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ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
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Vol 4, No. 8 10 Aug 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 NASA's Extreme Ultraviolet Explorer
(EUVE) satellite, which is compiled and published monthly by the EUVE Science
Archive group at the Center for EUV Astrophysics (CEA) in Berkeley, CA. The
EUVE observatory performed well throughout the month of July, completing
observations of the following Guest Observer (GO) targets: the planet Jupiter
for the comet Shoemaker-Levy 9 impact (see section 1.2 below), the early-type
star alpha Eri (spectral type B3vpe), the white dwarfs GD246 (DAw) and
RE2009-602 (DA), and the star cluster M15. (All spectral types indicated
above were taken from the SIMBAD database.) A short survey-mode observation
to calibrate the on-board gyroscopes was also conducted.
The contents of this issue of the EUVE electronic newsletter are as follows:
1. Notes from the EUVE Guest Observer (EGO) Center
1.1 Third EUVE NRA
1.2 Early Results of the SL-9/Jupiter Impact Observations
1.3 New Home Page on WWW
2. Notes from the EUVE Science Archive
2.1 GO Data Release List for September 1994
2.2 New Documentation and Services
2.3 Accessing the Archive
3. Abstracts of Recently *Accepted* EUVE Papers
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
==================================================
by Anne Miller, EGO Technical Writer
1.1 Third EUVE NRA
------------------
The 3rd EUVE Guest Observer Program NASA Research Announcement (NRA) will
be released on 16 August. The mailing will consist of a brief description of
the program and a call for proposals. All other materials, including the
complete NRA text and appendices, the forms for paper and electronic submission,
and the instrument calibration data will be made available on the same date on
the World-Wide-Web (WWW) using the Uniform Resource Locator (URL):
ftp://ftp.cea.berkeley.edu/pub/nra94
This path is equivalent to using standard ftp to open the anonymous site:
ftp.cea.berkeley.edu
and typing "cd /pub/nra94". A detailed overview of the electronic materials
for the NRA will be distributed in a future edition of this newsletter.
1.2 Early Results of the SL-9/Jupiter Impact Observations
---------------------------------------------------------
EUVE observed the impact of comet Shoemaker-Levy 9 on Jupiter which occurred
from 16-30 July. Dr. Randy Gladstone of the Southwest Research Institute, a
co-investigator GO with Doyle Hall of the Johns Hopkins University, reports the
following:
"The Jupiter spectrum obtained so far shows strong helium
emissions during the impacts that were not present immediately
before the impacts began. The strongest emission is at 584 A.
An additional feature at 504 A indicates that the emissions may
result from recombination of helium ions. The presence of these
emissions imply that substantial amounts of helium and/or helium
ions have been lifted to high altitudes in Jupiter's upper
atmosphere. Other features are present in the spectrum but are
currently unidentified."
1.3 New EGO Center Home Page on WWW
-----------------------------------
The EGO Center's WWW Home Page has a new format, with summary text on each
of the selections. New users may first select "how to use this site" for an
introduction. In addition to the existing "target visibility" and interstellar
medium (ISM) transmission "ISM" tool, there is a link to the new CEA "ISM
Hydrogen Column" tool. Given a set of coordinates and a distance, this tool
reports the measured hydrogen column densities for the ten objects nearest the
target location, using a list from "The Distribution of Neutral Hydrogen in the
Interstellar Medium (Fruscione et al., 1994)". Publicly available information
on EUVE GO program proposals for Cycles I and II has also been added, as well
as a link to the EUVE Science Archive which has facilities for ordering publicly
released spectral data sets. Please send your comments and feedback on the new
Home Page using the mail address at the bottom of that page.
2. Notes from the EUVE Science Archive
======================================
by Brett A. Stroozas, DASS/Archive Manager
2.1 GO Data Release List for September 1994
------------------------------------------------------
The table below lists the GO observations which become public on 1 September
1994. 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, an indication of which (if any) EUVE CD-ROM on which the
observation appears, and the data identification code. All public data sets
may be ordered from the archive via CEA electronic (e.g., "mailorder go0001")
or postal mail. Please be sure to include in your order the DataID(s) of
interest.
The data rights policy on GO observations states that the GO has 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 complete observation. An exception to the one-year rule occurs when the
target was designated for calibration purposes. At the discretion of the
EUVE Project Scientist, calibration observations may be released before the
expiration of the normal one-year period (usually by only a few months). In
the list below, calibration targets have been marked with a "*".
