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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
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Vol 5, No. 5 17 May 1995 ISSN 1065-3597
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Notes from the Editor
=====================
by Brett A. Stroozas, ISO Manager
Welcome to the electronic newsletter for NASA's Extreme Ultraviolet Explorer
(EUVE) satellite, compiled and published monthly by the Integrated/Intelligent
Science Operations (ISO) group at the Center for EUV Astrophysics (CEA) at the
University of California, Berkeley (UCB). The contents of this issue of the
EUVE electronic newsletter are as follows:
1. EUVE Science Highlights
2. Innovations in Electronic Documentation
3. EUVE Guest Observer Program News
3.1 EUVE NRA for Cycle 4
3.2 FITS Documentation Release
3.3 Bug in IRAF/EUV Task aspcorr
4. EUVE Science Archive News
4.1 Public Data Release for 1 Jun 1995
4.2 Accepted Public RAP Proposals
4.3 On-Line Access to EUVE
5. Abstracts of Recently *Accepted* EUVE Papers
To comment on or make suggestions for the EUVE electronic newsletter, please
send e-mail to ceanews@cea.berkeley.edu (Internet).
The observatory performed well throughout the month of April, performing
observations of the following guest observer (GO) targets (alternate name and
spectral type information taken from the SIMBAD or internal CEA databases;
"NOIDs" are unidentified objects):
===================================================================
Target Alternate Spectral Observation
Name Name Type GMT Date(s) Notes
===================================================================
GL 411 HD 95735 M2V 22 Mar - 04 Apr 1995 ---
epsilon CMa HD 52089 B2Iab: 04 Apr - 07 Apr 1995 ---
EUVE J1221+17.2 -------- NOID 04 Apr - 07 Apr 1995 RAP
RE 1032+532 EUVE J1032+53.4 DA: 07 Apr - 15 Apr 1995 ---
EUVE J1355-249 -------- NOID 07 Apr - 15 Apr 1995 RAP
BE UMa PG 1155+492 CV 15 Apr - 17 Apr 1995 ---
31 Com HD 111812 G0IIIp 17 Apr - 25 Apr 1995 ---
Mrk 421 UGC 6132 BL-Lac 25 Apr - 06 May 1995 ---
===================================================================
Key to Notes:
RAP = simultaneous Right Angle Program (RAP) imaging observation
1. EUVE Science Highlights
==========================
by Dr. Antonella Fruscione, EUVE Scientist
Using data from the public archive of the EUVE all-sky survey,
Dr. Antonella Fruscione has systematically searched for short wavelength
(58-174 A) EUV emission around approximately 2500 distinct positions in
the sky corresponding to known X-ray emitting extragalactic sources.
She finds that twenty X-ray galaxies are EUV bright and were detected with
significance above four sigma during the EUVE survey: eight (six Seyfert
galaxies and two BL Lacertae objects) are reported for the first time as
sources of EUV emission. Sixty-eight additional galaxies are detected
with a lower significance (sigma between three and four), but the list is
affected by a high percentage of spurious sources. The paper has recently
been submitted to the Astrophysical Journal.
Dr. Jurgen Schmitt, Dr. Jeremy Drake, and Dr. Robert Stern have summarized
their findings about resonant scattering in a paper recently submitted to
Astrophysical Journal Letters entitled "EUV Line Emission From Cool Stars:
Resonantly Scattered or Not -- That is the Question!". The authors argue,
based upon statistical analysis of fluctuations in the EUVE spectrum of
Procyon and ROSAT X-ray data, that resonance scattering (as proposed by
Dr. Schrijver and collaborators in a paper published in Astronomy and
Astrophysics) appears not to be relevant for the interpretation of the EUV
and X-ray spectra of cool inactive stars. Instead, a number of as yet
unidentified spectral lines not included in current plasma codes produces
a false "continuum" in excess of that predicted.
2. Innovations in Electronic Documentation
==========================================
by Frank Kronberg, EUVE Staff Research Associate
For payload controllers in the EUVE Science Operations Center (ESOC) quick,
efficient information retrieval during single-shift operations is an important
goal. Recently, a single document file containing the entire set of more than
50 payload operations procedures has been installed on the secure ESOC computer
network.
