Ultra-high-energy (UHE) cosmic neutrinos, with energies above 100 PeV, could be finally discovered in the near future. Measuring their flavor composition would reveal information about their production and propagation, but new techniques are needed for UHE neutrino telescopes to have the capabilities to do it.
In this talk I will introduce a new way to measure the UHE neutrino flavor...
One of the most interesting open questions in high-energy astrophysics concerns the origin of ultra-high energy cosmic rays: during their propagation, these charged particles are deflected by extragalactic and Galactic magnetic fields and, as a result, their arrival directions do not point directly to their sources, making their correlation with possible sources non-trivial to...
Measurement of the intracluster medium (ICM) in X-ray is being carried out with ever increasing influx of data from telescopes like Chandra, eROSITA, XRISM, XMM-Newton. The data we obtain from these telescopes is generally incomplete, uncertain (noisy) and convolved with complex instrument responses. Reconstructing multi-domain (spatial, spectral and temperature for example) images of the...
Astrophysical shocks play an important role a variety of processes such as supernovae, novae, and gamma-ray bursts. A shock-capturing radiation hydrodynamics scheme based on the Euler equations is developed for simulating the dynamics of gas in astrophysical systems. The scheme's validity is demonstrated by various test cases and comparison to analytically derived solutions. Since recent...
We present shell events of 4$\pi$-3D non-rotating 12.28 M$_{\odot}$ and 12.98 M$_{\odot}$ supernova progenitors simulated for a period of one-hour before core-collapse. The main interest is to study the interior shell properties (from the kinematic, thermodynamic to the chemical evolution) and their interactions for a period of one-hour before collapse. The high-resolution of these models as...
Cosmic rays (CRs) can be accelerated in voilent and magnetised astrophysical environment. Those with the highest energyies, up to 10^20 eV are likely associated with star-formation in galaxies and active galactic nuclei activities. Cosmological filaments connect these acceleration sites of CRs, as well as with voids. Due to hadronic pion-producing and photo-pair interactions, and entrainment...
We simulate the evolution of the helicity of relic neutrinos as they propagate to Earth
through a realistic model of the Galactic magnetic field, improving upon the rough estimates in
the literature. For magnetic moments consistent with experimental bounds and several orders of
magnitude smaller, we confirm that the helicity of relic neutrinos and anti-neutrinos rotates so
much that the...
Radio emissions of extensive air showers can be observed at the Pierre Auger Observatory with the AugerPrime radio detector (RD). As part of the AugerPrime upgrade, RD is being installed on $1660$ water-Cherenkov detectors on an area of about $3000 \text{ km}^2$ and consists of dual-polarized Short Aperiodic Loaded Loop Antennas (SALLA). To achieve high measurement precision, RD needs to be...
The Pierre Auger Observatory has detected downward terrestrial gamma-ray flashes (TGFs) with its Surface Detector. A key to understanding this high-energy radiation in thunderstorms is to combine such measurements with measurements of lightning processes in their earliest stages. With eleven modified Auger Engineering Radio Array (AERA) stations we can build an interferometric lightning...
Previous efforts at the Pierre Auger Observatory have shown that lightning related phenomena can be picked up by, and affect, each of its detector systems. Therefore as part of its monitoring, a system has been rolled out to detect thunderstorm conditions, enabling the investigation of thunderstorms and lightning using the Observatory’s hybrid detectors.
As a successful testbed for air...
The IceCube Neutrino Observatory is a cubic kilometer detector built into the Antarctic ice at the geographic south pole. By means of Cherenkov photon detection, the observatory detects charged secondaries that are emitted as a consequence of astrophysical neutrinos interacting with the ice. As a result of IceCube's successes, the next generation of the observatory, IceCube-Gen2, is foreseen...
The northern track event selection utilizes the event topology in the IceCube to select track-like up-going events, which are produced by high-energy muons induced by muon-neutrinos which penetrated the Earth and reach the detector from the Northern sky. The Efficiency of the selection is limited by the quality of event reconstructions, which might misidentify down-going muon tracks as...
The IceCube collaboration has recently found evidence for connecting the blazar TXS 0506+056 to high-energy neutrino events. Several other studies have independently investigated the hypothesis of blazars and specific subclasses thereof as neutrino emitters with mixed results, including constraints on the contribution of these sources to the observed astrophysical neutrino flux. As such, open...
