Related papers: The Comptel 1.809 Mev Survey
We estimate the 1.8 MeV luminosity of the Sco-Cen association due to radioactive decay of 26Al to (4-15) 10e-5 ph cm**-2 s**-1. We propose a low surface brightness, limb brightened bubble for the 1.8 MeV intensity distribution. The…
The EGRET instrument aboard the Compton Gamma Ray Observatory (CGRO) has completed the first all-sky survey in high-energy gamma rays and has repeatedly viewed selected portions of the sky. Analysis of the region with galactic latitude…
The COMPTEL and EGRET detectors aboard the Compton Gamma-Ray Observatory measured an extragalactic gamma-ray background extending from MeV energies up to about 100 GeV. Calculations performed making reasonable assumptions indicate that…
The Cygnus region harbours a huge complex of massive stars at a distance of 1.0-2.0kpc from us. About 170 O stars are distributed over several OB associations, among which the Cyg OB2 cluster is by far the most important with about 100-120…
Despite the impressive progresses achieved both by X-ray and gamma-ray observatories in the last decades, the energy range between $\sim 200\,\mathrm{keV}$ and $\sim 50\,\mathrm{MeV}$ remains poorly explored. COMPTEL, on-board CGRO…
The goal of the Medium Energy Gamma-ray Astronomy (MEGA) telescope is to improve sensitivity at medium gamma-ray energies (0.4-50 MeV) by at least an order of magnitude over that of COMPTEL. This will be achieved with a new compact design…
Significant 1.8 MeV emission from the Carina region has been detected by COMPTEL. The emission is concentrated within 6 degrees or less near the Carina nebula NGC 3372, one of the brightest HII regions known in our Galaxy. This region…
We present the results of a radio observing campaign on GRB 201216C, combined with publicly available optical and X-ray data. The detection of very high energy (VHE, >100GeV) emission by MAGIC makes this the fifth VHE GRB at time of…
The COMPTEL observations of the blazar-type quasar PKS 0528+134 in the energy range 0.75 MeV to 30 MeV carried out between April 1991 and September 1994 have been analyzed. During the first two years PKS 0528+134 was most significantly…
The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. Milagro is a water Cherenkov detector that…
Short-lived radionuclides, such as 26Al and 60Fe, are tracers of star formation. Therefore, their abundances can unravel the recent star formation history of the host galaxy. In view of future gamma-ray surveys, we predict the masses and…
Gamma-rays from the decay of $^{26}$Al offer a stringent constraint on the Galaxy's global star formation rate over the past million years, supplementing other methods for quantifying the recent Galactic star formation rate, such as…
We present a comprehensive search for non-thermal high-energy $\gamma$-ray emission from the nearby merging galaxy cluster Abell~119 ($z=0.044$) using archival observations spanning over seven decades in photon energy. Our analysis combines…
We discovered independently the shell-type supernova remnant G12.82-0.02, recently reported by Brogan et al. (2005), which is coincident with the unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic plane.…
Several independent observations of the galactic core suggest hitherto unexplained sources of energy. The most well known case is the 511 keV line which has proven very difficult to explain with conventional astrophysical positron sources.…
A search for ultra-high energy gamma-rays emitted by the young, nearby supernova remnant that was discovered recently by the COMPTEL and ROSAT satellites was made using the JANZOS database for the period 1987-1993. A 95% confidence upper…
We present the 12CO(1-0) and 13CO(2-1) line maps obtained observing with the SEST a $\sim 1\degr \times 1\degr$ region of the Vela Molecular Ridge, Cloud D. This cloud is part of an intermediate-mass star forming region that is relatively…
We present reverberation mapping measurements for the prominent ultraviolet broad emission lines of the active galactic nucleus Mrk817 using 165 spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our…
Using recently calculated yields for Type II supernovae, along with models for chemical evolution and the distribution of mass in the interstellar medium, the current abundances and spatial distributions of two key gamma-ray…
Many galaxy clusters have giant halos of non-thermal radio emission, indicating the presence of relativistic electrons in the clusters. Relativistic protons may also be accelerated by merger and/or accretion shocks in galaxy clusters. These…