Science and Technology with the Wetterstein Millimeter Telescope

Jun 23, 2025, 7:39 AM → Jun 24, 2025, 5:50 PM Europe/Berlin

Room "Prof. Specht" (Umweltforschungsstation Schneefernerhaus)

Christoph Wendel (Julius-Maximilians-Universität Würzburg), Florian Eppel (Julius-Maximilians-Universität Würzburg), Matthias Kadler

Workshop at the Environmental Research Station (UFS) Schneefernerhaus

June 23/24, 2025

 

The Wetterstein Millimeter Telescope (WMT) is a planned radio telescope associated with the Environmental Research Station (UFS) Schneefernerhaus at the Zugspitze in the Bavarian Wetterstein mountains.

The WMT is planned to operate at radio frequencies between 1.2GHz and 120GHz with the possibility to extend further towards shorter millimeter wavelengths. It is envisioned as an interdisciplinary research platform for astronomy, geo- and environmental research as well as for data and technology development. The WMT shall be integrated into international networks such as the European VLBI Network, the Global mm-VLBI Array, and provide long baselines to the upcoming next-generation Very Large Array (ngVLA) and Square Kilometre Array (SKA VLBI). It can further provide key contributions to satellite technology and operation, to worldwide geodetic-VLBI services, to space-situational awareness and to solar-system research. At this workshop, we will discuss science opportunities for the German and international community opened by the WMT.

Scientific Program:

Introduction of WMT key science areas:

-) Black Holes and Relativistic Jets

-) Dark Matter

-) Protoplanetary Disks

-) Galaxy Evolution

-) SSA and Solar System

-) Atmospheric Physics

-) Satellite Technology and RFI Mitigation

-) Space Communication

-) Geodesy

-) Data Science

-) Receiver Technology

 

SOC: Matthias Kadler, Simona Vegetti, Til Birnstiel, Guido Dietl, Hakan Kayal, Lars Fuhrmann, Paul Hartogh, Urs Hugentobler, Karl Mannheim, Eric Murphy, Agnieszka Słowikowska, Tobias Ullmann, Fabian Walter

 

LOC: Christoph Wendel (Chair), Florian Eppel, Christian Fromm, Till Rehm, Laura Schmidt

WMT Workshop Group Pic 1.webp

WMT Workshop Group Pic 2.webp

Mon, June 23

7:39 AM → 8:50 AM Special train directly to the UFS

On Monday, we have booked a special train that will take us directly to the UFS, starting at Garmisch-Partenkirchen Central Station at 7:39 am. The train ride is included in your conference fee. Additional stops at other stations are possible, please contact the LOC for further details.

9:00 AM → 10:30 AM Science and Technology with the WMT: Day 1 - Morning Session I

9:00 AM Welcome Notes

9:15 AM The Wetterstein Millimeter Telescope - Project Overview

The Wetterstein Millimeter Telescope (WMT) is a planned radio telescope associated with the Environmental Research Station (UFS) Schneefernerhaus at the Zugspitze in the Bavarian Wetterstein mountains.

The WMT is planned to operate at radio frequencies between 1.2GHz and 120GHz with the possibility to extend further towards shorter millimeter wavelengths. It is envisioned as an interdisciplinary research platform for astronomy, geo- and environmental research as well as for data and technology development. The WMT shall be integrated into international networks such as the European VLBI Network, the Global mm-VLBI Array, and provide long baselines to the upcoming next-generation Very Large Array (ngVLA) and Square Kilometre Array (SKA VLBI). It can further provide key contributions to satellite technology and operation, to worldwide geodetic-VLBI services, to space-situational awareness and to solar-system research. At this workshop, we will discuss science opportunities for the German and international community opened by the WMT.

Speakers: Kadler Matthias (Julius-Maximilians-Universität Würzburg), Simona Vegetti (MPA)

WMT_ProjectOverview_June23_2025.pdf

9:30 AM Science at the Environmental Research Station Schneefernerhaus

The Environmental Research Station Schneefernerhaus (UFS) was established in 1999 and is Germany’s highest research station at 2650 meters, just below the summit of Mt. Zugspitze.

Researchers from many different institutes monitor environmentally relevant parameters in the atmosphere, the cryosphere, the biosphere, the hydrosphere and the geosphere. The presentation will give a short overview of the scientific projects and groups active in all these spheres.

Speaker: Till Rehm (UFS)

UFS-von-osten-02.jpg

WMT_Science at the Schneefernerhaus.pdf

9:45 AM The Wetterstein Millimeter Telescope - Telescope Design and Feasibility

Speaker: Lutz Stenvers

10:00 AM Black Holes and AGN Jets: A Radio Perspective

Jets are about the most striking features of Active Galactic Nuclei (AGN). Driven by the extraction of rotational energy from a black hole and/or the accretion disk, jets can travel up to Mpc scales. Studying jets from both an observational and theoretical point of view is crucial to fully understand the AGN life cycle and the co-evolution of AGN jets and their hosts.
Given the synchrotron nature of the jet emission, radio astronomy is specifically well suited for analyzing their morphology from sub-pc to Mpc scales with resolutions down to $\mu$as with VLBI. While there is a long history of AGN research at m- to cm-wavelength, recent instruments enabled us to peak into the innermost regions in AGN at mm-wavelengths to map the black hole shadow with the EHT, the jet formation with the GMVA, and the jet collimation with global VLBI. But images are still rough with only a small number of telescopes, requiring more mm-telescopes to improve our understanding of AGN and their jets.
The next generation radio observatories will push the boundaries further: larger fov, higher resolution, higher sensitivity, enabling us to access AGN populations invisible before. With a new mm-telescope Germany will be in a prime position connecting to these facilities.

