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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
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Vol 4, No. 2 9 February 1994 ISSN 1065-3597
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Notes from the Editor
=====================
by Brett A. Stroozas, Data Analysis Support Staff (DASS) and Archive Manager
Welcome to the electronic newsletter for the Extreme Ultraviolet Explorer
satellite (EUVE), which is compiled and published monthly at the Center for
EUV Astrophysics (CEA) in Berkeley, CA. The EUVE observatory continued to
perform extremely well throughout the month of January, completing observations
of the following Guest Observer (GO) targets: U Gem (a Target of Opportunity),
WD1057+719, 3C273, Geminga, RE1309+081, Alpha Vir, RE1252-291, RE1016-053, and
the Moon.
The contents of this issue of the EUVE electronic newsletter are as follows:
1. Notes from the EUVE Guest Observer (EGO) Center
2. Abstracts of Recently *Accepted* EUVE Papers
3. IAU Colloquium Announcement: Astrophysics in the Extreme Ultraviolet
4. Right-Angle-Program Results at AAS
5. Notes from the EUVE Public Science Archive
To comment on, make suggestions for, or request subscriptions to the EUVE
electronic newsletter, send e-mail to ceanews@cea.berkeley.edu (Internet).
1. Notes from the EUVE Guest Observer (EGO) Center
==================================================
1.1 First Attempt to Map Deep Survey Detector Dead Spot a Partial Success
-------------------------------------------------------------------------
by Anne Miller, EGO Center Technical Writer [Editor's Note: This article
is based on an internal memo by Martin Sirk, DASS Research Associate.]
It was recently reported in these notes (5 November 1993) that a "dead spot"
had developed on the EUVE Deep Survey (DS) detector. Development of an area
of decreased sensitivity near boresight appeared after observations of the
bright white dwarf HZ43 in February of 1993.
On 28 November 1993, the DS was pointed directly at the full Moon in an at-
tempt to gather data that could be used to map the extent and effective depth
of the dead spot. Unfortunately the pointing coincided with a total lunar e-
clipse, and the resulting count rates were neither constant nor as high as was
hoped. However some estimates of the dead spot's characteristics have been
derived from the Moon data.
The dead spot appears to be centered at X = 1033, Y = 1025 (+/- 1 pixel) in
DS detector coordinates. It is somewhat asymmetrical; the width of the con-
tour at 85% of normal efficiency is 60 pixels (2.3 arc-minutes) in X and 50
pixels (1.9 arc-minutes) in Y. This means that pointings made one arc-minute
off-boresight, which were made starting 18 November 1993, will not move the DS
image completely off the dead spot, and DS pigeonhole data obtained for those
pointings may have inaccurate centroids. [Editor's Note: A "pigeonhole" is an
EUVE data file which contains photon information from within a given radius of
a given position on the sky.] The maximum loss of efficiency near the center
of the spot is nearly 80%, based on the average sensitivity of areas far from
bore-sight.
More Moon pointings are being planned to obtain better data on the DS de-
tector center region. Recent observations of the object U Gem saw transient
high count rates, but do not seem to have affected DS sensitivity.
1.2 Processing of Spectrometer Photons
--------------------------------------
by Dr. Mark Abbott, EGO Center Scientist
As of 5:00 PM on 1 February 1994, the EGO group had processed 552,661,776
photons from pointed spectrometer observations.
2. Abstracts of Recently *Accepted* EUVE Papers
===============================================
Included below are abstracts of EUVE-related papers recently *accepted* for
publication in refereed journals. GOs are encouraged to contribute *accepted*
abstracts for inclusion in future editions of this newsletter. Abstracts
should be sent to egoinfo@cea.berkeley.edu.
