-
Markus Boettcher (North-West University)13/09/2021, 13:30Opening
-
Anna Samara Larmuth (University of Johannesburg)13/09/2021, 13:40Opening
-
Mr Takalani Nemaungani (Department of Science and Innovation)13/09/2021, 13:55Opening
-
Fabian Schüssler (CEA)13/09/2021, 14:15
The last years have brought about unprecedented breakthroughs and discoveries in high-energy astro- physics. Most of them are related to transient phenomena and involve an increasing number of cosmic messengers ranging now from radiation across the full electromagnetic spectrum, to high-energy neutrino and gravitational waves. Due to their high sensitivity and increasingly optimized response...
Go to contribution page -
Xiang-Yu Wang (Nanjing University)13/09/2021, 14:45
Recently, very high-energy (VHE) photons above 100 GeV were detected from several GRBs (including GRB 190114C, GRB 180720B and GRB 190829A) by IACTs during the afterglow phase. We discuss the origin of VHE emission of GRBs and its implications. We propose that the available broadband data of these GRBs can be modelled with the synchrotron plus synchrotron self-Compton (SSC) emission of the...
Go to contribution page -
David A.H. Buckley (SAAO)13/09/2021, 15:15
From mid-2020, the SALT Large Science Program on transients has been following up on some X-ray transients discovered during the eROSITA all-sky survey. These include changing-look AGN, TDEs, Be X-ray and compact white dwarf binaries. I will review the results to date, including the discovery of two new examples of Quasi- Periodic Eruptions (QPEs) in non-active galaxies, the first time such...
Go to contribution page -
Dr Sara Issaoun (Radboud University)13/09/2021, 16:00
The Event Horizon Telescope (EHT) is a millimeter VLBI array observing supermassive black holes. Its 2017 observing run led to the first images of a black hole shadow in M87, in total intensity and later in polarization as well. These data and images have allowed us to conduct a black hole mass measurement and a null hypothesis test of general relativity, and to put significant constraints on...
Go to contribution page -
Venkatessh Ramakrishnan13/09/2021, 16:30
The transformational science enabled by the Event Horizon Telescope (EHT) observations of M87* has opened a new paradigm wherein imaging the accretion and jet flows around supermassive black holes has become feasible. We embark on this potential of the EHT by constructing a sample of nearby AGNs whose immediate environment around the black hole will be explored at a high angular resolution. In...
Go to contribution page -
Iniyan Natarajan13/09/2021, 16:45
The Event Horizon Telescope (EHT) is a global very long baseline interferometry (VLBI) network imaging supermassive black holes at horizon scales at millimetre wavelengths. In this talk, I will present an overview of the first polarised-light images of the black hole at the heart of the M87 galaxy, and the constraints they impose on the structure of the magnetic fields near the black hole. I...
Go to contribution page -
Jack Radcliffe13/09/2021, 17:00
It is now widely accepted that the evolution of galaxies and the growth of the central supermassive black hole (SMBH) are intimately connected. Those SMBH which are active (AGN) have been shown to influence the host galaxy and its evolution through various feedback mechanisms. This makes understanding the abundance of AGN within distant galaxies a cornerstone in current galaxy evolution...
Go to contribution page -
Natalia Zywucka (North-West Uniwersity)13/09/2021, 17:15
We present results of Fermi-Large Area Telescope (LAT) light curve (LC) modelling of selected blazars. All objects have densely sampled and long-term LCs. For each blazar we generated three LCs with 7, 10, and 14 days binning, using the latest 4FGL catalogue and binned analysis provided within the fermipy package. The LCs were modelled with several tools: the Fourier transformation, the...
Go to contribution page -
Joleen Barnard (University of the Free State)13/09/2021, 17:30
Blazars are a radio-loud subclass of AGN with relativistic jets closely aligned with our line of sight. The jet-emission in blazars is highly Doppler-boosted and non-thermal emission can be seen across the entire electromagnetic spectrum. These sources are highly variable across all timescales and display rapid flares across multiple wavelength bands. Blazar spectral energy distributions...
