A5082109338- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Advanced Vision and Imaging
- Hydrocarbon exploration and reservoir analysis
- Neutrino Physics Research
- Geochemistry and Geologic Mapping
- Advanced X-ray and CT Imaging
- Astrophysical Phenomena and Observations
- Image Processing Techniques and Applications
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Generative Adversarial Networks and Image Synthesis
- Cosmology and Gravitation Theories
- Satellite Image Processing and Photogrammetry
- Advanced Image Processing Techniques
HES-SO University of Applied Sciences and Arts Western Switzerland
2023
Universität Hamburg
2016-2021
FHNW University of Applied Sciences and Arts
2021
Hamburger Fern-Hochschule
2016-2018
The repeating fast radio burst source FRB 121102 has been shown to have an exceptionally high and variable Faraday rotation measure (RM), which must be imparted within its host galaxy likely by or local environment. In the redshifted ($z=0.193$) reference frame, RM decreased from $1.46\times10^5$~rad~m$^{-2}$ $1.33\times10^5$~rad~m$^{-2}$ between January August 2017, showing day-timescale variations of $\sim200$~rad~m$^{-2}$. Here we present sixteen RMs detections with Arecibo 305-m...
In this white paper we introduce the IMAGINE Consortium and its scientific background, goals structure. Our purpose is to coordinate facilitate efforts of a diverse group researchers in broad areas interstellar medium, Galactic magnetic fields cosmic rays, our goal develop more comprehensive insights into structures roles their interactions with rays. To achieve higher level self-consistency, depth rigour can only be achieved by coordinated experts astrophysics involved observational,...
We simulate the propagation of cosmic rays at ultra-high energies, $\gtrsim 10^{18}$ eV, in models extragalactic magnetic fields constrained simulations local Universe. use initial conditions with cosmological magnetohydrodynamics code {\sc ENZO}. The resulting distribution Universe are used \crpropa to energy rays. investigate impact six different magneto-genesis scenarios, both primordial and astrophysical, on over distances. Moreover, we study influence source distributions around Milky...
The origin of extragalactic magnetic fields is still poorly understood. Based on a dedicated suite cosmological magneto-hydrodynamical simulations with the ENZO code we have performed survey different models that may caused present-day in galaxies and galaxy clusters. outcomes these differ cluster outskirts, filaments, sheets voids use to find observational signatures magnetogenesis. With simulations, predict signal radio observations synchrotron emission from cosmic web, Faraday Rotation,...
We use the crpropa code to simulate propagation of ultrahigh energy cosmic rays (with ≥1018eV and pure proton composition) through extragalactic magnetic fields that have been simulated with cosmological enzo code. test both primordial astrophysical magnetogenesis scenarios in order investigate impact different field strengths clusters, filaments voids on deflection propagating across distances. also study effect source distributions around Milky Way-like observers. Our analysis shows...
We investigate the possibility of measuring intergalactic magnetic fields using dispersion measures and rotation fast radio bursts. With Bayesian methods, we produce probability density functions for values these measures. distinguish between contributions from medium, host galaxy local environment progenitor. To this end, use constrained, magnetohydrodynamic simulations Universe to compute lines-of-sight integrals position Milky Way. In particular, differentiate predominantly astrophysical...
The detection of the radio signal from filaments in cosmic web is crucial to distinguish possible magnetogenesis scenarios. We review status different attempts detect at wavelengths. This put into context advanced simulations magnetism carried out last few years by our MAGCOW project. While first imaging with MWA and LOFAR have been encouraging could discard some models, complexity behind such observations makes a definitive answer still uncertain. A combination total intensity polarimetric...
Context: Fast Radio Bursts are transient radio pulses from presumably compact stellar sources of extragalactic origin. With new telescopes detecting multiple events per day, statistical methods required in order to interpret observations and make inferences regarding astrophysical cosmological questions. Purpose: We present a method that uses probability estimates fast burst observables obtain likelihood for the underlying models. Method: Considering models all regions along line-of-sight,...
A major problem with deep generative models is verifying that the generated distribution resembles target while individual sample indistinguishable from original data. In particular, for application in astrophysics we need to be sure data matches our prior knowledge and samples entail all object types correct frequency diversity. We currently lack objective ways systematically assess these quality aspects, where human inspection reaches its limits, as this requires detailed analysis of a...
For the luck of humanity, there are way less big solar flares than small ones. Even if these good news, this makes it challenging to train machine learning algorithms able model activity. As a result, monitoring applications, including flare forecasting, suffer from lack input data. To overcome issue, generative deep models can be utilised produce synthetic images representing activity and thus compensating rarity events. This study aims develop method that generate Sun with ability include...
Given the rarity of significant solar flares compared to smaller ones, training effective machine learning models for activity forecasting is challenging due insufficient data. This study proposes using generative deep models, specifically a Denoising Diffusion Probabilistic Model (DDPM), create synthetic images phenomena, including varying intensities. By employing dataset from AIA instrument aboard SDO spacecraft, focusing on 171 {\AA} band that captures various activities, and classifying...
Investigating the solar magnetic field is crucial to understand physical processes in interior as well their effects on interplanetary environment. We introduce a novel method predict evolution of line-of-sight (LoS) magnetogram using image-to-image translation with Denoising Diffusion Probabilistic Models (DDPMs). Our approach combines "computer science metrics" for image quality and "physics accuracy evaluate model performance. The results indicate that DDPMs are effective maintaining...
Context: Fast radio bursts are transient pulses of extragalactic origin. Their dispersion measure is indicative the baryon content in ionized intergalactic medium between source and observer. However, inference using unlocalized fast degenerate to distribution redshifts host galaxies. Method: We perform a joint burst redshift with use Bayesian statistics by comparing likelihood different models reproduce observed order infer most likely models. In addition two medium, we consider...
We simulate the propagation of cosmic rays at ultra-high energies, $\gtrsim 10^{18}$ eV, in models extragalactic magnetic fields constrained simulations local Universe. investigate impact different magneto-genesis scenarios, both, primordial and astrophysical, on rays. Our study shows that scenarios do not have a large anisotropy measurements. The distribution nearby sources causes very high independent field model. compare our results to dipole signal measured by Pierre Auger Observatory....
A major problem with deep generative models is verifying that the generated distribution resembles target while individual sample indistinguishable from original data. In particular, for application in astrophysics we need to be sure data matches our prior knowledge and samples entail all object types correct frequency diversity. We currently lack objective ways systematically assess these quality aspects, where human inspection reaches its limits. order identify reasonable metrics generator...
The detection of the radio signal from filaments in cosmic web is crucial to distinguish possible magnetogenesis scenarios. We review status different attempts detect at wavelengths. This put into context advanced simulations magnetism carried out last few years by our {\magcow} project. While first imaging with MWA and LOFAR have been encouraging could discard some models, complexity behind such observations makes a definitive answer still uncertain. A combination total intensity...