Newsletter No. 80, May 2002
  1. Notes from the Editor - Matthew Baring
  2. Chandra Telescope Designer Wins 2002 Rossi Prize - Megan Watzke
  3. Second Schramm Prize Awarded to Naeye for Chandra Article - Christopher Wanjek and Lynn Cominsky
  4. HEAD in the News - Lynn Cominsky, Ilana Harrus, and Megan Watzke
  5. News from NASA Headquarters - Paul Hertz, Lou Kaluzienski and Don Kniffen
  6. Chandra Fellows Named - Nancy Evans
  7. GLAST Mission News - Lynn Cominsky
  8. Swift Mission News - Lynn Cominsky
  9. RXTE News - Padi Boyd, et al.
  10. RHESSI Mission News - David Smith
  11. FUSE Returns from the Brink - Bill Blair
  12. HETE Mission News - George Ricker
  13. Chandra X-ray Observatory Operations Report - Roger Brissenden
  14. Meeting Announcements:




from the Editor - Matthew Baring, HEAD Secretary-Treasurer, headsec@aas.org, 713-348-2983

HEAD only delivers the table-of-contents for HEADNEWS into your mailbox. The newsletter itself can be found online at http://www.aas.org/head/headnews/headnews.may02.html.

The next HEAD Division meeting is to be held in Mt. Tremblant, Canada in the mountains near Montreal from Sunday March 23rd, 2003 till Wednesday, March 26th 2003. This conference, to be hosted by McGill University, will revert to the normal HEAD meeting format, contrasting the recent joint meeting with the APS Division of Astrophysics (DAP) in Albuquerque, NM. The meeting will include invited and contributed talks, poster sessions, and afternoon/evening workshops as in recent HEAD meetings. Stay tuned for more information in the Fall; updates will be emailed to the membership as well as posted on the HEAD web site: http://www.aas.org/head/.

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2. Chandra Telescope Designer Wins 2002 Rossi Prize - Megan Watzke, Chandra Press Officer

Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts has been awarded the 2002 Bruno Rossi Prize of the High Energy Astrophysics Division of the American Astronomical Society. The prize includes an engraved certificate, a $1,500 award and the opportunity to give the prize lecture at the next winter meeting of the AAS.

Van Speybroeck, who led the effort to design and make the X-ray mirrors for NASA's premier X-ray observatory, the Chandra X-ray Observatory, was recognized for a career of stellar achievements in designing precision X-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Hughes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the X-ray mirror assembly that is the heart of the observatory.

"Leon is one of the master mirror designers of our time," said Harvey Tananbaum, director of the Chandra X-ray Center. "His contributions were crucial to the spectacular success of the Chandra mission."

The Chandra mirrors are the most precise mirrors ever made, smooth with tolerances of a few atoms. If the state of Colorado had the same relative smoothness as the surface of the Chandra X-ray Observatory mirrors, Pike's Peak would be less than an inch tall. The smoothness and alignment of the Chandra's mirrors are enabling scientists to make new discoveries about black holes, neutron stars, and galactic explosions.

"Many, many other people made essential contributions to the Chandra program, and hopefully some of them will receive proper recognition," said Van Speybroeck. "In the meantime, I am thoroughly enjoying my days in the sun, but quite humbled by the list of past recipients."

Van Speybroeck, a graduate of the Massachusetts Institute of Technology, once took a course in optics under Rossi, but his thesis work was in high-energy physics. Upon graduation, he joined the X-ray astronomy group at American Science & Engineering and became involved in the design of the X-ray mirrors for NASA's Skylab project. After moving to the Harvard-Smithsonian Center for Astrophysics, he had primary responsibility for designing and developing the mirrors for the Einstein X-ray Observatory, the predecessor of the Chandra X-ray Observatory.

For a picture of Van Speybroeck and more information on the Chandra X-ray Observatory, go to http://chandra.harvard.edu.

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3. Second Schramm Prize Awarded to Naeye for Chandra Article - Christopher Wanjek and Lynn Cominsky

The winner of the 2002 David N. Schramm Award for high-energy astrophysics science journalism proved to be more powerful than a locomotive with an article comparing Superman and the Chandra X-ray Observatory. Robert Naeye captured top honors for an article he published in the journal California Wild, entitled "Superman's Telescope."

Naeye, who is the editor of Mercury, the magazine of the Astronomical Society of the Pacific, received the $1,500 cash prize and a plaque honoring his achievement at the joint APS/DAP - HEAD meeting in Albuquerque in April. The award was presented by HEAD Chair Josh Grindlay and Schramm committee chair Lynn Cominsky, at the end of a special awards session during the meeting. Naeye also received travel expenses to the meeting, and the publisher of California Wild received a certificate honoring the work.

Naeye's article takes the reader through the history of X-ray astronomy, a world in which "photons punch right through normal mirror surfaces just like bullets zipping through Kleenex tissues," he wrote. The article also tells the tale of the Chandra X-ray Observatory: a 25-year saga in which the telescope fell victim of countless budget cuts and delays, yet, upon launch in 1999, now rivals the Hubble Space Telescope with its discovery potential.

"It's an honor to win this award, especially because it is named after one of the great physicists of our age," said Naeye, who is also the author of the book for junior high school students "Signals from Space: The Chandra X-ray Observatory," published by Raintree Steck-Vaughn in 2000. "I thank my editors at California Wild, Kathleen Wong and Keith Howell, and the thousands of people who made Chandra a reality, giving me such an exciting topic to write about."

California Wild is a quarterly magazine published by the California Academy of Sciences. Naeye's article appeared in the Summer 2001 issue and can be viewed online at http://www.calacademy.org/calwild/summer2001/stories/chandra2sl.html.

The HEAD journalism award is named in memory of David Schramm of the University of Chicago, a world leader in theoretical astrophysics and a leading authority on the Big Bang model of the formation of the universe. He was killed in 1997 when the twin-engine plane he was piloting crashed outside of Denver. Schramm was dedicated to public outreach, and the HEAD writing award that bears his name recognizes distinguished writing on high-energy astrophysics that improves the general public's understanding in and appreciation of this exciting field of research.

HEAD presents the Schramm award at least every 18 months at its division meetings. Entries are judged by a committee of distinguished scientists and journalists selected by the HEAD Executive Committee. Information about the prize is available at http://www.aas.org/head/schramm/schramm.prize.html.

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4. HEAD in the News (November 2001 - May 2002) - Lynn Cominsky, retiring HEAD Press Officer, Ilana Harrus, new HEAD Press Officer, and Megan Watzke, Chandra Press Officer

HEAD news coverage continued to increase during the past six months. We had coverage in the New York Times, the Washington Post, USA Today and many spots on the internet, television and radio. Here are some of the highlights.

NEWS from the AAS Meeting in Washington DC (January 2002)

During this meeting, Chandra had two major stories that were both featured in press conferences.

