GSNF Workshop @SA3CC
Tuesday, 6 May 2025
Many of the biggest scientific advances today require intense collaboration between organisations spanning the globe. The need for these collaborations to access, share and manage vast resources between hundreds or even thousands of researchers is in itself a major challenge.
Stemming from conversations initiated by CERN in 2023 with the R&E networks involved in the LHCOPN-ONE, the concept of a forum to discuss long-term, strategic challenges for large science organisations and NRENs was formed, which then materialised in the Global Science Network Forum, coordinated by a steering group composed by Tony Cass (CERN – later replaced by Eric Grancher), Eli Dart (ESnet), and Enzo Capone (GÉANT).
The forum is designed to be a space for the global NREN community to come together regularly with the big science collaborations to learn from each other on their respective future plans, share best practices and identify commonalities to maximise their effectiveness.
The scope would be to develop strategic plans with a 5 to 10 years’ time horizon so that NRENs can ensure that their future plans are fit to serve the evolution of these scientific projects.
The ultimate goal is to share experiences, best practices, strategies to tackle the common challenges facing key, large scientific communities and Research Networks, in relation to the acquisition, distribution, management, analysis of large volumes of data, often spanning several countries and many Data Centres all over the world, and the implied cross-national, multi-domain networking that underlies the data movement.
The first successful kick-off meeting happened at TNC24, with contributions from SKA, the WLCG, VRO and PIC, and around 100 people attending in presence. Then, thanks to the support from REUNA (the Chilean NREN), the South American-African Astronomy Coordination Committee (SA3CC) and the Vera Rubin Observatory Engineering Team, the second face-to-face meeting of the forum was dedicated to space observation, both optical and radio-based, having the opportunity to join the SA3CC 2025 Workshop + VRO NET engineering meeting, on the 6-9 of May 2025, in La Serena (Chile), hosted by AURA.
The highlight of the workshop was the visit to the Vera C. Rubin Telescope in person. This was a very exciting opportunity for the R&E network people involved in the support of this, and other, scientific collaborations, to experience first-hand (although only very briefly) what it means to work in very inhospitable environments, like the ones normally selected to host ground-based observatories. It also allowed the participants to see the status of the construction of the VRO telescope, which is now almost complete and in its testing phase, and to have a sneak peek at some of the early images that its largest-in-the-world optical detector has captured – which unfortunately wasn’t possible to take pictures of or share publicly, because of the temporary embargo enforced on the images produced by VRO, before they are validated and released to the public.
This second meeting covered a range of experiments showing how international cosmology is driving and delivering new knowledge and will require new communication and data management techniques to support future research.
CTAO – Presenter Gareth Hughes
When gamma rays reach the Earth’s atmosphere they interact with it, producing cascades of subatomic particles. These cascades are also known as air or particle showers. Nothing can travel faster than the speed of light in a vacuum, but light travels 0.03 percent slower in air. Thus, these ultra-high energy particles can travel faster than light in air, creating a blue flash of “Cherenkov light” (discovered by Soviet physicist Pavel Cherenkov in 1934) like the sonic boom created by an aircraft exceeding the speed of sound. Although this Cherenkov light is spread over a large area (250 m in diameter), it only lasts a few billionths of a second. It’s too faint and fast for the human eye to see but not for the sensitive light sensors of the CTAO’s telescopes. The current generation of ground-based gamma-ray detectors have cracked the door open to the high-energy Universe, giving us a glimpse of what there is to see. But with two arrays with three different classes of telescopes, the CTAO’s (Cherenkov Telescope Array Observatory’s) view of the full night sky with its unprecedented resolution will blow the door wide open. Telescope construction will start in 2026 in the two main sites of Cherro Paranal in the Atacama Desert (Chile) for the Southern Telescope, and of Roque de los Muchachos on the island of La Palma, in the Canary Islands (Spain), for the Northern Telescope.
Giant Magellan Telescope – Presenter Sam Chan
The Giant Magellan Telescope will be the largest Gregorian telescope ever (A “Gregorian Telescope” is one of the design types of optical telescopes). It will specialize in the infra-red region of the spectrum and will be located in Las Campanas (Chile). It will be composed of 7 mirrors of 8.4m each, for a total aperture of ~25m.
It will have a range of instruments to study galaxy evolution and creation and a Large Earth Finder to measure masses of earth-like exoplanets and look for biosignatures in the their atmospheres
Completion date is scheduled for early 2030s, projected data production is 2.4PB per year in total
Simons Observatory – Presenter Simone Aiola
https://simonsobservatory.org/
The Simons Observatory is a powerful new experimental cosmology facility comprising a set of millimeter-wavelength telescopes located at high-altitude in the Atacama Desert of Northern Chile. Formed through support from the Simons Foundation and its founding institutions, and with other collaborating institutions across the globe, the observatory is committed to expanding our understanding of the origin, evolution, and composition of the Universe and advancing the state-of-the-art of precision telescope technologies.
The Simons Observatory will be pursuing experimentally verifiable results that can confirm or challenge contemporary theoretical models describing the origin, composition, dynamics, and physical properties of the observable Universe.
The site is currently fully operational but not yet in science-production mode.
UKRI is a major contributor, hosting data at Manchester University.
ALMA NRAO – Presenter Sandy George
https://www.almaobservatory.org/en/home/
The purpose of ALMA is to study star formation, molecular clouds and the early Universe, closing in on its main objective: discovering our cosmic origins.
This radio telescope is composed of 66 high-precision antennas, which operate on wavelengths of 0.32 to 3.6 mm. Its main array has fifty antennas, each with 12-meter diameters, which act together as a single telescope: an interferometer. This is complemented by a compact array of four antennas with 12-meter diameters and 12 antennas with 7-meter diameters. ALMA’s antennas can be configured in different ways, spacing them at distances from 150 meters to 16 kilometers, giving ALMA a powerful “zoom” variable, which results in images clearer than the images from the Hubble Space Telescope.
The light in these millimetric and submillimetric wavelengths comes from vast cold clouds in space, at temperatures of just a few dozen degrees above absolute zero (-273oC), and from some of the earliest and furthest galaxies in our Universe. Astronomers can use this light to study the chemical and physical conditions in these molecular clouds, which are dense regions of gas and dust where new stars are forming.
At full production, the data rate is expected to be 3.5 to 6.6 PB/year. 3 Datacentres each will take full copy of the data for onward distribution.
ESO is currently funding an upgrade program for wideband sensitivity of ALMA.
FYST (a.k.a. CCAT) – Presenter Mike Nolta
https://www.ccatobservatory.org/
Fred Young Submillimeter Telescope (FYST) will be a 6-meter diameter telescope in Chile’s Atacama Desert, at Cerro Chajnator, at an elevation of 5612m. The FYST is specifically designed to measure the motions and temperatures of galaxy clusters via the Sunyaev-Zel’dovich effect, to trace the appearance of the first population of star-forming galaxies, and to probe, by mapping a variety of molecular spectral line tracers, the dynamics of the interstellar medium in a wide range of environments in the Milky Way, the Magellanic Clouds and other nearby galaxies. It will also be a next-generation Cosmic Microwave Background observatory offering the capability to map the sky some 10 times faster than current CMB facilities.
The FYST will achieve first light in Q2 2026
Event Horizon Telescope (EHT) – Presenter Jason G SooHoo
https://eventhorizontelescope.org/
A long standing goal in astrophysics is to directly observe the immediate environment of a black hole with angular resolution comparable to the event horizon. Such observations could lead to images of strong gravity effects that are expected near a black hole, and to the direct detection of dynamics near the black hole as matter orbits at near light speeds. This capability would open a new window on the study of general relativity in the strong field regime, accretion and outflow processes at the edge of a black hole, the existence of event horizons, and fundamental black hole physics.
The EHT is an international collaboration that has formed to continue the steady long-term progress on improving the capability of Very Long Baseline Interferometry (VLBI) at short wavelengths in pursuit of this goal. This technique of linking radio dishes across the globe to create an Earth-sized interferometer, has been used to measure the size of the emission regions of the two supermassive black holes with the largest apparent event horizons: SgrA* at the center of the Milky Way and M87 in the center of the Virgo A galaxy. In both cases, the sizes match that of the predicted silhouette caused by the extreme lensing of light by the black hole. Addition of key millimeter and submillimeter wavelength facilities at high altitude sites has now opened the possibility of imaging such features and sensing the dynamic evolution of black hole accretion. The EHT project includes theoretical and simulation studies that are framing questions rooted at the black hole boundary that may soon be answered through observations.
By linking together existing telescopes using novel systems, the EHT leverages considerable global investment to create a fundamentally new instrument with angular resolving power that is the highest possible from the surface of the Earth. Over the coming years, the international EHT team will mount observing campaigns of increasing resolving power and sensitivity, aiming to bring black holes into focus.
At present Max-Plank in Bonn and MIT process the raw data which due to the huge volumes (up to 700TB per station and data rates of up to 64Gbit/s is physically shipped to Max-Plank and MIT.
Image credit M D GorskiAaron M Geller Northwestern University CIERA the Center for Interdisciplinary Exploration and Research in Astrophysics
At the conclusion of the event it was clear that the next five years will see huge advances in the field of astronomy and cosmology and this will both offer huge opportunities for international science collaboration and result in growing needs for greater capabilities in NREN and pan-NREN networking to support them.
