Conveners
Astrophysics
- Christo Venter (North-west University, Potchefstroom Campus)
Astrophysics
- Markus Bottcher (University of North West)
Astrophysics
- Christo Venter (North-west University, Potchefstroom Campus)
Astrophysics
- Markus Boettcher ()
Astrophysics
- Christo Venter (North-west University, Potchefstroom Campus)
Astrophysics
- Christo Venter (North-west University, Potchefstroom Campus)
Astrophysics
- Markus Boettcher ()
Astrophysics
- There are no conveners in this block
Astrophysics
- There are no conveners in this block
Astrophysics
- Christo Venter (North-west University, Potchefstroom Campus)
Astrophysics
- Markus Boettcher ()
Mr
Feraol F. Dirirsa
(University of Johannesburg)
04/07/2017, 11:10
Track D1 - Astrophysics
Oral Presentation
Long duration Gamma-Ray Bursts (GRBs) may serve as new standard candles to constrain cosmological parameters by probing the Hubble diagram well beyond the range of redshift currently accessible using type-Ia supernovae. The standardization of GRBs is based on relations which correlate two or more parameters, found from gamma-ray spectral modelling of which one is strongly dependent on the...
Dr
Luis Salvador Miranda Palacios
(University of Johannesburg)
04/07/2017, 11:30
Track D1 - Astrophysics
Oral Presentation
The TeV blazar Markarian 421 underwent multi- TeV flaring during April 2004 and simultaneously obser- vations in the X-ray and TeV energies were made. It was observed that the TeV outbursts had no counterparts in the lower energy range. One implication of this is that it might be an orphan flare. We show that Fermi-accelerated protons of energy ≤168 TeV can interact with the low energy tail of...
Mr
Michael Hlabathe
(University of Cape Town and South African Astronomical Observatory)
04/07/2017, 11:50
Track D1 - Astrophysics
Oral Presentation
Echo mapping of Active Galactic Nuclei (AGNs) measures the time lag between the variable optical continuum from the accretion disk and spectral line emission from the photoionized gas in order to determine the size of the emitting region and subsequently measure the mass of the supermassive black hole from the resulting lag. Currently there is a dearth of galaxies with measured lags in the...
Prof.
Christo Venter
(North -West University)
04/07/2017, 14:00
Track D1 - Astrophysics
Oral Presentation
The number of gamma-ray pulsars has been steadily increasing since the launch of the Fermi Large Area Telescope in 2008, which was the catalyst for a great number of new pulsar detections. These rapidly rotating neutron stars exhibit rich phenomenology, indicating that there are still many unsolved mysteries regarding the magnetospheric conditions in these stars after 50 years of research....
Mr
Ayman Kudoda
(University of the Witwatersrand)
04/07/2017, 14:20
Track D1 - Astrophysics
Oral Presentation
The interaction of Extragalactic Background Light (EBL) photons and gamma-rays from distant quasars results in the attenuation of the high energy tail of the gamma-ray spectrum. The attenuation depends on the EBL photon density. Clustering of galaxies on a scale of up to 100 Mpc causes fluctuations in the EBL photon density. We present an analytical model of the EBL fluctuations and discuss...
Mr
Kleopas Shiningayamwe
(The University of Namibia)
04/07/2017, 14:40
Track D1 - Astrophysics
Oral Presentation
The High-Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes located in the Khomas Highland in Namibia, dedicated to very-high-energy (VHE, 100 GeV - 100 TeV) gamma-ray astronomy. It consists of four identical 12 m diameter telescopes (H.E.S.S.-I) which started operating in 2003 and a large 28 m diameter telescope (H.E.S.S.-II) which was brought...