The first was the work by Brian McNamara (Ohio University) et al. on the Abell 2597's so-called ghost cavities, vast regions containing almost no X-ray or radio emission. These are believed to be the relics of an ancient eruption that tore through this cluster of galaxies. (See ApJ 562, L149 or http://chandra.harvard.edu/press/02_releases/press_010802.html)

The next day, Daniel Wang (U Mass) et al. unveiled their Chandra mosaic of the galactic center, one Chandra's most striking images to date. The galactic center story made the front page of USA Today, LA Times, Science News and received heavy coverage in many other media outlets. See commentary by Andreas Eckert in Nature 415, 128 -129, Wang et al. in Nature 415, 148 - 150 and http://chandra.harvard.edu/press/02_releases/press_010902.html.

Other HEAD related press releases featured at this meeting included "The Big Glitcher pulsar PSR J0537-6910" by Frank Marshall (NASA/GSFC) et al., "Evidence of a black holes missing link" by Joel Bregman (U Michigan) et al. which was written up in Science by Govert Schilling Volume 25; 295: p. 616, "Astronomers try to Catch a Runaway Star SGR 1900+14" by Kevin Hurley (UCB) et al., "Seven pulsars discovered in Neighbouring Galaxy" by Silas Laycock (U Southampton) (A&A, v.385, p.464) and "Newly Discovered Sub-class of "Local" Gamma-ray Bursts May Solve a Mystery or Two" by Jay Norris (NASA/GSFC).

Joint HEAD/APS Division of Astrophysics Meeting in Albuquerque (April 2002)

The website for the press at this HEAD meeting can be found at: http://charmian.sonoma.edu/head2002.

The potential explanation for the existence of Ultra High Energy Cosmic rays was presented at a press conference held on Sunday, April 21. Correlating optical data with events from the Akeno Giant Air Shower Array (AGASA) near Yamanashi, Japan, Elihu Boldt (NASA/GSFC) et al. identified old quasars as possible sites of the acceleration of these highly energetic particles (above 100 EeV). Masahiro Teshima presented the results from the AGASA team, and Michael Cherry (Louisiana State University) provided commentary. This result was reported by MSNBC, the BBC, The Dallas Morning News, Science, New Scientist and several other media outlets. On the Web: http://xxx.lanl.gov/ps/astro-ph/0204419/. The final version of the paper is to appear in Physical Review D.

Later on Sunday, Michael Turner (Chicago) did a short presentation to the press and a much longer Q&A with the media about recommendations in Phase II of the "Turner Report" the National Academy of Sciences study from the Committee on the Physics of the Universe entitled "Quarks to the Cosmos." His entire presentation can be both viewed and downloaded from the HEAD press website listed above. The report itself is at: http://www.nationalacademies.org/bpa/projects/cpu/report/. This press conference was jointly sponsored by HEAD and the APS.

Millisecond pulsars were the stars (so to speak) of the press conference held on Monday, April 22. Craig Markwardt (Univ. of Maryland/GSFC) described a newly discovered binary system in which the companion star has all but disappeared (only 14 times as massive as Jupiter) and Todd Strohmayer (NASA/GSFC) described a superburst observed in another millisecond pulsar binary system, which provides the best evidence to date that the pulsations seen within the burst originate from the neutron star's spin. The article has recently been accepted by ApJ and can be found at: http://xxx.lanl.gov/ps/astro-ph/0205435/. MIT's Deepto Chakrabarty provided the independent commentary. Both discoveries were made using the Rossi X-ray Timing Explorer, and received coverage in several space and science publications including Science, Science News , and Sky and Telescope.

On Tuesday, April 23, the HEAD press conference dealt with X-ray flashes and their link to gamma-ray bursts. John Heise (SRON) and Marc Kippen (LANL) each presented their latest results and their consequences for the interpretation of this relatively newly discovered phenomenon. Heise showed data from Beppo-SAX, while Kippen correlated Beppo-SAX data with that from CGRO/BATSE. Bing Zhang (Penn State University) provided the independent commentary.

We also issued several printed press releases, some of which got some significant press coverage. Jon Miller (MIT) had an interesting result, using data from XMM-Newton, showing evidence for a spinning black hole pumping energy into its surroundings. The story was covered by Space News. Read more about it at: http://sci.esa.int/content/news/index.cfm?aid=23&cid=45&oid=29877 or in ApJL 570, p. L69-L73.

Demos Kazanas (NASA/GSFC) presented a new theory on cosmic ray energy losses occurring when they penetrate the Earth's atmosphere. Kazanas suggests that the missing energy could potentially creates tiny black holes or being transferred to gravitons which then escape to other dimensions. The story was picked up by UPI and several space-related media outlets.

A press release was issued describing the research of a team of astronomers led by David Clements (Imperial College) who used Chandra's observations of Arp 220 to study the head-on collision of two Milky Way-like galaxies.

Also at the HEAD meeting, Leisa Townsley (Penn State) and her colleagues released their spectacular X-ray image of 30 Doradus, one of the most active star-forming regions in our Local Group of galaxies. On the Web: http://chandra.harvard.edu/press/02_releases/press_041902.html http://chandra.harvard.edu/photo/2002/0057/index.html.

Finally, a non-publicized result from Arnold Rots (CfA) on a possible planetary system around a pulsar was written about by USA Today.

News from Chandra:

Strange Quark Stars: In April 2002, Chandra held a Space Science Update at NASA HQ in Washington, DC, that presented work by Jeremy Drake (Harvard-Smithsonian Center for Astrophysics) et al. that the data from RXJ1856.5-3754 could support evidence for quark star matter. Also presented were results from Patrick Slane (Harvard-Smithsonian Center for Astrophysics) and David Helfand (Columbia University) that 3C58 is unusually cold suggesting exotic cooling processes. The SSU received a great amount of interest from the press nationally and worldwide, and made the front pages of the New York Times, San Diego Tribune, and Orlando Sentinel. On the Web: article by Charles Seife in Science 2002 April 12; 296: 238, Slane et al. ApJ 571, L45 and the press release: http://chandra.harvard.edu/press/kits/strangematter/.

Venus and Jupiter: Two separate releases were issued during the past six months on objects in our Solar System, both garnering significant public interest. The discovery of X-rays in Chandra observations of Venus, made by Konrad Dennerl (Max Planck Institute for Extraterrestrial Physics), were announced in a press release on 11/29/01 (see also Dennerl et al. A&A, v.386, p.319.) In late February, a press release was issued regarding Chandra's discovery of a pulsating hot spot in the polar regions of Jupiter by Gladstone et al. (Nature 28 Feb 2002 v. 415, p. 1000). On the Web: http://chandra.harvard.edu/press/01_releases/press_112901.html, http://chandra.harvard.edu/press/02_releases/press_022702.html.

Double Bonus with a Distant Quasar: Chandra pulled double duty with quasar PKS 1127-145. One team, led by Aneta Siemiginowska (Harvard-Smithsonian Center for Astrophysics) used it to discover a previously unknown jet of a million light years (Siemiginowska et al. ApJ 570, 543). Jill Bechtold's group (University of Arizona) used PKS 1127-145 to study an intervening galaxy and determine it had just one-fifth the oxygen measured for typical stars in the Milky Way (Bechtold et al. ApJ 562, 133). See also the press release at: http://chandra.harvard.edu/press/02_releases/press_020602.html.