Speaker: Dr Anne-Kathrin Baczko (Chalmers University of Technology)

baczko.pptx

10:15 AM Talk about Black Holes and Relativistic Jets from a Radio-Astronomical Perspective 2

Relativistic jets launched from accreting supermassive black holes are among the most fascinating objects in Universe. Despite significant observational and theoretical progress the last decade the detailed processes regarding their launching, acceleration and emission remain still unclear. Future mm-VLBI observations will allow us to resolve both the horizon and jet launching zone with unprecedented resolution and sensitivity. During the talk I will provide some observable signature of jet launching and particle acceleration based on 3D GRMHD simulations which could be detectable with the WMT in combination with future arrays.

Speaker: Christian Fromm (University of Wuerzburg)

10:30 AM → 10:45 AM Coffee Break

10:45 AM → 12:15 PM Science and Technology with the WMT: Day 1 - Morning Session II

10:45 AM Interferometric Imaging with Information Field Theory

Imaging in interferometric settings requires that the not measured locations in the Fourier plane are reconstructed. This is particular important in Very Long Baseline Interferometry (VLBI). Information field theory (IFT) allows that this reconstruction is done probabilistically, such that prior information on the sky can be exploited. This includes the positivity of flux, its spatial, spectral, and temporal correlations, the statistics of point sources, and more. To this end, the IFT based imaging algorithm "resolve" is presented, including its application to temporally resolved VLBI imaging of black hole dynamics. Furthermore, the scaling of the achieved information gain of an interferometric measurement with the number of used antenna is discussed for instructive source scenarios.

Speaker: Torsten Ensslin

radio-IFT.pdf

11:00 AM The Next Generation Very Large Array

In collaboration with domestic and international partners, the U.S. National Radio Astronomy Observatory (NRAO) is currently designing and prototyping components of a next-generation Very Large Array (ngVLA) - a cm-mm radio interferometer to replace the Very Large Array and Very Long Baseline Array, producing a powerful astronomical tool for exploring the radio sky over a wide range of spatial scales and sensitivities. Elements of the ngVLA antenna design may have found additional application in the WMT design.

In this talk I will give an overview of ngVLA status and plans. Long baseline VLBI between VLBA (now), ngVLA (future), and WMT will improve understanding of radio source structures on milliarcsecond scales, and contribute to global efforts to measure/understand Earth Orientation parameters and rotation.

Speaker: Tony Beasley (NRAO)

beasly.pptx

11:15 AM The Global Millimetre VLBI Array

The Global Millimetre VLBI Array (GMVA) is a highly sensitive, global millimetre VLBI instrument that operates at wavelengths of 3 mm and 7 mm. Significant enhancements have been made in recent years through the incorporation of major facilities, including the phased Atacama Large Millimetre/submillimetre Array (ALMA) and the upgraded IRAM NOEMA Observatory. These additions have provided transformative capabilities for high-resolution astrophysical studies. The GMVA enables coordinated observations with sub-milliarcsecond angular resolution, which is crucial for probing the innermost regions of active galactic nuclei (AGN), black hole environments and relativistic jet formation. I will present the latest scientific findings, discuss recent technical upgrades such as increased recording bandwidth and sensitivity improvements, and review advancements in calibration and correlation. These developments establish the GMVA as a pivotal instrument for future millimetre-VLBI research. I will also discuss the role of the Wetterstein Millimetre Telescope (WMT) in the array and how it could expand the GMVA’s capabilities.

Speaker: Prof. Eduardo Ros (MPI für Radioastronomie)

Slide1.png

11:30 AM The Africa Millimetre Telescope

I will present Africa Millimetre Telescope (AMT) project. The AMT will be the first millimetre-wave telescope in Africa with the aim to be operational in 2028. The Telescope will join millimeter VLBI observations of the EHT, GMVA, and potentially future long baseline extensions to the ngVLA, offering synergies with the Wetterstein Millimeter Telescope. The AMT will also be able to observe at lower frequencies, down to 8 GHz, to be compatible with future lower frequency VLBI observations on the African continent together with the SKA. The low-frequency receivers also enable participation in the EVN and TANAMI arrays. The AMT single-dish observations will focus on transient follow-up, AGN monitoring, and deep integrations on molecular clouds at millimeter wavelengths.

Speaker: Michael Janssen

2025-06-WMTmeeting-AMT-slides.pdf

11:45 AM Constraining Models for Dark Matter with VLBI

Gravitational lensing provides a powerful probe of the global mass properties of galaxies, which are best tested using observations at extremely high angular resolution. Here, we review the current state-of-the-art, where sophisticated lens modelling algorithms are applied to high resolution imaging from ALMA and global VLBI. The analysis of these data demonstrates the mass complexity within galaxies at intermediate redshifts, but has also recently provided a detailed test of dark matter models through the direct detection of a million solar mass dark object. In addition, we will review recent work that aims to better understand flux-ratio anomalies at radio wavelengths, and present our current best constraints on dark matter with this method. Finally, we will demonstrate how gravitational lensing surveys with the SKA-MID and ngVLA have the potential to increase samples by several orders of magnitude, and how upgraded VLBI facilities are vital for utilising this unique test of dark matter.

