ECAP Seminar: Kavitha Arur, University of Maryland / NASA
2026-06-02 15:00 - 16:00 (Europe/Berlin) | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Introduction to and Science highlights from the Imaging X-ray Polarimetry Explorer
The Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer Mission resulting from the collaboration of NASA Marshall Space Flight Center, the Italian Space Agency and other partners. IXPE has been successfully performing science operations since January 2022. IXPE provides unique and powerful X-ray polarization capabilities and has been providing crucial insights into our understanding of X-ray production and the geometry of several objects such as neutron stars and pulsar wind nebulae, as well as stellar and supermassive black holes, among others. In this talk, I will give an overview of the mission, science highlights from IXPE, and upcoming opportunities to get involved.

ECAP Seminar: Ernst-Jan Buis, Nikhef
2026-05-28 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Fiber optic hydrophones for acoustic neutrino detection
The scientific potential for detecting cosmic neutrinos with energies at or above the GZK cut-off—the energy limit for cosmic rays due to interactions with the cosmic microwave background—has been extensively discussed in the literature. The recent observation of a very high-energy event by the KM3NeT telescope has further fueled this discussion, as it may represent the first detection of a GZK neutrino. However, despite this remarkable result, the extremely low expected flux of ultra-high-energy neutrinos (Eν > 10^18 eV) clearly indicates that their detection will require a telescope with an effective volume exceeding 100 km^3. Acoustic detection offers a promising approach for observing these ultra-high energy cosmic neutrinos. The sound waves generated by their energy deposition in the deep sea can propagate over many kilometers with little attenuation, making it feasible to instrument a vast volume of water for neutrino detection. Achieving this requires the development of acoustic detection technologies capable of supporting a large-scale, deep-sea sensor network. Fiber-optic hydrophone technology stands out as a promising candidate for such a network, combining the necessary sensitivity to detect the faint acoustic signals from neutrino interactions with the potential for cost-effective large-scale deployment. Nikhef is actively developing this fiber-optic hydrophone technology to meet the sensitivity and operational requirements of deep-sea environments. In this presentation, I will report on the progress of the hydrophone development and outline the plans toward a future acoustic neutrino telescope — opening a window to explore the universe beyond the GZK horizon.

ECAP Seminar: Tanguy Pierog, KIT
2026-04-30 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
EPOS LHC-R : a global approach to solve the muon puzzle
The hadron production in the simulation of extensive air showers is a long standing problem and the origin of large uncertainties in the reconstruction of the mass of the high energy primary cosmic rays. Hadronic interaction models re-tuned after early LHC data give more consistent results among each other compared to the first generation of models, but still can’t reproduce extended air shower data (EAS) consistently resulting in the so-called “muon puzzle”. Using more recent LHC data like in the QGSJET-III model improve further the description of EAS by such a model but is not enough to resolve the discrepancy. On the other hand, the EPOS project is a theoretical global approach aiming at describing data from very fundamental electron-positron interactions to central heavy ions collisions. We will demonstrate that this approach can provide new constraints, changing the correlation between the measured data at mid-rapidity and the predicted particle production at large rapidities, which drive the EAS development. Thus, using the same accelerator data, different predictions are obtained in air shower simulations in much better agreement with the current air shower data (for both the maximum shower development depth Xmax and the energy spectrum of the muons at ground). Using the EPOS LHC-R model, the detailed changes will be addressed and their consequences on EAS observable at various energies.

ECAP Seminar: Matthias Danninger, Simon Fraser University
2026-04-16 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
The Pacific Ocean Neutrino Experiment

Every time researchers have pushed the energy boundary in particle physics we have found something new about our Universe. Recently, IceCube has demonstrated that Neutrino Telescopes can use neutrinos from the cosmos as excellent tools to continue this exploration. To unlock the true potential of this field, advanced detectors are needed that will push the forefront of the cosmic frontier, revealing new knowledge of extreme astrophysical phenomena, including through multi-messenger follow-up programs, and testing fundamental physics at scales well beyond those reachable by Earth-bound accelerators. We aim to construct one of the largest neutrino telescopes deep in the northern Pacific Ocean off the coast of British Columbia, the Pacific Ocean Neutrino Experiment (P-ONE). The first detector line is planned to be deployed this year – marking the start of an exciting phase for this new project. In this talk I will cover results from early pathfinder missions and discuss a detailed status of the P-ONE detector concept.

