EEEEEEEEEEE U U V V EEEEEEEEEEE
E U U V V E
E U U V V E
EEEEEEE U U V V EEEEEEE
E U U V V E
E U U V V E
EEEEEEEEEEE UUUUU V EEEEEEEEEEE
---------------------------------------------------------------------------
ELECTRONIC NEWSLETTER OF THE EUVE OBSERVATORY
---------------------------------------------------------------------------
Vol 4, No. 9 14 Sep 1994 ISSN 1065-3597
---------------------------------------------------------------------------
Notes from the Editor
=====================
by Brett A. Stroozas, EUVE Data Analysis Support Staff (DASS)
and Science 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 August, completing
observations of the following Guest Observer (GO) targets (spectral types,
taken from the SIMBAD database, are indicated in parentheses): Wolf 630
(M3Ve), GD 246 (WD), Jupiter, EUVE J2214-49.3 (WD), RE 1844-741 (CV), the Moon,
and a calibration observation of HR 1099 (G5IV+K1IV). An engineering test to
calibrate the electronic "wedge-strip-zigzag" detectors was also conducted.
The contents of this issue of the EUVE electronic newsletter are as follows:
1. Notes from the EUVE Science Archive
1.1 Public Release of the EUVE Sky-Survey Data
1.2 GO Data Release List for October 1994
1.3 CEA Network Server Change
1.4 majordomo Server for Newsletter
1.5 Accessing the Archive
2. Abstracts of Recently *Accepted* EUVE Papers
3. CEA Job Listings
1. Notes from the EUVE Science Archive
======================================
by Brett A. Stroozas, DASS/Archive Manager
1.1 Public Release of the EUVE Sky-Survey Data
----------------------------------------------
As announced in the recent news "flash" of 29 August, CEA is pleased to
announce the public release of the EUVE sky-survey data. The completed survey
data sets cover approximately 97% of the sky in four band passes (60-740 A)
with exposures ranging from a few hundred seconds at the ecliptic equator to
20 kiloseconds at the poles.
The main science data products from the survey include the following:
o source catalogs -- Two catalogs of the survey results have been published in
the literature: "The Extreme Ultraviolet Explorer Bright Source List"
(Malina, et al. 1994); and "The First EUVE Source Catalog" (Bowyer, et
al. 1994). For the confirmed detected sources contained therein, these
catalogs furnish coordinates, approximate count-rates (to within ~50%),
and optical identifications (where available).
o skymaps -- The survey skymaps are packaged as sets of binned raw photon
(~1.3' resolution) and exposure (~10' resolution) FITS maps for each
survey band pass.
o pigeonholes -- An EUVE "pigeonhole" is a file which contains the time-tagged
photon event information within a small radius (typically 0.4 degrees)
of a given location on the sky. The pigeonhole files provide the
maximum amount of information for each target location and are
available in FITS bintable format.
The above science data products are available from the CEA World Wide Web
(WWW) URL:
http://www.cea.berkeley.edu
Three services -- the EUVE Count-Rate, the Skymap Request and the Pigeonhole
Request service -- provide access to the various data products. These data
products vary in their complexity and require different levels of processing,
delivery and analysis time. Because of this, and in order to minimize the
efforts required by the researcher, the Archive recommends that users access
the data in the following manner:
1. Search the available catalogs for sources of interest.
2. Use the EUVE Count-Rate service to obtain count-rate information on these
sources.
3. Use the Skymap Request service to obtain skymaps for interesting sources.
4. Use the Pigeonhole Request service to obtain source pigeonholes.
Detailed documentation on all of the above is available on-line. The Archive
will continue to improve and augment the available survey data, services and
accompanying documentation. Please help us to help you with your EUVE research
by sending your comments and/or suggestions to archive@cea.berkeley.edu.
1.2 GO Data Release List for October 1994
-----------------------------------------
The table below lists the GO observations which become public on 1 October
1994 (all have been reprocessed with the most recent versions of the EGO Center
software and reference data). 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 World Wide Web
URL 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 GO's 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 complete observation.
===============================================================
Target ~Exp Observation Date(s) SpT DataID
Name (ksec) Start End
===============================================================
Data Sets Available 1 Oct 1994:
CYG_1992 40 08/23/93 - 08/25/93 Nva go0093
EF_ERI 118 09/05/93 - 09/08/93 CV go0094
EQ_PEG 37 08/29/93 - 08/30/93 M4Ve go0095
EV_LAC 118 09/09/93 - 09/13/93 M4V go0096
GRB250392 39 08/25/93 - 08/26/93 GRB go0097
HD15638 84 09/02/93 - 09/05/93 F+WD go0098
HER_X-1 113 08/10/93 - 08/14/93 Puls go0099
MK478 70 04/09/93 - 04/11/93 AGN go0100
MK478 70 04/11/93 - 04/14/93 AGN go0057
MK478 66 04/14/93 - 04/16/93 AGN go0056
MK478 65 04/16/93 - 04/18/93 AGN go0055
RE2156-543 48 08/14/93 - 08/16/93 WD go0101
RE2214-491 78 08/26/93 - 08/29/93 WD go0102
RE2237-135 30 09/21/93 - 09/22/93 NOID go0103
RE2303+212 29 09/22/93 - 09/23/93 NOID go0104
WD2111+498 73 09/13/93 - 09/16/93 WD go0105
===============================================================
1.3 CEA Network Server Change
-----------------------------
In order to conform to a growing "standard" naming convention, as well as
to be more intuitive for users, the name of the CEA network server has been
changed to
www.cea.berkeley.edu
We encourage all users to access CEA at this address. The old address --
ftp.cea.berkeley.edu -- will continue to work for a time.