The Three Highest-Redshift Quasars: Pushing further back toward the first generation of objects to form in the Universe, Chandra observed the three most distant known quasars (z=5.82, 5.99, and 6.28) and found them to be prodigious producers of X-rays. The quasars were first discovered in optical wavelengths by the Sloan Digital Sky Survey, and then observed by Chandra with Director's Discretionary Time proposed by Niel Brandt (Penn State University). See the press release at: http://chandra.harvard.edu/press/02_releases/press_032802.html. To see all the Chandra news releases, check out http://chandra.harvard.edu/press/.

News from XMM-Newton

XMM-Newton news continues to increase as their observing program progresses. Here are some releases of interest:

ESA's X-ray Space Telescope Proves Supernova can cause Mysterious Gamma-ray Bursts: By analyzing the afterglow of the gamma-ray burst GRB 011211 in X-ray light, scientists produced the first ever evidence of the presence of chemical elements which were the unmistakable remnants of a supernova explosion which had occurred just a few days before. Originally spotted by Beppo-SAX, XMM-Newton obtained follow up observations 11 hours after the GRB trigger. See Reeves et al. Nature, Volume 416, Issue 6880, p. 512, the commentary by Herman Marshall in that same issue of Nature and the article by Govert Schilling in Science on 2002 April 5; v. 296, p. 41.

Mapping the Ingredients of an Exploded Star: Probably the most detailed analysis of the composition and dynamics of the supernova remnant Cassiopeia-A were published as elemental maps by Willingale et al. (A&A v.381, p.1039) using data from XMM-Newton's EPIC-MOS camera. In these maps, the distributions of silicon, sulphur, argon and calcium -all oxygen burning products- are similar and distinct from the carbon burning products, neon and magnesium. Iron abundance is seen to vary over the remnant with little correlation to other elements. The study also determined the Doppler velocities of the various elements. Iron, produced at the heart of the stellar explosion and present now in the furthest reaches of the remnant, was apparently expelled considerably faster to overtake other elements. For more about XMM-Newton news, see http://sci.esa.int/xmm/.

Other News

Scientists Detect First Afterglow of Short Gamma-ray Bursts: Scientists say they have detected for the first time a lingering afterglow of the shortest types of bursts, which themselves disappear within a second. Davide Lazzati and Enrico Ramirez-Ruiz (Institute for Astronomy, Cambridge, UK), along with Gabriele Ghisellini (Osservatorio Astronomico di Brera, Merate, Italy), published these results in a recent issue of Astronomy & Astrophysics, 379, L39. They summed the data from 76 short bursts seen by the BATSE on board CGRO, to see the elusive afterglow in hard X-ray emission using the same detectors. Also see: http://www.ast.cam.ac.uk/~lazzati/short/short.html.

Gamma-ray Bursts are Caused by Explosive Death of Massive Stars, New Study Reveals: Careful observations of gamma-ray burst GRB 011121 by Kulkarni et al. have uncovered remnants of the exploded star, along with two compelling tell-tale signatures: the data show that a supernova accompanied the burst and the explosion took place in a cocoon of gas fed by a "wind" of matter emanating from the progenitor star. To appear in ApJL (2002).

X-rays Limit Mass of Neutrino Dark Matter: A team of scientists at the University of California, San Diego has used data from X-ray telescopes to set a limit on the characteristics of a possible dark matter candidate sterile neutrinos. In a paper published in the December 1 issue of the Astrophysical Journal by Abazajian et al. (v. 562, p. 593), the scientists show that the decay of sterile neutrinos would produce a sharp peak in the X-ray spectrum from the hot gas clouds present in galaxy clusters. The predicted height of the peak in the spectrum increases with the assumed mass of the sterile neutrino.

Music of the Black Holes: They All Play the Same Tune: Astronomers at the University of Southampton have uncovered a remarkable connection between the monstrous black holes residing at the hearts of distant galaxies and their comparatively tiny cousins which inhabit star systems in our own Milky Way: they are playing the same tunes. Using the Rossi X-ray Timing Explorer, the scientists have found that the time-scales for variations seen in the power spectra are about a million or more times longer in active galaxies than in BHXRBs. See Uttley et al. MNRAS v. 332, p. 231.

Press Officer News: This column marks the final contribution as HEAD Press Officer from Lynn Cominsky, who has now officially turned over the duties to Ilana Harrus. Harrus worked with Cominsky throughout the April HEAD meeting, and assumed control of the final two press briefings. Thanks to everyone in HEAD for your support of the press activities during the last six years. It has made a big difference in the media's awareness and in the public perception of our science. Cominsky is continuing to support the AAS as Deputy Press Officer, and also will continue to serve as Press Officer for both Swift and GLAST.

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5. News from NASA Headquarters - Paul Hertz, Lou Kaluzienski and Don Kniffen, NASA Headquarters.

President's FY03 budget

The budget submitted by President Bush in January 2002 to the Congress for fiscal year 2003 (FY03) continues the recent trend of increased funding for NASA space science. A top level synopsis of major changes from the current budget includes:

  • An increase in the Office of Space Science (OSS) 5-year budget of $682M;
  • The addition of a Nuclear Systems Initiative to add radioisotope thermal generators to the 2009 Mars rover and to research nuclear electric power and nuclear electric propulsion for deep space missions;
  • The cancellation of the last remaining mission in the Outer Planets Program, the Europa Orbiter mission;
  • The creation of a New Frontiers Program for moderate ($650M), PI-class planetary missions;
  • The transfer of the Deep Space Network into OSS;
  • Support for SM-4 as the final Hubble servicing mission and the increase of funding for NGST as funding for Hubble decreases in the post-servicing era.

Detailed analyses of the NASA budget are usually done by the AAS and the AIP. Please check their web sites for more details.

OSS Strategic Plan and SEU Roadmap

NASA is required by law to update its strategic plan every three years. In support of the NASA strategic plan, OSS is updating its strategic plan. The contents of the OSS strategic plan will be set at a meeting of the Space Science Advisory Committee in November 2002; the plan will be published in 2003. The 2003 OSS strategic plan will be based on roadmaps prepared this year by each of the OSS science themes.

Most high energy astrophysics falls within the Structure and Evolution of the Universe (SEU) science theme within OSS. The SEU roadmap is the responsibility of the SEU Subcommittee (SEUS), and the SEUS has appointed a Roadmap Team to actually write the roadmap. At its April meeting, the SEUS decided on the outline of the SEU roadmap, and the contents of the SEU roadmap will be the discussed and decided upon at the August meeting.

The SEU roadmap will draw heavily upon community input. This input includes National Academy of Sciences surveys (e.g. Decadal Survey (McKee-Taylor Report), Committee on Physics of the Universe (a.k.a. Turner Committee) Report), white papers solicited from the broad SEU community, NASA sponsored and grass roots workshops and working groups, etc. The report will also draw upon the 1999 SEU Roadmap which was the outcome of a year of work by 9 discipline working groups.

The roadmap will identify two science programs which capture the highest science priorities within SEU. The first program, called "Beyond Einstein", will focus on science goals related to the nature of space and time. Constellation-X and LISA are identified as the highest priority missions to address these science goals. The second program, tentatively called "Cycles of Matter and Energy", will focus on science goals related to the formation of structure, nucleosynthesis, and the evolution of the contents of the universe.