=====================================================================
Target ~Exp Observation Date(s) SpT CD-ROM DataID
Name (ksec) Start End
=====================================================================
Data Sets Available 1 Sep 1994:
HD149499_B 99 23 Jun 1993 - 27 Jun 1993 K0V ---- go0086
HD165341 86 2 Jul 1993 - 5 Jul 1993 K0V ---- go0087
HD223816 67 6 Aug 1993 - 8 Aug 1993 F5IV ---- go0091
HR8210 98 23 Jul 1993 - 27 Jul 1993 A8m ---- go0090
HS1234+4811 86 19 Feb 1993 - 22 Feb 1993 WD ---- go0053
MCT2331-4731 57 8 Aug 1993 - 10 Aug 1993 WD ---- go0089
MOON 2 30 Jun 1993 - 30 Jun 1993 SS ---- go0088
SS_CYG 187 17 Aug 1993 - 23 Aug 1993 A1pe ---- go0092
=====================================================================
2.2 New Documentation and Services
----------------------------------
The Archive is pleased to announce some newly released EUVE material.
The following are now available via the WWW from the CEA URL
(http://ftp.cea.berkeley.edu):
* A new "Frequently Asked Questions" (FAQ) list is now available (see "FAQ"
listing under "About the EUVE Archive").
* A new service -- the ISM hydrogen column density search tool -- is now
available (see the "ISM Hydrogen Column Density Search Tool" listing
under "Software & Services"). Based on the database compiled by
Fruscione, et al. (1994), this service allows researchers to obtain
hydrogen column density information for the ten stars nearest a given
position (equatorial or galactic coordinates) within a given distance
(parsecs).
* The CEA EUVE bibliography is now available (see the "EUVE Bibliography"
listing under "Documentation"). The bibliography has been sorted and
categorized to assist researchers in locating papers of interest.
Hypertext links to over 60 on-line papers are now available; additional
links will continued to be added as more papers are put on-line.
* The first two issues of the EUVE Science Bulletin -- from January and June
1994 -- are now available (see the "Science Bulletin" listing under
"Documentation"). The Science Bulletin, issued twice each year, is a
collection of articles, abstracts and general information which focuses
on the science results from the EUVE mission.
* The spectral data browser (see the "Spectra" listing under "Data") has been
updated with the spectra for the GO data sets released 1 August.
In addition, a supplemental table to The First EUVE Source Catalog (FESC;
Bowyer, et al., 1994) is now available from the CEA node of NASA's Astrophysics
Data System (ADS). This catalog is called "euve_cat1supp" and is listed under
the "Data:Catalogs" menu in ADS. It corresponds to Table 7 from the FESC paper
and contains those sources from the Bright Source List (Malina, et al., 1994)
which did not meet the more stringent detection criteria set forth in the FESC.
2.3 Accessing the Archive
-------------------------
Listed below are the various methods for accessing EUVE archival material:
o CEA World Wide Web URL:
http://ftp.cea.berkeley.edu (Mosaic/lynx remotely)
telnet ftp.cea.berkeley.edu 200 (lynx locally at CEA)
o NASA's Astrophysics Data System (general and account information):
http://adswww.colorado.edu/adswww/adshomepg.html (Mosaic/lynx)
ads@cuads.colorado.edu
o CD-ROM Series: Volumes 1.1, 2.1, and 2.2 (seven separate CDs) available
o e-mail: archive@cea.berkeley.edu
(include word "help" -- quotes omitted -- as body of message)
o anonymous FTP (or gopher): ftp.cea.berkeley.edu
o EUVE Electronic Newsletters: ceanews@cea.berkeley.edu (to subscribe)
o 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
3. Abstracts of Recently *Accepted* EUVE Papers
===============================================
Included below are abstracts of EUVE-related papers recently *accepted*
for publication. GOs are encouraged to contribute *accepted* abstracts for
inclusion in future editions of this newsletter and for posting under the
EGO Center Mosaic "Home Page". All abstracts should be sent to
egoinfo@cea.berkeley.edu.
For those papers authored by CEA scientists, the EUVE publication number is
indicated. Unless otherwise noted, researchers may obtain preprints of these
papers by sending an e-mail request along with the publication number(s) of
interest to pub@cea.berkeley.edu.
--------------------------------------------------------------
A CATALOG OF FAR-ULTRAVIOLET POINT SOURCES DETECTED WITH THE FAUST TELESCOPE
ON ATLAS-1
S. Bowyer, T.P. Sasseen, X. Wu, and M. Lampton
To appear in Astrophysical Journal Supplement
[CEA publication #594]
We list the photometric measurements of point sources made by the Far
Ultraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 space shuttle
mission. The list contains 4,698 Galactic and extragalactic objects detected
in 22 wide-field images of the sky. At the locations surveyed, this catalog
reaches a limiting magnitude approximately a factor of 10 fainter than the
previous UV all-sky survey, TD1. The catalog limit is approximately 1e-14
ergs s^(-1) cm^2 A, although it is not complete to this level. We list for
each object the position, FUV flux, the error in flux, and where possible an
identification from catalogs of nearby stars and galaxies. These catalogs
include the Michigan HD (MHD) and HD, SAO, the Hipparcos Input catalog, the
Position and Proper Motion Catalog, the TD1 Catalog, the McCook & Sion Catalog
of white dwarf stars, and the RC3 Catalog of Galaxies. We identify 2239 FAUST
sources with objects in the stellar catalogs and 172 with galaxies in the RC3
catalog. We estimate the number of sources with incorrect identifications to
be less than 2%.
