ELECTRONIC NEWSLETTER OF THE HIGH ENERGY ASTROPHYSICS DIVISION OF THE AAS
Newsletter No. 68 May 1996
IN THIS ISSUE:
- Notes from the Editor - K. Hurley
- News from NASA Headquarters - A. Bunner, L.
Kaluzienski, G. Riegler
- Activities of the Gamma-Ray Astronomy Program Working
Group - N. Gehrels
- The Fall 1995 Australian Balloon Campaign - C.
Hailey, T. Prince, R. Sood, J. Tueller
- The High Energy Astrophysics Learning Center - L.
Whitlock and J. Lochner
- Future Meetings
by Kevin Hurley, Secretary-Treasurer (khurley@sunspot.ssl.berkeley.edu)
Fall 1995, a balloon campaign took place in Alice Springs, Australia. Details and
results of some of the flights are presented in this newsletter. As always, our Web site
contains the more complete versions of the articles, some with figures and hypertext
references. The url is http://ssl.berkeley.edu/head.opener.html. (It is also possible to
reach the site from the AAS homepage, at http://www.aas.org/.)
A. Message from the Science Program Director for Structure and Evolution of the
Universe - Alan Bunner
The coming year at NASA's Office of Space Science (OSS) will include strategic planning
activities aimed at establishing a queue of recommended new space science missions for the
period 2002-2025, to follow the launches of SIRTF and FUSE, the last of the presently
approved queue. This activity will involve several committees, special sessions, and
workshops, some of which are described below.
I now serve at OSS as Science Program Director for Structure and Evolution of the
Universe, which encompasses high energy astrophysics, galactic cosmic rays, extreme
ultraviolet astronomy, submillimeter and radio astronomy from space, and gravitation and
relativity studies in space. In simple terms, this theme covers space observations of the
electromagnetic spectrum roughly shorter than of 912 angstroms and longer than of 100
microns and the field often called "relativistic astrophysics." As your advocate
at NASA Headquarters for this thematic area, I will lead the effort to provide input for
the Office of Space Science's 1997 Strategic Plan.
The Space Studies Board of the National Research Council has formed a Task Group on
Space Astronomy & Astrophysics (TGSAA) which is sponsoring an open meeting in Madison
on Sunday June 9, at the start of the AAS meeting. This special session will provide a
forum for community dialog on scientific priorities. Please contact tgsaa@nas.edu if you
wish to actively participate.
The Structure and Evolution of the Universe Advisory Subcommittee (SEUS), for which
Roger Blandford is Chair, has its first meeting June 3-4, at NASA Headquarters. The
primary tasks of this committee are to synthesize the inputs from various community and
NASA activities, providing NASA Headquarters with advice on directions and priorities, and
to assist in the creation of a scientific "roadmap," a plan for a future concert
of space missions that together will probe the secrets of the Universe.
A parallel effort to the setting of scientific priorities is the creation of a strawman
timeline of future missions and the planning for the associated necessary technology
developments. This implementation and technology roadmap is being developed by a "SEU
Technology Working Group," co-chaired by Jon Ormes (GSFC) and Steve Kahn (Columbia).
A workshop on this topic will occur later this year, probably in September-October.
A few general comments about the prospects for future missions in a declining budget
climate: Several considerations carry more weight today than in the past: new mission
ideas should be (a) scientifically exciting and addressing fundamental scientific
questions, (b) publicly engaging, addressing fundamental issues that are understandable,
explainable and entertaining, and making astrophysics a part of the human experience, (c)
technologically challenging - driving but also capitalizing on technological developments,
(d) visionary but affordable ("reaching for the stars but keeping our feet on the
ground"), and (e) imaginative (providing breakthroughs or major steps towards
breakthroughs in science.)
The end result of this strategic planning will be the creation of a new NASA Office of
Space Science Strategic Plan in early 1997 and a corresponding plan for support of the
associated technology imperatives. Your input to this process will be appreciated.
B. Message from the Research Program Management Division Discipline Scientist for High
Energy Astrophysics - Lou Kaluzienski
Item 1: NASA High Energy Astrophysics (HEA) Supporting Research and Technology
(SR&T) Program--Update
The scientific and technical peer review of proposals received in response to the NASA
Research Announcement for this program (NRA 95-OSS-17) is planned for the latter part of
June. A total of ~ 50 proposals were received, divided roughly evenly between X- and
gamma-ray astronomy research. The anticipated funding available for the support of
selected proposals is ~$9M per year over the three-year period of the NRA, commencing in
October 1996. We expect to notify proposers of the outcome of the review before mid-July.