A series of indexes and topic lists with embedded hyper-links to the
relevant text gives operators the ability to quickly and easily search for and
electronically retrieve procedures, instructions, or explanations that they
need to complete any task at their workstation. Using capabilities inherent
in Frame Technology's Text Processing System "FRAMEMAKER" and "FRAMEVIEWER",
the 250-page electronic version of the procedures can be accessed from several
entry points, including the table of contents and subject index.
Two new indexes are under development: one that will list software components
and connect to the UNIX "man page" system, and another that will list the
computer file system components (directories and system files) so that this
information will be readily accessible when needed and so that timely updates
can be made regarding any changes in the computer/communication software or
hardware. In addition to the indexes, hyperlinks attached to terms and
paragraphs within each procedure will allow the operator to instantly jump
from one area of text to related information elsewhere in the document. A new
telephone listing system is also being developed that will allow operators to
automatically register telephone number changes in the procedure contact lists.
The procedures are revised and updated on workstations attached to file
servers through the regular CEA computer network; updated versions are then
transferred to the ESOC network. User feedback to the procedures is generated
in the following two ways:
o The user types the word "index" at their keyboard. The following text
entries are written to a file as a "wish list" or "change list" for
new revisions of the procedures.
o A more formal user input process uses the UNIX utility "SCCS" (Source Code
Control System). If an operator finds errors or needs to modify a
procedure immediately, the changes are recorded in an SCCS-controlled
file. These changes are automatically displayed to each operator as
they come on duty.
These two methods -- real-time user feedback and formal version control --
provide operators with a quick and easy means for modifying, and responding to
modifications in, the payload operations procedures.
3. EUVE Guest Observer Program News
===================================
3.1 EUVE NRA for Cycle 4
------------------------
by Dr. Ron Oliversen, EUVE Deputy Project Scientist (GSFC)
Early this summer NASA expects to release the EUVE NRA (NASA Research
Announcement) for the 4th episode Guest Observer Program, with a proposal
deadline of early Fall. Proposals will once again be accepted for the
spectrometer, deep survey, or scanner instruments. The following are a few
changes from the previous NRA:
(1) There will be funds for GO programs, but at approximately half the level
of previous awards.
(2) The Right Angle Program (RAP) is not part of this NRA, but should be
submitted through an ongoing program which uses an electronic
submission process (see http://www.cea.berkeley.edu/ or contact
egoinfo@cea.berkeley.edu for more information).
(3) The 4th episode will be 11 months in length.
(4) There are no PI guaranteed time observations (GTO).
(5) Some observing time, up to 25% maximum, may be committed to the technology
innovation/testbed program.
(6) The proprietary period for data will be decreased from 12 to 6 months.
3.2 FITS Documentation Release
------------------------------
by Anne Miller, EGO Center Technical Writer
The EGO Center has released Appendix B of the Data Products Guide (DPG),
which documents the FITS header cards for the standard data products provided
for each GO observation. The Appendix lists and defines FITS header cards
including those that provide general information to identify the observation,
specify time scales, and record parameters used in processing the data. This
information should be especially helpful to any GOs who wish to reduce their
EUVE data without using IRAF.
The DPG with the new Appendix is designated as version 1.5A. Users may
obtain the complete document, including Appendix B, revised table of contents,
and a bibliography including references for FITS information, from the CEA
ftp site (ftp.cea.berkeley.edu; /pub/documents/docs1.5/data_guide_1.5A).
The entire document is in the compressed tarfile datapg.tar.Z, while the
individual chapters are available as compressed PostScript files.
Users who already have version 1.5 of the DPG can add the new Appendix
and update other parts of the document by obtaining the PostScript files
datapgB.ps, datapg_int.ps, and datapg_bib.ps in the 1.5A directory. Pages
in the latter two files are used to update the table of contents and
bibliography of the previous version.
3.3 Bug in IRAF/EUV Task aspcorr
--------------------------------
The IRAF/EUV task euv.euvtools.aspcorr currently aborts with "segmentation
violation" errors when the first time of the input ephemeris table is less
then the first time of the AspectT column of table1.tab. This bug was
introduced in version 1.5 of the IRAF/EUV package. The problem can be avoided
by creating an ephemeris table with the first time greater then or equal to
the first time of the AspectT column of table1.tab. Note that this solution
to the problem is contrary to the instructions in version 1.4 of the EUVE Guest
Observer Center Software User's Guide, which directs users to create ephemeris
tables for use with aspcorr that have times before the first time and after
the last time in AspectT. This bug is well understood and will be fixed in
the next release of the IRAF/EUV package.