Go to contribution page -
Hester Schutte13/09/2021, 17:45
The radio through optical-UV/X-ray emission from blazars is dominated by highly polarised synchrotron emission from relativistic jet electrons. The total degree of polarisation is determined by the polarised non-thermal synchrotron emission and thermal unpolarised emission components from the dusty torus, host galaxy, emission lines from the broad line region (BLR) and accretion disk. The...
Go to contribution page -
Justin Cooper (University of the Free State)14/09/2021, 09:00
Blazars represent a subset of AGN with relativistic jets where the direction of a jet lies very close to our line of sight. The highly Doppler boosted emission from the blazar’s jet results in high apparent luminosities, and blazars display variability on periods from less than one day up to years. At optical wavelengths, the observed emission of the blazar is a superposition of the polarized...
Go to contribution page -
Patrick Reichherzer (Ruhr-University Bochum)14/09/2021, 09:15
This work provides the description of charged particle transport in magnetic fields via a correlated random walk of particles and derives a telegraph transport equation from first principles that describe the initial, ballistic, and later diffusive phases in a consistent manner. A novel high-performance numerical method based on the theoretical considerations is presented that propagates...
Go to contribution page -
93. Modellling the synchrotron emission of RMHD AGN jet simulations with the PLUTO par- ticle moduleIzak van der Westhuizen14/09/2021, 09:30
The spectral energy distribution of radio-loud AGN have a characteristic double bump structure, with emission at the lower wavelengths being dominated by synchrotron radiation from non-thermal electrons in relativistic jets. To investigate how the radio emission of these sources relate to the dynamical structure of the relativistic jets we model the synchrotron emission by using 3D hybrid...
Go to contribution page -
Natalia Zywucka (North-West Uniwersity)14/09/2021, 09:45
We present results of an optical variability study of 44 newly identified blazar candidates behind the Magellanic Clouds. The sample contains candidates for 27 flat spectrum radio quasars (FSRQs) and 17 BL Lacertae objects (BL Lacs), with nine of them recognized as blazars, while the classification of the remaining objects is still uncertain. All objects possess high photometric accuracy and...
Go to contribution page -
Joseph Omojola (University of the Witwatersrand)14/09/2021, 10:00
S5 1803+784 is a BL Lac object. Unlike most low synchrotron peaked (LSP) blazars, the spectrum of S5 1803+784 is poorly fitted with a single zone synchrotron self-Compton (SSC) leptonic jet model. This could be why recent multiwavelength studies show no clear correlation between the synchrotron emission and the gamma-ray emission in this blazar. We utilize a simple single-zone leptonic jet...
Go to contribution page -
Laenita Oberholzer (North West University)14/09/2021, 10:15
Blazars are a class of Active Galactic Nuclei (AGN) that are radio loud and have a small angle between the jet and the observer’s line of sight. In some cases, flaring events in one frequency band are not accompanied by flaring in other bands. Such events are termed orphan flares. The causes of this variabil- ity and conditions in and location of the high energy emission region are not...
Go to contribution page -
ROSA POGGIANI14/09/2021, 10:30
The third observation run (O3) of Advanced LIGO and Advanced Virgo started in April 2019 and ended in March 2020, with improved sensitivities compared to the previous observing run. The presentation will review the science results achieved during the O3 run, that include the GWTC-2, GWTC-2.1 catalogs of compact binary mergers and some exceptional events: GW190412, the merger of two black holes...
Go to contribution page -
Dr Evgeniya Kravchenko (Moscow Institute of Physics and Technology)14/09/2021, 13:30
Accreting systems in the centres of Active Galactic Nuclei (AGN) produce highly collimated relativistic jets.Magnetohydrodynamic simulations show that strong magnetic fields, twisted by the differential rotation of central black hole, play dynamically important role in these processes. Due to the dependence of the polarized radiation transfer coefficients on elementary composition and energy...