Mr
Baibhaw Singh
(Indian Institute of Technology,Kharagpur,India)
04/07/2017, 15:00
Synchrotron Radiation(SR) and Inverse Compton Scattering(ICS) are the two prime processes which lead to X-Ray and Gamma Ray emission in Gamma Ray Bursts and Active Galactic Nuclei. We focused on the ICS of relativistic electrons on target photon fields and studied the polarization of outgoing photons. We present the results by analyzing the cross section of the scattering process and the...
Dr
Jagdish Chandra Joshi
(University of Johannesburg)
05/07/2017, 10:20
Track D1 - Astrophysics
Oral Presentation
The flux of positrons observed at Earth produced as secondaries in the cosmic ray nuclei interactions. In the astrophysical scenario positrons are also injected as primaries, and this scenario is very peculiar if these objects are located in the sub-kpc range of solar system. We calculate the positron flux produced by cosmic ray interaction using the DRAGON code, and
also check the nearby...
Prof.
Werner Richter
(Stellenbosch University)
05/07/2017, 11:10
Track D1 - Astrophysics
Oral Presentation
The thermonuclear Cl-34(p,gamma)Ar-35 reaction rates are unknown at nova temperatures due to a lack of experimental nuclear physics data for the resonances up to about 800 keV above the Ar-35 proton separation energy. We present results of calculations in a
full (0+1)(h/2π)ω model space using the interaction sdpfmu. The basis consists of a complete 1(h/2π)ω basis made from all possible...
Mr
Matthew Unterslak
(Wits)
05/07/2017, 11:30
Track D1 - Astrophysics
Oral Presentation
It is widely accepted that during the cosmic evolution three stellar populations can be differentiated. The earliest stars, referred to as Pop III stars, form at redshifts (z) between 20 and 30. For those stars molecular hydrogen is dominant cooling agent within the proto-stellar clouds typically leading to giant stars with masses on the order of 100 Msun. These stars die quickly via...
Prof.
Pieter Wagener
(University of Fort Hare)
05/07/2017, 11:50
Track D1 - Astrophysics
Oral Presentation
A formula derived from a theory of gravitation is applied to periods, or distances from the sun, of orbiting bodies of the solar system extending to beyond the Kuiper belt and into the Van Oort Cloud. It includes the periodic comets and asteroids. The formula gives discrete distances for 38 selected solar bodies, as well as discrete periods of the major comets, within an average relative...
Ms
Kerry Paterson
(UCT)
05/07/2017, 14:00
Track D1 - Astrophysics
Oral Presentation
MeerLICHT is a 65cm optical telescope situated in Sutherland. The MeerLICHT project, as a part of the ThunderKAT project, will be linked to MeerKAT in real-time, in order to provide simultaneous optical and radio observations of the transient sky. Since transient events often requires multi-wavelength observations within a short time lapse, the combination of MeerLICHT and MeerKAT will provide...
Ms
Nigist Beyene
(AIMS South Africa)
05/07/2017, 14:20
Track D1 - Astrophysics
Oral Presentation
We introduce analytic tools we are designing for the study of cepheid and other variable stars. The study and analysis will include long terms variability analysis of these variable stars, using both archival and new data, and thus have potential to not only probe the physical properties of the stars, but also their evolutionary characteristics and use as distance probes.
Dr
Claudia Albers
(WITS university)
05/07/2017, 14:40
Track D1 - Astrophysics
Oral Presentation
Brown Dwarfs are sub-stellar objects, somewhat between gas giant planets and small stars. Brown Dwarf Stars are the remains of a main sequence star that has gone through the white dwarf stage after releasing its outer layers of gas. These stars are therefore surrounded by clouds of ionised gas. The Brown Dwarf Star stage is reached when the core of the once main sequence star, no longer...
Mr
THEOPHILUS ANSAH-NARH
(RHODES UNIVERSITY)
05/07/2017, 15:00
Track D1 - Astrophysics
Oral Presentation
The emerging observation technique to probe dark energy is HI intensity mapping (IM). The technique mainly depends on mapping the integrated intensity of HI (21 cm) emission of each pixel on the sky without absolutely resolving individual galaxies. However, the technique is faced with some challenges in terms of data analysis and specifically, in measuring the primary beam response of our...