4. Notes from the EUVE Science Archive
======================================
4.1 Public Data Release for 1 Jun 1995
--------------------------------------
by Dr. Nahide Craig, EUVE Science Archive Scientist
The table below lists the GO observations which become public on 1 Jun
1995. For each entry is given the target name, the approximate exposure time
in kiloseconds, the GMT start and end date(s) for the observation, the spectral
type of the target, and the data identification code. All public data sets
may be ordered from the archive via WWW and electronic or postal mail (see
addresses below). Please be sure to include in your order the DataID(s) of
interest.
The data rights policy for GO observations states that GOs have proprietary
rights to the data for one year from the date (s)he receives it. It is often
the case that long observations are broken up over many months; e.g., an
observation approved for 60 ksec may actually be observed for 10 ksec one
month, 20 ksec the next and 30 ksec three months later. In such cases the
one-year proprietary period begins after the GO receives the final piece of
the completed observation.
===============================================================
Target ~Exp Observation Date(s) SpT DataID
Name (ksec) Start End
===============================================================
Data Sets Available 1 Jun 1995:
alpha Cen 7 27 Mar - 27 Mar 1994 G+ go0176
alpha Cen 63 31 Mar - 02 Apr 1994 G+ go0177
BF Lyn 71 14 Apr - 16 Apr 1994 K2V/dK go0178
Capella 74 25 Feb - 27 Feb 1994 G5IIIe go0179
epsilon CMa 38 11 Mar - 12 Mar 1994 B2Iab go0180
HZ 43 43 25 Mar - 27 Mar 1994 DA go0181
HZ 43 46 28 Mar - 30 Mar 1994 DA go0182
Jupiter 85 22 Mar - 25 Mar 1994 comet go0183
LB 1919 168 16 Apr - 22 Apr 1994 DA go0184
Mrk 421 298 02 Apr - 12 Apr 1994 BL-Lac go0185
Procyon 166 12 Mar - 18 Mar 1994 F5IV-V go0186
RE 0623-374 14 25 Mar - 25 Mar 1994 DA go0187
===============================================================
For listings of all publicly available EUVE data sets please see the CEA
WWW site (http://www.cea.berkeley.edu/).
4.2 Accepted Public RAP Proposals
---------------------------------
by Brett A. Stroozas, ISO Manager
The EUVE Public RAP is a simple and convenient method for researchers to
acquire long-exposure EUV photometric data. CEA encourages all interested
researchers to submit RAP proposals! Proposing is quick and easy -- just
follow the simple directions provided on the CEA WWW site (see addresses
given below) or contact the EGO Center (egoinfo@cea.berkeley.edu) for more
information.
To date there have been 27 proposals submitted: 18 have been approved (of
which two were through the GO NRA Cycle and are marked "*") and 9 are currently
under review. The list of current approved proposals is listed below. For
each entry is given the name of the Principal Investigator (PI), the priority
assigned the proposed targets (1=high, 2=medium, 3=low), and the title of the
proposal. Priorities are used to resolve scheduling conflicts when more than
one approved RAP target is viewable at any one time.
------------------------------------------------------------------------
PI Priority Title
------------------------------------------------------------------------
Bowyer 3 RAP Proposal to Identify the Source EUVE J0425-572
Brown 1* Coronal Variability of RS CVn Binaries Due to Flaring,
Rotational Modulation, and Active Region Evolution
Callanan 2 EUVE Observations of Low Extinction LMXBs
Craig 2 Follow-up EUVE Observations of Previously Detected NOID
RAP Sources
Dupuis 3 EUV Lightcurves of White Dwarfs in Close Binaries
Dupuis 3 The Nature of the Dagwood Detections in the EUVE
All-Sky Survey
Edelstein 3 RAP Observation of Neutron Stars
Fruscione 1/2 Is There Any EUV Extended Emission from Planetary Nebulae?