DPG Spring Meeting at FAU
2026-03-15 14:00 - 2026-03-20 13:00 | Philosophie, Kollegienhaus and Alte Mathemathik, Erlangen, Universitätsstr. 15, Erlangen, 91054, Germany
ECAP is happy to organise the
89 Annual Conference of the DPG and DPG Spring Meeting of the Matter and Cosmos Section (SMuK)
15 – 20 March 2026
We expect around 2000 physicists to join this conference downtown Erlangen.
More information at https://erlangen26.dpg-tagungen.de

ECAP Seminar: Lucas de Sa, Heidelberg University
2025-11-20 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Prospects for pulsars and pulsar associations in multi-messenger astrophysics with population synthesis
Population synthesis seeks to integrate the full framework of stellar evolution with predictions for observations of different products of said evolution, potentially allowing constraints to be placed on multiple evolutionary steps at the same time. It has become a central tool in gravitational-wave astronomy when simulating populations of compact object mergers and predicting merger rates over redshift, where it nevertheless faces the challenge of dealing with the high level of uncertainty surrounding massive stellar evolution, and the degeneracy between multiple physical assumptions when making predictions for a single kind of event. This degeneracy, however, could be lifted in part by accounting for a broader range of stages a star goes through during its life, as well as alternative outcomes. In this talk, I will explore the prospects of using these same tools to study observed populations of pulsars and pulsar associations – pulsar wind nebulae and halos. In particular, I will highlight current advances in supernova theory and stellar angular momentum evolution, and the potential for a more detailed picture of pulsar formation. I will also present ongoing work on the generation of synthetic pulsar association populations for the study of observations of current gamma-ray observatories, in particular HAWC, and for the prediction of observations by the future SWGO.

ECAP Seminar: Milena Crnogorcevic, Stockholm University
2025-10-23 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Gamma Rays from the Littlest Galaxies: Tracing Accretion and Dark Matter in the Low-Mass Universe
Now in its 17th year of operation, the Fermi Large Area Telescope (LAT) continues to transform our understanding of the smallest galaxies in the Universe. Dwarf galaxies host some of the most extreme environments known—from ultra-faint systems dominated by dark matter to those harboring actively accreting intermediate-mass black holes (IMBHs). In the first part of this talk, I will present results from the first systematic Fermi-LAT search for gamma-ray emission from active galactic nuclei in dwarf galaxies, revealing hints of a soft-spectrum excess that may trace the onset of high-energy activity in low-mass black holes. In the second part, I will discuss our complementary search for dark matter annihilation in dwarf galaxies, including limits from ultra-faint systems. Together, these studies illustrate how the littlest galaxies provide powerful and complementary laboratories in gamma rays—probing both the physics of black hole growth and the nature of dark matter. Looking ahead, I will address the (exciting) uncertainties and challenges facing space-based gamma-ray astronomy, as well as highlight the promising prospects offered by next-generation ground-based gamma-ray observatories.

ECAP Seminar: Kendall Mahn, Michigan State University
2025-10-13 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
You’re sending particles across a country? The Tokai to Kamioka experiment
Neutrinos are a tiny subatomic particle with surprising properties under active study. In particular, neutrinos oscillate, that is, they convert from one type of neutrino to another, is a surprising phenomenon under active study. The origin of neutrino mass is important for astrophysics, cosmology and particle physics, and many open questions surrounding neutrino oscillation exist. The Tokai-to-Kamioka (T2K) neutrino oscillation experiment sends a beam of muon flavor neutrinos or antineutrinos 295km across Japan. This seminar will talk about the wonderful world of neutrinos, the surprising landscape of neutrino oscillation, through the lens of recent activities on T2K, and toward the future, global neutrino exploration of neutrinos.

ECAP Seminar: Mauricio Bustamante
2025-06-26 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Fundamental physics with high-energy and ultra-high-energy cosmic neutrinos
High-energy cosmic neutrinos probe fundamental physics at scales of energy and distance otherwise unreachable, where new physics may manifest. Since the discovery of TeV-PeV astrophysical neutrinos in 2013, we have explored this progressively more broadly and with increasing precision, thanks to a growing number of detected neutrinos and to improvements in reconstruction and analysis techniques. By means of illustration, I will survey the rich landscape of high-energy physics with cosmic neutrinos, from the perspectives of theory and experiment. I will also touch upon new opportunities made possible by the recent discovery of an ultra-high-energy neutrino, with about 200 PeV, by KM3NeT—with a warning. Looking ahead, I will show two prospects for transformative change in the next decade, driven by new, upcoming neutrino telescopes: a boost in the detection rate of TeV-PeV neutrinos and the possible detection of more ultra-high-energy neutrinos.