1.4 majordomo Server for Newsletter
-----------------------------------
The mail list for subscriptions to this newsletter has recently been added
to the CEA "majordomo" server. In addition to simplifying maintenance of mail
lists, majordomo provides flexible mail server utilities which allow users to
subscribe to and unsubscribe from lists, retrieve previous messages, and send
messages to the list subscribers.
The newsletter mail list -- euvenews -- is the most recent addition to the
available CEA lists. To retrieve information regarding the euvenews list and
its available associated material (e.g., past newsletter issues), send mail to
majordomo@cea.berkeley.edu
including one or more of the following commands in the body of the message:
* help --> request generic help on majordomo commands
* index euvenews --> request index of available files from euvenews list
* get euvenews --> request the file from euvenews list
All commands should be sent on a separate line in the mail message; a message
may contain multiple commands.
To post a message to all newsletter subscribers (not including yourself),
send mail to euvenews@cea.berkeley.edu. Please be *very* careful when using
this address; make sure that only relevant material is posted to the newsletter
subscribers. If you have comments and/or suggestions regarding the newsletter
and majordomo list/server, please send them to archive@cea.berkeley.edu.
1.5 Accessing the Archive
-------------------------
Listed below are the various methods for accessing EUVE archival material:
o CEA World Wide Web URL:
http://www.cea.berkeley.edu (Mosaic/lynx remotely)
telnet www.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): www.cea.berkeley.edu
o EUVE Electronic Newsletters:
Subscriptions: majordomo@cea.berkeley.edu ("subscribe euvenews")
Post message to subscribers: euvenews@cea.berkeley.edu
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
2. 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 the
CEA papers by sending an e-mail request along with the publication number(s)
of interest to pub@cea.berkeley.edu.
--------------------------------------------------------------
OBSERVATIONS OF HER X-1/HZ HER
S.D. Vrtilek, T. Mihara, F.A. Primini, P. Kahabka, H. Marshall, F. Agerer,
P.A. Charles, F.H. Cheng, K. Dennerl, C. la Dous, E.M. Hu, R. Rutten,
P. Serlemitsos, Y. Soong, J. Stull, J. Trumper, W. Voges, R.M. Wagner,
R. Wilson
To appear in Astrophysical Journal Letters
We present first results from a multiwavelength campaign to observe the
binary pulsar system Her X-1/HZ Her. The campaign spanned four days during
August 1993: observations were taken with 5 satellites and several ground-based
optical facilities. A substantial, unexpected drop in flux at X-ray energies,
with no change in absorbing column density, was observed. The pulse period has
increased from the previous measurement, contrary to the usual spin-up, and no
pulsed emission is detected above 0.9 keV in the low state. The optical and UV
fluxes continued to show 1.7 day modulation attributed to X-ray heating of the
companion star. However, the UV flux around eclipse was significantly reduced
implying an absence of the normally observed excess attributed to X-ray heating
of the disk. We conclude that we have observed an anomalous low state, seen
only once before (Parmar et al. 1985), in which the X-ray flux is not
redistributed but obscured. We suggest explanations for the behavior of the
flux at different wavelengths.
--------------------------------------------------------------
ASYMMETRIC MASS ACCRETION IN THE MAGNETIC CATACLYSMIC VARIABLE RE1149+28
S.B. Howell, M. Sirk, and R.F. Malina
To appear in Astrophysical Journal [CEA publication #605]
We present the first detailed extreme ultraviolet photometric observations
of a magnetic cataclysmic variable. Our two EUVE observations of the AM Her
star RE1149+28 were obtained about one year apart and show lightcurve
variations on orbital to yearly timescales, as well as long-term mean flux
level changes of a factor of two. The photometric data show a persistent
ingress EUV enhancement which lasts ~0.04 in phase. We attribute this to
a region of ~1e3 km in extent at the accretion impact site, on or very near
the surface of the white dwarf primary. Our observations of RE1149 are
consistent with a relatively low system inclination and provide a best fit
orbital period of 90.14 +/- 0.015 minutes.
Subject headings: Binaries: General -- cataclysmic variables, Stars:
individual (RE1149+28), Accretion, Ultraviolet: Stars
--------------------------------------------------------------
ACTIVE GALAXIES OBSERVED DURING THE EXTREME ULTRAVIOLET EXPLORER ALL-SKY SURVEY
H.L. Marshall, A. Fruscione, and T.E. Carone
To appear in Astrophysical Journal [CEA publication #604]
We present observations of active galactic nuclei (AGN) obtained with the
Extreme Ultraviolet Explorer (EUVE) during the all-sky survey. A total of 13
sources were detected at a significance of 2.5 sigma or better: seven Seyfert
galaxies, five BL Lac objects, and one quasar. The fraction of BL Lac objects
is higher in our sample than in hard X-ray surveys but is consistent with the
soft X-ray Einstein Slew Survey, indicating that the main reason for the large
number of BL Lac objects detected in the extreme ultraviolet (EUV) and soft
X-ray bands is their steeper X-ray spectra.