Fruscione 2/3 The Physical Origin of the EUV Emission from AGN from
Light Curve Studies
Howell 1* Accretion Studies in AM Herculis Stars -- The RAP Version
Hurwitz 2 RAP Light Curves of Intermediate Polar CVs
Lieu 3 Observation of AGN within the RAP
Mathioudakis 3 The Fundamental Heating Mechanism of Stellar Coronae
Mathioudakis 3 Coronal Activity Levels from the Least Massive Dwarfs
Roussel-Dupre 2 Monitor RE J1255+266 for Possible Next EUV Outburst
Vennes 3 Observation of KUV 00549-2239
Vennes 3 White Dwarf Study
Welsh 1 An EUV Survey of the beta CMa Interstellar Tunnel
------------------------------------------------------------------------
4.3 On-Line Access to EUVE
--------------------------
Listed below are the various methods for on-line access to EUVE:
o CEA World Wide Web (WWW) URL:
http://www.cea.berkeley.edu/ (for those with WWW browsers)
telnet www.cea.berkeley.edu 200 (for those without WWW browsers)
o anonymous FTP/gopher: ftp.cea.berkeley.edu
o EUVE Electronic Newsletters (past issues available via CEA WWW):
Subscriptions: mail majordomo@cea.berkeley.edu ("subscribe euvenews")
Post message to all subscribers: mail euvenews@cea.berkeley.edu
o For additional information contact the Archive:
The EUVE Science Archive
Center for EUV Astrophysics
2150 Kittredge St.
Berkeley, CA 94720-5030
510-642-3032 (voice) or 510-643-5660 (fax)
archive@cea.berkeley.edu
5. Abstracts of Recently *Accepted* EUVE Papers
===============================================
Included below are abstracts of EUVE-related papers recently *accepted*
for publication. For those papers authored by CEA scientists, the EUVE
publication numbers are indicated. Unless otherwise noted, researchers may
obtain preprints of CEA papers by sending an e-mail request containing the
publication number(s) of interest to pub@cea.berkeley.edu.
Researchers are encouraged to contribute *accepted* EUVE-related abstracts
for inclusion in future editions of this newsletter; abstracts or preprints
will also be posted under the CEA WWW Home Page. Please send all abstracts
or preprints to archive@cea.berkeley.edu.
--------------------------------------------------------------
THE EUV SPECTRUM OF AT MICROSCOPII
B.C. Monsignori Fossi, M. Landini, J.J. Drake, and S.L. Cully
To appear in Astronomy & Astrophysics.
The Extreme Ultraviolet Explorer (EUVE) spectroscopic and photometric
observations of the dMe close binary system AT Mic are investigated. The
photometric observation shows several small flare-like brightenings and,
just at the very end of the observation, a large flare. The spectrometer
observation has been used to study a model of the coronal differential
emission measure (DEM) as a function of temperature. The DEM shows a
minimum at ~1E6 K and a maximum at ~1E7 K. A number of highly ionized
lines of iron (Fe XVIII-XXIII) are identified by means of an EUV synthetic
spectrum calculated using the DEM model and the spectral code of
Monsignori-Fossi and Landini (1994).
--------------------------------------------------------------
SPECTROSCOPIC DIAGNOSTICS IN THE EUV-UV FOR SOLAR AND STELLAR PLASMAS
H.E. Mason and B.C. Monsignori Fossi
Astronomy & Astrophysics Review (1994), 6, 123.
The EUV-UV emission spectra from the solar atmosphere and stellar
atmospheres have been intensively studied during the past 25 years with
several major space programs. In this review we discuss the spectroscopic
diagnostic techniques used to study astrophysical plasmas, the atomic
processes involved, the recent observations and the plans for future
space missions.
