Download or read book OSSE Observations of the Vela Pulsar written by and published by . This book was released on 1993 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The OSSE detector on board the Compton Gamma Ray Observatory observed the Vela Pulsar (PSR 0833-45) during August-September 1991 and April-May 1992. Pulsed emission was detected at the 4-5 sigma level in the 0.06-0.57 MeV band in the sum of the two observing periods, as well as in each individual observation at lower significance. There is no significant variability observed. Light curves have a peak structure similar to that observed at higher energies. The spectrum is hard at lower energies and appears to require a break in the 0.5-2 MeV region.
Download or read book OSSE Observations of the Vela and Geminga Pulsars written by and published by . This book was released on 1996 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Oriented Scintillation Spectrometer Experiment (OSSE) on board the Compton Gamma Ray Observatory detected the Vela Pulsar (PSR B0833-45) during August-September 1991, April-May 1992, and August 1993. Observed light curves have a two-peak pulse profile similar to that observed at higher energies, although the second peak may be wider in the OSSE light curve. Pulsed emission in the first gamma-ray peak was detected with 4.6 sigma statistical significance in the 0.07-0.6 MeV band in the sum of all three observing periods. The second gamma ray peak was detected at no more than 3 sigma significance in the same band. Due to the low statistical significance of the observations, little can be said concerning longer-term temporal variability. The spectrum is hard at lower energies and, in combination with higher energy data, appears to require a break in the 20 MeV region. OSSE also observed Geminga during July 1992, December 1993, and July 1994. No significant pulsed or time averaged emission was observed on any occasion. Upper limits to the pulsed emission suggest, but do not require, a break from the extrapolation of the spectrum measured at higher energies.
Download or read book OSSE Observations of the Crab Pulsar written by and published by . This book was released on 1994 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results of the Compton Gamma Ray Observatory OSSE observations of the Crab pulsar, made during MJD 48373-48406 (27 April 1991-30 May 1991) and MJD 48798-48804 (25 June 1992-1 July 1992). Pulsar light curves and spectra over the ~0.05 to 10 MeV range are presented. The arrival time of the gamma-ray peak and the radio peak agree to within 30 microsecs, which is better than the ~300 microsecs accuracy of the measurements. The overall pulse phase averaged spectrum in the 0.1-10 MeV range is well-fit by a power law of the form 0:05 x (E/0.13 MeV)(exp 1.99 plus or minus 0.03) photons sq cm s(exp -1). The outer-gap model (with gap parameter equal to 0.46) provided to us by Ho agrees with the data to better than 20%. The spectra of the bridge and second peak are slightly harder that the first peak as measured by the hardness ratio (~110-220 keV)/(~50-105 keV): P1 = 0.54 plus or minus 0.01, P2 = 0.63 plus or minus 0.01, bridge = 0.68 plus or minus 0.03. The phase of the two peaks in the light curve is constant over the 50-550 keV range to within the accuracy of the measurements (better than 0.02 in in phase).
Download or read book Isolated Pulsars written by K. A. van Riper and published by Cambridge University Press. This book was released on 1993-03-25 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extreme properties of pulsars demand a broad range of physics. From The Los Alamos Workshop on Isolated Pulsars contributions have been selected to encompass all aspects of pulsar detection and understanding. Recent observational highlights include results from the Compton Gamma-Ray Observatory, ROSAT and GINGA and the Hubble Space Telescope. Well-illustrated theoretical contributions cover a wide range of topics. This volume forms a comprehensive and up-to-date guide to the observation and theory of solitary neutron stars.
Download or read book The Gamma Ray Sky with Compton GRO and SIGMA written by M. Signore and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume consists of invited lectures and seminars presented at the NATO Advanced Study Institute "The Gamma Ray Sky with COMPTON GRO and SIGMA" , which was held at the Centre de Physique Theorique of Les Houches (France) in January / February 1994. The school has been planned by a Scientific Organizing Committee. It was organized with the aim of providing students and young researchers with an up-to-date account of the high-energy phenomena in the vicinity of compact objets and the diffuse gamma-ray backgrounds after the early results from the gamma-ray telescope SIGMA and the four instruments onboard COMPTON GRO (Gamma Ray Observatory) : BATSE (Burst and Transient Source Experiment),COMPTEL(Compto'l Telescope),EGRET (Energetic Gamma Ray Experiment Telescope) and OS SE(Oriented Scintillation Spectrometer Experiment) . It was attended by more than sixty researchers from many countries. The lectures and seminars represent a complete coverage of our present knowledge and understanding of: Gamma-ray backgrounds, Gamma-ray Burts,Active Galactic Nuclei,Galactic Compact Objects, Gamma-ray Spectroscopy, Instrumentation and observation techniques, etc ... Most of these lectures are reproduced in this volume. Unfortunately, a few lecturers have chosen not to submit their manuscript.