Questions concerning the review process may be directed to the me at 202-358-0365 or
electronically at lkaluzienski@hq.nasa.gov.
Item 2: NASA Research Program Management Division (RPM) position in High Energy
Astrophysics
A position will become available to serve as a visiting scientist under the
Intergovernmental Personnel Act (IPA) program in the RPM Division at NASA Headquarters. We
are seeking a scientist at least two years beyond his/her doctorate with demonstrated
expertise in high energy astrophysics to assist in the management of NASA's research
program in this science area. The position will become available sometime around February
1997. The nominal appointment will be for one year, although extensions for up to four
years are possible. For more information concerning this opportunity, please contact me at
202-358-0365 or electronically at lkaluzienski@hq.nasa.gov.
C. Message from the Chief Scientist of the Research Program Management Division -
Guenther Riegler
1996 Senior Review of Astrophysics Mission Operations and Data Analysis (MO&DA)
Programs
NASA will host the next "Senior Review" - a comparative science review of
Astrophysics MO&DA Programs - during the summer of 1996. This will be the fifth review
of its type.
The Senior Review, held every two years by an ad hoc panel, complements the standing
working groups and other peer reviews by conducting a comparative evaluation of proposals
for continued funding or funding augmentation for missions and programs. It is the highest
level of peer review within the Astrophysics program.
The Senior Review assesses the balance between the science potential or science returns
and the resource requirements of a diverse set of Astrophysics programs, and then provides
detailed advice on relative priorities. Such a review is an opportunity for an overall
assessment of the relative scientific priorities among the various programs and missions.
Recommended outcomes may include program enhancements or reduction, and mission extensions
or terminations.
Content of the Senior Review: This Senior Review will concentrate on the science merits
of ten Astrophysics programs (in alphabetical order): ASCA (U.S. participation), CGRO,
EUVE, HETE, ISO (U.S. participation in the guest observing program), ISO (U.S. Guest
Observer Facility at IPAC), ROSAT (U.S. participation), SAX (U.S. participation in the
guest observing program), Space VLBI (U.S. participation at Government Laboratories and
Federally Funded Research and Development Centers) and XTE.
The currently planned funding for these ten programs per fiscal year is given below.
Fiscal Year 97 98 99 00
Total SR96 Funding Pool ($M) 39 18 19 06
Proposals are due on June 21, 1996. Publication of recommendations and instructions to
projects is planned for September 1996
N. Gehrels (NASA-GSFC) and T. Prince (CIT)
In 1995 NASA formed the Gamma Ray Astronomy Program Working Group (GRAPWG) to formulate
recommendations for future directions in NASA's gamma-ray astronomy program. The energy
range considered in this study extends from hard x-rays (~>10 keV) through TeV gamma
rays. The mandate of the working group is to recommend a road map to the future for use as
an input to the next NASA strategic plan, currently slated for 1997. The working group,
whose membership is given below, has met four times over the past 2 years. It has assessed
the state of the field including current missions and approved future missions, the
critical scientific problems open today, the promising technologies for the future, the
mission priorities for the future, and the needs for data analysis and theory. The working
group is nearing completion of its study and is formulating preliminary recommendations. A
brief summary of the findings and recommendations of the GRAPWG will be circulated via
HEADmail in the near future.
GRAPWG Members:
- Elena Aprile
- Alan Bunner - Ex-Officio (NASA Headquarters)
- Gerald Fishman
- Neil Gehrels - Co-Chair
- Jonathan Grindlay
- Kevin Hurley
- W. Neil Johnson
- Steve Kahn
- Richard Lingenfelter
- Peter Michelson
- Thomas Prince - Co-Chair
- Roger Romani
- James Ryan
- Bonnard Teegarden
- David Thompson
- Trevor Weekes
- Stanford Woosley
(Editor's note: when the document is complete, we will add a link to it from our Web
site.)