Speaker: Prof. John McKean (Kapteyn Astronomical Institute / SARAO / University of Pretoria)

12:00 PM Taking a Leap in Integration Density for ngVLA and Beyond with a SiGe-Based Single-Chip LO Generation

To achieve the sensitivity necessary for its key scientific goals, the ngVLA places high demands on its receivers. Traditionally, these requirements have been met with custom solutions based on the combination and interconnection of individual, bulky components. However, we are investigating the possibility of replacing the ngVLA’s Band 6 warm cartridge assembly with a small module based on a single-chip in a SiGe technology. Initial results demonstrate the ability to meet the NRAO's strict phase noise requirements for the ngVLA local oscillator. This approach dramatically miniaturizes the warm cartridge assembly while simultaneously reducing mechanical load, maintenance requirements, and cost. Additionally, the significant reduction in complexity could lead to new concepts and ideas for future radio telescope or the WMT in particular.

Speaker: Tobias T. Braun (Ruhr University Bochum)

TakingALeapInIntegrationDensity.pptx

12:15 PM → 1:00 PM Lunch Break

1:00 PM → 2:45 PM Science and Technology with the WMT: Day 1 - Afternoon Session I

1:00 PM Future Space Situational Awareness and Near-Earth Object Studies: A Multistatic Radar Network Including the WMT

Space Situational Awareness (SSA) is currently facing severe challenges in obtaining the necessary information for a complete, dynamical understanding of activities in the near-Earth Space environment. These challenges require new capabilities of ground-based space radars at Low-Earth Orbit (LEO) as well as larger distances ranging from MEO/HEO/GEO orbits up to cislunar space. In this framework, we started efforts in extending monostatic radars like Fraunhofer's TIRA and GESTRA systems with additional receive (RX) elements to form bi-/multistatic radar networks in the future. Combining high-sensitive single-dish RX antennas like the WMT in a bi-/multistatic configuration with a high-power transmitter like TIRA will significantly improve future SSA capabilities (in e.g. orbit determination, high-resolution ISAR imaging of LEO objects, space debris population studies), while a new dedicated deep-space radar facility for planetary science and near-Earth asteroid studies could also emerge.

As introduction to the topic and the presentations in this session, I will give a short overview of SSA and the near-Earth space environment, the upcoming challenges and the new perspectives for bi-/multistatic radar networks including the WMT as RX element.

Speaker: Lars Fuhrmann

overview_bi-multistatic_SSA_with_WMT_LF_vers1.2.pdf

1:15 PM Detection and Tracking in the GEO, Cislunar and Deep-Space Regime Using Bi-/Multistatic Radar Networks Including the WMT

In the realm of space situational awareness (SSA), detecting and tracking objects in the geostationary, cislunar, and deep-space regimes is becoming increasingly vital. Radar-based observations offer the significant advantage of directly measuring distances and radial velocities. However, the detection and tracking of objects in these regions present challenges due to large distances and intricate trajectories. Bi- and multistatic radar networks play a crucial role in enhancing these capabilities.
The introduction of the Wetterstein Millimeter Telescope (WMT), in conjunction with the Tracking and Imaging Radar (TIRA), enables the implementation of bistatic and possible future multistatic radar measurements of space objects. In this contribution, we discuss the significance of radar-based SSA in these regimes and explore the opportunities presented by integrating the WMT into the measurement framework.

Speaker: Marcus Albrecht (Fraunhofer-Institut für Hochfrequenzphysik und Radartechnik FHR)

WMT_Workshop_GeoLunarDeep_MA250621.pdf

WMT_Workshop_GeoLunarDeep_MA250621.pptx

1:30 PM Multistatic Long-Baseline Satellite Imaging with the WMT

Inverse Synthetic Aperture Radar (ISAR) imaging is an important tool to create high-resolution images of moving objects. It is used by the monostatic Tracking and Imaging Radar (TIRA) to observe satellites for SSA.
In this talk, we will discuss the possibility to extend TIRA's imaging to a network of widely distributed multistatic radio receivers like the WMT that also capture the reflected signal transmitted by TIRA. Such a network increases the three-dimensional geometric diversity for an observation. Therefore, we seek to enhance SSA by analyzing multistatic radar images in three dimensions. The WMT has the potential to deliver valuable multistatic data in this network.

Speaker: Mr Felix Rosebrock (Fraunhofer FHR)

Rosebrock_Felix.pptx

1:45 PM Characterization of Resident Space Objects (RSOs) Using Radar Networks Including the WMT

Space Situational Awareness (SSA) monitors Resident Space Objects (RSOs) to safeguard space missions. It involves observing and forecasting RSO behavior, with imaging used to determine characteristics like size, shape, and rotation for cataloging. Interferometric Inverse Synthetic Aperture Radar (ISAR) employs multiple receivers to measure phase differences, providing high-resolution 3D imaging and motion analysis for classifying RSOs. This presentation introduces a sophisticated simulation environment for RSOs, utilizing Keplerian and SGP4 models to simulate orbital dynamics, including object rotation. Radar backscattering is modeled via Physical Optics, discretizing RSOs into triangular facets for realistic electromagnetic signatures. ISAR images are produced at 200 aspect angles, leveraging TIRA as the transmitter-receiver and WMT as an additional receiver, enhancing resolution and target identification through multi-perspective views. A three-receiver setup near WMT enables interferometric processing, generating 3D point clouds compared against ISAR for ten RSOs. Deep learning evaluates classification accuracy under varying Signal-to-Noise Ratios (SNR). ISAR interferometry excels in low-SNR, enhancing satellite and debris identification.