We show that the number of AGN observed in both the EUVE and ROSAT Wide
Field Camera surveys can readily be explained by modeling the EUV spectra with
a simple power law in the case of BL Lac objects and with an additional EUV
excess in the case of Seyferts and quasars. Allowing for cold matter
absorption in Seyfert galaxy hosts drives up the inferred average continuum
slope to 2.0 +\- 0.5 (at 90% confidence), compared to a slope of 1.0 usually
found from soft X-ray data. If Seyfert galaxies without EUV excesses form a
significant fraction of the population, then the average spectrum of those
with bumps should be even steeper. We place a conservative limit on neutral
gas in BL Lac objects: N_H < 1e20 cm^(-2).
--------------------------------------------------------------
IN-ORBIT PERFORMANCE OF THE SPECTROMETERS OF THE EXTREME ULTRAVIOLET EXPLORER
W. Boyd, P. Jelinsky, D. S. Finley, J. Dupuis, M. Abbott, C. Christian,
and R.F. Malina
To appear in "EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy V,"
Proceedings of SPIE, 2280, 1994 [CEA publication #603]
The Extreme Ultraviolet Explorer (EUVE), launched on June 7, 1992, is an
extremely successful NASA astrophysics mission that contains three extreme
ultraviolet (EUV) spectrometers designed to be used in pointed spectroscopic
observations of astrophysical sources in the the 70-760 A wavelength region.
The spectrometers utilize a slitless design based on grazing-incidence optics
and variable line-space gratings. Detailed wavelength scales determined from
ground-based calibrations and refined with in-orbit data are used to assign
wavelengths for each detected photon to within half a resolution element (less
than 0.8 A in all cases). Spectral resolving power (FWHM of non-Gaussian
profiles) varies in the range R = lambda/Dlambda ~150-400. Spectrometer
throughputs were determined from an extensive laboratory calibration and then
were adjusted slightly based on in-flight calibration spectra of known
astrophysical continuum sources (hot DA white dwarf stars). We also have
measured count rates from the detector and the geocoronal and distributed
backgrounds, parameters critical to assessment of accurate flux levels from
the astrophysical sources.
--------------------------------------------------------------
LONG-TERM ORBITAL PERFORMANCE OF THE MCP DETECTORS ABOARD THE EXTREME
ULTRAVIOLET EXPLORER
J.V. Vallerga, M. Eckert, M. Sirk, O. Siegmund, and R.F. Malina
To appear in "EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy V,"
Proceedings of SPIE, 2280, 1994 [CEA publication #602]
The Extreme Ultraviolet Explorer (EUVE), launched June 7, 1992, conducted
an all-sky survey in the extreme ultraviolet wavelengths (70-760 A) for 6
months and is now performing spectroscopic pointings for Guest Observers. The
seven microchannel plate (MCP) detectors used on the instrument (four for
imaging in photometric wavebands and three for the spectrometers) have operated
successfully throughout the mission. The long-term (780 days) performance
characteristics such as quantum efficiency (QE), gain, and background count
rate, will be reviewed along with other interesting unexpected effects noted
during the mission. Because the QE has remained constant, the background has
been reduced, and other effects have been minimized, the EUVE instruments
currently operate better than after launch and will probably continue to do so.
--------------------------------------------------------------
3. CEA Job Listings
===================
by Cathie Jones, CEA Personnel Manager
Programmer Analyst -- Center for EUVE Astrophysics
Job #08-199-10/CP
University of California
NASA Extreme Ultraviolet Explorer Project
Work with a small team of programmers, scientists and engineers, to develop
and maintain the system of ground operations software that analyzes science
data from an astronomical instrument in Earth orbit. Provide software for
telemetry storage and analysis, and instrument monitoring and control. Design
new software and maintain existing software in a C/Unix environment on a
network of Sun workstations and servers. Provide support to programmers
working on innovative technology projects.
Qualifications: Strong background in computer science/software engineering.
Experience in advanced C/UNIX programming and UNIX tools. Ability to work
under pressure.
Combination of the following desired: satellite operations, expert systems,
lisp programming, shell programming, real-time data processing, networks,
innovative technologies for cost-reduction and automation, supervision of
small projects.
Resumes due by 9/23/94. Reference job number on cover letter.
REFERENCES
==========
o Bowyer, S., Lieu, R., Lampton, M., Lewis, J., Wu, X., Drake, J.J., and
Malina, R.F., "The First EUVE Source Catalog", Astrophysical Journal
Supplement, 93(2), 1994 [CEA publication #565]
o 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
[HomePage]
[Email]
[Search]
[Glossary]
Page created by webmastr@cea.berkeley.edu
Last modified 10/4/97