A. GRATIS - C. Hailey, Columbia University
The gamma-ray arcminute telescope imaging system (GRATIS) launched from Alice Springs
at 8 AM local time, Oct. 17, 1995. GRATIS is a coded mask experiment with ~2 arcmin
angular resolution and ~800 cm2 geometric area of alkali halide
scintillator/imaging photo tubes which operates in the 25-150 keV energy band. A very
quick ascent followed during which an extremely sophisticated new daytime tracking system
consisting of a suntracker and attitude GPS corrected fiber optic gyro was checked out.
This system was confirmed in flight to aspect reconstruct photons to better than 10
arcseconds. This aspect reconstruction system is crucial for GRATIS to obtain good imaging
and source localization capability.
At about 11:08 AM GRATIS locked onto its first target, Cen A, followed by observations
of galactic center targets for a full transit, including 4U1700-37, 1E1740.7, GRS1915,
GX1+4, GX301-2 and a few other targets. We then observed LMC X-3, Vela SNR/pulsar, 47 Tuc,
GRO1008 and the Crab. GRATIS also made multiple pointings of the hard x-ray, diffuse
emission from the galactic ridge. The payload was cut down after 32 hrs at float and was
recovered with only modest damage to the experiment.
We are now conducting an extensive post-flight calibration and beginning to analyze the
data. Preliminary analysis indicates that many of the sources listed above were detected.
Early analysis is centering on GRS1915, for which there is (very) preliminary indication
of unusual flaring activity. The amount of data obtained was enormous and should keep the
two graduate students working on it busy for some time! The GRATIS experiment was
designed, built and operated by a collaboration between Columbia University, Lawrence
Livermore National Laboratory and UC Santa Barbara. The GRATIS team thanks the BATSE/CGRO
team for making available their daily reports for flight planning purposes.
B. Hard X-ray Imaging Survey of the Galactic Plane with the Caltech Gamma-Ray Imaging
Payload GRIP-2
Stephane Corbel, Walter R. Cook, Fiona A. Harrison, Thomas A. Prince, Steven M.
Schindler, and Song Wang
Space Radiation Laboratory California Institute of Technology Pasadena, CA 91125
The Gamma Ray Imaging Payload (GRIP) is a coded-aperture telescope designed for imaging
observations of galactic and extragalactic gamma-ray sources. GRIP-2's large phoswich
detector (3830 cm2), 15 degree (FWHM) field of view, 30 arcmin angular
resolution and 6 arcmin point source localization ability make it well-suited for
surveying the accreting binary population of the Galaxy at high energies. In a recent
balloon flight on October 7-8, 1995 from Alice Springs Australia, GRIP-2 imaged several
fields in the galactic plane and center at energies above 30 keV. Numerous galactic
sources were detected above 30 keV including 1E 1740-2942, GRS 1758-258, GX 339-4, GX
354-0, GX 1+4, GRS 1915+105, 4U 1702-429, Terzan 2, Cyg X-1, Cyg X-3, the Crab pulsar and
4U 1700-377 in an unusual high luminosity state.
The GRIP-2 detector is a large-area imaging phoswich detector, and provides a
substantial collecting area and sensitivity improvement over previous hard X-ray imaging
detectors. The NaI(Tl)/CsI(Na) detector is optimized for imaging observations in the
energy range 30 keV to 600 keV, with usable sensitivity up to 2 MeV. The 1.5 cm thick
NaI(Tl) detection element is fabricated from a single crystal, while the CsI(Na) Compton
shield backing the NaI is composed of a mosaic of hexagonal scintillator pieces. The
detector is instrumented with 109 photomultiplier tubes (Hamamatsu 2.5" diameter
R1410) which view the scintillator through a lead glass optical window.
The GRIP-2 1995 flight yielded excellent results, including a rich set of source
detections in the Galactic Center region. Our analysis activities have concentrated on
energy, efficiency, and pointing calibration of the instrument using pre-flight, flight,
and post-flight data. Calibration observations on the Crab pulsar yield good agreement
with spectra measured by previous space instruments.
The Galactic Center sources exhibited variability on many scales. GRIP-2 detected
strong emission from the persistent black hole candidates such as 1E1740.7-2942, GRS
1758-258, GX 339-4 and GRS 1915+105. There are early indications of significant spectral
differences between these sources. Even more exciting is the indication that GRIP-2
achieved sufficient sensitivity to begin to see the hard tails of several LMXBs. Such hard
tails were seen earlier from GX 354-0 by GRIP-1 and from other LMXBs by SIGMA. While some
identifications are still tentative, we have indications that we have detected at least 3
LMXBs during the Fall flight: GX 354-0, Terzan 2, and 4U 1702-429. Analysis is continuing
and will be concentrated on the spectral evolution of these compact objects. Because of
the good time resolution (~1 microsec), GRIP-2 can perform valuable complementary studies
of time variability, pulse profile and also search for QPOs.