Speaker: Manjunath Thindlu Rudrappa (Fraunhofer FHR, Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Wachtberg, Germany)

Characterization of resident space objects_WMT_Presentation.pdf

2:00 PM The WMT as a RX Element in a Multistatic Radar Network: Technological Requirements

This contribution provides a short overview of the current and prospective multistatic concept for the TIRA system in the context of Space Situational Awareness (SSA). Initially, an introduction to SSA with TIRA is given, followed by an overview of the system architecture of our current development projects TIRA-Digital and TIRA-HD.

A particular focus is on the role of the WMT as a possible receiving element, which includes technological requirements such as the observation of LEO to HEO/GEO satellites and beyond, as well as the ability to receive data for detection, tracking and imaging in a multistatic radar network. Mechanical requirements, such as tracking angles and speed for LEO, are also discussed.

Precise synchronization in frequency and time is crucial for real-time tracking and coherent radar processing. The receiver section covers the frontend requirements for L, X, K_a band as well as the digital backend, which includes the digitization of time-domain I/Q raw data and data storage and transfer.

This presentation offers an analysis of the technological requirements for the effective use of a secondary receiver element within the TIRA system in a multistatic radar network, with the aim of enabling enhanced space situational awareness.

Speaker: Dr Simon Reuter (Fraunhofer FHR)

reuter.pdf

2:15 PM Operational Requirements for SSA with TIRA / WMT

This talk gives a brief overview of the operational procedures for measuring space objects with a radar sensor. With the WMT as an additional receiver, certain requirements arise in order to be able to use the sensor in a meaningful way. Furthermore, requirements for the confidentiality and integrity of the resulting data must be met and a sustainable cost model must be evaluated.

Speaker: Robert Perkuhn (Fraunhofer FHR)

2:30 PM Atmospheric Observations with the WMT

Millimeter wave observations of the solar system were performed since the early 1970s. They cover a wide range of topics including monitoring of the temperature structures of Venus and Mars and their wind patterns, detection of volcanic outgassing of Jupiter’s moon Io, tracing molecules of the comet Shoemaker-Levy 9 after its impact into the atmosphere of Jupiter and the molecular characterization of a large number of comets. The technological progress over the last decades resulted in receiver technology operating at the quantum limit. Moreover, array receivers were developed for faster mapping of extended sources. Applied to the Earth atmosphere these radioastronomical techniques offer the possibility to monitor minor components, present in the middle atmosphere and lower thermosphere (MLT), their horizontal and vertical distribution and wind patterns with unprecedented sensitivity and spatiotemporal resolution. These observational parameters are essential for new fundamental studies of physical and chemical processes in the MLT region, relevant e.g. for ozone and climate research. The potential of the WMT as a cutting edge atmospheric millimeter wave observatory will be presented.

Speaker: Paul Hartogh

Hartogh_WMT_250623.pdf

2:45 PM → 3:00 PM Coffee Break

3:00 PM → 4:45 PM Science and Technology with the WMT: Day 1 - Afternoon Session II

3:00 PM Chemical Heat as Nonlinear Feedback Mechanism in Mesosphere-Mesopause Region and its Relation to Anthropogenic Changes

The atmospheric system in the mesosphere–mesopause region is strongly nonlinear. It is characterized by feedback mechanisms between subsystems.There are positive and negative feedbacks, which lead to strengthening or suppression of external impacts, respectively. The positive feedbacks can lead to the destruction or transition of a system to a new state. To gain insight into nonlinear atmospheric system, it is essential to study these feedbacks.
The energy balance of this region is very complex, knowledge of it, is fundamental to understanding the processes in this region. One of the essential sources of energy is exothermic chemical heat.
We show importance of chemical heat based on common volume rocket-borne measurements of temperature, atomic oxygen, and air densities. This is the first retrieval of nighttime chemical heat by non-emissive in-situ observations. We compared the retrieved chemical heat with those from turbulent energy dissipation and find that the vertically averaged chemical heat is greater than the turbulent energy dissipation throughout the entire mesopause at night.
We derive analytical expression which shows that the chemical heat represents negative nonlinear feedback, and give some evidences based on model simulations.

Speaker: Dr Mykhaylo Grygalashvyly (Leibniz-Institute of Atmospheric Physics at the University of Rostock)

Grygalashvyly-Zugspitze-2025 - talk 34.pdf

3:15 PM Chemical Equilibria and Characteristic Times in Mesosphere-Mesopause Region during SSW Events

The chemistry of mesosphere-mesopause region is, to the large extend, odd-oxygen(O,O3)/odd-hydrogen(H,OH,HO2) chemistry. These species are highly important in the mesosphere-mesopause, governing the chemistry, airglow, and energy budget (taking part in exothermic reactions, radiative heating and microwave cooling). Hence, they are involved in the coupling between dynamics, chemistry and radiation. Large part of them is hardly measurable directly with reasonable uncertainty by satellite or ground based instruments. The techniques which based on assumptions of photochemical equilibria is often used. We study the behavior of O3, OH and HO2 equilibria at Sudden Stratospheric Warmings (SSWs). With 3D modelling we find that O3 and odd-hydrogens strongly deviate from photochemical equilibrium in the mesopause during SSWs at nighttime conditions. The lower boundary of equilibrium jumps up to 90 km, implying that traditional techniques for retrieving O, odd-hydrogens and chemical heat from airglow observations cannot be applied at times of SSWs below 90 km. We discuss and explain our result in terms of characteristic times. We found that at SSWs dynamics modulate chemical distributions, which modify O3 lifetime, then O3 can be transported directly by the dynamics.