Go to contribution page -
Imogen Whittam (Oxford University)14/09/2021, 14:00
MIGHTEE is a galaxy evolution survey currently underway with the MeerKAT radio telescope. Once complete, the survey will cover 20 square degrees in four fields to a depth of 1 uJy rms/beam at 1.28 GHz, providing a unique combination of depthand breath. Crucially, the MIGHTEE fields have excellent multi-wavelength coverage, enabling a full census of galaxy properties. I will provide an overview...
Go to contribution page -
Hartmut Winkler (University of Johannesburg)14/09/2021, 14:30
We have investigated the Balmer line profile of the AGN linked to the X-ray source RXS J08182+0122. We present a low-resolution spectrum of this target that we obtained at SAAO and subsequently analysed. This AGN displays broad emission lines with a double bump profile that is characteristic of fast moving gas in a Keplerian orbit around a supermassive black hole. This source is particularly...
Go to contribution page -
Hannes Thiersen (North-West University)14/09/2021, 14:45
In this work we investigate the nature of multi-wavelength variability of blazars from a purely numerical approach. We use a time-dependent one-zone leptonic blazar emission model to simulate multi-wavelength variability by introducing stochastic parameter variations in the emission region. These stochastic parameter variations are generated by Monte Carlo methods and have a characteristic...
Go to contribution page -
Daniel Kulik (N/A)14/09/2021, 15:00
Active Galactic Nuclei (AGN) are compact regions in the centre of galaxies exhibiting higher than normal luminosity. Radio loud AGN produce relativistic jets which exhibit variability over various time-scales. This has been attributed to the formation of blob/shock structures propagating along the jet. Using relativistic magnetohydrodynamic (RMHD) simulations we investigate how blob injection...
Go to contribution page -
Indu Kalpa Dihingia (Indian Institute of Technology Indore, India)14/09/2021, 15:15
Relativistic jets and disc-winds are typically observed in BH-XRBs and AGNs. However, many physical details of jet launching and the driving of disc winds from the underlying accretion disc (AD) are still not fully understood. This study will investigate the role of different flow parameters on the launching of jets, driving disc-winds, and the dynamical properties of the disc. We will also...
Go to contribution page -
Phil Charles (University of Southampton)14/09/2021, 16:00
The last decade has seen a significant gain in both space and ground-based monitoring capabilities, producing vastly better coverage of BH X-ray binaries during their (rare) transient outbursts. This interval also included two of the 3 brightest X-ray outbursts ever observed, namely V404 Cyg in 2015, and MAXI J1820+070 in 2018, as well as Swift J1357.2-0933, the first such system to show a...
Go to contribution page -
aru beri (IISER Mohali, India)14/09/2021, 16:30
X-ray binaries are among the brightest objects of our Galaxy in the high-energy domain (0.1-100 keV). Despite a relatively good knowledge of their basic emission mechanisms, we still lack a complete understanding of their time, energy, and luminosity dependence. We will present results obtained from a detailed study of a transient Be X-ray pulsar 4U 1901+03. This source was followed by NuSTAR...
Go to contribution page -
Natalie Matchett (University of the Free State)14/09/2021, 16:45
Gamma-ray binaries are a rare subclass of high mass binary systems that display non-thermal emission peaking at energies greater than 1 MeV. All the identified systems contain an O/Oe or B/Be type star and a compact object in the mass range of a neutron star or black hole. Correctly interpreting how these sources can produce non-thermal emission, up to very high energy gamma-rays, depends on...
Go to contribution page -
Brian van Soelen (University of the Free State)14/09/2021, 17:00
Gamma-ray binaries are a rare subclass of high mass binary systems, where the non-thermal emission peaks in the gamma-ray regime. Two scenarios have been proposed to explain the production of the emission; in the pulsar wind scenario the compact object is proposed to be a rapidly rotating pulsar, and the emission originates from particle acceleration that occurs at the shock that forms between...
