS1004+4112
11547     0.1 ACIS-S NONE    6.0 2010-06-19 Kochanek     SDSS1004+4112
11548     0.1 ACIS-S NONE    6.0 2010-09-23 Kochanek     SDSS1004+4112
11549     0.1 ACIS-S NONE    6.0 2011-01-30 Kochanek     SDSS1004+4112

We can see that there are 4 other observations that observed our source. Why where these not included in our original search results? Without doing much analysis, the easiest thing to notice is that the dates of the observations are in 2010. Version 1 of the catalog only includes data through 2009.


Retrieve Data Products

The data products used to create the source properties are also available for each source. This includes both observation level products, like full field event files, exposure maps, and background images, as well as per source products such as PSFs, ARF, RMF, spectra, and light-curves.

Both search_csc and obsid_search_csc have a download parameter. If set to none (default) no data products are retrieved. If set to ask or all then data products for each source and each observation will be downloaded as specified in the bands and filetypes parameters. To retrieve all the default data products for a small search would look something like this:

unix% search_csc "SDSS J1004+4112" radius=10 radunit=arcsec outfile= download=ask verbose=0 
Download data for CXO J100434.2+411243 in 05794_000 [y,n,a,q]: y
Download data for CXO J100434.8+411239 in 05794_000 [y,n,a,q]: y
Download data for CXO J100434.9+411242 in 05794_000 [y,n,a,q]: y

unix% /bin/ls -F
CXOJ100434.2+411243/  
CXOJ100434.8+411239/  
CXOJ100434.9+411242/

unix% find CXOJ100434.* -type f -print
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016_pha3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016b_psf3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016_regevt3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016_rmf3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016b_regexp3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016_arf3.fits.gz
CXOJ100434.2+411243/05794_000/r0016/acisf05794_000N001_r0016b_lc3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014_pha3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014b_psf3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014_regevt3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014_rmf3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014b_regexp3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014_arf3.fits.gz
CXOJ100434.8+411239/05794_000/r0014/acisf05794_000N001_r0014b_lc3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015_pha3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015b_psf3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015_regevt3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015_rmf3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015b_regexp3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015_arf3.fits.gz
CXOJ100434.9+411242/05794_000/r0015/acisf05794_000N001_r0015b_lc3.fits.gz

The search_csc script organizes the files into directories based on the source name, then OBS_ID, and then region number. All the files are returned gzip'ed.

If we use the obsid_search_csc script the same data products can be retrieved, but they are stored in a slightly different directory structure

unix% obsid_search_csc 5794 download=ask outfile="" col=INDEF filetypes=evt,pha,arf,rmf verb=0
Download data for CXO J100414.3+411259 in 05794_000 [y,n,a,q]: y
Download data for CXO J100415.2+411155 in 05794_000 [y,n,a,q]: y
Download data for CXO J100416.7+410813 in 05794_000 [y,n,a,q]: q
Skipping remaining sources

unix% /bin/ls -F
5794/

unix% find 5794 -type f -print
5794/CXOJ100414.3+411259/acisf05794_000N001_r0044_pha3.fits.gz
5794/CXOJ100414.3+411259/acisf05794_000N001_r0044_rmf3.fits.gz
5794/CXOJ100414.3+411259/acisf05794_000N001_r0044_arf3.fits.gz
5794/acisf05794_000N001_evt3.fits.gz
5794/CXOJ100415.2+411155/acisf05794_000N001_r0008_pha3.fits.gz
5794/CXOJ100415.2+411155/acisf05794_000N001_r0008_rmf3.fits.gz
5794/CXOJ100415.2+411155/acisf05794_000N001_r0008_arf3.fits.gz

Now the directory structure starts with the OBS_ID and with a sub directory for each source. Since the evt file is common to all the sources, it is stored in the OBS_ID directory. Note: by entering 'q' when prompted we quit out of downloading any more data products, so only the files for the first two sources were retrieved.


Using results with CIAO

The TSV format file that is returned by the CSC CLI interface and these scripts can be used by both CIAO and ds9.