Speaker: Mrs Krystine Naranjo Villalón (Leibniz Institute of Atmospheric Physics at the University of Rostock (IAP))

Krystine Naranjo-2025-6-23 STWMT.pdf

3:30 PM High-Frequency Radio Astronomy Developments in South Africa

I will provide a progress update on a range of mm-related developments in South Africa, including site characterisation for candidate mm-VLBI stations; new interferometric simulation software that includes frequency-phase transfer capability; and MeerKAT-South Pole Telescope survey results. Together, these highlight the rich synergies between deep cm and mm-wave observations of the future over a wide range of spatial scales, from cluster physics to dynamical imaging of black holes.

Speaker: Roger Deane (Wits University / University of Pretoria)

3:45 PM Potentials for Multiband Receiver Operations at the WMT

The Wetterstein Millimetre Telescope (WMT) is going to address a broad range of scientific topics, operating as a standalone instrument and as part of various interferometric arrays and very long baseline interferometry (VLBI) networks. Both these modes of operation would benefit strongly from outfitting the WMT with a multiband, shared-optical-path (SOP) receiver simultaneously covering up to four bands (22/43/86/230 GHz) and enabling observations to be made in the frequency phase transfer (FPT) mode. Combined with advanced backend technology, this would allow WMT to operate as an a very efficient multiband monitoring instrument while also making it one of the key elements of emerging FPT VLBI networks, including in particularly the Global Millimeter VLBI Array (GMVA) and the upgraded Event Horizon Telecope (EHT). This presentation will briefly review most important science applications of WMT operating with an SOP receiver and discuss a potential pathway toward its implementation at the telescope.

Speaker: Andrei Lobanov

4:00 PM Dealing with a Scarce Resource - Spectrum Management in the 21st Century

Radio astronomy increasingly faces challenges as the radio spectrum becomes ever more congested by skyrocketing commercial demands. We rely on wireless internet access, navigation systems and car parking radars, we need satellite imagery for monitoring climate change, disaster management, or weather forecasting, and much more. All active spectrum users have interference potential to our sensitive observatories.

The regulatory bodies, such as the International Telecommunication Union (ITU), struggle to keep pace with technological progress. The environment at the ITU is becoming very challenging for passive scientific spectrum users considering strong interests in developing active spectrum applications by various stakeholders. In Europe, the Committee on Radio Astronomy Frequencies (CRAF) advocates for the protection of radio astronomy facilities and geodetic VLBI stations. CRAF prepares countless regulatory documents, compatibility studies and policy papers for various national and international fora. We do this in close collaboration with our international partners, including the SKAO. Here, we report about our ongoing activities, successes but also challenges; and how this relates to establishing new observatories.

Speakers: Dr Benjamin Winkel (Max-Planck-Institut für Radioastronomie (MPIfR)), Frank Schinzel

Wetterstein-policy_Schinzel.pdf

4:15 PM Astrochemistry: A Key Tool to Probe Star and Disk Formation

The formation of stars and protoplanetary disks is governed by a complex interplay between gravity, turbulence, and magnetic fields. While gravity drives collapse, turbulence and magnetic fields act as counterforces, shaping the evolution of these structures. High-angular resolution interferometric observations have significantly advanced our understanding of disk properties, yet the role of environmental factors in their formation and evolution remains largely unexplored.
I present NOMEA 3mm observations (the highest frequency at ngVLA) to investigate multiple aspects of star and disk formation simultaneously. These observations provide key insights: (1) evidence for asymmetric accretion (streamers) feeding embedded protostars; (2) the first large-scale cosmic ray ionization and electron fraction maps, demonstrating the presence of locally generated cosmic rays that influence magnetic field coupling; and (3) a power spectrum of turbulence across more than two orders of magnitude, with a power-law behavior down to milliparsec scales, though without evidence of the ambipolar diffusion scale.
This reveals the crucial role of environmental factors in regulating mass inflow, ionization, and turbulence during star and disk formation to be probed with ngVLA.

Speaker: Jaime Pineda (Max-planck-institut Für Extraterrestrische Physik)

JEPineda_Talk_WMT.pdf

4:30 PM Chemical and Physical Properties of Pre-Stellar Cores

Pre-stellar cores are the preferred location for the formation of Sun-like stars. These dense and cold fragments of molecular clouds represent the initial conditions for the assembly of stellar systems. Furthermore, there is growing evidence that the chemical composition of evolved systems is at least partially inherited from the pre-stellar stages. The study of these objects is, therefore, crucial to understanding the subsequent planetary formation. Since they are short-lived, however, they are fairly rare. In this talk, I will present the most recent results in terms of the chemical compositions of nearby, pre-stellar sources, and I will show our recent efforts in trying to expand the sample of these objects to perform statistical studies. Moreover, since the analysis of molecular line emission unveils important information also on the physical properties, I will illustrate a few examples in this regard. In particular, I will focus on the importance and recent measurements of the ionisation rate due to cosmic rays in dense gas, and its dynamical implications.

