509 citations · 3.1k across the 33 of their papers we have counts for
33 papers
Revisiting the formaldehyde masers
D. J. van der Walt, L. L. Mfulwane
The 4.8 GHz formaldehyde masers are one of a number of rare types of molecular masers in the Galaxy. The aim of the present calculations is to explore a larger region of parameter…
Searching for TeV gamma-ray emission from SGR\,1935+2154 during its 2020 X-ray and radio bursting phase
H. E. S. S. Collaboration, :, H. Abdalla +251
Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness te…
Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow
H. E. S. S. Collaboration
Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events.…
Search for dark matter signals towards a selection of recently-detected DES dwarf galaxy satellites of the Milky Way with H.E.S.S
H. E. S. S. Collaboration, :, H. Abdallah +227
Dwarf spheroidal galaxy satellites of the Milky Way are prime targets for indirect detection of dark matter with gamma rays due to their proximity, high dark matter content and abs…
Probing the magnetic field in the GW170817 outflow using H.E.S.S. observations
H. E. S. S. Collaboration, :, H. Abdalla +230
The detection of the first electromagnetic counterpart to the binary neutron star (BNS) merger remnant GW170817 established the connection between short -ray bursts and BNS merg…
H.E.S.S. and Suzaku observations of the Vela X pulsar wind nebula
H. E. S. S. Collaboration
Pulsar Wind Nebulae (PWNe) represent the most prominent population of Galactic very-high-energy gamma-ray sources and are thought to be an efficient source of leptonic cosmic rays.…
Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3
H. E. S. S. Collaboration, H. Abdalla, A. Abramowski +253
Context. Recently, the high-energy (HE, 0.1-100 GeV) -ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day…
A search for new supernova remnant shells in the Galactic plane with H.E.S.S
H. E. S. S. Collaboration, :, H. Abdalla +263
A search for new supernova remnants (SNRs) has been conducted using TeV gamma-ray data from the H.E.S.S. Galactic plane survey. As an identification criterion, shell morphologies t…
Characterising the VHE diffuse emission in the central 200 parsecs of our Galaxy with H.E.S.S
H. E. S. S. Collaboration, :, H. Abdalla +256
The diffuse very high-energy (VHE, > 100 GeV) gamma-ray emission observed in the central 200 pc of the Milky Way by H.E.S.S. was found to follow the dense matter distribution in th…
Systematic search for very-high-energy gamma-ray emission from bow shocks of runaway stars
H. E. S. S. Collaboration, :, H. Abdalla +260
Runaway stars form bow shocks by ploughing through the interstellar medium at supersonic speeds and are promising sources of non-thermal emission of photons. One of these objects h…
The population of TeV pulsar wind nebulae in the H.E.S.S. Galactic Plane Survey
H. E. S. S. Collaboration, :, H. Abdalla +255
The nine-year H.E.S.S. Galactic Plane Survey (HGPS) yielded the most uniform observation scan of the inner Milky Way in the TeV gamma-ray band to date. The sky maps and source cata…
Gamma-ray blazar spectra with H.E.S.S. II mono analysis: the case of PKS 2155-304 and PG 1553+113
D. Zaborov, A. M. Taylor, D. A. Sanchez +2
The addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity to lower energies, providing new opportunities for studies of Active Ga…
Gamma-ray blazar spectra with H.E.S.S. II mono analysis: the case of PKS 2155-304 and PG 1553+113
H. E. S. S. Collaboration, :, H. Abdalla +332
The addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity to lower energies. The lowest energy threshold is obtained using monosc…
First limits on the very-high energy gamma-ray afterglow emission of a fast radio burst: H.E.S.S. observations of FRB 150418
H. E. S. S. Collaboration, :, H. Abdalla +265
Aims: Following the detection of the fast radio burst FRB150418 by the SUPERB project at the Parkes radio telescope, we aim to search for very-high energy gamma-ray afterglow emiss…
Deeper H.E.S.S. observations of Vela Junior (RX J0852.04622): Morphology studies and resolved spectroscopy
H. E. S. S. Collaboration, H. Abdalla, A. Abramowski +260
Aims. We study gamma-ray emission from the shell-type supernova remnant (SNR) RX J0852.04622 to better characterize its spectral properties and its distribution over the SNR. Me…
Characterizing the gamma-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT
H. E. S. S. Collaboration, H. Abdalla, A. Abramowski +244
Studying the temporal variability of BL Lac objects at the highest energies provides unique insights into the extreme physical processes occurring in relativistic jets and in the v…
The supernova remnant W49B as seen with H.E.S.S. and Fermi-LAT
H. E. S. S. Collaboration, H. Abdalla, A. Abramowski +253
The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology r…
H.E.S.S. observations of RX J1713.7-3946 with improved angular and spectral resolution; evidence for gamma-ray emission extending beyond the X-ray emitting shell
H. E. S. S. Collaboration, :, H. Abdalla +252
Supernova remnants exhibit shock fronts (shells) that can accelerate charged particles up to very high energies. In the past decade, measurements of a handful of shell-type superno…
A note on the periodic methanol masers in G9.62+0.20E
DJ van der Walt, JM Maswanganye, S Etoka +2
A number of mechanisms to understand the periodic class II methanol masers associated with some high-mass star forming regions have been proposed in the past. Two recent proposals,…
Discovery of periodic class II methanol masers associated with G339.986-0.425 region
J. P. Maswanganye, D. J. van der Walt, S. Goedhart +1
Ten new class II methanol masers from the 6.7-GHz Methanol Multibeam survey catalogues III and IV were selected for a monitoring programme at both 6.7 and 12.2 GHz with the 26m Har…
New Periodic 6.7 GHz Class II Methanol Maser Associated with G358.460-0.391
J. P. Maswanganye, M. J. Gaylard, S. Goedhart +2
Eight new class II methanol masers selected from the 6.7 GHz Methanol Multibeam survey catalogues I and II were monitored at 6.7 GHz with the 26m Hartebeesthoek Radio Astronomy Obs…
Pumping of the 4.8 GHz HCO masers and its implications for the periodic masers in G37.55+0.20
D. J. van der Walt
Periodic or regular flaring of class II methanol masers in nine high mass star forming regions is now a well established phenomenon. Amongst the nine star forming regions, G37.55+0…
Periodicity in Class II methanol masers in high mass star forming regions
S. Goedhart, J. P. Maswanganye, M. J. Gaylard +1
We report the results of 10 years of monitoring of six regularly varying 6.7 GHz methanol masers using the Hartebeesthoek 26m telescope. Observations were done at intervals of 1--2…
A near-infrared study of the star forming region RCW 34
D. J. van der Walt, H. M. de Villiers, R. J. Czanik
We report the results of a near-infrared imaging study of a arcmin region centered on the 6.7 GHz methanol maser associated with the RCW 34 star forming region…