Prof.
Markus Boettcher
(North-West University)
06/07/2017, 10:00
This talk provides a general introduction of the High Energy Stereoscopic
System (H.E.S.S.), the world's largest ground-based gamma-ray observatory,
located near Windhoek, Namibia. I will then present some highlights of
extragalactic science done with H.E.S.S., including the study of active
galactic nuclei, rapid follow-up observations of transients (including
gamma-ray bursts), the search for...
Mr
Riyaadh Jamodien
(SUN)
06/07/2017, 11:10
Track D1 - Astrophysics
Oral Presentation
A primary goal of data analysis is to determine what mathematical model can best describe how the data came about. Often, however, there are competing explanations in the form of different parametrisations, so that <it>model comparison</it> becomes necessary.
Within the Bayesian framework, model comparison is effected by means of the <it>evidence</it> and the <it>posterior odds</it> as well...
Dr
NCEBA MHLAHLO
(WITS UNIVERSITY)
06/07/2017, 11:30
Track D1 - Astrophysics
Oral Presentation
ACO2163 is one of the hottest Abell galaxy clusters which has been observed countless times through different wavelengths and has always shown remarkable properties. We report a detection of a shock front in ACO2163 through the use of the X-ray and radio observations which were combined to determine the shock location in relation to the radio emission and other specific parameters inherent to...
Mr
Thembaloxolo Gqaza
(University of Cape Town)
06/07/2017, 11:50
Track D1 - Astrophysics
Oral Presentation
The future of analysing HI-data cubes with respect to understanding the evolution of the neutral
gas content in galaxies will take a giant leap forward. This is due to the advent of the HI-survey projects
that will be pursued with the Square Kilometer Array (SKA) and its Pathfinders. The forthcoming
HI-surveys will produce spectral data cubes of unprecedented size. In preparation for the...
Prof.
Christo Venter
(North-west University, Potchefstroom Campus)
06/07/2017, 16:10
Mr
Jacques Pienaar
(Purdue University)
07/07/2017, 10:20
Track D1 - Astrophysics
Oral Presentation
XENON1T is a two-phase xenon TPC for the direct detection of dark matter. The target mass is 2 tons of liquid xenon. The detector was commissioned in the middle of 2016, and completed its first science run in January 2017. During the science run the detector has achieved the world’s lowest background among comparable experiments. This talk will present the detector performance, calibration,...
Dr
Geoff Beck
(University of Witwatersrand)
07/07/2017, 11:30
Track D1 - Astrophysics
Oral Presentation
The Madala hypothesis, invoked by South African scientists (von Buddenbrock et al 2015 & 2016), extends the standard model to cover anomalies in the transverse momentum of the Higgs boson (among other anomalous excesses) seen at the Large Hadron Collider. As the evidence continues to hint in favour of this scenario it is worthwhile to explore its cosmological and astrophysical consequences....
Mrs
Heba Abdulrahman
(North West University, South Africa)
07/07/2017, 11:50
Track D1 - Astrophysics
Oral Presentation
Recent developments in observational cosmology and astronomy (such as
the apparent discovery of the accelerated expansion of the Universe and the
existence of dark matter) have put theoretical physics in general and cosmology in particular into crisis. In this thesis, we introduce a detailed review of Einstein’s theory of general relativity by which standard cosmology based on.
We present...
Dr
Anslyn John
(Rhodes University)
07/07/2017, 12:10
Track D1 - Astrophysics
Oral Presentation
The inclusion of dissipative effects in cosmic fluids modifies their clustering properties and could have observable effects on the formation of large-scale structures. We analyze the evolution of density perturbations of cold dark matter endowed with causal bulk viscosity. The perturbative analysis is carried out in the Newtonian approximation and the bulk viscosity is described by the causal...