Speaker: Dr Elena Redaelli

5:00 PM → 6:15 PM Special train back to Garmisch

On Monday evening, a special train will take us back directly from the UFS to Garmisch-Partenkirchen (arrival ~6:15 pm), where we will have the conference dinner at 7:00 pm. The train ride is included in your conference fee.

7:00 PM → 9:00 PM Conference Dinner

Tue, June 24

8:15 AM → 10:15 AM Travel to UFS by Cable Car

10:15 AM → 12:00 PM Science and Technology with the WMT: Day 2 - Morning Session I

10:15 AM Galaxy Evolution with the WMT as a Single Dish Millimeter Observatory

Large statistical samples hold an increasingly prominent role in our modern understanding of galaxy evolution -- trends such as the star forming galaxy main sequence and the mass-metallicity relation are established based on samples of many thousands of objects. However, obtaining millimeter spectra -- which are crucial to measuring the properties of cold, star forming gas -- currently presents a significant bottleneck in developing a robust statistical understanding of galaxies. Even the largest spectral surveys of molecular gas are limited to a few hundred objects, 1000 times smaller samples than SDSS and other large optical surveys. A 10 to 20 meter class millimeter telescope can detect the 3mm CO(1-0) emission of a Milky Way-like galaxy at a distance of 175 Mpc in under an hour. A dedicated, extended survey by a facility like the Wetterstein Millimeter Telescope could produce hundreds or thousands of spectra per year, significantly increasing the sample of galaxies with available molecular gas measurements. I will outline the scientific return and possible implementations of of such a survey, and describe a similar filler project at Arizona Radio Observatory's Submillimeter Telescope.

Speaker: Ryan Keenan (Max Planck Institute for Astronomy)

10:30 AM The BEST-18M-RAS Station

Recently we ITU registered the BEST-18M-RAS, a possible site to host the first Hungarian radio telescope for cm-mm band observations. We will briefly summarize our site selection and approval work, including also climatological, geophysical, geographical, and sociological research besides radio spectrum monitoring and attenuation modelling. We will show based on the technical parameters and the expected measurement capabilities the advantages of installing a new Central-European station to be operated as part of the GMVA and in collaboration with the planned LEVERAGE radio interferometer system.

Speaker: Dr L. Viktor Tóth (University of Debrecen)

TothLV_BEST_Zugspitze_2025.pdf

10:45 AM VLBI with the Square Kilometre Array Observatory

Very Long Baseline Interferometry (VLBI), using both SKA-Low and SKA-Mid, is poised to deliver groundbreaking observations with milliarcsecond resolution, surpassing the capabilities of the standard SKAO array.

VLBI, in conjunction with the SKAO, holds the promise of unlocking profound insights across various astrophysical topics. VLBI with the SKA stands to revolutionise our understanding of galaxy evolution and the physics of jet accretion by studying Active Galactic Nuclei (AGN) at low luminosities. Moreover, it is poised to make significant contributions to cosmology by constraining dark energy and dark matter through gravitational lensing and the study of water masers. The exploration of the stellar lifecycle, including the temporal evolution of supernova remnants, as well as the rapid follow-up of transients (e.g., localising FRBs and tidal disruption events), adds another dimension to the diverse range of science that VLBI can be used to investigate with the SKAO.

In this talk, I will highlight a subset of scientific achievements that can be achieved through VLBI with the SKA, elucidate the operational aspects of SKA VLBI, and discuss how the WMT can contribute to these efforts.

Speaker: Dr Jack Radcliffe (University of Manchester)

WMT_SKAOVLBI_Radcliffe.pptx

11:00 AM The AtLAST Project - Overview and Status

I will present the Atacama Large Aperture Submillimeter Telescope (AtLAST) project. AtLAST is a concept for a 50m diameter single dish telescope to be built on the Chajnantor Plateau, close to the ALMA/APEX site. Its design is under study in EU funded programs, the first lasting from March 2021 to August 2024, the second four year study has just started in January 2025, with a kickoff meeting in April. I will give an overview of the envisaged telescope design, ideas for instrumentation, and the science case studies used to arrive at the requirements for the telescope and instrumentation.

Speaker: Thomas Stanke (Max-Planck-Institut für extraterrestrische Physik)

tstanke-atlast-Zugspitze.pdf

11:15 AM Importance of Modeling Source Structure for Geodesy and Astrometry

The new generation geodetic very-long-baseline interferometry (VLBI) system, named VLBI Global Observing System (VGOS), has started to make regular observations of active galactic nuclei (AGNs) to measure station positions of globally distributed antennas and Earth Orientation Parameters since 2019. It is currently understood that it is the astrophysics of the AGNs that limits the accuracy of the geodetic products from VGOS data --- the AGNs are all resolved to have angular structure on the milli-arcsecond scales that is varying with both time and frequency. Based on the actual VGOS data, in this talk we will discuss the impacts of source structure on the VGOS data and geodetic results. We will also report the progresses in modeling source structure for the VGOS observations. Some discussions about Wetterstein and ngVLA for geodesy and astrometry in terms of technical aspects will be present as well.