--------------------------------------------------------------
THE PRE-CATACLYSMIC BINARY EUVE 2013+400
J.R. Thorstensen, S. Vennes, and A. Shambrook
To appear in Astronomical Journal
[CEA publication #596]
New optical spectroscopy shows a 0.706 d orbital period for EUVE 2013+400
and confirms its membership in a class of close binary systems emerging from
common-envelope evolution. This binary, like the prototype Feige 24, consists
of an extreme ultraviolet (EUV)-emitting hot white dwarf and a late-type dwarf.
Bergeron et al's (1994) optical spectroscopy and ultraviolet spectrophotometry
indicate that the white dwarf is hot (T_eff ~= 50,000 K) and therefore very
young (T_age <= 5e6 yrs), and extreme ultraviolet photometry places EUVE
2013+400 along a neutral hydrogen column density in the interstellar medium
of n_H ~= 1e19 cm^(-2). The white dwarf is a DAO-type and we obtained two
independent estimates of the helium abundance from EUV photometric measurements
(log(y) ~= -3.2) and from the HeII 4686 A line profile (log(y) ~= -2.8).
The data possibly indicate a level of heterogeneity expected in the context
of on-going chemical separation in the photospheric layers. The Balmer lines
show narrow emission that varies with binary phase with the equivalent widths
of the emission trailing the radial velocities by 1/4 cycle: this phasing
shows that most of the emission arises on the EUV-illuminated face of the red
dwarf. A spectrophotometric decomposition shows that the secondary's spectral
type is near M3 and that it contributes about 15-25% of the total light near
6500 A; the resulting H-alpha emission is twice as strong as in Feige 24,
with an equivalent width of 37-61 A with respect to the red dwarf continuum.
EUVE 2013+400 is an important addition to the class of close binary stars
discovered in EUV all-sky surveys.
--------------------------------------------------------------
THE LOCAL DISTRIBUTION OF NaI INTERSTELLAR GAS
B.Y. Welsh, N. Craig, P.W. Vedder, and J.V. Vallerga
To appear in Astrophysical Journal
[CEA publication #597]
We present high-resolution absorption measurements (lambda/d-lambda ~75,000)
of the interstellar NaI D-lines at 5890 A toward 80 southern hemisphere
early-type stars located in the local interstellar medium (LISM). Combining
these results with other sodium measurements taken from the literature, we
produce galactic maps of the distribution of neutral sodium column density for
a total of 293 stars generally lying within ~250 pc of the Sun. These maps
reveal the approximate shape of the mid-plane contours of the rarefied region
of interstellar space termed the Local Bubble. Its shape is seen as highly
asymmetric, with a radius ranging from 30-300 pc, and with an average radius
of 60 pc. Similar plots of the galactic mid-plane distribution of sources
emitting extreme ultraviolet radiation show that they also trace out similar
contours of the Local Bubble derived from NaI absorption measurements. We
conclude that the Local Bubble absorption interface can be represented by a
hydrogen column density, N_H = 2e19 cm^(-2), which explains both the local
distribution of NaI absorption and the observed galactic distribution of
extreme ultraviolet sources. The derived mid-plane contours of the Bubble
generally reproduce the large-scale features carved out in the interstellar
medium by several nearby galactic shell structures.
--------------------------------------------------------------
REFERENCES
==========
Bowyer, S., et al., The First EUVE Source Catalog, Astrophysical Journal
Supplement, 93(2), 1994 [CEA publication #565]
Fruscione, A., et al., The Distribution of Neutral Hydrogen in the Interstellar
Medium. I. The Data, Astrophysical Journal Supplement, September 1994
(in press) [CEA publication #575]
Malina, R.F., et al., The Extreme Ultraviolet Explorer Bright Source List,
Astronomical Journal, 107(2), 751-764, 1994 [CEA publication #553]
---------------------------------------------------------------------------
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: Drs. R.F. Malina and C.S. Bowyer. EGO and Archive Science Manger:
C.A. Christian. Archive 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.
The GSFC Project Manager: Paul Pashby, Project Scientist: Dr. Yoji Kondo,
Deputy Project Scientist: Dr. Ronald Oliversen. NASA HQ Program Scientist:
Dr. Robert Stachnik, 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 at
(301) 286-6247 or e-mail to euve@stars.span.nasa.gov.
END-----------EUVE------------ELECTRONIC---------------NEWS-------------END
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