The final roadmap will be completed by September and published in November. Progress may be monitored at http://universe.gsfc.nasa.gov/roadmap.

Explorer Selections

Selections for concept studies in the Medium-class Explorer (MIDEX) Program were announced on April 17. Four MIDEX missions and one mission-of-opportunity (MO) were selected for study. These missions are:

  • The Astrobiology Explorer (ABE), PI: Scott Sandford, NASA/Ames. A cryogenic telescope and high resolution infrared spectrometer to measure interstellar organic compounds and determine the abundance, distribution and identities of the chemical building blocks of life.
  • The Next Generation Sky Survey (NGSS), PI: Ned Wright, UCLA. A cryogenic telescope designed to conduct an all-sky 4-color mid-infrared survey with 1,000 times more sensitivity than previous missions.
  • The Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission, PI: Vassilis Angelopoulos, UC Berkeley. A study of the onset of magnetic storms within the tail of the Earth's magnetosphere which would fly five microsatellite probes through different regions of the magnetosphere and observe the onset and evolution of storms.
  • The Advanced Spectroscopic and Coronagraphic Explorer (ASCE), PI: John Kohl, SAO. A solar coronagraph and high resolution spectrometer that would reveal the physical processes in the outer atmosphere of the Sun leading to the solar wind and explosive coronal mass ejections.
  • US Participation in the Extreme Universe Space Observatory (EUSO), PI: Jim Adams, NASA/Marshall. An ESA mission to study the highest energy cosmic rays from the International Space Station.

A downselection for flight among these missions is expected in March 2003. In other Explorer Program news, a downselect among the Small Explorer (SMEX) missions current conducting concept studies is expected in early July 2002, and the next SMEX Announcement of Opportunity (AO) is planned for the first quarter of 2003. Information on the MIDEX concept studies may be found at http://spacescience.nasa.gov/midex/ and on the SMEX concept studies at http://spacescience.nasa.gov/smex/ .

Senior Review of Astrophysics Missions

NASA will hold its biennial review of operating astrophysics missions on June 11-13, 2002. This review will evaluate and prioritize the science value in continuing science operations of seven missions which have, or will have by the end of FY04, completed their prime missions: 2MASS, FUSE, HETE-2, MAP, RXTE, SWAS, XMM-Newton (US participation only). NASA has a limited budget for mission operations and data analysis. Each mission's science team, and often the user community, has proposed the science which could be accomplished with continued operations. The Senior Review panel is a community peer review panel made up of experienced, senior members of the broad user community. NASA will use the findings, priorities, and recommendations of the Senior Review panel to allocate these funds with the goal of optimizing the science return for the community. NASA also uses the Senior Review report as the principal input in decisions to terminate missions when their science return decreases. The reports of previous Senior Reviews may be found on the Astronomy and Physics Division Homepage at http://spacescience.nasa.gov/admin/divisions/sz/.

Astronomy and Physics Working Groups

Two new working groups have been established to provide input on NASA's Astronomy and Physics program to the two Astronomy and Physics advisory committees (Origins Subcommittee and SEUS). These working groups are the Astronomy and Physics Working Group (APWG, chaired by Doug Richstone, U. Michigan) and the Science Archives Working Groups (SAWG, chaired by Joel Bregman, U. Michigan). Both working groups had their first meetings in April 2002. The APWG is chartered to look at the research and analysis (R&A) programs within astronomy and physics. The SAWG is chartered to look at NASA's astronomy and physics science data program including data centers and data archives. The reports of both working groups will be posted on the Astronomy and Physics Division Homepage at http://spacescience.nasa.gov/admin/divisions/sz/.

Proposal Deadlines

Anticipated proposal deadlines for the remainder of 2002 (and early 2003) include:

  • ADP/LTSA - July 10, 2002
  • ATP - August 30, 2002
  • RXTE Cycle 8 - September 2002 **
  • HST Cycle 12 - September 2002 **
  • FUSE Cycle 4 - October 2002 **
  • Chandra Cycle 5 - Early 2003 **
  • SMEX - May 2003 **
** denotes call for proposals not released yet, date could change.

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6. Chandra Fellows Named - Nancy Evans

The Chandra X-ray Center is pleased to announce the new Chandra Fellows for 2002:

  • Ann Hornschemeier from Penn State will be a Fellow at Johns Hopkins
  • Julia Lee from Cambridge will be a Fellow at MIT
  • Eric Pfahl from MIT will be a Fellow at Harvard
  • Anatoly Spitkovsky from Berkeley will be a Fellow at Berkeley
  • Licia Verde from Edinburgh will be a Fellow at Princeton

The competition for 2003 Fellows will be held this fall, with proposals due in mid-November. The announcment of opportunity (AO) giving the details of the program will be updated in the summer. However, the previous AO is available from: http://cxc.harvard.edu/fellows/Chandra_fellow.2002.summer.html. The Annual Chandra Fellows Symposium will be held Oct. 7, 2002 at the Harvard-Smithsonian Center for Astrophysics, where interested people can hear what the Chandra Fellows have been doing. Further details can be found from the website above.

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7. GLAST Mission News - Lynn Cominsky, GLAST Press Officer

In January, NASA and the Department of Energy (DOE) signed the Implementing Arrangement concerning cooperation on the GLAST Mission. The signing of this agreement establishes the roles of DOE and NASA in their joint sponsorship of the Large Area Telescope (LAT). Agreements with international partners are now in progress.

The GLAST project has undergone two major reviews during the past 6 months. The joint NASA/DOE PDR/Baseline review for the LAT was held in early January, 2002. The LAT passed the PDR, however changes to the mechanical/thermal sub-system will be needed to accommodate the spacecraft. This sub-system will be reviewed in a "delta-PDR" in late July. The PDR for the GLAST Burst Monitor (GBM) was held in February. Review teams from both GSFC and MSFC participated. The consensus of the review teams was that the GBM design is at or beyond PDR level. No areas of concern surfaced that indicated substantial programmatic or technical risk. The spacecraft RFO was released in mid-May with vendor selection expected in August. The GLAST launch is now scheduled to occur in September 2006.

There were several key personnel changes on the GLAST project, including a new project manager at GSFC, Elizabeth Citrin, and the addition of a LAT Deputy Project Manager at SLAC, Jim Martin. Under the management of Jay Norris, staffing for the GLAST Science Support Center is ramping up: David Band is leading the scientific effort, and Dave Davis is also on the SSC staff at GSFC. Yasushi Ikebe, Masaharu Hirayama, and Dirk Petry are expected to join the GLAST SSC later this summer.

A GLAST Science Working Group meeting was held at UC Santa Cruz in December. This meeting included a special workshop on pulsars, organized by GLAST InterDisciplinary Scientist (IDS) Stephen Thorsett (UCSC). The next face-to-face science team meeting will be in Huntsville, Alabama in late September, hosted by the GBM team.