DM ASCII Kernel

To use the output with CIAO tools you must explicitly specify that the file is in TSV format using the [opt kernel=text/tsv] directive as part of the virtual file syntax.


unix% obsid_search_csc 5794 out=5794.tsv column=o.theta,o.cnts_aper_b,o.ks_prob_b,o.flux_significance_b verb=0
unix% dmlist "5794.tsv[opt kernel=text/tsv]" cols

--------------------------------------------------------------------------------
Columns for Table Block 5794.tsv
--------------------------------------------------------------------------------
 
ColNo  Name                 Unit        Type             Range
   1   name                              String[20]                          Source name in the format 'CXO Jhhmmss.s +/- ddmmss'
   2   ra                   deg          Real4          -Inf:+Inf            Source position, ICRS right ascension
   3   dec                  deg          Real4          -Inf:+Inf            Source position, ICRS declination
   4   instrument                        String[4]                           Instrument used for the observation; 'ACIS' or 'HRC'
   5   obsid                             Int4           -                    Observation identifier
   6   obi                               Int4           -                    Observation interval number
   7   region_id                         Int4           -                    Source region identifier
   8   match_type                        String[1]                           A Source Observation association with a single Master Source is unique ('u'), wi
   9   theta                arcmin       Real4          -Inf:+Inf            Source aperture position, off-axis angle
  10   cnts_aper_b          counts       Int4           -                    Total counts observed in the modified source region aperture; ACIS broad energy 
  11   ks_prob_b                         Real4          -Inf:+Inf            Kolmogorov-Smirnov variability probability; ACIS broad energy band
  12   flux_significance_b               Real4          -Inf:+Inf            Significance of the source determined from the ratio of the source flux to the e
unix% dmstat "5794.tsv[opt kernel=text/tsv][cols ks_prob_b]" sig+ med+

ks_prob_b
    min:	0 	      @:	23 
    max:	1 	      @:	14 
   mean:	0.4827142852 
 median:	0.48300001025 
  sigma:	0.29924729863 
    sum:	16.894999982 
   good:	35 
   null:	0 

unix% dmsort "5794.tsv[opt kernel=text/tsv]" sort_by_theta.fits theta
unix% prism "5794.tsv[opt kernel=text/tsv]"
prism displaying ASCII 5794.tsv file

See also ahelp dmascii


Using with SAOImage ds9

The TSV file can be loaded directly into SAOImage ds9. You can load it via the command line

unix% ds9 5794/acisf05794_000N001_evt3.fits.gz -catalog import tsv 5794.tsv

Or the file can be loaded from with the GUI itself. Once the event file is loaded you can goto: Analysis → Catalog Tool ... then in the catalog tool window goto File → Import → Tab-Separated-Value → 5794.tsv

ds9 catalog display

Users can then use the catalog tool to interact with the catalog table and source properties. The data can also be transmitted to other SAMP enabled applications such as TOPCAT.


Upper Limits

If a source is not detected, but an observation covering that part of the sky is included in the catalog, then an upper limit on the source flux (in photon units) is also available.

unix% search_csc "10 04 34.2 +41 12 40" radius=1 radunit=arcsec outfile=
search_csc
             pos = 10 04 34.2 +41 12 40
          radius = 1
         outfile = 
         radunit = arcsec
         columns = INDEF
     sensitivity = no
        download = none
            root = ./
           bands = broad,wide
       filetypes = regevt,pha,arf,rmf,lc,psf,regexp
         catalog = csc1
         verbose = 1
         clobber = no
            mode = ql


0 rows returned by query
0 Different Master Source(s).
0 Different Observation(s).

unix% search_csc "10 04 34.2 +41 12 40" radius=1 radunit=arcsec outfile= sensitivity=yes
search_csc
             pos = 10 04 34.2 +41 12 40
          radius = 1
         outfile = 
         radunit = arcsec
         columns = INDEF
     sensitivity = yes
        download = none
            root = ./
           bands = broad,wide
       filetypes = regevt,pha,arf,rmf,lc,psf,regexp
         catalog = csc1
         verbose = 1
         clobber = no
            mode = ql

CSC Sensitivity for position: 151.1426,41.2112
  broad band : 3.3601e-7 [photons/cm^2/s]
  wide band : NaN [photons/cm^2/s]

0 rows returned by query
0 Different Master Source(s).
0 Different Observation(s).

In this example, a source at 10:04:34.2 +41:12:40, would need to have been brighter than 3.36 e-7 photon/cm^2/sec in the broad band to be included in the catalog. If there is no sensitivity in the catalog then a value of NaN is returned. This does not mean that the part of the sky was not observed by Chandra at all, just that, if it was observed, the data were not included in the catalog. To determine if a point was observed use the find_chandra_obsid tool


More options?

Users who need to construct more complicated queries (eg variable sources with some range of hardness ratios etc.) or who need to perform cross matches, must use the CSCView application or use the CSCCLI interface directly.

Research that makes use of the data in the catalog should site Evans et al 2010, ApJS 189, 37.


History

25 Jul 2013 Initial version.
25 Nov 2013 Review for CIAO 4.6. No changes.
16 Dec 2014 Review for CIAo 4.7. No changes.


Last modified: 16 Dec 2014
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