Markus Boettcher
A5011189362- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Cosmology and Gravitation Theories
- Magnetic confinement fusion research
- Computational Physics and Python Applications
- Astro and Planetary Science
- Relativity and Gravitational Theory
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Ionosphere and magnetosphere dynamics
North-West University
2013-2024
Astronomical Observatory of Rome
2022
Agenzia Spaziale Italiana
2022
Rice University
1997-2020
Universitat de Barcelona
2020
University of Udine
2019
Universität Innsbruck
2019
Universities Space Research Association
2019
Goddard Space Flight Center
2019
University of Würzburg
2019
(Abridged) We have conducted a detailed investigation of the broad-band spectral properties \gamma-ray selected blazars Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months LBAS data taking period, we were able to assemble high-quality quasi-simultaneous Spectral Energy Distributions (SED) for 48 blazars.The SED these sources is similar that...
Abstract The unification of quantum mechanics and general relativity has long been elusive. Only recently have empirical predictions various possible theories gravity put to test, where a clear signal properties is still missing. dawn multi-messenger high-energy astrophysics tremendously beneficial, as it allows us study particles with much higher energies travelling longer distances than in terrestrial experiments, but more progress needed on several fronts. A thorough appraisal current...
We report on the multi-wavelength observations of PKS 1510-089 (a flat spectrum radio quasar (FSRQ) at z = 0.361) during its high activity period between 2008 September and 2009 June. During this 11 month period, source was characterized by a complex variability optical, UV, γ-ray bands, timescales down to 6–12 hr. The brightest isotropic luminosity, recorded March 26, ≃2 × 1048 erg s−1. in Fermi Large Area Telescope energy range shows mild curvature described well log-parabolic law, can be...
Abstract The measurement of the flux muons produced in cosmic ray air showers is essential for study primary rays. Such measurements are important extensive shower detectors to assess energy spectrum and chemical composition flux, complementary information provided by fluorescence detectors. Detailed simulations carried out, using codes such as CORSIKA, estimate muon at sea level. These based on choice hadronic interaction models, which improvements have been implemented post-LHC era. In...
Aims. TXS 0506+056 was the first active galactic nucleus to be identified as a convincing counterpart of an extremely high-energy neutrino, IceCube-170922A. Prior this, IceCube data revealed evidence enhanced neutrino activity in 2014–2015 from direction same source. Renewed confirmed by Baikal-GVD on April 18, 2021, and another detection September 2022. We revisited this blazar study its evolution light new data. Methods. reanalyzed VLBA observed at 8 GHz between 2010 2019, well 15 2019...
The results of the first extragalactic gamma-ray survey by High Energy Stereoscopic System (H.E.S.S.) are presented. comprises 2720 hours very high-energy observations sky, recorded with H.E.S.S. from 2004 up to end 2012. These data have been re-analysed using a common consistent set up-to-date calibration and analysis tools. From this analysis, list 23 detected objects, predominantly blazars, was obtained. This catalogue assessed in terms source class populations that it contains. level...
Using particle-in-cell simulations, we study the kinetic physics of relativistic shear flow in collisionless electron–positron (e+e−) plasmas. We find efficient magnetic field generation and particle energization at boundary, driven by streaming instabilities across interface sustained flow. Nonthermal, anisotropic high-energy particles are accelerated lines to produce a power-law tail turning over just below Lorentz factor. These results have important implications for dissipation radiation...
In this review, recent progress in theoretical models for blazar emission will be summarized. The salient features of both leptonic and lepto-hadronic approaches to modeling spectral energy distributions reviewed. I present sample results (SEDs) different types blazars along the sequence, including Fermi high-energy gamma-ray data, using models. Special emphasis placed on implications very-high-energy (VHE) detections non-traditional VHE blazars, intermediate low-frequency-peaked BL Lac...
The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array will be composed of nine imaging atmospheric Cherenkov telescopes at the Observatorio del Teide site. array best suited for astrophysical observations in 0.3–200 TeV range with an angular resolution few arc-minutes and energy 10-15%. A core-science programme first four years devoted to limited number key targets, addressing most important open scientific questions very-high domain. At same time, thanks wide field...
In this study, we use a one-zone leptonic and lepto-hadronic model to investigate the multi-wavelength emission prominent flare of flat spectrum radio quasar 3C 454.3 in Nov 2010. We perform parameter study with both models obtain broadband fits spectral energy distribution 454.3. Starting baseline parameters obtained from fits, then different flaring scenarios for explain an extreme outburst hardening that occurred find one zone can successfully light curves optical R, Swift XRT Fermi...
A bstract In the era of precision measurements neutrino oscillation parameters, upcoming experiments will also be sensitive to physics beyond Standard Model. KM3NeT/ORCA is a detector optimised for measuring atmospheric neutrinos from few GeV around 100 GeV. this paper, sensitivity decay has been explored. three-flavour scenario, where third mass state ν 3 decays into an invisible state, e.g. sterile neutrino, considered. We find that would with 1 /α = τ /m < 180 ps / eV at 90% confidence...
We present particle-in-cell simulation results of relativistic shear flows for hybrid positron–electron–ion plasmas and compare to those pure e+e− e− ion plasmas. Among the three types flows, we find that only flow is able energize electrons form a high-energy spectral peak plus hard power law tail. Such electron spectra are needed model observational properties gamma-ray bursts.
Extreme blazars have exceptionally hard intrinsic X-ray/TeV spectra and extreme peak energies in their spectral energy distribution (SED). Observational evidence suggests that the non-thermal emission from is typically non-variable. We aim to explore X-ray GeV observational features of a variety also test applicability various blazar models could explain very TeV spectra. perform analysis AstroSat Swift-XRT data, along with gamma-ray data Fermi-LAT, for sources; 1ES 0120+340, RGB J0710+591,...
This white paper highlights compact object and fundamental physics science opportunities afforded by high-throughput broadband (0.1-60 keV) X-ray polarization observations. polarimetry gives new observables with geometric information about stellar remnants which are many orders of magnitude too small for direct imaging. The polarimetric data also reveal details the emission mechanisms structure magnetic fields in around most extreme objects Universe. Whereas Imaging Polarimetry Explorer...
Abstract The Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in fields of $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -ray astronomy, respectively. Possible simultaneous production rays neutrinos astrophysical accelerators cosmic-ray nuclei motivates a combination their data. We assess potential combined analysis CTA data to determine contribution hadronic emission processes known Galactic...
Abstract The KM3NeT neutrino telescope is currently being deployed at two different sites in the Mediterranean Sea. First searches for astrophysical neutrinos have been performed using data taken with partial detector configuration already operation. paper presents results of independent from compact binary mergers detected during third observing run LIGO and Virgo gravitational wave interferometers. first search looks a global increase counting rates that could be associated inverse beta...
Gamma-ray bursts are promising candidate sources of high-energy astrophysical neutrinos. The recent GRB 221009A event, identified as the brightest gamma-ray burst ever detected, provides a unique opportunity to investigate hadronic emissions involving KM3NeT undersea neutrino detectors participated in worldwide follow-up effort triggered by searching for events. In this letter, we summarize subsequent searches, wide energy range from MeV up few PeVs. No events found any searches performed....
The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of Mediterranean Sea, consisting two telescopes, both composed a three-dimensional array light detectors, known as digital optical modules. Each module contains set 31 three-inch photomultiplier tubes distributed over surface 0.44 m diameter pressure-resistant glass sphere. also includes calibration instruments and electronics for power, readout, data acquisition. power board was developed to supply all...