--------------------------------------------------------------
THE EXTREME ULTRAVIOLET CORONAL SPECTRUM OF THE SOLAR-TYPE STAR CHI ORI
B. Haisch (UCB/CEA, Lockheed), J.J. Drake (UCB/CEA) and J.H.M.M. Schmitt (MPI)
Astrophysical Journal (Letters), 421:L39-L42, 1994 January 20
We present an extreme ultraviolet coronal spectrum of the solar-type star
chi Ori (G0V), one of the first spectra obtained as a guest observation using
the Extreme Ultraviolet Explorer (EUVE). This star is younger and more active
than the Sun. Since no large-scale flare activity was evident in the simul-
taneous deep survey EUV photometry, we simulated the spectrum using a solar
active region differential emission measure (DEM) together with the plasma
emissivity code of Mewe, Gronenschild and van den Oord (1985). The spectral
simulation was normalized to the soft X-ray flux (0.1 to 2.4 keV) observed
during the ROSAT all-sky survey and also to the EUVE all-sky survey Lexan/B
filter count rate to generate predicted counts in spectral bins in order to
identify lines and line blends in the observed spectrum. The difference be-
tween these two normalizations was found to be less than 20 percent. We also
compare both the observed and simulated spectra to the Capella observations
of Dupree et al. (1993). The accuracy of the emission code and of this spectra
simulation is demonstrated by its excellent fit to the high signal-to-noise
data in the short-wavelength spectrum of Capella. For chi Ori we conclude the
following: (1) apart from the He II lines, we do not see many of the expected
lines forming at log T <= 6.2; (2) in the range log T = 6.3-6.8 we find rea-
sonable agreement with a spectrum simulating the DEM of a solar active region;
(3) material appears to be present at temperature as hot as log T = 7.2 (Fe
XXIV).
--------------------------------------------------------------
ERRATA
This abstract citation listed in the 6 January 1994 issue was incorrect:
EXTREME ULTRAVIOLET SPECTROSCOPY OF PKS 2155-304
Antonella Fruscione, Stuart Bowyer (CEA/UCB) and Steven M. Kahn (U. Chicago)
to appear in Astrophysical Journal Letters, 1994
The correct citation is:
EXTREME ULTRAVIOLET SPECTROSCOPY OF PKS 2155-304
Antonella Fruscione, Stuart Bowyer (CEA/UCB), Arieh Konigl (U. Chicago),
and Steven M. Kahn (UCB/SSL)
to appear in Astrophysical Journal Letters, 1994
--------------------------------------------------------------
3. IAU Colloquium Announcement: Astrophysics in the Extreme Ultraviolet
=======================================================================
First Announcement
IAU COLLOQUIUM NO. 152
ASTROPHYSICS IN THE EXTREME ULTRAVIOLET
University of California, Berkeley
March 27-30, 1995
Sponsored by IAU Commissions 48, 29, 34, 42 and 44
Chaired by: Stuart Bowyer and Bernhard Haisch
Scientific Organizing Committee:
P.C. Agrawal, A. Dupree, G. Fontaine, E. Jenkins, R.F. Malina, R.
Mewe, Y. Kondo, J. Sahade, J. Schmitt, A. Vidal-Madjar, K. Yamashita
Partial list of topics:
Coronae of Cool Stars
White Dwarfs
Photospheres and Winds of Early-Type Stars
Accretion Driven Sources
The Interstellar Medium
Neutron Stars
Cataclysmic Variables
Supernova Remnants
Extragalactic Sources in the EUV
Solar System Observations
Theoretical Modeling and Laboratory Measurement of Plasma EUV Emission
Results of recent Missions (EUVE, ROSAT, HUT, DXRBS, ALEXIS)
If you wish to receive the second announcement and registration material
please contact Ms. Sharon Lilly by e-mail (iau152@cea.berkeley.edu) or FAX
(510-643-5660) and indicate whether you wish to receive future material
by e-mail or postal mail.
4. Right-Angle-Program Results at AAS
=====================================
by Kelley McDonald, DASS Research Associate
During the GO phase of the EUVE Mission, data are being collected with the
three all-sky survey telescopes (scanners) and the Deep Survey (DS) imaging
telescope (which points 90 degrees away from the scanners). The EUVE
Right-Angle-Program (RAP) involves (1) the scheduling of target observations
in the scanners during GO observations in the DS, (2) the analysis of the
resulting non-GO data sets and (3) the coordination of possible simultaneous
observations with ground based instruments. All three aspects of the RAP are
now implemented and in operation. The resulting data sets consist of discrete
pointings performed at a much deeper level than the all-sky survey, although
covering only a small fraction of the sky.
The preliminary RAP results were presented in a poster paper at January's
183rd meeting of the American Astronomical Society (AAS) in Washington, D.C.
Analysis of the data has so far yielded 89 sources from ~90 scanner and DS
fields-of-view, a large number of which are previously undetected EUV sources.
About 80% of these sources had count-rates less than 0.01 counts/second and 76
of the 89 sources were not detected according to the First EUVE Source Catalog
(Bowyer, 1994). Strategies are currently being investigated which will open
up the RAP externally to the general astronomical community.