ECAP Seminar: Branden Allen, University of Hawaii
2025-06-12 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Introduction to the Space Science and Engineering Initiative, and Opportunities and Applications for the Next Generation of X and gamma-ray Detector Systems and Technologies
The Space Science and Engineering Initiative (SSEI) was created as a joint effort between the UHM College of Engineering (CoE) and the Institute for Astronomy (IfA) for the establishment of an interisland advanced technology research and development center based in Hilo, which aims to significantly expand technical capabilities to support the space sciences, particularly targeting application for the observatories on Maunakea and Haleakalā. Here, I will discuss the current status of the SSEI and give a brief overview of our current portfolio of activities.
Afterward, I will discuss my own research program which focuses primarily on the development of high-energy detectors, associated technologies, telescopes and missions for spaceflight. This will be followed by a discussion of plans and potential for their future deployment for use in astrophysics and planetary science.

ECAP Seminar: Benedikt Bergmann, IEAP/CTU, Prague
2025-06-05 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Particle tracking and identification with Timepix-series detector setups in nuclear, particle and astrophysics
In high energy physics experiments, hybrid pixel detectors are an integral part of the tracking systems closest to the interaction points, where their good spatial resolution and high radiation resilience allow for particle tracking by connection of “dots” registered in different layers of an onion-like detector. Another approach to particle detection and tracking relies on a complex analysis of the imprints seen in the pixel matrices (tracks), which provide a rich set of features. These allow for identification of impinging particles, particle trajectory or reaction kinematics reconstruction. The latter is particularly valuable for applications with limited resources, for example in space experiments, but it also enables fundamental-science-reach measurements with simple table-top experiments. In this contribution, I will present the latest results from Timepix-type detectors used within LHC experiments, as space radiation monitors in low Earth orbit, their possible application for measurement for galactic-cosmic-ray properties or as an X-ray polarimeter.

ECAP Seminar: Philipp Windischhofer, U Chicago
2025-05-22 13:00 - 14:00 | Physikum, Hörsaal HF, Staudtstr. 5, Erlangen, 91058, Germany
Exploring the Universe at the Highest Energies: when Particle Physics and Astronomy meet
High-energy neutrinos propagating over cosmological distances are the ideal messenger particles for astrophysical phenomena, but the neutrino landscape above 10 PeV is still mostly unexplored. At these extreme energies, neutrinos can image the most extreme objects in remote corners of our cosmos and help access fundamental physics at extremely short distances.In this talk, I will show how we are presently constructing the Radio Neutrino Observatory in Greenland, the largest-ever terrestrial neutrino detector, and how the century-old physics of electrodynamics plays a central role in its operation. Combining ideas from particle collider instrumentation with high-performance computing, we will see what it takes to fully exploit the science potential of this unique instrument and thereby extend neutrino astronomy into the regime of the exaelectronvolt.

ECAP Seminar: Oliver Friedrich, LMU Sternwarte
2025-05-08 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Forcing neutrinos to obey the holographic principle
Gravity does not like the vast amounts of states present in QFT, and
quantum gravitational effects are expected to drastically reduce the
dimension of the QFT Hilbert space. This is e.g. achieved by “operator
dressing”, which changes the commutation relations of quantum fields.
In https://arxiv.org/abs/2402.11016 we build a model for neutrinos,
that incorporates this dressing and fixes it such that neutrinos obey
a cosmic entropy bound. A key consequence of this construction is that
particles scatter in the vacuum. This e.g. implies a finite mean free
path of cosmic neutrinos. We confront this result with observed
neutrino emissions and find that the holographic principle is
potentially in tension with current neutrino data.