The power of the GRIP wide-field (15 degs FWHM) coded mask imaging technique for
observations of bright Galactic sources is demonstrated by the composite images made from
13 hours of observation. The sensitivity achieved is comparable to that of images made in
few-week integrations by the SIGMA satellite instrument.
Further information on the GRIP 1995 Alice Spring Expedition can be found at http://www.srl.caltech.edu/astro/grip.html
including a "photo album" of snapshots of the recent expedition at http://www.srl.caltech.edu/astro/gripphoto.html.
C. AXEL - A Balloon-Borne X-ray Astronomy Experiment
R. K. Sood (Australian Defence Force Academy, Univ. of NSW, Australia)
Following a successful programme to investigate the physics of ultra high pressure
proportional counters (UHPC's) at ADFA, a counter array has been developed for hard X-ray
astronomy. A parallel investigation has evaluated the performance of a large area phoswich
scintillator detector for the same purpose. The two detectors have been integrated in a
balloon-borne payload, the Astrophysical X-ray Experimental Laboratory (AXEL).
The UHPC detector is the prototype of a much larger detector system. It consists of 32
cylindrical counters, arranged in four layers. The 8 counters in each layer are divided
into two modules of 4 counters each. Each counter, 1100 mm long and of internal diameter
30 mm, is made of magnesium alloy AZ31. It is possible to fabricate large area detectors
using this modular approach. The top layer is filled with argon-methane (98:2) at 30
atmospheres, while the lower three layers are filled with xenon-methane (98:2) at 7.5
atmospheres. While argon exhibits excellent energy resolution (8.0% FWHM at 60 keV) at the
highest pressure, the performance of xenon deteriorates rapidly above 10 atmospheres. The
high operating voltages necessary for proportional operation (6000 V for argon, 4000 V for
xenon) make it vital for the 25 micron anode wire to be of a high level of uniformity for
stable operation. Careful cleaning methods have resulted in exceptional stability of the
counters. In particular, the xenon counter has shown little degradation in resolution in a
five month period which included a balloon flight. The UHPC arrangement enables one to
extract the position of interaction of the incoming X-ray, thus providing the capability
of a large area imaging instrument.
The phoswich detector, of diameter 292 mm and thickness 10 mm NaI(Tl) and 30 mm
CsI(Na), is viewed by 7 photomultiplier tubes. This instrument is used in the Anger mode.
Each detector has positioned above it a passive collimator, made out of laminates of
Cu-Sn-Pb, with a FOV of 4.5 deg. In addition, the phoswich detector has a
rotation-modulation collimator placed above the collimator to provide imaging capability.
Both detector systems are surrounded by passive shields and active scintillator shields.
The maiden flight of the AXEL payload took place from Alice Springs in Central
Australia, on 27 September 1995. This was the first payload launched during the NASA
Spring 1995 Australian campaign, when gamma-ray payloads from Caltech, GSFC, and the
Lawrence Livermore Laboratory were also flown. All systems performed to specification
during a 24 hour flight. The background at 3.9 mb altitude was as predicted (800 counts
per second for the UHPC, and 1050 counts per second for the phoswich). The primary
pointing system relied on the Australian Geophysical Reference Field, an improvement on
the IGRF, taking into account local anomalies. Use of the AGRF model meant that pointing
corrections of less than 0.2 deg were necessary during flight. The following sources were
successfully observed during the flight: 3C273, NGC5506, Sco X-1, 1E1740-29, GX1+4, MK509,
and H215-086. Data analysis is continuing at the collaborating institutions of University
of NSW, Australia (PI: R.K.Sood), University of Tubingen, Germany (R.Staubert), TIFR,
India (R.K.Manchanda), and Imperial College, UK (G.K.Rochester).