Blazars are a unique subclass of active galactic nuclei (AGN) characterised by their relativistic jets oriented towards Earth. This study focuses on the blazar PKS 2155-304, a high synchrotron-peaked BL Lac object located at a redshift of z = 0.116. We utilised multiwavelength observations, ranging from optical to gamma-ray, primarily from the Fermi Large Area Telescope (LAT) and the Swift...
Astrospheres are bullet-shaped structures resulting from the relative motion through the interstellar medium and comprise of three distinct features: a termination shock, astropause, and a bow shock. This work investigates the astrosphere of λ Cephei. λ Cephei is a bright runaway star. Previous 3D magnetohydrodynamic (MHD) simulations by Baalmann et al. (2021) showed the position of the...
In addition to its capabilities for precise measurement of ultra-high-energy (UHE, $E > 10^{17}\:\mathrm{eV}$) cosmic rays with the observation of extensive air showers, the Pierre Auger Observatory also encompasses the potential of effectively detecting UHE photons. These are closely connected to the origin or propagation of hadronic cosmic rays. Moreover, such UHE photons are also theorized...
The winding angle of the heliospheric magnetic field (HMF) is investigated by analyzing approximately 60 years of in situ spacecraft observations of the solar wind and the HMF at Earth. Yearly averages of the winding angle of the Low-Resolution OMNI (LRO) dataset, hosted on the NASA OMNIWeb website, are calculated taking into consideration the sector structure of the magnetic field...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a proposed next-generation water-Cherenkov gamma-ray observatory in the Southern Hemisphere, thus being complementary to other water-Cherenkov detectors like HAWC (Mexico) and LHAASO (China), which are both located in the Northern Hemisphere.
One of the primary challenges of the water-Cherenkov technique, is the effective discrimination...
The Imaging X-ray Polarimetry Explorer (IXPE) is the state-of-the-art of astrophysical X-ray polarimetry. Launched on 9 December 2021, IXPE is the product of a collaboration between NASA and ASI. It can measure the linear polarization of different astrophysical sources over the photon energy range 2-8 keV. Polarization can provide a new observable to get information about the geometry both of...
The last decade has seen tremendous advances in astroparticle physics and neutrino detection. The IceCube neutrino observatory has successfully measured the cosmic neutrino flux and identified several new sources. The next generation of neutrino telescopes aim at even more energetic neutrinos in the EeV range. In-ice radio detection is a promising approach to tap into the rapidly decreasing...
Radio detection of cosmic rays has not only been shown to be complementary to classical detection methods but also advantageous as the full shower profile can be extracted, which in turn can provide more physical knowledge about the air shower than already known today. However, the full reconstruction of the profile requires an efficient 4-D imaging algorithm due to the strong spatial and...
Extensive air showers (EAS), created from interactions of highly energetic cosmic particles with the atmosphere, produce radio emission via the geomagnetic and Askaryan effect. These radio signals provide valuable information about the properties of the primary particle that started the air shower. Dense radio detector arrays such as LOFAR and the future SKA-low allow high-precision...
Very high energy gamma-rays induce an air-shower in our atmosphere. These particles, traveling faster than light in the medium, emit Cherenkov light. Using Cherenkov telescopes, this radiation can be measured and properties such as energy or direction from the primary gamma-ray can be deducted. A proposed camera for such a telescope is FlashCam. In this talk, FlashCam and the tests we want to...
The Imaging X-ray Polarimetry Explorer (IXPE) is the state-of-the-art of astrophysical X-ray polarimetry. Launched on 9 December 2021, IXPE is the product of a collaboration between NASA and ASI. It can measure the linear polarization of different astrophysical sources over the photon energy range 2-8 keV. Polarization can provide a new observable to get information about the geometry both of...
The IceCube Neutrino Observatory has detected neutrino emission from the active galactic nuclei (AGNs) NGC 1068 and TXS 0506+056. While there has been a general consensus regarding the neutrino emission region in Seyfert galaxy NGC 1068, there has been an ongoing debate regarding the neutrino emission region in the blazar TXS 0506+056. This presentation aims to address this debate by arguing...
The Southern Wide-field Gamma-ray Observatory (SWGO) is an upcoming ground-based gamma-ray detector. It will consist of double-layered water tanks covering a square kilometer area at a high altitude in South America. Such a detector will be subject to constant bombardment with cosmic rays causing a high data rate in the readout electronics. To limit the readout data rate while maintaining a...