ECAP Seminar: Foteini Oikonomou
2025-02-06 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Ultra-high energy cosmic rays: Constraints on the maximum-energy distribution of the sources and the possible role of ultra-fast outflows in active galactic nuclei
An open question in the search for ultra-high-energy cosmic-ray (UHECR) sources is whether they are few and prominent or if a large population of sources collectively contributes to the diffuse flux. Motivated by this question, we investigated whether the latest UHECR data are consistent with originating from a population of sources that exhibit substantial diversity in terms of the cosmic-ray spectra they produce. We found that the fit to the cosmic ray data requires sources that are intrinsically very similar in terms of the maximum energy reached. This is surprising, considering the sizeable astrophysical diversity exhibited by the candidate astrophysical source populations. One source class that may satisfy the constraints imposed by the UHECR observations is non-jetted active galactic nuclei. An increasing number of observations suggest that semi-relativistic winds, termed ultra-fast outflows, are present in a large fraction of these sources. In this talk, I will show that cosmic ray nuclei can be accelerated to ultra-high energies in such ultra-fast outflows. Ultra-fast outflows can, therefore, possibly account for a substantial fraction of the observed diffuse UHECR flux.

ECAP Seminar: Elisa Pueschel
2025-01-23 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Dark Matter Searches with VERITAS and Dark100
Indirect dark matter searches are an important piece of the search for dark matter. One indirect search method is to use very-high-energy (E > 100 GeV) gamma rays as a probe of dark matter annihilation or decay in dark-matter-rich astrophysical systems. Gamma rays in this energy range can be used to search for both classical TeV-scale weakly interacting particles and for ultra-heavy dark matter particles predicted in e.g. models of composite dark matter. I will describe efforts to chase light from dark matter using ground-based imaging atmospheric Cherenkov telescopes, including the current generation VERITAS instrument and the upcoming Dark100 array.

ECAP Seminar: Sebastian Schoenen
2025-01-09 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
From Research to Practice: Applying Artificial Intelligence in the Insurance Industry
This presentation provides insights into the practical applications of artificial intelligence (AI) and machine learning in the insurance sector. Using examples from our work at ControlExpert, I will demonstrate how advanced image recognition and natural language processing (NLP) technologies are leveraged to automate and optimize processes. Additionally, the talk will highlight how data scientists with backgrounds in physics, mathematics, and other disciplines can effectively translate their skills into valuable contributions within the industry.

ECAP Seminar: Katarzyna Nowak
2024-12-12 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Finding evidence for self-enrichment and supermassive stars in forming globular clusters
Self-enrichment is one of the leading explanations for chemical anomalies in globular clusters. In this scenario, a polluter star enriches a forming cluster with its yields, likely ejecting radioactive 26Al into its surroundings. Young massive star clusters, as potential progenitors of globular clusters, provide a valuable setting to investigate self-enrichment processes and assess the role of supermassive stars (>1000 M), which are considered likely polluters contributing to these chemical anomalies.
In the first part of this talk, I will focus on 26Al as a potential tracer of ongoing self-enrichment in young massive star clusters. Detecting 26Al, particularly through its gamma-ray decay lines at 1.8 MeV and 511 keV, as well as 26AlF molecules and positronium radio recombination lines, could provide direct evidence of active self-enrichment. These detections, especially in nearby clusters like R136 in the Large Magellanic Cloud, would offer strong support for self-enrichment scenarios.
The second part of the talk will explore the potential of using 22.2 GHz water kilomasers as tracers of supermassive stars within forming young massive star clusters. Kilomasers, such as the W1 source found in NGC 253, may originate from accretion discs around supermassive stars. Using 2D hydrodynamic simulations, I model the maser spectra for accretion discs around these stars and find that the kilomaser features align well with observed sources like W1, suggesting that kilomasers could indeed signal the presence of supermassive stars.
By examining these two detection methods, I aim to demonstrate how 26Al and kilomasers together provide complementary insights into the processes of self-enrichment and the potential role of supermassive stars in the formation and chemical evolution of globular clusters.

ECAP Seminar: Eli Kasai
2024-12-05 13:00 - 14:00 | Physikum, Hörsaal HF, Staudtstr. 5, Erlangen, 91058, Germany
Optical spectroscopy and imaging of blazars for the Cherenkov Telescope Array Observatory
Blazars are the brightest persistent sources in the high-energy and very-high-energy (VHE) gamma-ray sky. Because their UV/optical radiation is often dominated by non-thermal, and, in the case of BL Lacs, featureless continuum radiation, the determination of their redshift is extremely difficult. Only about 50% of gamma-ray blazars have a firm measurement of their redshift. This strongly reduces the precision in the modelling of their VHE emission, involving the absorption due to the extragalactic background light, which is dependent on redshift. Furthermore, the effects on their radiation of proposed physics beyond the Standard Model such as Lorentz Invariance Violation and Axion-Like Particles cannot be reliably investigated. During the Cherenkov Telescope Array Observatory (CTAO) operations, several hundreds of new blazars will be detected, most of them without redshift. In order to mitigate this condition, we devised an optical observing campaign. Likely targets were selected through simulations of CTAO observations using the Fermi-LAT 3FHL catalog as a starting point. Our campaign, started in 2019, has been recognized as necessary support for the AGN Key Science Project of the CTAO. It involves deep observations using, among others, 10-m class telescopes such as Keck, SALT, GTC and the VLT. In this talk, I will present the status of our campaign, its future developments and other activities we are pursuing.

