Related papers: The first COMPTEL Source Catalogue
The comparison of COMPTEL 1.8 MeV gamma-ray line data to an extended data base of tracer maps revealed an extremely close correlation between 1.8 MeV gamma-ray line emission on the one side and 53 GHz microwave free-free emission and 158 um…
The last measurement of the diffuse emission spectrum of the Milky Way in the megaelectronvolt (MeV) photon energy range was performed by CGRO/COMPTEL more than 20 years ago. We report a new analysis with the spectrometer SPI aboard…
The soft MeV gamma-ray sky, from a few hundred keV up to several MeV, is one of the least explored regions of the electromagnetic spectrum. The most promising technology to access this energy range is a telescope that uses Compton…
The COMPTEL instrument on the Compton Gamma Ray Observatory is used to measure the locations of gamma-ray bursts through direct imaging of MeV photons. In a comprehensive search, we have detected and localized 29 bursts observed between…
We report the COMPTEL detection of pulsed $\gamma$-emission from PSR B1509-58 up to at least 10 MeV using data collected over more than 6 years. The 0.75-10 MeV lightcurve is broad and reaches its maximum near radio-phase 0.38, slightly…
We report the direct detection of gamma-ray emission from the Galactic center in the 150-600 keV band using the electron-tracking Compton camera (ETCC), which has a wide field of view of 3.1 sr. This represents the first application of this…
Inverse Compton scattering appears to play a more important role in the diffuse Galactic continuum emission than previously thought, from MeV to GeV energies. We compare models having a large inverse Compton component with EGRET data, and…
Gamma-ray lines from radioactive isotopes, ejected into interstellar space by cosmic nucleosynthesis events, are observed with new space telescopes. The Compton Observatory had provided a sky survey for the isotopes 56Co, 22Na, 44Ti, and…
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.…
We search for MeV gamma-ray emission between 0.75-30 MeV from five galaxy clusters, viz. Coma, VIRGO, SPT-CL J2012-5649, Bullet, and El Gordo, using archival data from the COMPTEL telescope. For this purpose we use three search templates:…
The COMPTEL experiment aboard the COMPTON Gamma-Ray Observatory (CGRO) has observed the prominent TeV-blazars Mkn 421 and Mkn 501 many times between the start of its mission in April '91 and December '98. This paper reports first COMPTEL…
In 2020, the HAWC Collaboration presented the first catalog of gamma-ray sources emitting above 56 TeV and 100 TeV. With nine sources detected, this was the highest-energy source catalog to date. Here, we present the results of re-analysis…
The SHALON atmospheric Cherenkov telescope has detected very high energy gamma-ray emission at TeV energies from eight red dwarfs, namely, V388 Cas, V547 Cas, V780 Tau, V962 Tau, V1589 Cyg, GJ 1078, GJ 3684 and GL 851.1. Consequently, these…
A subset of the unidentified EGRET gamma-ray sources with no active galactic nucleus or other conspicuous counterpart appears to be concentrated at medium latitudes. Their long-term variability and their spatial distribution indicate that…
Despite the impressive progress achieved both by X-ray and gamma-ray observatories in the last few decades, the energy range between $\sim200\;\mathrm{keV}$ and $\sim50\;\mathrm{MeV}$ remains poorly explored. COMPTEL, on-board the Compton…
We have investigated the MeV behaviour of the \gray blazars 3C~454.3 and CTA 102 by analyzing all COMPTEL observations of this sky region during the complete CGRO mission. Both sources are detected by COMPTEL at the upper COMPTEL energies;…
Compton telescopes rely on the dominant interaction mechanism in the MeV gamma-ray energy range: Compton scattering. By precisely recording the position and energy of multiple Compton scatter interactions in a detector volume, a photon's…
The COMPTEL experiment aboard CGRO, exploring the previously unknown sky at MeV-energies, has so far detected 10 Active Galactic Nuclei (AGN): 9 blazars and the radio galaxy Centaurus A. No Seyfert galaxy has been found yet. With these…
The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton…
In this paper, we suggest a new hypothesis for explaining the spectrum of the extragalactic MeV gamma-ray background as observed by COMPTEL and SMM. We propose that both the flux level and spectrum can be accounted for as a superposition of…