Go to contribution page -
Itumeleng Monageng (University of Cape Town)14/09/2021, 17:15
Be X-ray binaries, which make up the largest subclass of the high mass X-ray binary systems, comprise a neutron star in an eccentric orbit around Be star companion with a geometrically thin Keplerian disc. The interaction of the neutron star with the Be disc results in the accretion of matter leading to X-ray outbursts. The X-ray outbursts occur in two flavours: type I (or normal, with...
Go to contribution page -
Mika Naidoo (University of the Witwatersrand)15/09/2021, 13:30
Hydra A is a type I Fanaroff-Riley radio galaxy that hosts a pair of 300-kiloparsec diameter radio lobes that are being powered by one of the most of the powerful AGN outbursts known to date. Radio observations provide us with an excellent probe for the study of high-energy particles residing in the lobes. The MeerKAT radio telescope carried out observations of Hydra A, from which we obtained...
Go to contribution page -
Sayan Basu (University of the Witwatersrand)15/09/2021, 13:45
Extragalactic radio sources selected for geodetic and astrometric VLBI observations are expected to have a core-dominated point-like structure. However, it is a well-known fact that extragalactic radio sources often exhibit time- and frequency-dependent intrinsic source structure at milliarcsecond (mas) scale, making them subjects of routine monitoring. In this talk, I will present mas...
Go to contribution page -
Dr Sunil Chandra (SAAO)15/09/2021, 14:00
1ES 1959+650 is a well known HBL with its synchrotron peak lying in soft X-ray band (0.3-10.0keV). It is also observed that the peak position of synchrotron component changes significantly with the brightness state of this blazar. This source underwent first major TeV activity in 2015 after a long silence in VHE bands. We have compiled all the multi-wavelength data between 2015 to 2021...
Go to contribution page -
Kshitij Thorat15/09/2021, 14:15
The nuclei of galaxies show episodes of activity and of quiescence. Through feedback mechanisms, such episodes have significant effects on their surroundings. Radio observations can be excellent probes of such episodes, measuring time-integrated influence of the AGN jet activity. Sensitive radio observations can record faint emission associated with the previous epochs of activity, and it is...
Go to contribution page -
Markus Boettcher (North-West University)15/09/2021, 14:30
Previous work on time-dependent shock-acceleration and radiation transfer in relativistic jets has successfully reproduced many spectral variability features of blazars if flaring activity is mediated by increasingly efficient diffusive shock acceleration. However, flaring events exhibiting a significant increase of the Compton dominance, or even "orphan" gamma-ray flares, are very difficult...
Go to contribution page -
Michael Zacharias (Laboratoire Univers et Théories, Observatoire de Paris, Université PSL, CNRS, Université de Paris, 92190 Meudon, France)15/09/2021, 14:45
Blazars – active galaxies with the jet pointing at Earth – emit across all electromagnetic wavelengths. The so-called one-zone model has described well both quiescent and flaring states, however it cannot explain the radio emission. In order to self-consistently describe the entire electromagnetic spectrum, extended jet models are necessary. Notably, kinetic descriptions of extended jets can...
Go to contribution page -
Mfuphi Ntshatsha15/09/2021, 15:00
Blazars emit powerful electromagnetic (EM) radiation across all wavelengths. The broadband spectral energy distributions (SEDs) of EM emissions from these objects are characterised by two humps. The low frequency hump ranging from radio to infrared/X-ray emission is accepted as synchrotron radiation by primary leptons. The high frequency hump from X-rays to gamma-rays is attributed to...
Go to contribution page -
Tej Chand (North-West university, Centre for Space Research)15/09/2021, 15:15
The supermassive black holes in the centers of some active galaxies (AGN) eject powerful relativistic jets which propagate over kpc scales, showing no significant momentum loss. Both observational evidence as well as theoretical considerations from MHD simulations of jets suggests that they are radially stratified, with a fast inner spine surrounded by a slower-moving outer sheath. The...