ECAP Seminar: Olivier Hainaut
2024-11-14 13:00 - 14:00 | ECAP, room 307, Erwin-Rommel-Str 1, Erlangen, 91058, Germany
Satellite Constellations & Astronomy: What is the problem? What are we doing about it?
In recent years, large satellite constellations have been launched into low-Earth orbit to provide low-latency, global communication coverage. As a result, the number of satellites in orbit has surged from approximately 2,500 to over 10,000, raising concerns about the sustainability of this endeavor and its impact on astronomical observations and the night sky.
I will discuss the current situation, the effects of key constellation parameters (number of satellites, altitude, inclination, satellite size, etc.), and the impact on astronomical observations. I will also explore various mitigation methods. While this talk primarily focuses on astronomy, I will briefly touch on non-astronomical aspects.
Background information: https://www.eso.org/~ohainaut/satellites/

ECAP Seminar: Jonas Neuser
2024-10-31 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Black hole evaporation and quantum gravity
Hawking’s seminal result, that black holes behave as black bodies with a non-vanishing temperature, suggests that black holes should evaporate. However, Hawking’s derivation is incomplete as it neglects the backreaction between radiation and geometry. Including it requires to incorporate quantum gravity. This talk focuses on the description of the conceptual challenges associated with black hole evaporation and sketches a recent proposal designed for meeting them. The intention is to eventually derive quantum gravity triggered deviations from Hawking’s evaporation formula and to convert them into measurable data.

Tag der offenen Tür der Dr. Karl Remeis-Sternwarte
2024-10-26 15:00 - 23:59 | Dr. Karl Remeis-Sternwarte, Sternwartstr. 7 96049 Bamberg, Sternwartstr. 7, Bamberg, Bavaria, 96049, Germany
Wir laden ein zum:
Tag der offenen Tür der Dr. Karl Remeis-Sternwarte Bamberg
Astronomisches Institut der Friedrich-Alexander Universität Erlangen-Nürnberg
Samstag, 26. Oktober 2024 von 15 – 24 Uhr
Programm:

Kinderprogramm (15-19 Uhr)
Kurzvorträge zu jeder vollen Stunde
Sonnen- und Himmelsbeobachtung
Rundgang durch die historische Sammlung
Tombola

Vortragsprogramm:

Vortragsthema
Vortragender
Uhrzeit

135 Jahre Dr. Remeis-Sternwarte: Forschung und Lehre
Prof. Dr. Ulrich Heber
16:00 Uhr

Explosion in unserer Nachbarschaft – Supernova 1987A
Dr. Martin Mayer
17:00 Uhr

Expedition zum Schwarzen Loch
Dr. Thomas Dauser
18:00 Uhr

Die unermessliche Größe des Universums
M.Sc. Roman Laktionov
19:00 Uhr

Neutronensterne
Dr. Ingo Kreykenbohm
20:00 Uhr

Expedition zum Schwarzen Loch (Wiederholung)
Dr. Thomas Dauser
21:00 Uhr

Der Himmel im Roentgenlicht
Prof. Dr. Jörn Wilms
22:00 Uhr

Poster: OpenDay_SternwarteBamberg_2024

ECAP Seminar: Christopher Burger-Scheidlin
2024-09-12 13:00 - 14:00 | ECAP, room 307, Erwin-Rommel-Str 1, Erlangen, 91058, Germany
Intricacies of searching for supernova remnants at (very) high energies off the Galactic plane
Supernova remnants (SNRs) have traditionally been considered prime candidates for the acceleration of particles to high energies and to thus significantly contribute to the Galactic cosmic ray (CR) density. Most of them are first seen at radio wavelengths, around 10% are subsequently also detected at γ-ray energies. Current-generation radio surveys, such as the EMU survey with ASKAP, are revealing an increasing number of low-surface-brightness radio SNRs at high Galactic latitudes. We are searching for high-energy counterparts, which can provide important insights into understanding cosmic ray physics and constraining theories of CR acceleration and escape. These objects expanding in low-density media probe unperturbed environments that complement the population of (very-)high-energy-emitting SNRs in the Galactic plane.