Download or read book Particle Astrophysics and Cosmology written by M.M. Shapiro and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute, Erice, Sicily, Italy, June 20-30, 1992
Download or read book An OSSE Search for the Binary Radio Pulsar 1259 63 written by and published by . This book was released on 1993 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have searched data from the Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma Ray Observatory (GRO) for evidence of low-energy gamma-ray emission from the binary radio pulsar PSR 1259-63. This 47 ms pulsar is in a long-period, highly eccentric orbit around a Be stellar companion and was observed by OSSE approximately 400 days after periastron. The period derivative allowed by the published radio ephemeris (Johnston et al. 1992) suggests that the pulsar might be relatively young, and therefore a gamma-ray source. However, the ephemeris is not sufficiently accurate to allow the traditional epoch folding technique over the full OSSE observation. Instead, the OSSE data were analyzed using Fourier transform spectral techniques after applying trial accelerations to correct for a range of possible orbital accelerations. We searched 48 accelerations; each FFT was 2(exp 29) points sampled at 2 ms, spanning ~10(exp 6) seconds of observation time. There was no evidence of pulsed emission in the 64-150 keV band, with a 99.9% confidence upper limit of 6x10(exp -3) photons sq cm s(exp -1) MeV(exp -1) or ~40 m Crab pulsars, which suggests that the pulsar's intrinsic period derivative is small and its magnetic field weak. This work was performed on the Concurrent Supercomputing Consortium's Intel Touchstone Delta parallel supercomputer as part of a GRO Phase I Guest Investigation.
Download or read book OSSE Observations of X Ray Pulsars written by and published by . This book was released on 1995 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on OSSE observations of the Be binary pulsars A0535+26, GRO J1008-57, and 4U 0115+63 at energies above 50 keV. The spectra are generally thermal, with exponential folding energies of 15-25 keV, and no evidence for hard power-law tails. We have clearly detected a strong cyclotron absorption line at 110 keV from A0535+26 [1], and we find a suggestion of an absorption line near 90 keV from GRO J1008-57.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992-06 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Lives of the Neutron Stars written by M. A. Alpar and published by Springer Science & Business Media. This book was released on 1994-12-31 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This NATO AS! was the third in the series of Advanced Study Institutes on neutron stars, which started with 'Timing Neutron Stars', held in Qe§me near izmir, Turkey (April 1988), followed by 'Neutron Stars, an Interdis ciplinary Subject', held in Agia Pelagia on the island of Crete (September 1990). The first school centered on our main observational access to neu tron stars, i. e. the timing of radio pulsars and accretion powered neutron stars, and on what timing of neutron stars teaches us of their structure and environment. The second school had as its theme the interplay between diverse areas of physics which find interesting, even exotic applications in the extreme conditions of neutron stars and their magnetospheres. As the field has developed, with the number of observed neutron stars rapidly in creasing, and our knowledge of many individual neutron stars getting deeper and more detailed, an evolutionary picture of neutron stars has started to emerge. This led us to choose 'The Lives of the Neutron Stars' as the uni fying theme of this third Advanced Study Institute on neutron stars. Different types of neutron star activity have been proposed to follow one another in stages during the lives of neutron stars in the same basic population; the evolutionary connection between low-mass X-ray binaries and millisecond radio pulsars is perhaps the prime example.
Download or read book Soft X ray Observations of the Vela Pulsar PSR 0833 45 written by Hakki Ögelman and published by . This book was released on 1988 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Referativny zhurnal written by and published by . This book was released on 1999 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Timing Observations of the Vela Pulsar PSR0833 45 written by Andrew Reid Klekociuk and published by . This book was released on 1989 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray and Extreme Ultraviolet Optics written by Richard B. Hoover and published by SPIE-International Society for Optical Engineering. This book was released on 1995 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Gamma Ray Observatory Science Workshop written by W. Neil Johnson and published by . This book was released on 1989 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Millisecond Pulsars written by Andrew S. Fruchter and published by . This book was released on 1995 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clocks in the Sky written by Geoff McNamara and published by Springer Science & Business Media. This book was released on 2009-04-24 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsars are rapidly spinning neutron stars, the collapsed cores of once massive stars that ended their lives as supernova explosions. In this book, Geoff McNamara explores the history, subsequent discovery and contemporary research into pulsar astronomy. The story of pulsars is brought right up to date with the announcement in 2006 of a new breed of pulsar, Rotating Radio Transients (RRATs), which emit short bursts of radio signals separated by long pauses. These may outnumber conventional radio pulsars by a ratio of four to one. Geoff McNamara ends by pointing out that, despite the enormous success of pulsar research in the second half of the twentieth century, the real discoveries are yet to be made including, perhaps, the detection of the hypothetical pulsar black hole binary system by the proposed Square Kilometre Array - the largest single radio telescope in the world.