E/PO News: The GLAST Active Galaxies poster was finished, and has been widely distributed. Over 5000 have been handed out so far, most in kits of materials developed for the SEU Forum, entitled "Seeing and Exploring the Universe." These kits were big hits at the ITEA, NSTA and NCTM national meetings of technology educators, science teachers and mathematics teachers. A workshop on GLAST science by Cominsky and Ambassador Mike Ford was also held at the National Science Teacher's Association meeting The GLAST movie has also been released, and can be viewed through a link on the home page of the newly redesigned EPO web site: http://glast.sonoma.edu. GLAST mission trading cards have also been printed. The GLAST card is one of five mission cards that are part of the Cosmic Journeys card game, which will soon be available for distribution. The GLAST booth made appearances at local and national meetings such as the January AAS in DC, and the Expanding Your Horizons conference, held at SSU in March, that was attended by ~500 7th and 8th grade girls. A poster on the GLAST Telescope Network was presented at the January AAS meeting by Mattox, Cominsky and Spear. The GBM is contributing to the GLAST EPO effort by providing support to a High-Energy Astrophysics Workshop for Amateur Astronomers. The workshop will be held in conjunction with the 91st Spring Meeting of the AAVSO in Kona, Hawaii on June 30 July 6.

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8. Swift Mission News - Lynn Cominsky, Swift Press Officer

The team behind the NASA gamma-ray burst satellite called Swift has completed construction of a massive "coded aperture mask," the largest such device ever built, marking another milestone on its path to a September 2003 launch. The mask, the size of a standard piece of plywood (4 by 8 feet, or 1.2 by 2.4 meters), comprises approximately 52,000 tiny lead squares spaced in a computer-generated random pattern.

"Each of the 52,000 tiles was hand-placed 'upside down,'" said Danielle Vigneau, the lead engineer for the team that designed and built this coded aperture mask at NASA Goddard Space Flight Center. "We then used a thin coat of wet adhesive to bond all of the tiles to the panel simultaneously as the panel was lowered down on top of the tiles."

The mask together with a set of gamma-ray detectors, totaling 32,768 pieces of cadmium-zinc-telluride each measuring four square millimeters are the main components of Swift's Burst Alert Telescope (BAT). BAT will locate hundreds of bursts to better than 4-arcminute accuracy and provide enhanced sensitivity to faint bursts that earlier detectors have missed. The Swift team is now preparing for environmental tests of the BAT components, including a vibration test of the coded aperture mask.

The mission also includes narrow-field x-ray and UV/optical telescopes, being developed in the UK, Italy and at Penn State University. Both of these instruments are nearing completion for delivery to Goddard this summer.

The spacecraft is being developed by Spectrum Astro. The pre-ship review for the spacecraft will be held in late July. The operations readiness review is planned for late August.

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9. Rossi X-ray Timing Explorer News - Padi Boyd, Keith Jahoda, Craig Markwardt, Alan Smale, Evan Smith, Tod Strohmayer and Jean Swank, NASA's Goddard Space Flight Center

The Rossi X-ray Timing Explorer (RXTE) is now well into its 7th observing cycle and continues to perform well. Operations of all instruments remain stable. Exciting science results continue to be generated both from new observations as well as from the extensive RXTE public archive. RXTE continues to support multi-wavelength efforts, as well as coordinated observing with the imaging and high spectral resolution capabilities of Chandra and XMM/Newton. For example, through AO7 RXTE has carried out about 3.3 Msec of coordinated observing with these observatories. A few short snapshots of recent RXTE science highlights follows.

It took a little more than two years for RXTE to discover the first accreting millisecond pulsar (SAX J1808.4-3658). Recently, within the space of a month, RXTE has found two more of these ultra-compact systems, cementing the connection between accreting neutron stars and millisecond radio pulsars. In early April, 2002 Craig Markwardt (UMD/GSFC) discovered the 435 Hz pulsar XTE J1751-305 in his twice weekly Galactic Bulge monitoring campaign with the PCA (IAUC 7867). Pulse timing analysis revealed a 42 minute binary orbital period and a minimum companion mass of only 0.015 Solar masses, barely 15 Jupiters. The X-ray outburst from this system lastest only 10 days. This discovery received substantial press attention at the recent APS/HEAD meeting in Albuquerque, NM. For more details, follow the links at http://heasarc.gsfc.nasa.gov/docs/xte/xhp_new.html#cm_pulsar.

Only a few weeks later, Ron Remillard (MIT) and his colleagues discovered a new X-ray transient, XTE J0929-314, with the RXTE ASM (IAUC 7893). Subsequent pointed observations with the PCA revealed this new source to be a 185 Hz pulsar. These findings triggered additional TOO observations led by Duncan Galloway (MIT). Galloway and his colleagues found a 43 minute orbital period for the system and an even lower mass companion (about 10 Jupiters) than for XTE J1751-305 (IAUC 7900). More details and press information can be found at http://web.mit.edu/newsoffice/nr/2002/pulsars2.html.

In a related discovery, Tod Strohmayer (NASA/GSFC) and Craig Markwardt (UMD/GSFC) reported evidence for a millisecond pulsar in the LMXB 4U 1636-53. They found pulsations at 582 Hz during a ``superburst", a powerful 3 hour-long thermonuclear explosion in the surface ``ocean" of the neutron star. The pulsations were transient, but lasted long enough to reveal the signature of orbital modulation. Details of this work can be found at http://xxx.lanl.gov/abs/astro-ph/0205435.

A number of new and recurrent black hole candidates have also been active over the last few months. SAX J1805.5-2031 (IAUC 7843) remains active after discovery in March by both BeppoSAX and RXTE PCA scans. XTE J1908+094 (IAUC 7856) rose gradually in February and continues in outburst. GX 339-4, which had been off since the high state outburst in 1998, reappeared and reached a very high state, exhibiting quasiperiodic oscillations, in X-ray and optical, as it did in 1988 GINGA observations. SAX J1819.3-2525 = XTE J1819-254 = V4641 Sgr remerged from being off since its dramatic disappearance in September, 1999 with X-ray sputters and flares accompanying dramatic optical variability (IAUC 7906; 7908). Our Galaxy's black hole population remains very active.

Amongst the BL Lac sources for which RXTE has had monitoring programs for several years, 1ES 1959+650 has had a dramatic TeV outburst (IAUC 7907; 7903). Observations of Seyfert galaxies are even allowing behavior like that of microquasars to be discerned (Uttley et al. MNRAS 2002; Marscher et al. 2002).

Cycle 8 Announcement: Preparations for the RXTE cycle 8 Guest Observer Program have begun. We currently anticipate the release of the cycle 8 NRA in mid-June, 2002 with a proposal due date in late September. When finalized, specific dates will be posted on the Proposals & Tools link on the RXTE website: http://rxte.gsfc.nasa.gov/.

RXTE Data Analysis and Calibration News: Everything is in place for the soon to be released HEASoft v5.2 (hitting the streets on or about June 1, 2002). New versions of the RXTE response matrix generation tools PCARMF, XPCAARF and the wrapper script PCARSP are included, as is an updated energy-to-channel FITS file pca_e2c_e05v02.fits. Response matrix improvements include applicability of the tools to PCU0 for dates after the loss of the propane layer on May 12, 2000.