ECAP Seminar: Martin Mayer
2024-06-27 13:00 - 14:00 | ECAP, room 307, Erwin-Rommel-Str 1, Erlangen, 91058, Germany
Rotation-powered pulsars and their nebulae – the eROSITA view
SRG/eROSITA is a soft X-ray (0.2 – 10 keV) telescope which has carried out the deepest X-ray all-sky survey to date. In this talk, I will present how the eROSITA data can be used to study rotation-powered pulsars and their pulsar wind nebulae, exemplified by two projects:
Firstly, the surveying power of eROSITA has allowed us to carry out a systematic search for new high-energy pulsars through a cross-match with gamma-ray sources detected by Fermi-LAT. The resulting candidate list is expected to yield detections of several tens of new pulsars, and can ideally be followed up by looking for signatures of pulsed radio emission, or orbitally modulated optical emission from a binary companion, at the candidate positions.
Secondly, eROSITA’s sensitivity has enabled us to study the X-ray synchrotron emission of Vela X, the wind nebula of the Vela pulsar, at unprecedented detail. This study led to the discovery of an extremely extended nonthermally emitting component, reaching radii up to 15 pc from the Vela pulsar. Its large size can possibly be explained through particle transport by diffusion, akin to the halos discovered around older pulsars in gamma-rays.

ECAP Seminar: Philipp Frank
2024-06-07 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Signal reconstruction for fields using probabilistic forward modeling
Many inference tasks in observational astronomy take the form of reconstruction problems where the underlying quantities of interest are fields (functions of space, time and/or frequency) that have to be recovered from noisy and incomplete observational data. These problems are in general ill-posed, as many different field configurations may be consistent with the observed data, and therefore their solutions are inherently of probabilistic nature. Forward modeling, that is combining an accurate description of the observing instrument’s response to a field configuration occurring in nature with the rules of probability & information theory provides a robust and scalable framework to solve such problems. I will give a brief overview on the involved theoretical concepts and numerical techniques employed to do so in practice, and show a selection of applications to real-world astrophysical data-analysis problems ranging from results in the radio- up to the gamma-ray-regime.

ECAP Seminar: Ekaterina Makarenko
2024-06-06 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Thermal X-ray emission from supernova remnants in 3D (M)HD simulations
Every supernova (SN) injects around 10^51 ergs into the interstellar medium (ISM), shaping the ISM’s chemical, thermal, and dynamic evolution. Around 70% of the injected energy is subsequently lost by radiative cooling. However, the fate of the emitted cooling photons is usually neglected in simulations as the surrounding ISM is treated as optically thin. This makes high-resolution 3D simulations quite unphysical. The growing ability of X-ray spectroscopy allows observations of SN remnants (SNRs) to define pixel-by-pixel based parameters (such as plasma temperature, ionisation state, and abundance of different elements). We therefore urgently need more realistic simulations of SNRs.
In this talk, I will present state-of-the-art (magneto-)hydrodynamic simulations of SN explosions using the FLASH code, which include radiative cooling from the SN event. Radiative cooling is calculated on-the-fly and is fully consistent with the code’s radiative transfer, physics, and chemistry modules. Therefore, we created synthetic maps of the simulated SNR in several X-ray energy bands (e.g. Chandra energy bands in the range 0.1-10 keV) as well as for selected lines. These synthetic X-ray maps provide unique information about the physics of shock/cloud interactions, the general morphology of the remnants, as well as a better comparison (and prediction) for SNR observations.

ECAP Seminar: Lucy Fortson
2024-05-23 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Muon Hunting with the Crowd: Combining Humans and Machines to Solve Big Data Problems
In this presentation, I will describe the Zooniverse.org citizen science platform as a tool to gather labels from over 2.7 million dedicated volunteers worldwide who are motivated to participate in scientific research. Hundreds of research teams now turn to Zooniverse for crowdsourcing tasks such as image classification and annotation, which provide the large labeled data sets needed for optimal training of machine algorithms. I will demonstrate the ease with which a project can be developed with the Zooniverse Project Builder tools and describe the infrastructure available for integrating machine learning with Zooniverse including sophisticated active learning techniques. I will provide examples from across several projects in astronomy and astroparticle physics, with a focus on the Muon Hunter project used to gather millions of labels to train a machine algorithm for an imaging air Cherenkov telescope calibration pipeline. I will finish with a look at how we are working to combine human and machine intelligence to probe large data sets, including those from Cherenkov telescopes, for scientifically interesting anomalous events.

ECAP Seminar: Katharina Breininger
2024-05-16 12:30 - 13:30 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Improving our understanding of machine learning robustness – in microscopy and beyond
A central goal when applying machine learning in the biomedical research and medical imaging is to answer relevant interdisciplinary questions robustly and reliably across various setups and ideally modalities; however, this is challenged by different imaging systems, differences between a laboratory setting and the real world as well as a multitude of other factors. This talk will explore the challenge of domain generalization in digital pathology, microscopy, and beyond. Specifically, we will discuss the Mitosis Domain Generalization (MIDOG) Challenge that took place at the International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) in 2021 and 2022 as one example how we can work toward more robust machine learning approaches. Furthermore, we will explore how we can potentially transfer the corresponding machine learning insights from imaging very tiny structures close-by to structures far, far away.

Physics Department Colloquium: Yuri Y. Kovalev
2024-05-08 12:00 - 13:00 | Hörsaalgebäude Physikum, Staudtstr. 5, Erlangen, 91058, Germany
Multi-messenger Lighthouses of the Universe: The many extremes of Active Galactic Nuclei
Abstract: Active galactic nuclei (AGN) make the most significant contribution to the overall energy balance in the Universe in all electromagnetic bands not dominated by the cosmic microwave background. A good understanding of physical processes and phenomena driving this contribution is paramount for addressing the key challenges in astrophysics and cosmology, including accretion onto black holes, electromagnetic fields, and shock waves in relativistic plasma.
These factors can be best studied with comprehensive programs combining dedicated multi-band and multi-messenger measurements with ultra-high angular resolution imaging in the radio regime enabled by the technique of very long baseline interferometry (VLBI).
In this talk I will discuss results from several such studies which we have conducted recently, targeting different aspects of AGN physics.
The discovery of extreme brightness in blazars, made with space VLBI observations, has set new limits on the very high rates of energy release in plasma.
The mounting observational indications for extragalactic neutrino production in blazar-type AGN now begin to deliver key understanding about the physics of proton
acceleration in blazars, either nearby central supermassive black holes or in plasma shocks embedded in the relativistic jets. Deriving from these results,
the continued improvements of sensitivity and fidelity of VLBI observations, and the expected advent of a true era of multi-messenger astronomy,
I will conclude by outlining several fundamental directions for studying the physical nature of AGN which will become feasible in the coming years.

ECAP Seminar: Atreya Acharyya
2024-04-25 13:00 - 14:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Recent Highlights from the VERITAS AGN Program
VERITAS is one of the world’s most sensitive detectors of astrophysical very high energy (VHE; E > 100 GeV) gamma rays. This observatory began full-scale operations in 2007, and more than 8,000 hours of its good-weather observations have been targeted on active galactic nuclei (AGN). Approximately ~250 AGN were observed with VERITAS, many of these as part of a comprehensive program to discover new VHE AGN. VERITAS spectral and variability measurements, and accompanying broadband observations, are key probes of the underlying jet-powered processes in AGN. Recent scientific highlights from the VERITAS AGN discovery program will be presented.

ECAP Seminar: Ellis Owen
2024-03-11 14:00 - 15:00 | ECAP Laboratory, 00.061, Nikolaus-Fiebiger-Str. 2, Erlangen, 91058, Germany
Exploring the signatures of cosmic ray feedback effects in galaxy ecosystems
Cosmic rays go hand-in-hand with violent and energetic astrophysical conditions. They are an active agent within galactic and circumgalactic ecosystems, where they can deposit energy and momentum, modify the circulation of baryons, and even have the potential to regulate star-formation on local and galactic scales. Their influence in galaxies can be probed using observable signatures across the electromagnetic spectrum, with high energy radiation being particularly important to determine their energy budget, feedback power and hydrodynamic effects. In this talk, I will discuss some of the astrophysical impacts hadronic and leptonic cosmic rays can have in and around galaxies, how their influence can be probed using signatures in X-rays and gamma-rays, and the opportunities soon to open-up that will allow us to map-out the multi-scale effects of cosmic rays in galaxies near and far.