Speaker: Minghui Xu (GFZ)

WMT_v3.pptx

11:30 AM The International VLBI Service for Geodesy and Astrometry (IVS) as potential partner for the Wetterstein Millimeter Telescope

The IVS is an international collaboration of worldwide organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The IVS bundles geodetic, geophysical, and astrometric research, operational coordination of radio telescopes, promotes research and development activities in all aspects of the geodetic and astrometric VLBI techniques, and interacts with the community of users of VLBI products. The service integrates VLBI into a global Earth observing System with data for Earth orientation parameters (EOP), the international celestial reference frame (ICRF), and a terrestrial reference frame (TRF). These results form the foundation for space missions, Earth observations and thus also for climate research and the observation of temporal changes. The talk introduces the IVS, it's concept of a VLBI Global Observing System (VGOS), and shows ideas for the WMT to support this work.

Speaker: Alexander Neidhardt (FESG - Technical University of Munich)

IVS_Neidhardt.pdf

IVS_Neidhardt.pptx

11:45 AM Bridging Geodesy, Astrometry and Astonomy

This presentation highlights recent developments at the intersection of geodesy, astrometry, and astronomy.

In the first part, I discuss recent progress in the planning of observation programs for global absolute astrometry and astronomy. Unlike regional networks such as the VLBA, global VLBI networks face significant challenges due to a fragmented commonly visible sky. This is demonstrated through K-band sessions involving a global network of 25+ stations. I will outline a newly developed processing pipeline, from source selection through scheduling strategy, and conclude this section by examining the potential role of the Wetterstein Millimeter Telescope (WMT) in enhancing these global sessions.

In the second part, I explore the WMT’s potential for geodetic applications. Thanks to its high-altitude location, the WMT is subject to reduced tropospheric delays, one of the primary error sources in space geodetic parameter estimation. Beyond its role in producing conventional geodetic products, like the determination of Earth's phase of rotation (UT1-UTC), I also discuss innovative observing opportunities that would benefit from a denser European VLBI network, such as support for geodetic satellite missions.

Speaker: Matthias Schartner (ETH Zurich)

talk.pptx

12:00 PM → 12:30 PM Lunch Break

12:30 PM → 2:00 PM Science and Technology with the WMT: Day 2 - Afternoon Session I

12:30 PM Lifting the Veil on Planet Formation: Reviewing the Science Case of Planet Formation for ngVLA

In the last ten years, the field of protoplanetary disks and planet formation has gone through a complete revolution sparked by ALMA’s transformational observations. These same observations, however, have also revealed various observational challenges caused by the high optical depths of these objects at (sub)mm wavelengths. Observations at (sub)cm wavelengths are key to measure the real budget of solids in disks and how this might evolve during the lifetime of protoplanetary disks. Similarly, characterizing these solids is critical to identify the potential sites of planet formation, especially at Solar System scales. In this talk, I will review the recent advances in the field of planet formation and the remaining open questions, focusing on those science cases that are most relevant for a potential future involvement of Germany into the ngVLA.

Speaker: Enrique Macias

WMT_Macias_public.pdf

12:45 PM Protoplanetary Disks from a Radio-Astronomical Perspective - Talk 2

This talk focuses on the scientific potential of the planned Wetterstein Millimeter Telescope for probing the structure and evolution of protoplanetary disks. Central topics include the spatial and temporal variability of disk environments, particularly within the planet-forming zones. The role of magnetic fields, grain growth and settling, and the detection and characterization of embedded protoplanets and circumplanetary disks are also addressed. Polarimetric observations are discussed as a means to constrain dust grain properties and the underlying polarization mechanisms. Beyond the protoplanetary phase, the telescope is highly relevant for studying debris disks — especially in relation to the poorly understood phenomenon of hot exozodiacal dust, which must be characterized before future exoplanet imaging missions can be successfully implemented. The talk highlights the unique role the Wetterstein Telescope could play — both as a standalone instrument and as part of existing or planned arrays—in advancing high - resolution studies of protoplanetary disk evolution.

Speaker: Sebastian Wolf

2_Wetterstein.wolf.v1.pdf

1:00 PM Radio Astronomy at DZA

Speaker: Stefan Wagner (University of Heidelberg & DZA)

1:15 PM Coexistence of Radio Astronomy in an Increasingly Congested Environment

The growing use of the electromagnetic spectrum by communication services has pushed radio astronomical facilities into increasingly remote areas, such as the U.S. Southwest, Western Australia, or central South Africa. However, with the explosive growth in satellite communications in the past five years, even such remote locations are not spared by interference from these signals. I'll be highlighting some of the spectrum congestion issues that are expected to increasingly impact radio astronomical observations from the ground, together with some possible solutions that might become a necessity to operate radio astronomical facilities in the future. In this context, I'll be presenting results from collaborative work with satellite industry, where NRAO led the implementation of an operational data sharing system at the Very Large Array and Green Bank Telescope to allow for effective satellite bore-sight avoidance. This system is in the process of being adopted by other observatories, including the Very Long Baseline Array, with an expectation that more large satellite constellation operators adopt this concept to reduce the impact of satellite interference on radio astronomical facilities.