D. GRIS - J. Tueller, NASA GSFC
The Gamma Ray Imaging
Spectrometer (GRIS) balloon instrument was launched three times in a single campaign
from Alice Springs, Australia last fall (October 4 for ~24 hours, October 24 for ~36
hours, and November 14 for ~12 hours). The instrument performed flawlessly in all three
flights and it was quickly recovered after each flight without significant damage. This
extraordinary success was the direct result of an outstanding effort by the NSBF launch
team and the members of the GRIS team, who worked very hard under difficult field
conditions to quickly prepare the instrument for reflight.
Figure 1. GRIS ready for launch.
Figure 2. GRIS coming down on the parachute.
GRIS uses a large (~2000 cm3) array of Ge detectors with a thick (15 cm) NaI
shield to make sensitive gamma-ray measurements with excellent energy resolution (1.9 keV
at 511 keV and 3.4 keV at 1809 keV). GRIS has previously made important spectroscopic
measurements of line profiles for the Galactic Center 511 keV positron annihilation line
and the SN1987a 56Co lines. The GRIS instrument has recently been reconfigured with a wide
field collimator (~100 degrees FOV) and a movable NaI blocking crystal to search for
nucleosynthetic edges in the cosmic diffuse background. Nuclear lines like those GRIS
observed from SN1987a have been predicted to produce strong edges in the diffuse continuum
from the integral of gamma-ray emission at varying redshifts throughout the universe (
The, Leising and Clayton 1993, and Zdziarski 1996). Our measurement is the only high
resolution spectrum of the gamma-ray cosmic diffuse background. As in all cosmic diffuse
measurements, the background subtraction will require detailed modeling. Arguably, GRIS
has the most studied background of any gamma-ray instrument for astronomy. Thick active
shielding and a favorable equatorial location for maximum shielding by the Earth's
magnetic field yield a very low and stable background. High resolution spectroscopy
facilitates the detailed fitting and modeling of all the features in the background
spectrum. The instrument has been extensively modeled by the Goddard team and
independently by a team at CNES in Toulouse, France, where it is being used to verify the
INTEGRAL background calculations. Analysis is in progress, but we expect GRIS to produce a
measurement of the diffuse continuum as good as any previous observation. This observation
has acquired increased interest because the new COMPTEL results contradict the MeV bump
observed by Apollo 15 (Trombka et al. 1977). The high resolution search for edges in the
diffuse spectrum is unique to this observation and if detected, would yield the average
rate of nucleosynthesis and even the evolution of the rate.
Figure 3. 1809 keV line energy spectrum
The resolved 26Al line from the Galactic Center is much broader than can be explained
by galactic rotation. Since both the GRIS and COMPTEL flux values are highly model
dependent, the difference should be taken to indicate the systematic uncertainties. We are
presently working with the COMPTEL team on a joint fit to our combined data which should
significantly reduce the uncertainties in the flux.
To minimize variation in the background, the collimator was pointed at the zenith
during each of the flights. Alice Springs is a near perfect site for this kind of drift
scan, as both the Galactic Center and the south galactic pole transit nearly overhead. The
integrated fluxes from the Galactic Center for the well known lines at 511 keV (positron
annihilation) and 1809 keV (26Al) were measured. The most statistically significant
previous measurement of this kind was made by the gamma-ray spectrometer on SMM. Although
we do not have a decade of observing time like SMM, the systematic uncertainties in the
background subtraction are significantly smaller for our observations. More importantly,
GRIS is a high resolution instrument that can detect these lines with sufficient
sensitivity to measure the line profiles. The figure above shows the background subtracted
Galactic Center spectrum in the region of the 1809 keV line. The best fit to the FWHM of
the 1809 keV line is 6.3 keV, but the instrumental resolution at this energy is only 3.4
keV. The implied line width of 5.4 keV is significantly greater than the 1.8 keV which
could be explained by galactic rotation. The energy and resolution of this kind of
spectrometer is very well calibrated by background lines and it is extremely unlikely that
this excess line width could be some instrumental problem. The figure below shows the
observed width for the 1809 keV line and the strong background line at 1779 keV for
different sections of the drift scan. Note that the simultaneously accumulated 1779 keV
line does not show the same variability in width we observe at 1809 keV. It is quite
plausible that the 26Al was created with this kind of velocity (+/-500 km/s), but it is
hard to understand how the material could still be traveling at this velocity one million
years later! The density of material in the plane should have stopped its expansion in <100,000 years. This observation puts a third (velocity) dimension on the COMPTEL map of the 1809 keV line and must be telling us something very important about nucleosynthesis in our galaxy.
