ROSAT Status Report #112:

Dec 5, 1994

Contents:

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://www.mpe.mpg.de/xray/wave/rosat/mission/rosat/

XUV Center: 29382::GXUVDC or GXUVDC@AIT.PHYSIK.UNI-TUEBINGEN.DE

WFC Archive access via telnet/ftp ait.physik.uni-tuebingen.de user: xuv (password: xuv_archive)

Contents:

- SATELLITE STATUS

- ROSAT CONFERENCE 1995

- ROSAT SOURCE CATALOGS

- EXSAS

SATELLITE STATUS

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.

ROSAT CONFERENCE 1995

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 address 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 touch).

Details will be distributed in a special Conference Circular.

ROSAT SOURCE CATALOGS

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.

EXSAS

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 #14

IMPORTING MPE REV 0 PSPC DATA FROM THE US ARCHIVE INTO PROS

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.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_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_attitude.tfits

wp_difevents.tfits

wp_drmpspc.ifits

wp_effarea_pspcb.tfits

wp_eventrates.tfits

wp_events.tfits

wp_image1.ifits

wp_image2.ifits

wp_image3.ifits

wp_imageec.ifits

wp_mexmap.ifits

wp_moimp.ifits

wp_orbit.tfits

wp_quality.tfits

REMEMBER: wp.fits *MUST NOT* be in the directory!

F. Primini

ABOUT HINTS & POINTERS

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: 128.103.42.3

[Name: anonymous]

[Password: ]

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:

http://hea-www.harvard.edu/PROS/pros.html

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