Speaker: Mr Frank Schinzel (NRAO)

Wetterstein-practice_Schinzel.pdf

1:30 PM WMT within the EVN: Enabling the Science at the Highest Resolution

From nearby stars to distant blazars or fast bursts, astronomical breakthroughs across different research domains are multiple times constrained by the angular resolution and sensitivity achievable with current observational facilities.
Very long baseline interferometry (VLBI) has transformed our capacity to probe the finest structures in the Universe, achieving milliarcsecond resolution. The European VLBI Network (EVN) is the world’s most sensitive VLBI array operating at centimeter wavelengths, as is an always-expanding network. The planned radio antenna at Wetterstein represents a significant opportunity to enhance the network’s capabilities and expand its scientific reach, combining single-dish and very-high-resolution science. The integration of WMT into the EVN would also put the antenna in a suitable position for SKA-VLBI in the new future.

This talk will explore the contribution that the Wetterstein antenna would enable within the EVN framework, and will be a review on the science cases where WMT would be able to contribute to (from Galactic to extragalactic phenomena), with special emphasis to transient science. And how both the German and international community would benefit from this new telescope.

Speaker: Dr Benito Marcote (Joint Institute for VLBI ERIC)

talk WMT.pdf

1:45 PM Operational and Technical Apects of the EVN

This presentation will review operational and technical aspects of the European VLBI Network (EVN), with a focus from the perspective of both the EVN users and also the participating telescopes. The EVN remains a cooperative effort among several radio-astronomy institutes in Europe,Asia, and Africa, with agreements in place for co-observing with NRAO (US) and LBA (AU) antennas. The manner in which EVN observations themselves are conducted continues to evolve in order to accommodate better the changing mix of scientific priorities of our users. We will sketch these developments, also in light of the various constraints of the individual telescopes. The capabilities at the EVN telescopes, as well as the growth of the network itself, are also in a never-ending race with the astronomers' insatiable desires. We will discuss aspects of the data itself (formats,rates, and transfer/storage), back-ends, time/frequency control, and calibration inputs -- along with the assistance available through the EVN and JIVE.

Speaker: Dr Bob Campbell (Joint Institute for VLBI ERIC)

WMT_campbell.pptx

2:00 PM → 2:15 PM Coffee Break

2:15 PM → 3:00 PM Science and Technology with the WMT: Day 2 - Afternoon Session II

2:15 PM Science and Communication in Deep Space: The Role of the Wetterstein Millimeter Telescope

The Wetterstein Millimeter Telescope (WMT) is a high-performance ground-based facility designed to support advanced research and technology demonstrations for current and future space missions. With capabilities in high-frequency communication, it serves as key infrastructure for innovative, small-scale missions with global impact.

Three core projects highlight WMT's role:

1. TLP Observation Mission: A small satellite mission to observe Transient Luminous Phenomena on the Moon. WMT enables continuous, interference-free monitoring—timely amid growing lunar exploration efforts.

2. NEA-Light: A lightweight satellite targeting the near-Earth asteroid Apophis during its 2029 flyby. WMT supports deep-space communication and navigation for this critical mission.

3. VaMEx/MarsSymphony: A robotic swarm mission to Valles Marineris, Mars. WMT supports testing of advanced protocols for non-line-of-sight communication.

Conducted under the Interdisciplinary Research Center for Extraterrestrics (IFEX) at the University of Würzburg, these projects show WMT’s strategic value. As a Bavarian initiative with global reach, WMT strengthens both scientific progress and regional aerospace capabilities.

Speaker: Prof. Guido Dietl (University of Würzburg)

2025-06-24_wmt_workshop_kayal_dietl.pdf

2:30 PM Advances in Satellite Communications: Enabling Future Networks through Small Satellite Missions

This talk presents recent advances in satellite communications with a focus on small satellite systems developed at the University of Würzburg. Highlighting the UWE-5 mission, we demonstrate a dual-satellite backhaul link supporting 5G mobile communication networks. We also introduce routing strategies optimized for low latency and energy efficiency in CubeSat constellations, enabling robust and scalable communication architectures. Furthermore, we explore the use of Long Range (LoRa) modulation for direct satellite-to-internet-of-things-device links, showing its potential for global, low-power connectivity using nanosatellites. On the signal processing side, we present a novel modulation approach based on conjugate-reciprocal zeros, offering robustness under challenging channel conditions. These contributions, supported by simulations and planned in-orbit experiments, underline the growing role of small satellites in building flexible, resilient, and cost-effective communication networks for future terrestrial and space applications.

Speaker: Prof. Guido Dietl (University of Würzburg)

2:45 PM Synergies Between the WMT and the Upcoming CCAT/FYST Telescope in Chile

The Wetterstein Millimeter Telescope (WMT) will enable novel observations in the 25cm to 2.5mm wavelength range from a unique site in on the Zugspitze Bavaria. Starting early 2026, the CCAT/FYST telescope, partially funded by institutions in North Rhine Westfalia and Bavaria, will enable unprecedented wide-field observations in the 1.5mm to 0.2mm wavelength range from the best possible site in Chile, on the 5600m mountaintop of Cerro Chajnantor. Given their relative dish sizes, both facilities offer matched resolution at their respective "workhorse" wavelengths, making them highly complementary. I will describe how a combination of these facilities will provide exciting new constraints for studies of galaxy evolution and large scale structure across cosmic history.

Speaker: Prof. Dominik Riechers (Universität zu Köln)

3:00 PM → 3:15 PM Workshop Summary & Concluding Remarks

Speaker: Fabian Walter (MPIA)

3:30 PM → 5:50 PM Travel back to Garmisch-Partenkirchen by Cable Car