Go to contribution page -
Andrzej Zdziarski15/09/2021, 16:00
I will review our current knowledge about three well-studied jets in X-ray binaries, MAXI J1820+070, Cyg X-1, and Cyg X-3. The first two accrete from their donors onto black holes, while this is likely but not certain in Cyg X-3. Thanks to an extensive multi-wavelength campaign during the recent outburst of MAXI J1820+070, the structure of its compact jet emitting in radio to optical...
Go to contribution page -
Denis Leahy (University Of Calgary)15/09/2021, 16:30
Her X-1 is an accreting X-ray binary with well-determined properties based on measurements of light- curves and spectra since its discovery in 1972. Since discovery, it has been observed with most major X-ray astronomy instruments. Observations of Her X-1 over the past decade include those from AstroSat, Swift, and MAXI. These have added to the range of phenomena detected from this system. The...
Go to contribution page -
Kelebogile Bonokwane (University of Cape Town)15/09/2021, 16:45
X-ray binaries (XRBs) comprise of compact objects, black hole or a neutron star, and a companion (donor) star. Depending on the mass of the companion, the XRB is classified as low-mass (Mdonor < 1 M⊙) or high-mass (Mdonor > ∼ 8 M⊙). SAX J1808.4–3658 is a low-mass neutron star XRB, the first accreting millisecond pulsar (AMXP) known. The pulsar was confirmed with the detection of 401 Hz...
Go to contribution page -
Henric Krawczynski (Washington University)15/09/2021, 17:00
The Imaging X-ray Polarimetry Explorer (IXPE), scheduled for launch in Fall 2021, will open up the window of X-ray polarimetry. IXPE will be joined by XL-Calibur in 2022, adding 15-75 keV polarimetric capabilities to IXPE’s 2-8 keV coverage.The exciting science topics that can be addressed with IXPE include observations of stellar mass black holes and observations of magnetars. I will report...
Go to contribution page -
Lente Dreyer (North-West University)15/09/2021, 17:30
The spectral energy distributions (SEDs) of some blazars exhibit an ultraviolet (UV) and/or soft Xray excess, which can be modelled with different radiation mechanisms. Polarization measurements of the UV/X-ray emission from blazars may provide new and unique information about the astrophysical environment of blazar jets and could thus help to distinguish between different emission scenarios....
Go to contribution page -
Maria Petropoulou (National & Kapodistrian University of Athens)16/09/2021, 13:30
Active galactic nuclei (AGN) with relativistic jets, powered by mass accretion onto the central supermassive black hole of their host galaxies, are the most powerful persistent sources of broadband electromagnetic radiation in the Universe. Despite decades of multi-wavelength observations, there are still several key questions about AGN jet physics that remain open, such as "What is the plasma...
Go to contribution page -
Soebur Razzaque (University of Johannesburg)16/09/2021, 14:00
Blazars are potential candidates of cosmic-ray (CR) acceleration up to ultrahigh energies (UHE, E > 1017 eV). Association of a number of blazars with IceCube neutrino events supports this hypothesis. If the intergalactic magnetic field strength is reasonably low, the UHECRs escaping from the blazar jet will produce neutrinos and gamma rays along the line-of-sight (LoS) by interacting with the...
Go to contribution page -
Pieter Van der Merwe (North-West University)16/09/2021, 14:15
In 2015 the advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) detected the first ever gravitational event, gravitational wave event GW150914, with multiple new gravitational wave events, originating from both binary neutron stars and binary black hole (BBH) mergers, detected in subsequent years. In light of these detections, we simulate the dynamics of ambient test particles...
Go to contribution page -
Lutendo Nyadzani (University of Johannesburg)16/09/2021, 14:30
Ultraluminous X-ray sources (ULXs) were first discovered in the 1980s by the Einstein Observatory. The most interesting property of ULXs is that they exceed the Eddington luminosity of a neutron star. Data from the 2XMM-Newton and Chandra contain 470 ULX candidates in 238 galaxies (Walton et al. 2011) and 629 ULX candidates in 309 galaxies (Kovlakas et al. 2020), respectively. In this study,...
