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Full-Text Articles in Physical Sciences and Mathematics
The Optical-Ultraviolet-Γ-Ray Spectrum Of 3c 279, Hagai Netzer, D. Kazanas, Beverley J. Wills, D. Wills, Han Mingsheng, M. S. Brotherton, J A. Baldwin, Gary J. Ferland, I. W. A. Browne
The Optical-Ultraviolet-Γ-Ray Spectrum Of 3c 279, Hagai Netzer, D. Kazanas, Beverley J. Wills, D. Wills, Han Mingsheng, M. S. Brotherton, J A. Baldwin, Gary J. Ferland, I. W. A. Browne
Physics and Astronomy Faculty Publications
We have obtained spectrosocpy of the violently variable quasar 3C 279, simultaneous with γ-ray observations, in 1992 April. Our combined optical (McDonald Observatory and Cerro Tololo InterAmerican Observatory (CTIO) and ultraviolet (HST) observations, made when the source was faint, show a very steep power-law continuum (Fν∝ν-1.95) and strong broad emission lines. This is the first time that the broad ultraviolet lines of this object have been measured, and we note several unusual properties of the spectrum. In particular, the profiles of C IV λ1549 and Mg II λ …
Comptel Imaging Of The Galactic Disk And The Separation Of Diffuse Emission And Point Sources, H Bloemen, W Hermsen, B Swanenburg, C De Vries, R Diehl, V. Schonfelder, H Steinle, A W. Strong, A Connors, Mark L. Mcconnell, D Morris, G Stacy, K Bennett, C Winkler
Comptel Imaging Of The Galactic Disk And The Separation Of Diffuse Emission And Point Sources, H Bloemen, W Hermsen, B Swanenburg, C De Vries, R Diehl, V. Schonfelder, H Steinle, A W. Strong, A Connors, Mark L. Mcconnell, D Morris, G Stacy, K Bennett, C Winkler
Physics & Astronomy
The first MeV image of the inner Galaxy obtained with the COMPTEL telescope aboard the Compton Gamma-Ray Observatory shows a structured ridge of emisssion along the Galactic equator which probably consists of diffuse radiation and unresolved discrete sources. The intensity distribution of this ridge distinctly differs from the expected distribution for a simple model of the diffuse radiation. Most remarkable are the observed excursions out of the disk, which may hint at the presence of gamma-ray point sources located several degrees away from the mid-plane, but a diffuse origin cannot be excluded. If these are indeed discrete sources, a substantial …
Observations Of Cygnus X-1 Comptel During 1991, Mark L. Mcconnell, D J. Forrest, James M. Ryan, W Collmar, V. Schonfelder, H Steinle, A W. Strong, R Van Dijk, W Hermsen, K Bennett
Observations Of Cygnus X-1 Comptel During 1991, Mark L. Mcconnell, D J. Forrest, James M. Ryan, W Collmar, V. Schonfelder, H Steinle, A W. Strong, R Van Dijk, W Hermsen, K Bennett
Physics & Astronomy
The Compton Telescope (COMPTEL) experiment on the Compton Gamma-Ray Observatory (CGRO) has observed the Cygnus region on two occasions during the first (sky survey) phase of its mission. These data represent the most sensitive observations to date of Cygnus X-1 in the 0.75-30 MeV range. The observations in 1991 June and August both showed evidence for emission in the 0.75-2 MeV energy range. The flux level was larger by about a factor of 2 during the August observation. The spectral data were analyzed in the context of a Wien spectral model (the high-energy limit of the Sunyaev-Titarchuk Comptonization spectrum). Fits …
An Overview Of First Results From Comptel, V. Schonfelder, H Aarts, K Bennett, H Bloemen, H Deboer, M Busetta, W Collmar, A Connors, R Diehl, J W. Den Herder, W Hermsen, L Kuiper, G G. Lichti, J Lockwood, John R. Macri, Mark L. Mcconnell, D Morris, R Much, James M. Ryan, G. Simpson, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, B G. Taylor, M Varendorff, C De Vries, W Webber, C Winkler
