ROSAT Guest Observer Facility

The ROSAT Results Archive
Catalog of High Resolution Imager Detections


The ROSAT Consortium (the Max-Planck-Institut für extraterrestrische Physik, the Goddard Space Flight Center, the Smithsonian Astrophysical Observatory, Leicester University, and the Astrophysikalisches Institut Potsdam) announces an update to "THE ROSAT SOURCE CATALOG OF POINTED OBSERVATIONS WITH THE HIGH RESOLUTION IMAGER" (ROSHRICAT). This updated catalog (version of August 1999) contains arcsecond positions and count rates of detected sources from nearly 3000 public ROSAT HRI observations, including more than 7500 firm sources (signal-to-noise ratio > 4).

The catalog consists of all primary source parameters from the automated detection algorithm employed by the Standard Analysis Software System (SASS). In addition each observation has been quality checked, both by automatic algorithms and by detailed visual inspection. The results of this quality checking are contained as a set of logical-value flags for each principal source parameter. If a source parameter is suspect, the associated flag is set to "TRUE"; parameters with no obvious problems maintain the default, "FALSE", value. In addition to the catalog, data products for each screened observation are also available. These data products include the screened source lists, FITS images, and ASCII files containing information about obvious real sources not detected by the SASS detection algorithms.

Below we describe the Sequence and Source flags which are currently defined:

Sequence flags:

FLAG NAME              "True" condition
---------               ---------------- 
ASP_SUSP                obvious aspect problems (sources appear multiple or
                        have obvious ellipticity) 
EXT_EMIS                presence of extended emission over most of the field 
FIELD_FDET              one or more detected sources deemed false 
DEFERRED                data screening not done 
MISS_SRC                one or more obvious sources not detected by SASS 
BKG_SUSP                Field background may be incorrect (due to inclusion 
                        of high background intervals or extended emission) 
SLIS_MIS                source list is missing (no sources detected by SASS or
                        source detection stopped) 

Source Flags:

FLAG NAME              "True" condition
----------              ----------------
CONFUSED                close sources confused detection algorithm
DET_STRUCT              source near detector structure
EXTENDED                source is probably resolved
FALSE_DET               detection judged to be spurious
INTEN_SUSP              source brightness suspect
MULT_DET                complex emission split into individual sources
NOT_CHECKED             source not checked
POS_SUSP                source position suspect
ASSOCIATED              another source nearby may influence derived source
VARFLG_SUSP             SASS variability flag suspect
WITHIN_EXT              source within extended emission
UN_UNIQUE               source matched with another source which was identified
                        in a smaller detect cell (HRI only)

The ROSAT High Resolution Imager Source Catalog will continue to be updated as new HRI observations are screened and become public. New versions will be announced via the electronic ROSAT Status reports and on the RRA web sites at MPE, GSFC, SAO, AIP and Leicester.

Access to the Catalog

Web-Based Access


    The ROSHRI catalog is installed as a one of the standard ROSAT catalogs in the Browse archive interface. To access the ROSHRI catalog, select ROSAT from the list of missions and select the "Advanced Query", then select ROSHRI from the list of catalogs. You can then start a query right away by entering a source name or position and clicking "Start Query". If you want to set other parameters besides position, click 'Parameter Query' and you will be given a form where you can change the parameter defaults.

    To easily search ROSHRI on source coordinates or source names with un-unique, false, and not-checked sources excluded, users can access the ROSHRI Browse interface directly.


    Users can also query the ROSHRI using the ROSAT SOURCE BROWSER developed by MPE at


    The ROSHRI catalog is also accessible via the Leicester Archive Network Interface, or ARNIE, at

FTP Access

Users can also access an ASCII listing of all the parameters for all the sources in the ROSHRI catalog. This listing is availabele (in gzipped form) via anonymous ftp:
% ftp
username: anonymous
password: you@your-email-address
ftp> cd /rosat/doc/archive/RRA/hri/1rxh
ftp> binary
ftp> hash
ftp> get roshricat.txt.gz
ftp> get roshricat-short.txt.gz
ftp> quit
% gunzip roshricat.txt.gz
% gunzip roshricat-short.txt.gz
The roshricat.txt file contains the full source list ; the roshricat-short.txt file is a version of the source list in which deferred fields, un-unique sources, sources with s/n < 4 and sources flagged as "false" have been excluded.

Data products associated with each screened ROSHRI sequence can be obtained via anonymous ftp at; for example

Other RRA Sites

Page Author: Michael F. Corcoran
Last modified August 18, 1999