Figure 4. 1809 and 1779 keV line widths
FWHM of the 1809 keV line (source plus background) and the 1779 keV background line is
shown for 4 intervals in the GRIS drift scan (1st Galactic Center pass, South Galactic
Pole, galactic plane, and second Galactic Center). Note that the variability in the width
observed at 1809 keV is not seen in the nearby background line.
We also observed the 511 keV line from our galaxy in our drift scan. The flux from the
Galactic Center is identical to the value of 1.6 x 10-3 ph cm-2 s-1 observed by the TGRS
instrument on WIND (Teegarden 1996). We also observed a bump in the 511 keV drift scan
when the FOV passed over the plane at 240 degrees galactic longitude. Surprisingly, this
bump is about the same peak intensity as the Galactic Center. We are studying this
lightcurve intensively for instrumental effects and we have proposed observations with
OSSE and BATSE to try and confirm the strong emission from the plane. This emission could
possibly be explained with either point source or diffuse emission models.
Since CdZnTe background information has not been readily available, we have fabricated
a simple CdZnTe instrument - the Piggyback Room Temperature Instrument for Astronomy
(PoRTIA) - for GRIS. PoRTIA has two room temperature semiconductor detectors housed in a
small pressure vessel. PoRTIA was flown on three balloon flights with three different
shielding configurations. Initially, PoRTIA was flown without GRIS on a small balloon from
Palestine, Texas in June 1995. During this flight, the detector was passively shielded
with 2 mm of lead and collimated to a 5 x 5 deg FOV. In October 1995, PoRTIA flew on GRIS
in Alice Springs. It was mounted on top of the GRIS blocking crystal and the 15 cm thick
NaI GRIS anticoincidence shield used veto background events. The detectors were passively
shielded from above and collimated to a 10 x 10 deg FOV. In the third flight, the PoRTIA
instrument was mounted inside the GRIS NaI shield and blocking crystal. A Ge detector
served as a monitor of the radiation environment inside the shield. Completely enclosed in
the GRIS active shield, PoRTIA used minimum passive shielding and no collimator. A large
(2.5 x 2.5 x 0.19 cm) CdZnTe detector was flown in all three flights so that valid
background comparisons could be made. During each flight, the PoRTIA pressure vessel was
surrounded by an evaporative cooler to provide a stable operating temperature below 0 deg
C during flight. Data from the larger CdZnTe detector are shown in the figure below. All
three flights are included; the data from the two Alice Springs flights were divided by
0.72 to correct for the difference in background levels between Palestine and Alice
Springs (Gehrels 1992). Clearly, active shielding that completely surrounds the detector
is crucial to achieve a low background with CdZnTe detectors.
Figure 5. This is a plot of the CdZnTe
differential background rate per unit detector volume as a function of energy for all
three flights. Note the large background reduction in the fully shielded case.
REFERENCES
- Gehrels, N. (1992). Instrumental Background in Gamma-Ray Spectrometers Flown in Low
Earth Orbit. Nuclear Instruments and Methods in Physics Research, A313, 513-528.
- The, L-S, Leising, M.D., Clayton, D.D; Ap J; 403; 32; 1993.
- Teegarden B.J., et al.; ApJ; 463; L25; 1996.
- Trombka J.A., Dyer C.S., Evans L.G., Bielefled M.J, Seltzer S.M, Metzger A.E.; ApJ; 212;
925; 1977.
- Zdziarski, A.A, MNRAS Letter; in press; 1996.
L. Whitlock (HEASARC) and J. Lochner (XTE GOF)
We are pleased to announce the generation of the High-Energy Astrophysics Learning
Center site on the World Wide Web. This Center provides information about X-ray and
gamma-ray astronomy for a wide range of ages and education levels. At present, our pages
are developed primarily for the 14 and up age group. We will soon add on a section for
younger users.
Thus far, the material has been developed by volunteer effort on the part of Laboratory
for High Energy Astrophysics (LHEA) scientists and programmers at GSFC. We have recruited
a number of teachers and their students around the country to actively review the material
and its presentation on the site. We are also working with a group of teachers to develop
material for younger users, and we are investigating ways to further increase teacher
contributions.