The default values of the geometric areas of four of the five PCUs has changed in the new XPCAARF. This will introduce a step function in long term monitoring fluxes; to remove this effect, long term programs will need to be reanalyzed with one consistent set of XPCAARF coefficients. This release also includes updated software for background estimation, including a new PCABACKEST which uses the recently released Combined Models (CM) and records more information about models used in the headers. In addition, XTEFILT (ie, FCOLLECT and XTEDERIVE) has been modified to add a new derived quantity, L6CNTPCU0, to the filter file. This can be used to filter out times when large flares appear in the background model due to the loss of the propane layer in PCU0. Details about the use of these new tools will be included in the HEASoft release notes, and will also appear on the RXTE GOF recipes pages. See the PCA Digest (http://rxte.gsfc.nasa.gov/docs/xte/pca_news.html) for useful links and summary information.

The new CM background models incorporate numerous improvements over the previous versions for both bright and faint sources. A good source of information about their performance, as well as practical advice in the use of the models can be found on Craig Markwardt's summary Web page at http://lheawww.gsfc.nasa.gov/users/craigm/pca-bkg/bkg-users.html.

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10. RHESSI Mission News - David M. Smith, U. C. Berkeley

The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite was successfully launched as HESSI on February 5th and renamed in March in honor of the late Dr. Ramaty, whose theoretical work and personal efforts were both vital to its creation and success. RHESSI is a Small Explorer mission headed by Principal Investigator Prof. Robert P. Lin of U. C. Berkeley (UCB), and is a joint project of the Space Sciences Laboratory (SSL) at UCB, NASA's Goddard Space Flight Center, the Paul Scherrer Institute in Switerland, and other institutions. RHESSI was launched by an aircraft-borne Pegasus XL rocket from Cape Canaveral Air Force Station into its desired circular orbit of 600 km altitude and 38 degrees inclination. As a Small Explorer mission operating in "PI mode", RHESSI's mission operations are the responsibility of UCB, and are done via an 11-meter dish and full operations center at SSL.

RHESSI's primary goal is to understand the mechanisms for the acceleration, interaction, and energy loss of energetic particles associated with solar flares. It consists of a 9-detector germanium x/gamma-ray spectrometer covering 3 keV to 17 MeV, with each detector sitting below a pair of grids which function as a rotating modulation collimator (RMC) when the spacecraft spins. The result is imaging spectroscopy of flares with energy resolution down to 1 keV and spatial resolution down to 2.3 arcsec. The energy range covers thermal and non-thermal bremsstrahlung emitted by accelerated flare electrons as well as gamma-ray lines from nuclear de-excitation, neutron capture, and positron annihilation due to interactions of accelerated ions.

Since the RHESSI detectors are unshielded, and every photon is recorded with its energy and interaction time even when flares are not in progress, RHESSI functions as a high-energy-resolution, all-sky detector for non-solar astrophysics.

The first non-solar results from RHESSI were presented at the joint HEAD/APS meeting in Albuquerque in April. These included a lightcurve and energy spectrum for a bright burst from the soft gamma repeater SGR 1900+14 and a spectrum of the extremely rare, bright outburst of Cyg X-1 reported by Golenetskii et al. (IAUC #7840). Earth occultation of this event seen by RHESSI also verifies its position as being consistent with Cyg X-1. Since that meeting, RHESSI has seen several cosmic gamma-ray bursts (one extending beyond 1 MeV). RHESSI is being incorporated into the Interplanetary Network (IPN) for triangulation of cosmic gamma-ray bursts, and has already helped in the prompt localization of a burst from another soft gamma repeater, SGR 1806-20 (Hurley et al., GCN circular #1391).

In mid-June, the Crab Nebula will enter RHESSI's imaged (solar) field of view. If all goes well, the team will repoint the spacecraft for a couple of days to image the nebula from 3-100 keV or more with resolution down to 2.3 arcsec. Other non-solar projects have begun to study the 511 keV and 1809 keV lines from the Galactic Center, cyclotron lines and other spectral features in pulsars, and monitoring of bright sources using Earth occultation and detector/detector occultation.

Oral and poster sessions with RHESSI solar results will be presented at the Solar Physics Division meeting in conjunction with the full AAS meeting in June, and at the COSPAR meeting in Houston in October. New RHESSI non-solar results will be presented at the SPIE meeting "Astronomical Telescopes and Instrumentation" in Hawaii in August.

All RHESSI data are immediately available to the public; anyone interested in working on RHESSI science should visit the RHESSI general web page and the RHESSI data and software center (http://hessi.ssl.berkeley.edu/ and http://rhessidatacenter.ssl.berkeley.edu/). Since the data analysis software is primarily designed to study solar flares, anyone wishing to use RHESSI for non-solar astrophysics is encouraged to contact the RHESSI non-solar coordinator, David Smith, at dsmith@ssl.berkeley.edu.

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11. FUSE Returns from the Brink - Bill Blair, FUSE Chief of Observatory Operations

The Far Ultraviolet Spectroscopic Explorer (FUSE) mission has recovered from a difficult situation and is back in normal science operations mode. Two of the four available reaction wheels on FUSE malfunctioned over a two week period in late-2001, leaving the satellite unable to perform pointed science operations. (Only two of three axes could be stabilized.) Attempts since that time to restart either of the errant wheels have not met with success. However, the Science Operations team at JHU worked closely with engineers at Orbital Sciences Corporation, NASA-GSFC, and Honeywell Technical Services, Inc., to develop and test a new control system that placed the Magnetic Torquer Bars (MTBs) into active service. The new system uses the two remaining reaction wheels and the MTBs to maintain three-axis control, and provides sub-arcsecond pointing control in regions where the magnetic control is stronger than the gravity-gradient disturbances on the satellite.

This new system was uplinked to the satellite in late-January 2002, just seven weeks after the problem occurred. February was spent testing the new system and performing science when we could, but since March 1, 2002, we have been back on-line. We continue to develop tools to make planning easier (there are many complicated, time-variable aspects to operations now), and we continue to "push the boundaries" of the stable regions to increase our sky coverage and target availabilities. This activity will be on-going through the summer. From tests to date, we are hopeful that pointing capability over the entire sky can be re-established at a significant level.

FUSE is a NASA Origins mission that performs high resolution (R=20,000) far-UV (905-1187 Angstroms) spectroscopy of a wide range of astrophysical objects. It was developed and is operated for NASA by Johns Hopkins University. The NASA Research Announcement for Cycle 4 of FUSE observations is expected in July 2002, with proposals due in October.

To learn more about FUSE, visit the following web site: http://fuse.pha.jhu.edu/ and to read more about the reaction wheel anomaly and recovery, see Status Reports 52-56 in the Status Report Archive: http://fuse.pha.jhu.edu/facts/stat_arch.html.

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12. HETE Mission News - George Ricker, MIT Center for Space Research, Principal Investigator for the HETE Mission

Now in its second year of operation, the High Energy Transient Explorer (HETE) mission is devoted to the study of gamma-ray bursts (GRBs) using soft X-ray, medium X-ray, and gamma-ray instruments mounted on a compact spacecraft. A science team from France, Japan, Brazil, India, Italy, and the US is responsible for the HETE mission, which was completed for ~1/3 the cost of a NASA Small Explorer (SMEX). The HETE mission is unique in that it is entirely "self-contained," insofar as it relies upon dedicated tracking, data acquisition, mission operations, and data analysis facilities run by members of its international Science Team since the launch into equatorial orbit in October 2000.

