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ROSAT Status Report # 112

		ROSAT Status Report # 112
			Dec 5 1994


1) MPE News Report # 33
2) PROS Hints and Pointers # 14

=                                                                       =
=              ROSAT NEWS No. 33   ---      1-Dec-1994                  =
=                                                                       =
=                 ROSAT Scientific Data Center at the                   =
=       Max-Planck-Institut fuer Extraterrestrische Physik (MPE)        =
=               Postfach 1603, D-85740 Garching, Germany                =
=  e-mail addresses (Uli Zimmermann):                                   =
=   rosat_svc@mpe-garching.mpg.de (Internet) or  MPE::ROSAT_SVC (SPAN)  =
=  ROSAT Service Area (including ROSAT Data Archive):                   =
=   ftp rosat_svc.mpe-garching.mpg.de      user: anonymous              =
=   WWW address:  http://rosat_svc.mpe-garching.mpg.de/                 =
=   interactive account (including ROSAT Result Archive):               =
=     telnet xray.mpe-garching.mpg.de  user: xray  no password          =
=   WFC Archive access via telnet/ftp ait.physik.uni-tuebingen.de       =
=                                user: xuv  (password: xuv_archive)     =

          - ROSAT CONFERENCE 1995
          - EXSAS 

The (unplanned) solar eclipse of November 3 presented an especially 
delicate problem for the somewhat handicapped attitude control system. 
To compensate for the loss of the z-gyro the fine sun sensor is now 
needed on the day side in the attitude determination procedure when no 
star sensor information is available. During the solar eclipse ROSAT was
just flying over the south atlantic and through the rather extended 
region from which the partial eclipse phase was visible when the fine 
sun sensor noticed that the sun signal dropped. In a case of 
exceptional celestial conspiracy not only the Sun was eclipsed by
the Moon, but also the guide stars were eclipsed by the earth (during a 
regular earth block) so that no star sensor information was available. 
The lower readings of the sun sensor were interpreted by the AMCS 
software as a tilt of the satellite's solar panels with respect to the 
Sun. In this case the software allows for 5 min during which the nominal 
Sun angle must be reassumed. Of course, there was no direction in which 
the satellite could be turned to make the sun sensor signal higher so 
that after 5 min the safe mode was triggered. The nominal timeline was 
resumed on the next day.

We plan to held an International Conference entitled 
         "R"ontgenstrahlung from the Universe"

at the University of W"urzburg from September 25 to 29, 1995.

This conference will contribute to the events commemorating the 
centennial of the discovery of X-rays by Wilhelm Conrad R"ontgen on 
November 8, 1895 at the University of W"urzburg.  At the same time the 
conference will celebrate the fifth anniversary of the launch of ROSAT 
which was named after R"ontgen.

The conference shall adress the whole field of X-ray astronomy. Although
results from the R"ontgen Observatory (ROSAT) will form the backbone of 
the scientific program, we expect that ASCA and perhaps even early
XTE results will be presented as well. Invited reviews, contributed 
talks and poster sessions should cover all major scientific aspects of 
X-ray observations.

The conference will be jointly organized by MPE and the Astronomisches 
Institut of the University of W"urzburg (a city with a bright historical 

Details will be distributed in a special Conference Circular.

A few days after the FIRST ROSAT Source Catalogue of the ROSAT consortium
has been made public (October 26, see ROSAT NEWS No. 32), a second 
source catalog (WGA catalog) was also made available (implemented as
BROWSE databases rosatsrc and wgacat on the interactive account xray). 
Both catalogs have been derived from a similar set of ROSAT data from 
the public data archive and contain about 50 000 sources each. The WGA 
catalog authors (White, Giommi, Angelini) applied a sliding window 
technique for the detection of point sources in the images, while the 
ROSAT Catalogue team (Voges et al.) used a maximum likelihood method in 
the central 20' of the images and a sliding window method with a 
smoothed background estimate at larger off-axis angles. There are also 
a number of other differences, which lead in some cases to obvious 
differences between the 2 catalogs in the number of detected sources in 
a specific field and/or the countrates of individual sources.