An Overview Of First Results From Comptel, V. Schonfelder, H Aarts, K Bennett, H Bloemen, H Deboer, M Busetta, W Collmar, A Connors, R Diehl, J W. Den Herder, W Hermsen, L Kuiper, G G. Lichti, J Lockwood, John R. Macri, Mark L. Mcconnell, D Morris, R Much, James M. Ryan, G. Simpson, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, B G. Taylor, M Varendorff, C De Vries, W Webber, C Winkler
Space Science Center
COMPTEL is the first imaging telescope to explore the MeV gamma-ray range (0.7 to 30 MeV). At present, it is performing a complete sky survey. Targets of special interest in the COMPTEL energy range are radio pulsars, X-ray binaries, novae, supernovae, supernova remnants, mulecular clouds, the interstellar medium within the Milky Way, active galactic nuclei, and the diffuse cosmic background radiation. The data from the first half year of the mission have demonstrated that COMPTEL performs as expected. The Crab is clearly seen at its proper position in the first images of the anticenter region of the galaxy. The Crab …
First Results From Comptel Measurement Of The Al-26 1.8 Mev Gamma-Ray Line From The Galactic Center Region, R Diehl, K Bennett, H Bloemen, H Deboer, M Busetta, W Collmar, A Connors, J W. Den Herder, C. Devries, W Hermsen, J Knodlseder, L Kuiper, G G. Lichti, J Lockwood, John R. Macri, Mark L. Mcconnell, D Morris, R Much, James M. Ryan, V. Schonfelder, G. Simpson, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, M Varendorff, P. Von Ballmoos, W Webber, C Winkler
First Results From Comptel Measurement Of The Al-26 1.8 Mev Gamma-Ray Line From The Galactic Center Region, R Diehl, K Bennett, H Bloemen, H Deboer, M Busetta, W Collmar, A Connors, J W. Den Herder, C. Devries, W Hermsen, J Knodlseder, L Kuiper, G G. Lichti, J Lockwood, John R. Macri, Mark L. Mcconnell, D Morris, R Much, James M. Ryan, V. Schonfelder, G. Simpson, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, M Varendorff, P. Von Ballmoos, W Webber, C Winkler
Physics & Astronomy
The COMPTEL instrument on GRO is designed to image celestial gamma radiation in the approximately 0.7-30 MeV region of nuclear lines. Within a large field of view of about 1 sr its angular resolution of about 1 deg enables mapping of extended emission and location of (strong) point sources to an accuracy of better than 0.5 deg. The Galactic center region was observed by COMPTEL for a 2-week period in July 1991. Here we report the detection of the line at 1.8 MeV attributed to Al-26, addressing in particular the extent of the emission and the 1.8 MeV line flux.
The Gamma-Ray Burst Of 3 May 1991 Observed By Comptel On Board Gro, C Winkler, K Bennett, H Bloemen, W Collmar, A Connors, R Diehl, J W. Den Herder, W Hermsen, R M. Kippen, L Kuiper, G G. Lichti, J Lockwood, Mark L. Mcconnell, D Morris, James M. Ryan, V. Schonfelder, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, B G. Taylor, M Varendorff, C De Vries
The Gamma-Ray Burst Of 3 May 1991 Observed By Comptel On Board Gro, C Winkler, K Bennett, H Bloemen, W Collmar, A Connors, R Diehl, J W. Den Herder, W Hermsen, R M. Kippen, L Kuiper, G G. Lichti, J Lockwood, Mark L. Mcconnell, D Morris, James M. Ryan, V. Schonfelder, J G. Stacy, H Steinle, A W. Strong, B Swanenburg, B G. Taylor, M Varendorff, C De Vries
Physics & Astronomy
The Compton Gamma-Ray Observatory was launched on April 5, 1991, carrying the imaging Compton telescope COMPTEL. Since its activation on April 25, 1991, COMPTEL has observed several gamma-ray bursts in its 1-sr field of view. The strongest of these bursts was observed on May 3, 1991. Event data over 0.8 MeV to 30 MeV as well as time resolved spectra over 0.1 MeV to 10 MeV have been recorded. For the first time, a direct single-telescope MeV image of a cosmic gamma-ray burst has been produced. The burst is located at (l,b) = (171.8 deg, 6.4 deg) with a statistical …