We are intending to exhibit the site at future National Science Teachers Association
conventions. Typically attended by over 15,000 teachers, we will work hands-on with
educators of all levels and disciplines, showing them how to access and use our site to
their best advantage. We also expect to release a CD-ROM version of the materials
available in the site sometime in 1997, for schools which have limited Internet access.
The HEA Learning Center is available via the HEASARC's home page: http://heasarc.gsfc.nasa.gov.
The Learning Center is best be viewed by a browser which supports "frames",
such as Netscape 2.0 or higher. (We are working on making the site more attractive to
other browsers !)
A very complete list of astronomical meetings exists on the Hawaii web site http://cadcwww.dao.nrc.ca/meetings/meetings.html
. Here is my partial list of meetings that I have received notices for.
188th AAS, Madison, WI, June 9-13, 1996. Contact: aas@aas.org
Aspen Center for Physics, Workshops on High Energy Neutrino Astrophysics (May 27 - June
6), Galaxy Interactions at Low and High Redshift (June 10 - June 30), and Galactic and
Cosmological Magnetic Fields (August 19 - September 8), Aspen, CO. Contact: Sally
Mencimer, (970) 925-2585
Summmer Course on New Detectors for Radiation Measurements and Related Applications,
July 1-12, 1996, CNR Conference Center, Bologna, Italy. Contact: detectors@tesre.bo.cnr.it
31st COSPAR Scientific Assembly, Birmingham, UK, July 14 - 21, 1996. Includes meetings
on X-ray Timing, July 15-16 (Contact holt@lheavx.gsfc.nasa.gov), Cosmic Gamma-Ray Bursts,
July 17-18 (Contact kouveliotou@ssl.msfc.nasa.gov), a Symposium on Satellite and Ground
Based Studies of Radiopulsars, July 18-19 (Contact pac@ifctr.mi.cnr.it), among others.
SPIE Annual Meeting, Denver, CO August 4 - 9, 1996. Includes sessions on Gamma Ray and
Cosmic Ray Detectors, Techniques, and Missions, and EUV, X-ray, and Gamma-Ray
Instrumentation for Astronomy, among others. Contact: colo96@spie.org
Tata Institute for Fundamental Research Golden Jubilee Meeting on Perspectives in High
Energy Astronomy and Astrophysics, Mumbai, India, August 12-17, 1996. Contact:
heap@tifrvax.tifr.res.in
The Transparent Universe (Second INTEGRAL Workshop), St. Malo, France, September 16 -
20, 1996. Contact: integral@astro.estec.esa.nl
5th International Workshop on Data Analysis in Astronomy, Erice, Italy, October 27 -
November 3, 1996. Contact: cettina@ifcai.pa.cnr.it
18th Texas Symposium on Relativistic Astrophysics, Chicago, IL, December 15-20, 1996.
Contact: frieman@fnal.fnal.gov
Fourth Compton Symposium, Williamsburg VA, April 28-30, 1997. Contact:
kurfess@osse.nrl.navy.mil
25th International Cosmic Ray Conference, Durban, South Africa, July 28 - August 8,
1997. Contact: icrc97@physics.puk.ac.za
23rd General Assembly of the IAU, Kyoto, Japan, August 18-30, 1997. Contact: iau@iap.fr
HEADNEWS, the electronic newsletter of the High Energy Astrophysics Division of the
American Astronomical Society, is issued by the Secretary-Treasurer, at the University of
California Space Sciences Laboratory, Berkeley, CA 94720-7450. The HEAD Executive
Committee Members are:
- Neil Gehrels, Chair (gehrels@lheavx.gsfc.nasa.gov)
- Gordon Garmire, Vice-Chair (garmire@astro.psu.edu)
- David Burrows (burrows@astro.psu.edu)
- Lynn Cominsky (lynnc@charmian.sonoma.edu)
- Chuck Dermer (dermer@osse.nrl.navy.mil)
- Martin Elvis, Member and Past Chair (elvis@cfa.harvard.edu)
- Kevin Hurley, Secretary-Treasurer (khurley@sunspot.ssl.berkeley.edu)
- Chryssa Kouveliotou (kouveliotou@batse.msfc.nasa.gov)
- Chip Meegan (meegan@ssl.msfc.nasa.gov)
- Paula Szkody (szkody@astro.washington.edu)
Please send newsletter correspondence to khurley@sunspot.ssl.berkeley.edu