Go to contribution page -
Geoff Beck (University of the Witwatersrand)16/09/2021, 14:45
Emerging anomalies in both di and multi-lepton data from the LHC have been used to motivate for an extension to the Standard Model in the form of a second Higgs doublet and a singlet scalar (2HDM+S). Here we explore a dark matter candidate drawn from this model: a scalar particle that couples to the Standard Model through the 2HDM+S degrees of freedom. Using the best-fit 2HDM+S model from LHC...
Go to contribution page -
Michael Kreter16/09/2021, 15:00
Blazars are powered by super-massive black holes in their centers and are known for extreme variability on time scales from minutes to years. In case of a binary black hole system, this duality is traceable as periodic modulation of their gamma-ray emission. So far, high-significance periodicity has been reported for a very few blazars with standard approaches. We developed a method to search...
Go to contribution page -
Hambeleleni Davids (University of Namibia, North-West University)16/09/2021, 16:00
At present, only a single Globular Cluster (GC) has plausibly been detected at very high energies (VHEs) by H.E.S.S. The future CTA is expected to detect more GCs in this band. We present results from an emission code that assumes millisecond pulsars (MSPs) to be sources of relativistic particles diffusing through GCs that will give broad-band radiation due to their interaction with the...
Go to contribution page -
Anu Kundu (NWU)16/09/2021, 16:25
The Neutron star Interior Composition Explorer (NICER) was installed aboard the International Space Station (ISS) in 2017 with the major aim of gaining a better understanding of the extreme nature and composition of neutron stars (NSs). With its exceptional sensitivity, it hopes to constrain the equation of state for these compact objects to high precision. Modelling thermal X-ray light curves...
Go to contribution page -
Louis Du Plessis (Centre for Space Physics, North-West University)16/09/2021, 16:40
Marsh et al. detected radio and optical pulsations from the binary system AR Scorpii (AR Sco). This system, with an orbital period of 3.55 h, is composed of a cool, low-mass star and a white dwarf (WD) with a spin period of 1.95 min. Takata et al. also detected X-ray pulsations from this source. These observations indicate no presence of an accretion disk or column. Buckley et al. found that...
Go to contribution page -
Quinton Kaplan (University of the Free State)16/09/2021, 16:55
Previous studies indicate that AR Sco’s surrounding region complicates the search for Gamma-ray emission from this source. The fact that AR Sco lies close to the Galactic plane and strong nearby VHE Fermi sources, make it difficult to constrain and quantify an upper-limit of the emission from AR Sco’s location in the sky. In this study, a search for high energy gamma-ray emission was...
Go to contribution page -
Spencer Tendai Madzime (University of the Free State)16/09/2021, 17:10
Here we present the first report of pulsed emission at the spin period of the white dwarf in MeerKAT data, which is also the first report of pulsed emission at the spin period of the white dwarf in radio frequencies (L-band). Further support for the pulsar-like behaviour of AE Aqr is the detection of pulsed emission at the spin period of the white dwarf in AE Aqr in Fermi-LAT data. By...
Go to contribution page -
Alice Harding (Los Alamos National Laboratory)16/09/2021, 17:25
Ground-based Air-Cherenkov telescopes have detected pulsations at energies above 50 GeV from a growing number of Fermi pulsars. These include the Crab, Vela, PSR B1706-44 and Geminga, with the first two having pulsed detections above 1 TeV. There appears to be VHE emission that is an extension of the Fermi spectra to high energies as well as additional higher-energy components that require a...
Go to contribution page -
Hannah Dalgleish (University of Oxford)17/09/2021, 13:30Pulsars, Other High-Energy Sources and OutreachInvited talk
Astronomy for development is making great strides in Namibia. Forged by a collaboration between the Universities of Oxford and Namibia, together we are using astronomy as a means for capacity-building and to benefit Namibia socio-economically. Namibia is already recognised as a world leader in sustainable tourism; astronomy offers great potential to expand and diversify the market with minimal...