A powerful feature of HETE is its potential for localizing GRBs within seconds of the trigger with good precision (~10') using medium energy X-rays and, for a subset of bright GRBs, improving the localization to ~30" accuracy using low energy X-rays. Real-time GRB localizations are transmitted to ground observers within seconds via a dedicated network of 14 automated "Burst Alert Stations", thereby allowing prompt optical, IR, and radio follow-up, leading to the identification of counterparts for a large fraction of HETE-localized GRBs. HETE is the only satellite that can provide near-real time localizations of GRBs, and that can localize GRBs that do not have X-ray, optical, and radio afterglows, during the next two years.

To date, HETE has produced 17 gamma-ray burst (GRB) localizations. Localization accuracies are routinely in the 4' - 20' range. In addition, it has detected ~25 bursts from soft gamma repeaters (SGRs), and >150 X-ray bursts (XRBs). During the past 8 months the mission has produced 10 localizations, corresponding to a rate of ~15 per year. (This rate of localizations is ~2 times the rate achieved by the BeppoSAX satellite in its six years of operations). Four of the 10 recent localizations have yielded optical afterglows (with 2 redshifts measured so far); one more has yielded probable X-ray and radio afterglows. Two Chandra Target of Opportunity (TOO) observations have been carried out based on HETE localizations. HETE has detected a dozen short (< 2s) duration GRBs. HETE has also discovered 18 unusually "X-ray rich" GRBs, for which more than 30% of the energy is emitted in the 2-10 keV band. Of these 18 "X-ray rich" GRBs, 8 have been localized. (In total, HETE has detected ~100 GRBs of all types.)

The spacecraft power system, momentum management, and sun tracking are working perfectly. During orbit night, the satellite drift rate is now controlled to ~1"/s. The star camera aspect system provides the actual pointing direction of the satellite to an accuracy of ~10".

The in-orbit performance of the HETE science instruments has been as follows-- * FREGATE (French Gamma-Ray Telescope): Completely nominal, with in-orbit sensitivity about 2x better than pre-launch predictions. * WXM (Wide Field X-ray Monitor): Hardware performance has been completely nominal, with in-orbit sensitivity equal to pre-launch predictions. Optimization of on-board triggering and localization software has been an ongoing activity. * SXC (Soft X-ray Camera): The density of atomic oxygen at the altitude of the HETE orbit was >1000 times greater than pre-launch predictions, due to intense solar activity during the first few months of the mission. This effect led to erosion of the SXC thin, outer optical blocking filter (a thick inner filter, which protects only 1/2 of the CCD array, was unaffected by atomic oxygen). By 5 months post-launch, the consequent light leak resulted in loss of X-ray sensitivity for 1/2 of the CCD array, and necessitated a change in the flight software to correct for the light-induced variable bias level for the other 1/2 of the CCD array. A software modification, implemented in July 2001, fully restored the SXC localization precision (<30" at present), as verified by successful SXC localizations of 9 Galactic transients (produced by 4 X-ray bursters and 1 soft-gamma repeater) in July-August 2001. The SXC is currently in observing mode with a sensitivity of 1/sqrt(2) the pre-launch prediction for 2/3 of each lunar month; SXC observations are not possible for 4-5 days on each side of full moon because of a residual light leak. The HETE secondary science goal of soft X-ray observations below 1.3 keV is also not realizable due to the light leak.

However, despite the recent successes of the HETE mission in localizing GRBs, the scientific yield from the first year of the HETE mission was less than had been anticipated. Even now -- with instrumental and operational challenges overcome -- the GRB localization rate, while twice the BeppoSAX mean rate of ~9 localizations per year, is ~1/3 the rate that had been expected for HETE prior to launch. Although 6 SGR and 27 XRB Wide-Field X-Ray Monitor (WXM) localizations have gone out in near-real time, no accurate near-real time GRB localizations have been circulated.

Several factors contributed to the first year problems of the HETE mission. Difficulties of the kind that most missions experience during their Performance Verification phase had to be overcome, including issues involving optical aspect, spacecraft system reboots, an unreliable Cayenne Primary Ground Station, and implementation and testing of the sophisticated WXM flight software that localizes bursts. All of the above problems are now fixed, but because of manpower shortages in the first year arising from initial underfunding of the MO&DA effort, fixing them took much longer than had been expected (ie, ~9 months rather than the ~3 months anticipated).

The rate of HETE GRB localizations is lower than was expected prior to launch due to two factors: 1) a much smaller than expected "live time" for the instruments; and 2) a lower-than-expected rate of detection of GRBs by the WXM. It has been necessary to operate FREGATE and WXM only from terminator to terminator and often only from orbit "dusk" to orbit "dawn," in order to safeguard the health of these instruments because of solar activity (solar maximum occurred in January 2001 and an unexpected secondary maximum has occurred recently). This has reduced the WXM localization rate by a factor of about 1.5 compared to that expected prior to launch.

Three additional factors affected the rate: 1) the BATSE GRB rate, from which we scaled the predicted HETE rate, was reduced by a factor of 0.82 in the 4B catalog (Paceisas et al 1999); 2) it is becoming apparent that short GRBs, which have very hard gamma-ray spectra, may also be X-ray poor; and 3) the average ratio of Lx/Lgamma for GRBs is lower than was expected. While these three factors -- taken together -- reduce the expected rate of HETE GRB localizations by a factor of about 1.9 compared to the rate expected before launch, their quantification also represents new knowledge about GRBs that has important implications for future GRB missions. The result of the lower than expected "live time" and the reduction in the expected localization rate is a reduction in the HETE GRB localization rate of a factor of about 1.5 x 1.9 = 2.8 compared to the rate that was expected prior to launch.

What about the future? With a 2-year extended mission, the 4-year HETE mission can be expected to produce totals of ~60 localizations, ~25 optical afterglows, and >25 redshifts. The actual numbers are likely to be larger, as solar activity declines and the "live time" of the FREGATE and WXM instruments can be safely increased from 40 minutes to as much as 55 minutes per orbit. There is also every reason to believe that the HETE mission will soon produce its first near real-time localization. In addition, the demonstrated sensitivity of the SXC holds out the possibility for a number of near real-time < 30" localizations and the detection of X-ray emission lines in the spectra of a few very bright GRBs. All in all, with the mysteries that still surround GRBs and the (currently) unique capabilities of the HETE FREGATE, WXM and SXC instruments, the scientific promise of the extended HETE mission is great. The extended HETE mission will yield new knowledge about GRBs and will continue to serve as a means of developing and testing flight software that is similar to the flight software for the BAT on the upcoming Swift mission; both will enhance the scientific productivity of the Swift mission.

The HETE mission should continue addressing basic questions about GRBs over the next 2.5 years: What are the "X-ray Rich" GRBs? What are the short GRBs? Are there other, rarer types of GRBs? Why do only ~1/2 of all GRBs have optical afterglows ? Are there GRBs at z>10?