--------------------------------------------------------------
OPTICAL IDENTIFICATION OF EUVE SOURCES: THE SECRETS OF EUVE J2056-17.1
M. Mathioudakis, J.J. Drake, N. Craig, D.W. Kilkenny, M. Sirk, J. Dupuis,
A. Fruscione, C.A. Christian, and M.J. Abbott
To appear in Astronomy & Astrophysics. [CEA publication #650]
We present optical, ultraviolet (UV), and extreme ultraviolet (EUV) results
for a new active late-type dwarf star discovered by the Extreme Ultraviolet
Explorer (EUVE). A large flare with an energy in excess of 1E35 erg and
duration of ~1.1 days was detected in the EUVE Lex/B band (60-200 A). The
energetics of the event indicate that radiative losses in the EUV are a
significant contributor to the energy budget in stellar flares. The
"quiescent" EUV emission of the source is similar to the most active flare
stars with the "quiescent" optical spectrum showing strong H-alpha, Ca II
H & K, and Mg II h & k emission. A strong Li I 6707.8 A absorption line
is also present in the spectrum. We have estimated a Li abundance of log
N(Li) = 2.5 +/- 0.4. Although the high Li abundance suggests that EUVE
J2056-17.1 is a young object having recently arrived on the main sequence,
the high flare activity favours an interpretation where the enhanced Li
is sustained by spallation reactions.
--------------------------------------------------------------
EVIDENCE FOR LARGE DIFFERENCES IN THERMAL GAS PRESSURES IN THE
LOCAL INTERSTELLAR MEDIUM
S. Bowyer, R. Lieu, S.D. Sidher, M. Lampton, and J. Knude
To appear in Nature. [CEA publication #651]
Despite some thirty years of effort, the characteristics and
interrelationships between the warm (~1,000 K to 10,000 K) and hot
(~1,000,000 K) phases of the interstellar medium (ISM) are not well
understood. Beginning with the original suggestion of Spitzer,
through the work of Field and collaborators, to the currently
popular model of McKee and Ostriker, a key underlying assumption
of most models is that thermal pressure equilibrium exists between
these two phases. Alternatives have been suggested, but these have
not received a wide following. Here we utilize the discovery of a
shadow in the diffuse extreme ultraviolet background to obtain a
direct measurement of the thermal pressure of the nearby (<= 40 pc)
hot phase of the local ISM. This pressure is more than 20 times
larger than the thermal pressure of the warm cloud surrounding the
sun. This result directly contradicts the basic assumption of
models which assume thermal pressure equilibrium in the ISM.
--------------------------------------------------------------
DISCOVERY OF EXTREME ULTRAVIOLET RADIATION FROM THE SEYFERT GALAXY TON S180
(= EUVE J0057-223)
S. Vennes, E. Polomski, S. Bowyer, and J.R. Thorstensen
To appear in Astrophysical Journal Letters. [CEA publication #652]
We report the detection of intense EUV radiation from the Seyfert 1 galaxy
Ton S180. The source EUVE J0057-223, discovered in the Extreme Ultraviolet
Explorer all-sky survey, is only 25" away from its optical counterpart, well
within the position error circle. We present a complete broad-band energy
distribution of Ton S180 using infrared (IRAS), optical, ultraviolet (IUE),
and X-ray (ROSAT) flux measurements, and we find that the measured EUV flux,
corrected for neutral hydrogen and helium absorption in the Galaxy, suggests
the presence of a strong EUV to soft X-ray flux excess. We briefly discuss
the implications for models of active galaxies.
--------------------------------------------------------------
---------------------------------------------------------------------------
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. EUVE Principal
Investigators and Newsletter Publishers: Dr. R.F. Malina and Professor
C.S. Bowyer. EUVE Science and Technology Manager: Dr. C.A. Christian.
ISO Manager and Newsletter Editor: B.A. Stroozas. Funded by NASA contracts
NAS5-30180 and NAS5-29298. Send newsletter correspondence to:
ceanews@cea.berkeley.edu. The EUVE project is managed by NASA's GSFC:
Paul Pashby, GSFC Project Manager; Dr. Yoji Kondo, Project Scientist;
Dr. Ronald Oliversen, Deputy Project Scientist; Mr. Kevin Hartnett,
Project Operations Director. NASA HQ: Dr. Robert Stachnik, Program
Scientist; Dr. G. Riegler, Program Manager. Information on the EUVE
Guest Observer Program is available from: Dr. Y. Kondo, Mail Code 684,
GSFC, Greenbelt, MD 20771 at (301) 286-6247 or e-mail to
euve@stars.span.nasa.gov.
END-----------EUVE------------ELECTRONIC---------------NEWS-------------END
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