Go to contribution page -
Iurii Sushch (North-West University)17/09/2021, 14:00Pulsars, Other High-Energy Sources and OutreachContributed talk
The very-high-energy (VHE; E>100 GeV) gamma-ray emission observed from a number of Supernova rem- nants (SNRs) suggests that particles are accelerated to high energies at the shock of the remnants. However, it is extremely difficult to determine which particles are responsible for this emission as both protons (through hadronic interactions and subsequent pion decay) and electrons (through...
Go to contribution page -
Christo Venter (North-West University Potchefstroom Campus)17/09/2021, 14:15Pulsars, Other High-Energy Sources and OutreachContributed talk
Being less than a thousand years old, Kes 75 (G29.7-0.3) represents one of the youngest composite supernova remnants in the Milky Way. It contains the nebula of PSR J1846-0258, a glitching young pulsar with a particularly high spin-down luminosity of 8e36 erg/s. This pulsar has furthermore manifested magnetar-like bursts in 2006. The H.E.S.S. Collaboration detected gamma-ray emission from HESS...
Go to contribution page -
Dimakatso Maheso (University of Johannesburg)17/09/2021, 14:30Pulsars, Other High-Energy Sources and OutreachContributed talk
Gamma-ray bursts (GRB’s) are highly energetic impulses of γ−rays that are categorised into two major categories, namely long and short GRBs. Their distinction lies in their duration, the former lasts for more than 2 s whilst the latter lasts for less than 2 s. Their prompt emission has an energy range of keV to GeV energy band. On the 10th of April 2021, the \emph{Fermi} Large Area Telescope...
Go to contribution page -
Zorawar Wadiasingh (NASA GSFC)17/09/2021, 14:45Pulsars, Other High-Energy Sources and OutreachContributed talk
I will briefly introduce fast radio bursts and highlight recent developments of the field from a theorist’s perspective, as well as exciting observational developments presented at FRB 2021. I will also discuss the low-twist magnetar model for FRBs.
Go to contribution page -
Hend Yassin (North-West University)17/09/2021, 15:00Pulsars, Other High-Energy Sources and OutreachContributed talk
The number of detected gamma-ray millisecond pulsars (MSPs) has been increasing rapidly since the launch of the Fermi Large Area Telescope (LAT) in 2008. The Third Fermi LAT Pulsar Catalogue (3PC) will present high-quality data for about 250 gamma-ray pulsars based on 11 years of observation. Out of that number, more than 100 are MSPs. The stability of MSPs light curves makes them interesting...
Go to contribution page -
Anton dmytriiev (Observatoire de Paris)17/09/2021, 15:15Pulsars, Other High-Energy Sources and OutreachContributed talk
Despite the growing amount of observational data, the physical conditions in the vicinity of supermassive black holes (SMBH) are still poorly understood. Thanks to its proximity, Sgr A*, being the SMBH located in the center of our Galaxy, represents an ideal target to probe physical processes in the surroundings of massive compact objects, including details of accretion/advection flows,...
Go to contribution page -
Ronald Remillard (Massachusetts Institute of Technology)17/09/2021, 16:00
The Neutron Star Interior Composition Explorer (NICER) began science operations from the International Space Station in 2017 July, conducting observations in X-rays (0.4-12 keV) with sub-microsecond time resolution. Accomplishments to date are briefly reviewed for several types of sources. Pulse profiles for rotation-powered millisecond pulsars are modeled to constrain the equation of state of...
Go to contribution page -
Soebur Razzaque (University of Johannesburg), Markus Boettcher (North-West University)17/09/2021, 16:30
-
Justine Tarrant (WITS)
Useful to LIGO detections would be an electromagnetic signal which heralds the start of a binary black hole inspiral. Primarily, this would also aid in multi-messenger follow-up studies. We look to the potential presence of an accretion disk as a source of emissions. We consider this problem by computing geodesics numerically from an approximate, analytic metric to determine the amount of...
Go to contribution page
Choose timezone
Your profile timezone: