Blazar

THE TEAM

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The Team

Group picture during the pandemic.

group

Prof. Anna Franckowiak (PI)

Anna

During my PhD within the IceCube Collaboration I worked on probing the connection of jets, Supernovae and Gamma-Ray Bursts using TeV neutrinos. As a postdoc at the SLAC National Linear Accelerator Laboratory I studied the morphology and the spectrum of the Fermi bubbles and searched for gamma-ray emission from Type IIn supernovae using Fermi-LAT data as a member of the Fermi-LAT Collaboration.

From 2017-2022 I led a Helmholtz Young Investigator Group at DESY Zeuthen and since October 2020 I'm a full professor for multi-wavelength astronomy at the Ruhr-Universität Bochum (RUB). I served as the IceCube analysis coordinator (2019-2021) and the multi-messenger co-coordinator of the Zwicky Transient Facility (2019-2022). I coordinated the Fermi-LAT diffuse working group in 2015-2016.

I'm a member of the of the IceCube, Fermi-LAT, CTA, ASAS-SN, ZTF and Large Array Survey Telescope (LAST) collaborations.

Vera Nowak (Team Assistance)

Vera

Vera is the most important member of the group. She helps us to survive the bureaucracy djungle.

Dr. Elisa Pueschel (Staff Scientist)

Elisa

My research focuses on very-high-energy gamma-ray astronomy, particularly gamma-ray cosmology, blazar science, and the search for astrophysical dark matter. On the technical side, I am interested in developing analysis methods for gamma ray astronomy. I come from a particle physics background: my PhD was on the CDF experiment at the Tevatron, and my first postdoc on the ATLAS experiment at CERN. In 2013, I moved to gamma-ray astronomy via an Irish Research Council Fellowship and then a Marie Curie Fellowship at University Dublin. From 2017-2022 I led a Helmholtz Young Investigator group at DESY Zeuthen, and stayed on as a staff scientist. Since August 2023 I am a staff scientist in the Multimessenger Group at RUB.

I am a member of the VERITAS collaboration and the CTA consortium. Currently I am the co-chair of the VERITAS Time Allocation Committee, and deputy chair of the CTA Extragalactic Science working group.

Dr. Emma Kun (Alexander von Humboldt Fellow), based at RUB

Emma

Emma completed her PhD in 2017 at the University of Szeged, Hungary, on the topic of revealing supermassive black hole binaries via the signatures in the jets of radio-loud active galactic nuclei. She analyzed decade-long very long baseline interferometric data of AGN jets and modeled the evolution of the jet structure by hypothesizing an orbiting supermassive black hole at the base of the jet. After finishing a three years grant hosted by the Konkoly Observatory (Budapest, Hungary) and remotely already collaborating with Julia Becker Tjus and Anna Franckowiak, she joined RUB in October 2022 to work on the multimessenger astronomy of blazars, mainly from the angle of neutrino (IceCube Neutrino Observatory), gamma-ray (Fermi-LAT) and radio astronomy (various interferometric and single dish measurements).

Emma started her Humboldt Fellowship with Anna on 1 April, 2023. They carry out s tacking analysis of IceCube neutrino data to probe a sample of roughly 300 gamma-ray blazars. Emma is a member of the IceCube Collaboration.

Dr. Vandad Fallah Ramazani (Postdoc), based at RUB

Vandad

After having 7 years of professional experience in industries as a mechanical engineer, I started my desired field of interest by undertaking a master's and then Ph.D. degree program in physics and astronomy at Tuorla Observatory, Turku, Finland. During my Ph.D. within the MAGIC Collaboration, I worked on BL Lac objects. BL Lac objects are the most numerous extragalactic sources to be detected at very high energy (VHE, >100 GeV) gamma rays and are a sub-class of blazar-type active galactic nuclei, with their relativistic jet points very close to our line of sight.

Starting in February 2020 I am acting as the multi-wavelength/multi-messenger deputy coordinator of MAGIC collaboration and since January 2021, I joined the team of astrophysicists at the Ruhr-Universität Bochum (RUB) as a postdoctoral fellow. At RUB, we are building and testing a cost-efficient optical telescope with polarization capability using a state-of-art approach. Once the design is approved it will be used as part of the Large Array Survey Telescope (LAST) or the optical support telescope of the future generation of imaging air Cherenkov telescopes.

I'm a member of the MAGIC, Fermi-LAT, and Large Array Survey Telescope (LAST) collaborations.

Simeon Reusch (PhD Student)

Simeon

I am a PhD student at DESY since October 2019. In my master thesis at Humboldt-University Berlin I discovered a time-dependent bias in the calibration pipeline of the Zwicky Transient Facility (ZTF). As part of the Helmholtz-Weizmann International School on Multimessenger Astronomy, I am mainly concerned with optical follow-up to high-energy neutrinos detected by IceCube.

We have already discovered two exciting potential counterparts to these - a TDE (see Robert) and a quite mysterious flare in a Narrow-Line Seyfert Galaxy – stay tuned! I am also focusing on the integration of neutrino and optical candidate correlation schemes into the AMPEL framework, have developed a forced photometry framework for quick retrieval via Slack and work on the ZTF Supernova Ia Sample with the Cosmology Group at Humboldt.

Cristina Lagunas Gualda (PhD Student)

Cristina

I started my PhD at DESY in November 2019. I did both my Bachelor's and my Master's degree at the University of Valencia. I completed my master thesis in "Instituto de Física Corpuscular", where I worked with ANTARES on dark matter searches. Now I will focus on point source detection during my PhD with IceCube.

Jannis Necker (PhD Student)

Jannis

Jannis did his Bachelor thesis in the cosmology group at Humboldt University. Then he spend a year studying in Madrid. He joined that group as a master student and worked on an algorithm to estimate the explosion time of core-collapse supernovae in order to define a search window for high-energy neutrinos. In addition he compares different neutrino stacking codes.

In November 2020 Jannis started his PhD in the multi-messenger group as a member of the Helmholtz-Weizmann research school. He expands his work on core-collapse supernovae light curves.

Sven Weimann (PhD student, based at RUB)

Sven

In October 2020 I started my PhD thesis in the Multi-Messenger Group at the Ruhr-University. My work is focused on developing the new LAST telescope together with other astronomers at DESY in Zeuthen and the Weizmann Institute in Israel and finding optical counterparts of the IceCube neutrino events using real-time observations of the Zwicky Transient Facility.

Before joining Anna Franckowiak's group, I worked at the Astronomical Institute of the Ruhr University on photometry of large-scale structures in galaxies, including the study of the Low Surface Brightness Universe. In my master thesis I worked on the detection of diffuse dust in the disk-halo interface of nearby edge-on galaxies.

Anastasiia Omeliukh (PhD student, based at RUB with DAAD scholarship)

Anastasiia

Anastasiia got her master's degree at University of Kiev. She worked on simulations for IceCube-Gen2 and spend an extended period at DESY Zeuthen working with Markus Ackermann. In October 2021 she started her PhD at RUB where she works on multi-messenger modeling of blazars.

Paul-Simon Blomenkamp (PhD student, based at RUB)

Paul

I did my master's degree at TU Dortmund as part of the E5b physics working group. There I worked on the automatic detection of radio astronomical sources using methods of machine learning. In March 2022, I started my PhD at Anna Franckowiak's working group in Bochum. Here I study the diffuse gamma-ray emissions in the Milky Way galaxy, by comparing state-of-the-art models to Fermi-LAT data.

Giacomo Sommani (PhD student, based at RUB)

Giacomo

Giacomo spend 8 months at RUB as an ERASMUS intern to work on his master thesis. Now he's a PhD student at RUB. He studies the angular uncertainty of IceCube alert event with a focus on the influence of systematic uncertainties introduced by a limited understanding of the ice properties.

Patrik Milan Veres (PhD student, based at RUB)

Patrik

Patrik started his PhD at RUB in October 2022. He did his master thesis in Budapest where he studied EVN radio imaging and HST optical data of a dual AGN candidate. He now works on gamma-ray and radio emission of tidal disruption events.

Maurice Weigelt (Master student, based at RUB)

Maurice

I got my Bachelor’s degree at the Astronomical Institute of RUB In 2021. I analysed stellar tidal streams of nearby spiral galaxies with deep photometry of amateur telescope images. Since June 2023, I work on my master thesis in the Multi-Messenger Group at RUB and study the feasibility of future Kilonova detection with the upcoming UV telescope ULTRASAT.

Frederike Apel (Master student, based at RUB)

Frederike

Frederike did her Bachelor thesis in the group (graduation 2021), where she the modeled the low-frequency emission from the blazar PKS 1502+106. In her master thesis she investigates the multi-dimensional parameter space of lepto-hadronic models for the blazar PKS 0735+178.

Julia Baßier (Bachelor student, based at RUB)

Julia

I am a Bachelor's student at RUB, and my favorite subjects are astrophysics and anything math-related. Currently, I am working on my Bachelor's thesis in cooperation with the Institute of Stochastics since September. The thesis focuses on the stability of cross-correlation of multi-wavelength blazar light curves depending on the data quality.

Past Team Members

Dr. Massimiliano Lincetto (Postdoc), based at RUB 2020-2023, now postdoc at University of Wuerzburg

Massimiliano

After my master at the University of Padua, I pursued my PhD at the CPPM of Marseille as part of the KM3NeT Collaboration. My thesis has been centred on the capability of detecting low-energy neutrinos from a future nearby core-collapse supernova with the KM3NeT detectors. In this time I had the chance to discover the world of neutrino telescopes and get in touch with the community of multi-messenger astronomy. I have been involved in the birth of the SNEWS2.0 Collaboration, aimed to build the next generation supernova early warning system based on the coincident detections of neutrinos around the globe.

As of January 2021, I entered the Multi-Messenger Group as a postdoc at the Ruhr-Universität Bochum, aiming to explore the high-energy neutrino frontier. Here, I have joined the efforts to discover astrophysical sources with the IceCube Neutrino Observatory, exploiting the potential of multi-messenger observations.

Dr. Simone Garrappa (former PhD Student at DESY and postdoc based at RUB, now postdoc at Weizmann Instutite in Israel)

Simone

Simone started his PhD at DESY in January 2018. He did his master thesis at University of Bari working on photon identification in the Dark Matter Particle Explorer (DAMPE) with machine learning algorithms.

During his PhD at DESY he worked with Fermi data to look for gamma-ray counterparts of high-energy neutrinos detected by IceCube. Now he is leading the Fermi-LAT flare advocate activities and got involved in optical polarization measurements with LAST.

Dr. Xavier Rodrigues (Postdoc, based at RUB 2021-2023), now postdoc at ESO

Xavier

I'm a postdoc currently interested in the numerical modeling of high-energy phenomena that take place in the most powerful objects in the Universe, such as active black holes and gamma-ray bursts. I did my PhD at DESY, where I studied Active Galactic Nuclei, or AGNs, as potential sources of neutrinos and cosmic rays.

I joined the Multi-Messenger group in October 2019, and I am currently working on identifying the sources of the astrophysical neutrinos observed by IceCube, whose origin is not yet understood. For that I develop astrophysical simulations involving high-performance numerical algorithms and machine learning, and I work closely with my experimental IceCube colleagues in understanding the analysis of the observational data.

Anatolii Zenin (PhD student, based at RUB)

Anatolii

I got my master's degree at Nagoya University. I was working on hardware for the Medium-Sized Telescopes of the Cherenkov Telescope Array (CTA), and I studied silicon photomultipliers as a potential replacement for conventional photomultiplier tubes, aiming to improve the instrument's sensitivity to potential signal from dark matter self-annihilation.

Now I work on the Large Array Survey Telescope (LAST) with the focus in hardware for polarization measurements and instrument calibration. I am also planning to study the capabilities of LAST in joint observations with other types of instruments, such as gamma-ray telescopes, neutrino observatories, and gravitational-wave observatories.

Tianyu Zhao (Bachelor student, based at RUB, graduation in 2023)

Tianyu

Tianyu is a Bachelor student at RUB. He employs IceCube neutrino alert data and cosmological information to estimate the number of transients potentially associated with IceCube neutrinos.

Simon Pick (Bachelor student, based at RUB, graduation in 2023)

Simon

Simon is a Bachelor student at RUB and started his bachelor's thesis in October 2022. He investigates the excess of neutrinos from blazars in the Roma-BZCAT by matching these sources to point-like neutrino hotspots detected by IceCube in the Southern sky.

Yannik Pospiech (Bachelor student, based at RUB, graduation in 2023)

Yannik

Yannik is a Bachelor student at RUB. He studies the connection between supernovae and magnetars, to learn about their emission processes with the goal to probe them as neutrino emitters.

Andreas Willeke (Bachelor student, based at RUB, graduation in 2022)

Andreas

I studied mechanical engineering at RUB and received my degree Dipl.-Ing. in 1984. After working in the energy business for more than three decades, I decided to learn more about modern physics and returned to RUB as a student. During my studies I focused on astronomy and particle physics.

I work with Massimiliano on a search for high-energy neutrinos with IceCube from the direction of the peculiar supernova iPTF14hls.

Robert Stein (PhD Student from 2017 to 2021 - now postdoc at Caltech)

Robert

Since July 2017 I've been a PhD student at DESY. I'm originally from London, and did my undergraduate studies at Imperial College. I completed my masters project, as part of an Erasmus Exchange, in the Astroparticle Physics group of the University of Hamburg. The thesis topic was Reconstruction of Heavy Cosmic rays using Cherenkov Light, giving me a background in Cherenkov Telescopes and Cosmic Rays. But I've now moved into the exciting field of high-energy neutrino physics and multi-messenger astronomy.

My research specialism is Tidal Disruption Events (TDEs), which can occur when a star passes close to a Super Massive Black Hole. If the Star passes between the tidal radius and the event horizon of the Black Hole, the star is torn into two halves. One half is accreted by the black hole, while the other half is ejected. The entire process can be highly luminous, allowing us to detect it on Earth. Though we have not observed many TDEs (so far less than 100 have been discovered), the ones we have found are extremely energetic. Though the physics mechanisms are not well understood, they are likely to be strong particle accelerators. This makes them an interesting potential candidate for the source of high energy neutrinos that we detect on Earth. My analysis is based on a multi-messenger approach, trying to correlate neutrinos from IceCube to TDE sources detected with telescopes (such as ASAS-SN or ZTF).

Dr. Vaidehi Paliya (Postdoc from 2018-2020, now assistent professor at IUCAA in India)

Vaidehi

Vaidehi started as a postdoc in the group in November 2018. He did his PhD at the Indian Institute for Astrophysics and continued his career as a postdoc at Clemson University. He is an expert on blazar jets and worked with X-ray and gamma-ray data. He was the coordinator of the Fermi-LAT AGN working group.

Dr. Shan Gao (Postdoc from 2020-2021), now in data science

Shan

Shan did his PhD at Penn State University, where he modelled GRBs under supervison of Peter Meszaros. He participated in the foundations of the Astrophysical Multi-messenger Observatory Network (AMON). In 2014 he moved to a postdoc position in the theory group at DESY, where he developed the state-of-the-art lepto-hadronic modeling code AM3. The code was successfully applied to model the spectral energy distribution of the blazar TXS 0506+056.

Shan works on the code optimization, developing interface to couple the code with other simulation software and using big simulation data and machine learning technology to search for promising neutrino source candidates.

Dr. Ludwig Rauch (Postdoc from 2017-2019), now in data science

Ludwig

I am a postdoc at DESY since August 2017 working on multi-messenger astronomy combining ZTF and IceCube data. During my PhD at the Max-Planck-Institut für Kernphysik in Heidelberg I was a member of the XENON collaboration which tries to directly detect dark matter with liquid xenon dual-phase time projection chambers. My work included the analysis of the combined science data of XENON100 to constrain the WIMP model as well as the construction and performance tests of the photomultiplier arrays of next generation experiment XENON1T.

At DESY I am working on a novel transient pipeline for ZTF allowing for data processing and event selection, designed to be automated and adaptive to manage the large number of expected transient detections. The pipeline will enable multiple analyses starting from target of opportunity observations for multi-messenger astronomy to a magnitude limited and complete transient catalogue.

Richard Naab (Master Student, now PhD student at DESY in the neutrino astronomy group, working with Dr. Markus Ackermann)

Richard

My name is Richard, and I am a physics student at Humboldt University. I did my Bachelor's degree in Heidelberg and spent one year in Grenoble with the Erasmus program. At the LPSC in Grenoble, I got in touch with high-energy physics at the LHC and did my Bachelor's project on the prospects of searching for Dark Matter with the ATLAS detector.

Ulas Oeren (Master Student, now software developer in Istanbul)

Ulas

Ulas works with Fermi-LAT data. Starting from photons at energies above 100 GeV he looks for not catalogued sources and studies their multi-wavelength behavior. The data is then fit with a leptonic model.