Compton Observatory Science Report #122 Thursday, June 3, 1993 Eric Chipman, Compton Observatory Science Support Center Questions or comments can be sent to the Compton SSC. Phone 301/286-7764, e-mail SPAN GROSSC::CHIPMAN, Internet chipman@grossc.gsfc.nasa.gov. The Compton spacecraft continues normal operations. There was a maneuver on Monday, May 31, to the attitude of period 223. The z-axis and x-axis targets are 1E1740-2942 and Cyg X-3, respectively. The times of the maneuver were 1334Z to 1410Z. The maneuver angle was 122 degrees, and the boom angle from the equator is now 59 degrees. Second Call for Papers for the Second Compton Symposium We include here the list of invited speakers and topics for the Second Compton Symposium, to be held at the University of Maryland Conference Center on September 20-22, 1993. If you need the Information Request Form or the Abstract Form, contact the Science Support Center by phone or e-mail (Ms. Sandra Barnes, 301-286-7780, barnes@grossc.gsfc.nasa.gov). The regular registration fee is $160. A special registration fee of $60 will be available for students, and registrations after September 1 will be $200. Note that abstracts are due by July 1, 1993. On July 1, the conference managers Jorge Scientific Corp. will be mailing out a logistics package containing registration form, hotel listings, shuttle service information, etc. to all those who have requested more information. SECOND COMPTON SYMPOSIUM Invited Speakers Introductions by Neil Gehrels, James Trainor, and University of MD (?) SOLAR AND BURST SUMMARIES Compton Observatory Solar Flare and Neutron Measurements, James Ryan Gamma-ray Bursts: Observational Overview, Gerald Fishman Gamma-ray Burst Models: Present Problems and Possible Solutions, Alice Harding GALACTIC SOURCES Energetic Radiation from Spin-Powered Pulsars, David Thompson Timing Irregularities in Pulsars, Joseph Taylor Accreting Neutron Stars, Thomas Prince Supernova Puzzles and Gamma Ray Astronomy, Donald D. Clayton BATSE Observations of Transient Hard X-Ray Sources, Alan Harmon Quasi-Periodic Oscillations of Hard X-Ray Transients Observed with BATSE, Chryssa Kouveliotou TBA, Michael Hillas CENTRAL GALACTIC REGION OSSE Observations of Galactic Positron Annihilation Radiation, William Purcell Galactic Nucleosynthesis Measurements Through 26Al, Roland Diehl Multiwavelength Approach to Gamma-ray Sources in the Galactic Center Region, Felix Mirabel Particle Acceleration and Gamma-ray Emission by Low-mass X-ray Binaries, Fred Lamb COSMIC RAYS AND GALACTIC DIFFUSE RADIATION Galactic Cosmic Rays, Vladimir Ptuskin Diffuse Continuum Emission from the Galaxy, Andrew Strong ACTIVE GALACTIC NUCLEI The Canonical Seyfert Spectrum: The Implications of OSSE Observations, Neil Johnson Models of Gamma Rays and X-rays from Non-beamed AGNs, Andrzej Zdziarski EGRET Observations of AGN's, Robert Hartman Variability of EGRET-Detected AGN's and Acceleration Mechanism, Peter Michelson Non-thermal Gamma-ray Emission from Blazars, Alan Marscher BATSE ----- During viewing period 223 BATSE folded-on-board pulsar data was collected for the Crab pulsar, PSR J0437-471, and Her X-1. The Her X-1 data was collected from LADs and SDs simultaneously. In addition, 31 ms resolution single sweep data was collected for pulsar searches using LADs 0 and 2 combined. During viewing period 224 BATSE folded-on-board pulsar data is being collected for the Crab pulsar, PSR 0611+22, PSR 0656+14, Her X-1, SMC X-1 and PSR 1641-45. A popular article about gamma-ray bursts, "The Great Gamma Ray Mystery", appeared in the June/July issue of Air & Space. The article draws on interviews with gamma-ray burst astronomers including many members of the BATSE team. It also includes several photos including a photo of the BATSE burst team hard at work in the infamous "Bat Cave." As of June 1st, BATSE has detected 659 cosmic gamma-ray bursts out of a total of 2258 on-board triggers in 770 days of operation. There have been 650 triggers due to solar flares with emission above 60 keV. COMPTEL ------- The COMPTEL experiment is performing well and continues routine observations; the COMPTEL operations group reports that COMPTEL is a happy and contented instrument. Presentations by the COMPTEL team at next week's meeting of the American Astronomical Society in Berkeley will include: reports on the gamma-ray bursts of 31 January (GRBeatrix) and 9 March, 1993; latest results on the black-hole candidate Cyg X-1; and the application of Bayseian statistical methods to COMPTEL data. EGRET ----- EGRET operations were normal this week. Several new results will be presented at the AAS next week. Two presentations will be made on the AGN results and two on the galactic plane. In addition, talks will be given on sections of the sky; these will be forerunners of what is planned to be a series of papers covering the whole sky. Dr. Hester De Jager is joining us for the month of June. Interactions with guest investigators are continuing on the planned schedule. OSSE ---- OSSE operations are normal. For viewing period 223, the Z-axis target was 1E 1740.7-2942 (GI: N. Gehrels) and the X-axis target was the black hole candidate Cyg X-1 (PI team). When both targets were occulted by the Earth, the OSSE detectors slewed to a third target, the COS-B source 2CG 135+01 (PI team). For viewing period 224, the Z-axis target is the X-ray binary SMC X-1 (PI team) and the X-axis target is the Seyfert galaxy 3C 120 (GI: G. Reichert). The Sun is available on OSSE's scan plane, and the slewing response to BATSE solar triggers is enabled.