In the near term, during the upcoming June-August 2002 period the fields-of-view of the HETE science instruments will include the Galactic Bulge region. Many of the known sources in this region of the sky are scientifically interesting (i.e., X-ray bursters, SGRs, AXPs). They will also be useful for further reducing the systematic errors in the accuracy of the WXM and SXC localizations. Although HETE will continue to be "tuned" for the detection of GRBs, the number of "classical" GRBs localized during the June-August period may be somewhat reduced due to the elevated X-ray background arising from the ensemble of Galactic Bulge sources. The Galactic Bulge will exit the HETE FOV in August, allowing sensitive GRB operations to resume away from the Galactic plane in September.

HETE is a collaboration between NASA; MIT; Los Alamos National Laboratory, New Mexico; France's Centre National d'Etudes Spatiales (CNES), Centre d'Etude Spatiale des Rayonnements (CESR), and Ecole Nationale Superieure de l'Aeronautique et de l'Espace (Sup'Aero); and Japan's Institute of Physical and Chemical Research (RIKEN) and National Space Development Agency of Japan (NASDA). The Science Team includes members from Brazil's Instituto Nacional de Pesquisas Espaciais, India's Tata Institute of Fundamental Research, Italy's Consiglio Nazionale delle Ricerche, the University of California (Berkeley and Santa Cruz), and the University of Chicago. Ongoing updates and further details are provided by the HETE Mission Operations Team at the official website: http://space.mit.edu/HETE/.

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13. Chandra X-ray Observatory Operations Report - Roger Brissenden, Manager, Chandra X-ray Center, Smithsonian Astrophysical Observatory

Chandra passed its 1000th day of operation on 18 April 2002 and both the spacecraft and science instruments continue to operate exceptionally well.

Operational highlights during the last six months have included the use of an increased momentum unloading threshold intended to reduce the number of Momentum Unloading Propulsion System firings. The increased threshold coupled with a new model for predicting momentum build-up has succeeded in bringing the rate of firings below the qualification limit - a potentially life-limiting value. Projections now give 17-20 years before the qualification limit will be reached.

Chandra passed through the 2002 Spring Eclipse season in February with nominal power and thermal performance, and passed though a 4% lunar eclipse on May 11 without incident. On January 23 the spacecraft went to a bright star hold after a long maneuver. The maneuver resulted in a pointing error of 150 arcsec that exceeded the aspect camera star search box size of 120 arcsec. The error resulted from the combination of the specific eigenaxis alignment for the maneuver and a slightly inaccurate on-board gyro scale-factor and alignment matrix. An updated gyro scale-factor and alignment matrix is expected to be up-linked in June. IOn the meantime, all maneuvers are being screened for similar cases.

The science observing schedule was halted 9 times between November and May due high levels of solar activity and twice due to unwanted trips of the radiation monitor fault flag (the cause has been traced to a subtle interaction related to the timing of radiation belt entry and exit and has been mitigated by increasing two counter values on-board). The team continues to monitor the solar activity carefully because of the impact on ACIS, and has insured that the CTI degradation over the last 6 months is within expectations. One impact of the stoppages however, has been to decrease the scheduled observing efficiency from the expected 70% to 60%. The Mission Planning team worked very hard to return to science operations as soon as possible after a solar event, and was also successful in replanning 8 fast-turn around Targets Of Opportunity.

The processing, archiving and distribution of data have continued smoothly with the average time from target observation to data distribution to user remaining about a week. The Chandra archive has grown to a total size of 2.9TB and is growing at 0.5TB/year. A web-based interface to the archive, ChaSeR, was released in December.

Observations for Cycle 3 are in full swing, and over 800 cycle 4 proposals were received by the deadline on March 15. The Peer Review is scheduled for June 18-20 and we expect to start the transition to cycle 4 targets in December.

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14. Meeting Announcements

The Riddle of Cooling Flows in Galaxies and Clusters of Galaxies (31 May - 4 June 2003 @ Charlottesville, VA, USA)
Recent observations, especially by XMM-Newton and Chandra, have significantly broadened our view on cooling flows in galaxies and clusters of galaxies. The wealth of new information through observations has led to a flourishing development in theoretical modelling. The purpose of this conference is to summarize relevant observational results at all wavelengths, to compare the predictions of models and simulations to these observations, and to assess the impact of processes in cluster cores on the application of galaxy clusters as cosmological probes. Please visit the conference web page for further details http://www.astro.virginia.edu/coolflow/.

Soft X-ray Emission From Clusters of Galaxies and Related Phenomena (11-13, December 2002 @ Huntsville, AL, USA)
Exciting new data from XMM/Newton observations, along with an in-depth analysis of ROSAT PSPC archives, have recently led to a wealth of new information about the soft X-ray `excess' emission from clusters of galaxies. Not only is the phenomenon spatially very extended, but the details being revealed mean that we now have a realistic possibility of solving the puzzle concerning the origin of the radiation. However the correct interpretation may unfold, indications are that it will be one of cosmological importance. The purpose of this meeting is to (a) review the current observational status of the soft excess, identifying priority issues to be settled in the next rounds of XMM and Chandra opportunities (other timely missions such as Astro-E, may also be addressed); (b) review the theoretical interpretations and how they are constrained by the data; and (c) discuss the prospects of future missions and the optimal payload designs to further our understanding of this new radiation component and its place in cosmology. More details of our first announcement may be found on "http://www.uah.edu/news/ClusterGalaxies.

Globular Clusters: Formation, Evolution and the Role of Compact Objects (27-31 January, 2003 @ ITP, UC-Santa Barbara, CA USA)
Our understanding of the formation and evolution of globular clusters (GCs) is rapidly improving. Much recent progress on GC formation has come from new observations of extragalactic GCs and, in particular, from HST observations of cluster formation in starburst galaxies and in interacting galaxies. Significant advances have also been realized in numerical simulations of structure formation in the high-redshift universe, which are now beginning to probe the relevant scales. In spite of this tremendous recent progress, important questions remain unresolved. These include whether the absence of dark matter halos around GCs can be accommodated in any early formation model, why GCs do not have a mass-radius relation when the clouds from which they form almost certainly do, and how well our current models of their dynamical evolution match the available data. This conference provides a forum for discussing the latest contributions to this field. For further information about the scientific aspects of the meeting and/or presenting new results, please feel free to contact any of the coordinators: L. Bildsten (bildsten@itp.ucsb.edu), A. Cool (cool@stars.sfsu.edu), F. Rasio (rasio@northwestern.edu), or S. Zepf (zepf@pa.msu.edu). For logistic details, please contact Susan Alemdar (sue@itp.ucsb.edu). Registration can be filled out on the ITP web site at http://www.itp.ucsb.edu/activities/conferences/.

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HEADNEWS, the electronic newsletter of the High Energy Astrophysics Division of the American Astronomical Society, is issued twice yearly by the HEAD Secretary-Treasurer. The HEAD Executive Committee Members are:

    Comments, questions, or feedback to headsec@aas.org, Updated June 3, 2002