5. Notes from the EUVE Public Science Archive
=============================================
by Elisha Polomski, Archive Research Associate
and Brett Stroozas, DASS/Archive Manager
The Archive CD-ROM effort was well received at the AAS meeting -- more than
350 copies of the EUVE CD-ROM V2.1 set (Stroozas, 1994) were distributed. The
Archive poster paper "Expansion of the EUVE Science Archive: New Products and
Services" was displayed at the conference and incited a number of queries, in-
cluding requests for the all-sky survey Catalog (Bowyer, 1994), for available
EUVE images and for copies of CD-ROM V1.1 (Drake, 1993). All of this material,
or related information, is available in the CEA Archive anonymous FTP site
(ftp.cea.berkeley.edu). There were also a number of new subscriptions to
the EUVE Electronic Newsletter (ceanews@cea.berkeley.edu). Some additional
requests were for various CEA preprints (the CEA booth ran out!) which may be
obtained from the CEA editorial group (pub@cea.berkeley.edu).
On another note, the Archive continues to work hard to make EUVE data and
information available via Mosaic on the World Wide Web (WWW). The Archive has
received over 200 external queries since its inception on the Web in late De-
cember, 1993. We expect to see interest grow as additional material becomes
available in the coming months (e.g. as data rights begin to expire in the
Spring).
EUVE Archive Access Reminders
-----------------------------
* CEA WWW Server:
http://ftp.cea.berkeley.edu (Mosaic)
telnet ftp.cea.berkeley.edu 200 (lynx)
* NASA's ADS: contact ads@cuads.colorado.edu for account information
* CD-ROM Series: Volumes 1 and 2 (four separate CDs) are available
* anonymous FTP (or gopher): ftp.cea.berkeley.edu
* e-mail: archive@cea.berkeley.edu (include word "help" -- quotes omitted
-- as body of message
* EUVE Electronic Newsletters: ceanews@cea.berkeley.edu (to subscribe)
* Postal Mail:
The EUVE Public Science Archive
Center for EUV Astrophysics
2150 Kittredge St.
Berkeley, CA 94720
510-642-3032 (voice) or 510-643-5660 (fax)
archive@cea.berkeley.edu
REFERENCES
==========
Bowyer, C.S., et al., The First EUVE Source Catalog, Astrophysical Journal
Supplement, 1994 (in press)
Drake, J.J., et al., The Extreme Ultraviolet Explorer Science Archive:
Selected Data and Software, Eds. S. Bowyer and R.F. Malina,
1:1 in the CD-ROM series (ISSN# 1069-7497), 1993
Dupree, A.K., et al., The Extreme Ultraviolet Explorer Spectrum of Alpha
Aurigae (Capella), Astrophysical Journal (Letters), V417, 20 November
1993
Stroozas, B.A., et al., The Extreme Ultraviolet Explorer Science Archive:
Selected Data and Software, Eds. S. Bowyer and R.F. Malina,
2:1 in the CD-ROM series (ISSN# 1069-7497), 1994
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The EUVE Electronic Newsletter is issued by the Center for Extreme
Ultraviolet Astrophysics, University of California, Berkeley, CA 94720,
USA. The opinions expressed are those of the authors. Publishers:
Drs. R.F. Malina and C.S. Bowyer. Editor: B.A. Stroozas. Funded by
NASA contracts NAS5-30180 and NAS5-29298. Send newsletter correspondence
to: ceanews@cea.berkeley.edu. The EUVE Public Science Archive is accessible
via FTP: ftp.cea.berkeley.edu, /pub/archive. The EUVE project is
managed by NASA's GSFC. The GSFC Project Manager: Paul Pashby, Project
Scientist: Dr. Yoji Kondo, Deputy Project Scientist: Dr. Ronald Oliversen.
NASA HQ Program Scientist: Dr. Robert Stachnik, Dep. Program Scientist:
Dr. D. Buzasi, Program Manager: Dr. G. Riegler. GSFC Project Operations
Director: Mr. Kevin Hartnett. Information on the EUVE Guest Observer
Program is available from: Dr. Y. Kondo, Mail Code 684, GSFC, Greenbelt,
MD 20771 (301)286-6247; e-mail to euve@stars.span.nasa.gov.
END-----------EUVE------------ELECTRONIC---------------NEWS-----------------END
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