Both the ROSAT and the WGA catalog are based on standard procedures and 
therefore cannot replace a careful analysis of the data. Investigations 
are in progress to find systematic problems in both catalogs and we are 
grateful for any information regarding significant discrepancies.  
Information on the detected differences will be placed in the directory 
archive/sourcecat in the ROSAT Service Area. Please read also the
specific database help text in BROWSE.

In the next days we will also put an ASCII version of the FIRST ROSAT 
Source Catalogue to directory archive/sourcecat, for those who wish to 
use it outside the BROWSE utility.

Updated versions of the EXSAS Users Guide and the EXSAS Command
Summary have been sent to the EXSAS sites.

ROSAT PSPC data sets distributed since mid October contain now also
the lightcurves of all brighter sources in the field. With the next
patch of the EXSAS software an update of the command intape/rdf will 
properly handle this new structure.

[                                                                      ]
[                    HINTS & POINTERS for PROS Users                   ]
[   1 DECEMBER 1994                                             #14    ]
[                                                                      ]


   Recently, some PROS users have reported difficulty in converting
MPE rev. 0 data into qpoe files, using the XDATAIO task RARC2PROS. The
problem arises in attempting to convert fits files with names such as

		wp<sequence number>.fits. 

This file is not part of the set of fits files generated by
standard processing (see the help file for RARC2PROS), but is
generated by the RSDC for the convenience of users of other x-ray
analysis software systems. It contains only a subset of the data in
wp<sequence number>_events.tfits, and, since it does not follow the
naming conventions for either Rev. 0 or Rev. 1 data, it causes
RARC2PROS to misinterpret its origin, and fail.

   PROS users should use the XDATAIO task RARC2PROS to import MPE
Rev.0 data into PROS, but should avoid the file mentioned above
(should it be present in the user's data directory, it will cause
RARC2PROS to fail even if the correct Rev. 0 fits files are present).

The following files (or subset of files) are valid input to RARC2PROS:

	wp<sequence number>_attitude.tfits
	wp<sequence number>_difevents.tfits
	wp<sequence number>_drmpspc.ifits
	wp<sequence number>_effarea_pspcb.tfits
	wp<sequence number>_eventrates.tfits
	wp<sequence number>_events.tfits
	wp<sequence number>_image1.ifits
	wp<sequence number>_image2.ifits
	wp<sequence number>_image3.ifits
	wp<sequence number>_imageec.ifits
	wp<sequence number>_mexmap.ifits
	wp<sequence number>_moimp.ifits
	wp<sequence number>_orbit.tfits
	wp<sequence number>_quality.tfits

REMEMBER: wp<sequence number>.fits *MUST NOT* be in the directory!

						F. Primini

As the provider of the PROS software package ("xray" in IRAF), the
ROSAT Science Data Center (RSDC) at SAO distributes HINTS & POINTERS
to PROS Users via email.  When we find answers to often asked
questions, or when we have implemented new software solutions to
longstanding problems, we will send this information directly to our
users.  These messages will also be available via anonymous ftp*, but
to receive the email version, you should register with us. If your
username is the one associated with your site registration, you are
already registered for "HINTS & POINTERS", but we encourage other
users (even at the same sites) to register.

Mailings will be sent as the need arises.  If you would like to
suggest items for future issues of H&P or add your name to our
distribution list, please contact us at the following address:

Internet - rsdc@cfa.harvard.edu         RSDC    MS-3
DECnet   - CFA::RSDC (6699::RSDC)       Center for Astrophysics
UUCP     - ...!harvard!cfa!rsdc         60 Garden St. Cambridge MA 02138 USA
BITNET   - rsdc@cfa                     tel: (617) 495-7134  FAX: 495-7356

* to access our anonymous ftp service:
    o   ftp -i sao-ftp.harvard.edu              # node address:
        [Name: anonymous]
        [Password: <yourusername@yoursite>]

   ftp> cd pub/pros/Hints

N.B.: you can obtain your own copy of the PROS USERS GUIDE by
anonftp from subdir /pub/pros/PUG.  The PUG is also on the WorldWideWeb: