The RRL spectra, the light from the RRLs goes through the telescope and a prisma and produces spectra that are used to estimate their radial velocities (the velocity along the line of sight) and their iron abundances. These information together with proper motions (tangential velocity components) and distances provided by the astrometric satellite Gaia allowed us to perform a detailed 6D+chemistry investigation of the early formation of the Milky Way. The position, the velocity and the distance allow us to investigate their origin. In particular, we can trace their movements back in time and in space at the epochin which the Milky Way was forming. This means that they are fundamental stellar tracers because they provide direct evidence of these  past events. We succeeded in the identification of RRLs belonging to different Galactic components (halo, thin/thick disk) and we found that they have similar properties, thus suggesting, that they formed on a relatively short timescale. The main difference is in the metallicity distribution that becomes systematically more metal-rich when moving from the Halo to the Thick and to the Thin disk. The very first stellar populations (those formed soon after the Big Bang) were metal-free. All the metals were formed by stars, and subsequent stellar populations become systematically more metal-rich. The chemical enrichment history is a complex phenomenon affected by different astrophysical ingredients and by the environment.

The results of our paper indicate that the environment played a key role in their chemical enrichment history. We also identified the most populous stellar streams (GSE, Sequoia, Sagittarius, Helmi) and they show evidence of substructures that need to be investigated in more detail. The main implication of the current findings is that Halo and disks formed at very similar epochs. Moreover, the comparison between the variation of the iron abundance as a function of the Galactocentric distance in our Galaxy (based on RRLs) and in M31 (based on globular glusters and red giants) are quite similar. This means that these two galaxies, in spite of the difference in the total mass, and the significant difference in their accretion history experienced very similar early formation processes. The most popular theories concerning the MW formation date back to the sexties suggesting a dissipative collapse (monolithic collapse) and to the end of the seventies suggesting a dissipation-less mechanism (coalescence of 
smaller progenitors). The latter scenario is supported by Cold Dark Matter cosmological simulations suggesting that the Halo formed from the aggregation of protogalactic fragments (dwarf galaxies).

The discovery of stellar streams and the merging of the Sagittarius dwarf galaxy further supported this hierarchical mechanism. More recently, the astrometric satellite Gaia provided new signatures of major/minor mergers (Gaia Sausage Enceladus, Sequoia, Helmi). To constrain the different models of galaxy formation we need firm constraints on the fraction of stars that formed "in situ", in our own galaxy, from those that have been "accreted" as a consequence of a galaxy merger.  The results of our paper open the path for constraining this crucial parameter.

For the first time we succeeded in using a primary distance indicator to trace old stellar populations in three Galactic components (Halo, thick/thin disk) and in the most populous stellar streams. We adopted two different Galactic potentials and different selection criteria to identify the Galactic components and the stellar streams. Moreover, we also performed a homogeneous comparison of their metallicity (iron, alpha elements) distributions including also RRLs that are in retrograde orbits.

Furthermore, we performed for the first time a detailed comparison of the iron radial gradient in our Galaxy and in M31 by using old stellar tracers. There is the common believe that the work done by Astrophysicists share several methodologies in common with archeologists/paleontologists. Indeed, this field of modern Astrophysics is called "Galactic Archeology". In particular, we investigate the physical mechanisms and the physical conditions driving the early formation of cosmic structures by using fossil records. The RRLs can be considered "living relics" of these early epochs. Seventy-five years after the early evidence for a revision of the cosmic distancescale brought forward by Baade, based on the non-detection of RRLs in thefield of M31 in blue and red photographic plates collected with the Palomartelescope, and the seminal discovery of stellar populations, Galactic RRLs andM31 appear to be once again crucial to improve our knowledge of evolutionary andpulsation properties of old stellar populations and galaxy formation.

Link to the preview of the paper:

"On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid" G. Bono, V. F. Braga, M. Fabrizio, M. Tantalo, K. Baeza-Villagra, J. Crestani, V. D'Orazi, M. Dall'Ora, M. Di Criscienzo, G. Fiorentino, M. Gholami, M. Marengo, C. E. Martínez-Vázquez, M. Monelli, J. P. Mullen, A. Nunnari, V. D. Pipwala, Z. Prudil, C. Sneden, G. Altavilla, M. Bergemann, G. Böcek Topcu, R. Buonanno, A. Calamida, E. Carretta, G. Ceci, B. Chaboyer, M. Correnti, R. da Silva, I. Ferraro, F. A. Gómez, G. Iannicola, R.-P. Kudritzki, A. Kunder, S. Kwak, M. Marconi, S. Marinoni, N. Matsunaga, F. Matteucci, A. Monachesi, I. Musella, M. G. Navarro Ovando, G. W. Preston, V. Ripepi, M. Salaris, M. Sánchez-Benavente, E. Spitoni, P. B. Stetson, F. Thévenin, I. B. Thompson, P. B. Tissera, T. Tsujimoto, E. Valenti, A. K. Vivas, A. R. Walker, M. Zoccali, A. Zocchi

A stellar explosion, a pulsar, and a supernova remnant - that’s the story of Calvera. Positioned more than 6,500 light-years above the Galactic plane, this system is rewriting what we know about stellar evolution in our galaxy. The research originates from a team at the Italian National Institute for Astrophysics (INAF), in collaboration with the University of Palermo, and is detailed in a study published in Astronomy & Astrophysics.

Rome, 29 August 2025 - Researchers from the Italian National Institute for Astrophysics (INAF) and the University of Palermo have conducted a detailed study of a truly unique system: a pulsar and its associated supernova remnant located over 6,500 light-years above the Milky Way’s disk, an area previously considered nearly devoid of such objects. Based on new observations and analysis published in Astronomy & Astrophysics, this research challenges the notion that the Galaxy’s peripheral regions are energetically inactive, offering fresh insights into the origins and evolution of massive stars.

In a region where stellar density thins out, and the interstellar emptiness dominates, a rare supernova remnant with its runaway pulsar - named Calvera - is rewriting the rules of stellar life cycles. The pulsar’s name pays homage to the antagonist from the 1960 western film The Magnificent Seven, evoking its identity as a rebel on the fringes.

The story of Calvera’s supernova remnant begins in 2022, when LOFAR - a European network of radio telescopes designed for low-frequency sky surveys - detected an extended, nearly circular structure suggestive of a supernova remnant. Located at a galactic latitude of 37 degrees, far from the densest regions where such explosions typically occur, the remnant was found just arcminutes away from the well-known X-ray-emitting pulsar, Calvera. With a high proper motion measured at ~78 milliarcseconds per year, Calvera appears to be moving away from the explosion site, suggesting a physical link between the two: a massive star exploded millennia ago, leaving behind an expanding gas shell and a fleeing neutron star.

To reconstruct this cosmic story, the research team led by Emanuele Greco (INAF) analysed detailed X-ray data from ESA’s XMM-Newton satellite. Combined with the pulsar’s motion and multi-wavelength observations, the analysis estimates the remnant’s distance to be between 13,000 and 16,500 light-years and its age to be between 10,000 and 20,000 years - entirely consistent with the pulsar’s data, reinforcing their shared origin from the explosion.

“Massive stars - at least eight times the mass of the Sun - form almost exclusively in the galactic plane, where dense gas fosters star birth,” explains Greco. “Finding their remnants at such heights above the disk is exceedingly rare. Our study refined the distance, age, and even potential progenitor of the Calvera system with higher precision.”

Adding intrigue, the system resides in a notably different environment than the galactic plane. Despite expectations that high-energy gamma emissions require dense particle environments (primarily protons), the observed gamma-ray output originates in a remarkably diffuse region. This shows that even the Galaxy’s “outskirts” can host conditions capable of generating intense, high-energy emissions.

“Thanks to telescopes like XMM-Newton and Fermi/LAT, as well as ground-based facilities like the Telescopio Nazionale Galileo, we can examine supernova remnants and pulsars across the electromagnetic spectrum,” Greco continues. “We demonstrated that even sparse regions - if they contain local overdensities - may emit multi-million-degree plasma. These features reflect the progenitor’s evolutionary history.”

The study represents a collaboration between INAF facilities in Palermo and Milan, combining expertise in compact objects and diffuse supernova structures. Observations from the Telescopio Nazionale Galileo revealed ionised hydrogen filaments. At the same time, X-ray data revealed a spatially extended but compact structure with shockwave interactions, indicating that the area, although remote, can locally contain concentrations of matter, contrary to what is usually assumed for high galactic latitude regions.

The results - and the connection between the pulsar Calvera and its supernova remnant - show that massive stars can unexpectedly be found far from the Galactic plane. Some of these stars escape their birthplace and explode as supernovae in remote regions of the Galaxy, leaving behind an expanding cloud of gas and a compact object such as a neutron star.

“Calvera shows that even seemingly quiet and empty zones of our Galaxy can harbour extreme processes,” Greco concludes. “We’ve tightly constrained Calvera’s physical properties and confirmed that locally dense pockets, even far from the plane, can produce X- and gamma-ray emissions. The discovery encourages us to view the Milky Way’s periphery with fresh eyes.”

Related journal article: “Multi-wavelength study of the high Galactic latitude supernova remnant candidate G118.4+37.0 associated with the Calvera pulsar”, by Emanuele Greco et al. Forthcoming in: Astronomy & Astrophysics.

Multimedia:

Fig.1: X-ray image of the Calvera neutron star, marked by the yellow circle, and of the diffuse emission, identified by the white ellipse. The material responsible for the observed emission has a temperature between 1 and 10 million degrees Celsius. Credits: E. Greco/INAF.

Photo: Emanuele Greco, researcher at INAF in Palermo. Credits: INAF

Contacts:

INAF Press Office - Marco Galliani, +39 335 1778428, ufficiostampa@inaf.it - Eleonora Ferroni +39 3313144670 eleonora.ferroni@inaf.it

These Schools are directed to PhD students and young Post-Docs in Physics, Astronomy and Mathematics who are interested in widening their knowledge in the fields of Physical Cosmology, Relativistic Astrophysics, General Relativity, Experimental Gravity and the Modern Quantum Theories of Gravitation.

The theme selected for the School considers a dilemma that today cosmology and astrophysics are experiencing: on one side, we have a very successful model, the ΛCDM model, able to adjust to almost all observations. On the other hand, such a model requires 96% of stuff about whose nature we have yet no certain knowledge: 26% of dark matter and 70% of dark energy, with only 4% left for the known matter, mostly in the form of hydrogen and helium nuclei. While dark matter seems to be necessary to explain the formation and the dynamics of galaxies and of larger structures, such as galaxy clusters and super clusters, dark energy is required to explain why our universe is in a state of accelerated expansion. The school aims at providing master’s and doctoral students and young post doctoral researchers with a perspective on the most important proposals on the nature of the dark components of the universe, not only from the theoretical point of view, but also from the experimental and observational one.

A significant number of students, both from Italy and abroad, participated to the School (co-funded by INAF Scientific Direction together with other Research Institutions and Universities), with a rare opportunity: a truly ‘wide field’ perspective on this theme. It has been indeed a precise choice of the Scientific Committee to include as many points of view as possible, from the more canonical to the more contentious. The lectures have been estremely interesting, from the standard cosmological model and its possible extensions to theoretical hypotheses and experimental searches on the origin of dark matter and energy, observational constraints on Hubble Constant and other fundamental cosmological parameters, the phenomenology in support of general relativity, alternative theories of gravitation.

The lectures given at the School:

• Elena Aprile (Columbia University, USA) and Elisabetta Barberio (University of Melbourne, Australia) – The search for dark matter
• Indranil Banik (University of Portsmouth, UK) – The local supervoid solution to the Hubble tension
• Karl van Bibber (UC Berkeley, USA) – Axion and axion-like particle dark matter
• Filipe Costa (Minho University, Portugal) – Astronomical reference systems in the framework of General Relativity
• Mariateresa Crosta (INAF, Turin, Italy) – Dark Matter as a possible effect of General Relativity
• Joshua A. Frieman (University of Chicago, USA) – Dark Energy: Theory and Observations
• Brenda L. Frye (University of Arizona, USA) – Measuring the Hubble–Lemaître Constant by Time Delay Cosmography
• Asta Heinesen (Bohr Institute, Denmark) – Backreaction from inhomogeneities
• Ruth E. Kastner (University of Maryland, USA) – Transactional Entropic Gravity and MOND
• Pavel Kroupa (University of Bonn, Germany) – Cosmological models based on MOND
• Andrea Lapi (SISSA, Italy) – Stochastic approach to dark energy
• Roberto Peron (INAF, Rome, Italy) – Precision tests of GR in the Solar System
• Joseph Silk (University of Oxford, UK) – Gamma ray probes of dark matter in galaxies and primordial black holes as dark matter
• Constantinos Skordis (CEICO, Czech Republic) – Extensions of General Relativity and cosmological dark matter
• Sandro Tacchella (University of Cambridge, UK) – The newest from JWST: implications for cosmology and galaxy formation
• Tim Tait (UC Irvine, USA) – Building realistic models of dark matter
• Michael Turner (University of Chicago, USA) – The big cosmological picture and the big open questions

The Lucchin Schools, first established in 1991 at the initiative of Francesco Lucchin — a renowned cosmologist and a central figure in the growth of Italian astrophysical research — and later named in his honor, became a longstanding benchmark for the education of PhD students across Italian universities and research institutes. From the inaugural session in Monteporzio (Rome), “Stellar Astrophysics – Active Galactic Nuclei”, to the last one held in Bertinoro (Bologna) in 2016, over 50 schools were organized. These were structured in biennial cycles, each focusing on orthogonal topics to foster cross-disciplinary dialogue and collaboration between different scientific communities.

This was the tenth time a Lucchin School was hosted in Asiago. This edition revives the original spirit of the initiative: to offer PhD students a broad, cross-cutting educational experience — beyond the increasingly narrow focus of academic research. The school aims to achieve two main goals: to present the state of the art in both theoretical and observational astrophysics, and to build networks of scientific collaboration that will support young researchers throughout their careers.

The school was officially opened by the President of INAF, who, visibly moved, emphasized the Institute's strong commitment to reviving this format as an essential tool for shaping the next generation of astrophysicists. “The sine qua non condition for relaunching the Lucchin Schools,” he stated, “was preserving the interdisciplinary approach that has made them so unique within the educational landscape.

The figure of Francesco Lucchin, to whom the schools are dedicated, remains central in the collective memory of the scientific community. Born in 1944 in Santorso (Vicenza), he earned his degree in 1968 under the supervision of Professors Bertola and Dallaporta. He was a pioneer in theoretical cosmology in Italy and played a key role in forming an influential research school in the field. In addition to serving as Director of the Department of Physics at the University of Padua, he was also a founding member of the institution that would later become INAF. Lucchin passed away prematurely in 2002, leaving behind a lasting scientific and human legacy.

With a three-year program already in the works, the new INAF PhD Schools “Francesco Lucchin” are expected to return on a semiannual basis. The next session is already scheduled for late October in Agerola (Napoli), promising another week of scientific immersion and vibrant exchange among brilliant young minds.

The revival of this initiative is not just a tribute to the past — it is a strategic investment in the future of Italian astrophysical research.

MISTRAL is an innovative receiver in many ways. Radio astronomy receivers are typically "mono-pixel", i.e. sensitive to radiation coming from a single direction. Creating panoramic images of the area of the sky of interest requires long scans with the telescope. One way to overcome this limitation is to build "multi-pixel" receivers, i.e. sensitive to radiation coming from multiple directions simultaneously. MISTRAL takes this concept to the extreme. It contains an ultra-cold core composed of a matrix of 415 Kinetic Inductance Detectors (KIDs), developed in collaboration with CNR-IFN in Rome, and cooled to just a fraction of a degree above the temperature of absolute zero, or -273.15 degrees Celsius. "It is precisely this high number of detectors, combined with a specifically developed optical system, that makes MISTRAL an extremely effective and fast instrument for wide-field imaging of weak and extended sources", comments Paolo de Bernardis, Scientific Coordinator of the receiver for Sapienza University of Rome. MISTRAL was installed in May 2023 in the Gregorian focus, located at the center of the large 64-meter diameter SRT dish. Commissioning of the receiver began soon after and consisted of an intensive series of technical and observational tests aimed at integrating the receiver into the telescope system. A team of researchers from INAF and Sapienza have been working side by side with the aim of bringing MISTRAL to its maximum performance, and making it available to the scientific community for regular observations. “Commissioning”, explains Matteo Murgia, Scientific Manager of the receiver for INAF, “is normally a routine phase in the installation of new instrumentation. However, it becomes a real challenge in the case of a millimeter-wave receiver like MISTRAL, which requires the telescope’s performance to be pushed to the limit in every respect”.

“Initially, we faced and overcame several obstacles related to the truly exceptional cryogenics of the receiver, finally obtaining the temperature necessary for the activation of the KIDs, that is, just 0.2 degrees above absolute zero”, says Elia Battistelli, Project Manager of the receiver for Sapienza University of Rome.

Starting in September 2024, the improvement in the performance of the SRT active surface allowed us to reach the sensitivity required to calibrate the instrument. It was then possible to proceed with the optimization of the alignment between the MISTRAL optics and those of SRT.

The commissioning team also worked tirelessly to develop the procedures and software needed for pointing and focusing. At the same time, INAF and Sapienza developed the calibration and imaging procedures. MISTRAL was finally ready for “first light” observations of extended radio sources. Three iconic celestial objects were observed in succession: the Orion Nebula, the radio galaxy M87, and the supernova remnant Cassiopeia A. These observations highlighted MISTRAL’s remarkable versatility and confirmed its ability to produce highly detailed images of celestial objects in extremely diverse astrophysical contexts.

“The milestone achieved with the first light images of SRT at 90 GHz,” commented Isabella Pagano, Scientific Director of INAF, “marks an important step in broadening the scientific horizons of this radio telescope, thus demonstrating its ability to operate successfully at the high radio frequencies for which it was designed.” With the “first light” obtained by observing these fascinating cosmic objects, this first phase of technical tests is concluded and a no less important phase of scientific validation begins, aimed at verifying the performance of MISTRAL with increasingly weak sources, to ensure that it is ready for the numerous scientific challenges for which it was designed. MISTRAL will address a wide range of scientific questions, from cosmology and the physics of galaxy clusters, to the study of active galactic nuclei, the structure of molecular clouds and their relationship with star formation in nearby galaxies and the Milky Way, and the study of celestial bodies in our Solar System. The commissioning team's activities therefore continue, with the aim of verifying MISTRAL's performance in each of these scientific cases and making the receiver available to the scientific community as soon as possible.

The first images acquired by MISTRAL

In December 2024, MISTRAL was pointed at the famous Orion Nebula (also known as M42) in the center of the Orion constellation. Located about 1350 light-years from Earth, M42 is one of the closest active star-forming regions and is characterized by ionized hydrogen excited by a group of massive stars known as the Trapezium. M42 is part of a vast complex of molecular clouds that extends over 30 degrees across the sky, and MISTRAL observed its central part at an angular resolution of 12 arcseconds. The Orion Bar is clearly visible in the image to the south, marking a sharp boundary between the region of ionized hydrogen and the molecular cloud below. Emission peaks can also be seen near the stars of the Trapezium and the Kleinmann–Low Nebula, a dense star-forming molecular cloud that hosts a star cluster which underwent an explosive event in the past. The emission from M42 visible at 90 GHz is an almost equal mixture of radiation from ionized hydrogen and that from cold dust contained in the underlying molecular cloud complex.

M42: The left panel shows the image of the nebula M42 taken at 90 GHz with the MISTRAL receiver. On the right, an overlay of the MISTRAL image with a wider-field image obtained by the Hubble Space Telescope (Credits: MISTRAL commissioning team; NASA, ESA, and The Hubble Heritage Team (STScI/AURA)).

In February 2025, MISTRAL observed the radio galaxy M87 in the constellation Virgo, whose active nucleus contains a now famous supermassive black hole, directly imaged thanks to the historic observation of the Event Horizon Telescope in 2019. The radio source surrounding M87 has a complex structure, made up of internal lobes measuring about thirty thousand light years (just over the distance that separates us from the center of the Milky Way) surrounded by an external plasma bubble on a larger scale. These structures are the result of the activity of the central black hole over the past several million years. The internal radio lobes are visible in MISTRAL's image – the most recent structures still powered by a pair of relativistic radio jets propagating from the central black hole. Observing these structures at such high frequencies provides new and valuable insights into the physical mechanisms powering the radio-emitting particles inside the source.

M87: Image of the radio source around M87 detected by MISTRAL at 90 GHz represented in red tones and contour lines, superimposed on an optical image, in blue tones, of the galaxy (Credits: MISTRAL commissioning team; Sloan Digital Sky Survey).

Finally, in the April 2025 session, MISTRAL observed – through two cross-scans of about half an hour each – the supernova remnant Cassiopeia A (Cas-A), one of the most intense radio sources in the sky, with an angular size of about 5 arcminutes (about one-sixth the apparent diameter of the full Moon). The expanding gas shell is visible in its entirety and, thanks to the angular resolution of SRT at these wavelengths, it is possible to appreciate the details and brightness variations of the filamentary structure.

Cassiopeia A: Image of the supernova remnant Cassiopeia A taken at 90 GHz with the MISTRAL receiver (Credits: MISTRAL commissioning team).

December 13, 2024 – In April 2019, the Event Horizon Telescope Collaboration (EHT) scientists released the first image of a black hole in the galaxy Messier 87 (M87), and since then have been busy imaging several other black holes. The same EHT Collaboration has recently coordinated a second campaign on M87 and detected a spectacular flare from the powerful relativistic jet emanating from the very centre of the same galaxy at multiple wavelengths. Also known as Virgo A or NGC 4486, M87 is the brightest object in the Virgo cluster of galaxies, the largest gravitationally bound type of structure in the universe. Led by the EHT-MWL working group, the study presents the data from the second EHT observational campaign conducted in April 2018, involving over 25 ground-based and space-based telescopes. The authors report the first observation in over a decade of a high-energy gamma-ray flare (detecting photons up to thousands of billions of times the energy of visible light) from the supermassive black hole M87* after obtaining nearly simultaneous spectra of the galaxy with the broadest wavelength coverage ever collected.

"We were lucky to detect a gamma-ray flare from M87 during this Event Horizon Telescope's multi-wavelength campaign. This marks the first gamma-ray flaring event observed in this source in over a decade, allowing us to precisely constrain the size of the region responsible for the observed gamma-ray emission. Observations—both recent ones with a more sensitive EHT array and those planned for the coming years—will provide invaluable insights and an extraordinary opportunity to study the physics surrounding M87’s supermassive black hole. These efforts promise to shed light on the disk-jet connection and uncover the origins and mechanisms behind the gamma-ray photon emission." says Giacomo Principe, the project coordinator, a researcher at the University of Trieste associated with INAF and INFN. The article has been published in Astronomy & Astrophysics.

The relativistic jet examined by the researchers is surprising in its extent, reaching sizes that exceed the black hole’s event horizon by tens of millions of times - akin to the difference between the size of a bacterium and the largest known blue whale.

The energetic flare, which lasted approximately three days and suggests an emission region of less than three light-days in size (~170 AU, where 1 Astronomical Unit is the distance from the Sun to Earth), revealed a bright burst of high-energy emission—well above the energies typically detected by radio telescopes from the black hole region.

"Together with the sub-millimetre observations from EHT, the new multi-wavelength data offer a unique and unprecedented opportunity to understand the properties of the gamma-ray emission, link it to potential changes in the M87 jet, and allow for more sensitive tests of general relativity," emphasises Principe, underlining the potential for ground-breaking discoveries.

The second EHT and multi-wavelength campaign in 2018 leveraged more than two dozen high-profile observational facilities, including NASA’s Fermi-LAT, HST, NuSTAR, Chandra, and Swift telescopes, together with the world’s three largest Imaging Atmospheric Cherenkov Telescope arrays (H.E.S.S., MAGIC and VERITAS). These observatories are sensitive to X-ray photons and high-energy, very-high-energy (VHE) gamma-rays, respectively. During the campaign, the LAT instrument aboard the Fermi space observatory detected an increase in high-energy gamma-ray flux with energies up to billions of times greater than visible light.

Elisabetta Cavazzuti, head of the Fermi program for ASI, underscores the critical importance of coordinated multi-wavelength observations: "Fermi-LAT detected a significant increase in flux during the same period as other observatories, aiding in the identification of the gamma-ray emission region during these brightness surges. M87 serves as a laboratory, underscoring the critical importance of coordinated multi-wavelength observations and thorough sampling to fully characterise the source's spectral variability. This variability likely spans different time scales, providing a comprehensive view across the entire electromagnetic spectrum."

Chandra and NuSTAR then collected high-quality data in the X-ray band. The VLBA (Very Long Baseline Array) radio observations - for which the INAF radio astronomy stations were also involved - show an apparent annual change in the jet's position angle within a few milliarcsec from the galaxy's core.

Principe continues: "These results offer the first-ever possibility to identify the point from where the particles causing the flare are being accelerated. This could potentially resolve a long-standing debate about the origin of cosmic rays (very high-energy particles from space) detected on Earth."

Data also show a significant variation in the position angle of the asymmetry of the ring (the so-called 'event horizon' of the black hole) and the jet’s position, suggesting a physical relation between these structures on very different scales. The researcher explains: “In the first image obtained during the 2018 observational campaign, the emission along the ring was not homogeneous, thus presenting asymmetries (i.e., brighter areas). Subsequent observations conducted in 2018 and related to this paper confirmed the data, highlighting that the asymmetry's position angle had changed.”

“How and where particles are accelerated in supermassive black hole jets is a longstanding mystery.  For the first time, we can combine direct imaging of the near event horizon regions during gamma-ray flares from particle acceleration events and test theories about the flare origins,” says Sera Markoff, a professor at the University of Amsterdam and co-author of the study.

This discovery paves the way for stimulating future research and potential breakthroughs in understanding the universe.

Related journal article: "Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode", by The Event Horizon Telescope- Multi-wavelength science working group, The Event Horizon Telescope Collaboration, The Fermi Large Area Telescope Collaboration, H.E.S.S. Collaboration, MAGIC Collaboration, VERITAS Collaboration, and EAVN Collaboration. In: Astronomy & Astrophysics.

The images can be used to cover this topic. Please include credits as follows:

Figure 1:

Light curve of the gamma-ray flare (bottom) and collection of quasi-simulated images of the M87 jet (top) at various scales obtained in radio and X-ray during the 2018 campaign. The instrument, the wavelength observation range and scale are shown at the top left of each image. Credits: EHT Collaboration, Fermi-LAT Collaboration, H.E.S.S. Collaboration, MAGIC Collaboration, VERITAS Collaboration, EAVN Collaboration

Figure 2:

The observatories and telescopes that participated in the 2018 multiband campaign to detect the high-energy gamma-ray flare from the M87* black hole. Credits: EHT Collaboration, Fermi-LAT Collaboration, H.E.S.S. Collaboration, MAGIC Collaboration, VERITAS Collaboration, EAVN Collaboration

Animation: https://www.dropbox.com/scl/fi/onwoa80ypymd6mm0exlr7/VHE_LC_skymap_animation.mp4?rlkey=vdnph7b5f5be10ae4aqeo2h52&dl=0

Very high energy gamma-ray flare observed by Cherenkov telescopes (H.E.S.S., MAGIC and VERITAS). Credits: EHT Collaboration, Fermi-LAT Collaboration, H.E.S.S. Collaboration, MAGIC Collaboration, VERITAS Collaboration, EAVN Collaboration

Contacts:

INAF Press Office - Marco Galliani, +39 335 1778428, ufficiostampa@inaf.it

November 20, 2024 – In the article published today in the Astronomy & Astrophysics journal, new evidence suggests how supermassive black holes, with masses of several billion times that of our Sun, formed so rapidly in less than a billion years after the Big Bang. The study, led by researchers of the National Institute for Astrophysics (INAF), analyses a sample of 21 quasars, among the most distant ever discovered, observed in the X-rays band by the XMM-Newton and Chandra space telescopes. The results suggest that the supermassive black holes at the centre of these titanic quasars, the first formed during the cosmic dawn, may have reached their extraordinary masses through very rapid and intense accretion, thus providing a plausible explanation for their existence in the early stages of the Universe.

Quasars are active galaxies powered by the central supermassive black holes (known as active galactic nuclei), which emit an enormous amount of energy as they attract matter. They are extremely luminous and distant from us. In particular, the quasars examined in this study are among the most distant objects ever observed, dating back to a time when the Universe was less than a billion years old.

In this work, the analysis of X-ray emissions from these objects revealed an entirely unexpected behaviour of the supermassive black holes at their centres: a connection emerged between the shape of the X-ray emission and the speed of the winds of matter ejected by the quasars. This relationship links the wind speed, which can reach thousands of kilometres per second, to the temperature of the gas in the corona, the region that emits X-rays closest to the black hole. Thus, the corona turned out to be connected to the powerful accretion mechanisms of the black hole itself. Quasars with low-energy X-ray emission, and thus a lower temperature in the corona, show faster winds. This indicates a highly rapid growth phase that exceeds a physical limit for the accretion of matter called the Eddington limit, which is why this phase is called "super-Eddington." Conversely, quasars with higher-energy X-ray emissions tend to exhibit slower winds.

"Our work suggests that the supermassive black holes at the centre of the first quasars formed within the first billion years of the Universe's life may have actually increased their mass very rapidly, challenging the limits of physics," says Alessia Tortosa, lead author of the study and researcher at INAF in Rome. "The discovery of this connection between X-ray emission and winds is crucial for understanding how such large black holes could have formed in such a short time, thus providing a concrete clue to solve one of the greatest mysteries of modern astrophysics."

The result was achieved mainly by analysing data collected with the XMM-Newton space telescope of the European Space Agency (ESA), which allowed for approximately 700 hours of observations of the quasars. Most of the data, collected between 2021 and 2023 as part of the Multi-Year XMM-Newton Heritage Programme, under the direction of Luca Zappacosta, a researcher at INAF in Rome, is part of the HYPERION project, which aims at studying hyperluminous quasars during the cosmic dawn of the Universe. The extensive observation campaign was led by a team of Italian scientists and received crucial support from INAF, which funded the program, thereby supporting cutting-edge research on the evolutionary dynamics of the early structures of the Universe.

"In the HYPERION program, we focused on two key factors: on one hand, the careful selection of quasars to observe, choosing the titans, meaning those that had accumulated as much mass as possible, and on the other hand, the in-depth study of their properties in X-rays, something never attempted before on such a large number of objects from the cosmic dawn," says Luca Zappacosta, a researcher at INAF in Rome. We hit the jackpot! The results we're getting are genuinely unexpected, and they all point to a super-Eddington growth mechanism of the black holes."

This study provides important insights for future X-ray missions, such as ATHENA (ESA), AXIS, and Lynx (NASA), which are scheduled for launch between 2030 and 2040. In fact, the results obtained will be useful for refining the next-generation observational instruments and for defining better strategies for investigating black holes and active galactic nuclei in X-rays at more distant cosmic epochs. These are key elements for understanding the formation of the first galactic structures in the primordial Universe.

Related journal article: “HYPERION. Shedding light on the first luminous quasars: A correlation between UV disc winds and X-ray continuum”, di Tortosa A. et al. 2024, Astronomy & Astrophysics.

INAF PRESS OFFICE:

Marco Galliani | M +39 335 177 8428 - marco.galliani@inaf.it - ufficiostampa@inaf.it

Representatives of the SKAO's 12 member states unanimously approved the appointment by election of Dr Zerbi during the Observatory’s thirteenth Council meeting in Kimberley, Northern Cape, South Africa, on 5-6 November. The Council also appointed Ms Inmaculada Figueroa, Vice Director General for Internationalisation of Science and Innovation at the Spanish Ministry of Science, Innovation and Universities and Spain’s representative on the Council, as the body’s new vice-chair. The Council meets three times per year and oversees the Observatory’s funding and strategic direction.

"I am honoured to assume the role the SKAO Council has assigned me, and I am looking forward to contributing to the Observatory’s development in this exciting and interesting phase," Dr Zerbi said.

Dr Zerbi will take up the role from 3 February 2025 until 31 December 2026. He will succeed Dr Catherine Cesarsky, who has held the position since the Observatory was founded in 2021. Dr Cesarsky also chaired the Board of Directors of its precursor, the SKA Organisation, from 2017.

“I am very happy to be handing over this important role to such a highly regarded colleague, who I have had the pleasure of knowing for many years, sharing many ideas, experiences and valuable conversations,” Dr Cesarsky said.

“I join the rest of the Council in congratulating Dr Zerbi on this appointment and wishing him the best for his tenure.”

Born in Milan, Italy, Dr Zerbi completed his PhD in Astrophysics at the University of Pavia and University of Milan. Following pre-doctoral and post-doctoral roles in Spain, he joined the Astronomical Observatory of Brera in Milan in 1997, reaching the position of senior researcher in 2016, when he was appointed as INAF’s Science Director, a post in which he has just completed his second term. He also worked at the European Southern Observatory during the development of the Extremely Large Telescope (ELT) Construction Proposal.

A prolific scientific author with more than 330 papers to his name, Dr Zerbi is an expert in stellar astrophysics, and has extensive experience in multiwavelength and multi-messenger astronomy through the design and construction of instrumentation for visible and infrared ground-based and space-borne observatories, particularly robotic telescopes and high-resolution spectroscopy.

“I would like to give my personal thanks to Dr Cesarsky for her years of service as the chair of the SKAO Council, and the guidance and vision she brought to our Observatory. Her boundless enthusiasm and passion for the SKA project have been infectious, inspiring all of us to push boundaries and reach for the stars – quite literally,” said Prof. Philip Diamond, SKAO Director-General.

“I look forward to working with Dr Zerbi in the coming months and years. Having seen the extremely valuable contributions he has made to the Observatory in his capacity as the Italian representative in the Council, I’m confident the Council is in good hands for the challenges to come and for guiding us towards new achievements.”

Source: SKA Observatory Website

Emanuele Dalessandro, researcher at INAF in Bologna, lead author of the article and coordinator of the working group, explains: "Understanding the physical processes behind the formation and early evolution of globular clusters is one of the most fascinating and debated astrophysical questions of the past 20–25 years. The results of our study provide the first solid evidence that globular clusters formed through multiple star formation events and place fundamental constraints on the dynamical path followed by the clusters throughout their evolution. These results were made possible by a multi-diagnostic approach and the combination of state-of-the-art observations and dynamic simulations."

The study highlights that the kinematic differences between multiple populations are key to understanding the formation and evolution mechanisms of these ancient structures.

With ages that can reach 12-13 billion years (thus dating back to the dawn of the cosmos), globular clusters are among the first systems to form in the Universe. They represent a typical population of all galaxies. They are compact systems (with masses of several hundred thousand solar masses and sizes of a few parsecs), and they can be observed even in distant galaxies.

"Their astrophysical significance is huge," says Dalessandro, "because they not only help us to test cosmological models of the formation of the Universe due to their age but also provide natural laboratories for studying the formation, evolution, and chemical enrichment of galaxies." Despite globular clusters have been studied for over a century, recent observational results show that our knowledge is still largely incomplete.

"Results obtained in the last two decades have unexpectedly shown that globular clusters consist of more than one stellar population: a primordial one, with chemical properties similar to other stars in the Galaxy, and another with anomalous chemical abundances of light elements such as helium, oxygen, sodium, and nitrogen," says Mario Cadelano, researcher at the Department of Physics and Astronomy at the University of Bologna and INAF associate, one of the authors of the study. "Despite the large number of observations and theoretical models aimed at characterising these populations, the mechanisms regulating their formation are still not understood."

The study is based on the measurement of 3D velocities, i.e., the combination of proper motions and radial velocities, obtained with the ESA Gaia telescope and with data from, among others, the ESO VLT telescope, primarily as part of the MIKiS survey (Multi Instrument Kinematic Survey), a spectroscopic survey specifically aimed at exploring the internal kinematics of globular clusters. The use of these telescopes, from space and the ground, has provided an unprecedented 3D view of the velocity distribution of stars in the selected globular clusters.

The analysis reveals that stars with different abundances of light elements are characterised by different kinematic properties, such as rotational velocities and orbital distributions.

"In this work, we analysed in detail the motion of thousands of stars within each cluster," adds Alessandro Della Croce, a PhD student at INAF in Bologna. "It quickly became clear that stars belonging to different populations have distinct kinematic properties: stars with anomalous chemical composition tend to rotate faster than the others within the cluster and progressively spread from the central regions to the outer ones."

The intensity of these kinematic differences depends on the dynamical age of globular clusters. "These results are consistent with the long-term dynamical evolution of stellar systems, in which stars with anomalous chemical abundances form more centrally concentrated and rotate more rapidly than the standard ones. This, in turn, suggests that globular clusters formed through multiple star formation episodes and provides an important piece of information in defining the physical processes and timescales underlying the formation and evolution of massive stellar clusters," Dalessandro emphasises.

This new 3D view of the motion of stars within globular clusters provides an unprecedented and fascinating framework for the formation and dynamical evolution of these intriguing systems. It also helps to clarify some of the most complex mysteries surrounding the origin of these ancient structures.

Related journal article: “A 3D view of multiple populations kinematics in Galactic globular clusters”, by  E. Dalessandro, M. Cadelano, A. Della Croce, F. I. Aros, E. B. White, E. Vesperini, C. Fanelli, F. R. Ferraro, B. Lanzoni, S. Leanza, L. Origlia. In: Astronomy & Astrophysics.

Contacts:

INAF Press Office - Marco Galliani, +39 335 1778428, ufficiostampa@inaf.it

AGU, the world's largest Earth and space science association, celebrates individuals and teams through its annual Honors and Recognition program for their accomplishments in research, education, science communication, and outreach. These honorees have transformed our understanding of the world, impacted our everyday lives, improved our communities and contributed to solutions for a sustainable future.

Orosei's research focuses on the nature, structure and origin of planetary surfaces and subsurfaces, focusing on the search of water and ice on Mars to assess its past and current habitability. He is a science team member of space experiments for the Rosetta and Jupiter Icy Moons Explorer missions of the European Space Agency, and for NASA's Cassini, Mars Reconnaissance Orbiter, Dawn and Juno probes. He is the principal investigator of the MARSIS radar on board ESA's Mars Express spacecraft, which provided evidence of the presence of liquid water beneath the South polar cap of Mars.

"I feel deeply honored by this recognition. I am still amazed at how actual Sagan's reflections on science, society and the human condition are even today," said Orosei. "He seems almost prescient when he describes the future of society in an information economy. However, my favorite quote still remains “Science is not only compatible with spirituality; it is a profound source of spirituality.”"

Roberto Orosei joins a distinguished group of scientists, leaders and communicators recognized by AGU for advancing science. Each honoree reflects AGU's vision for a thriving, sustainable and equitable future supported by scientific discovery, innovation and action.

Honorees will be recognized at AGU24, which will convene more than 25,000 attendees from over 100 countries in Washington, D.C. and online everywhere on 9-13 December 2024. Reflecting the theme 'What's Next for Science' at AGU24, the Honors Reception will recognize groundbreaking achievements that illustrate science's continual advancement, inspiring the AGU community with their stories and successes.

Observations of this quasar (already described by the same authors in another study published last May), one of the first studied with NIRSpec when the universe was less than a billion years old (redshift z = 6.2342), have revealed data of sensational quality: the instrument “captured” the quasar’s spectrum with an uncertainty of less than 1% per pixel. The host galaxy of PJ308–21 shows high metallicity and photoionisation conditions typical of an active galactic nucleus (AGN), whereas one of the satellite galaxies exhibits low metallicity (which refers to the abundance of chemical elements heavier than hydrogen and helium) and photoionisation induced by star formation; a higher metallicity characterises the second satellite galaxy, which is partially photoionised by the quasar.

Map of the line emission of hydrogen (in red and blue) and oxygen (in green) in the PJ308-21 system, shown after masking the light from the central quasar ("QSO"). The different colours of the quasar's host galaxy and companion galaxies in this map reveal the physical properties of the gas within them. Credits: Decarli/INAF/A&A 2024

The discovery has enabled astronomers to determine the mass of the supermassive black hole at the centre of the system (about 2 billion solar masses). It also confirmed that both the quasar and the surrounding galaxies are highly evolved in mass and metal enrichment, and in constant growth. This has profound implications for our understanding of cosmic history and galaxies' chemical evolution, highlighting this research's transformative impact.

Roberto Decarli, a researcher at INAF in Bologna and first author of the article, explains: "Our study reveals that both the black holes at the centre of high-redshift quasars and the galaxies that host them undergo extremely efficient and tumultuous growth already in the first billion years of cosmic history, aided by the rich galactic environment in which these sources form". The data were obtained in September 2022 as part of Program 1554, one of the nine Italian-led projects of the first observation cycle of JWST. Decarli leads this program to observe the merger between the galaxy hosting the quasar (PJ308-21) and two of its satellite galaxies.

The observations were carried out in integral field spectroscopy mode: for each image pixel, the spectrum of the entire optical band (in the source rest frame) can be observed, shifted towards the infrared by the universe’s expansion. This allows for the study of various gas tracers (emission lines) using a 3D approach. Thanks to this technique, the team led by INAF detected spatially extended emissions from different elements, which were used to study the properties of the ionised interstellar medium, including the source and hardness of the photoionising radiation field, metallicity, dust obscuration, electron density and temperature, and star formation rate. Furthermore, the researchers marginally detected the starlight emission associated with companion sources.

(Click on the image to start the animation) Map of ionised oxygen emission in the PJ308-21 system, observed with the James Webb Space Telescope. Each frame shows a different speed range. In the animation, we see the complex three-dimensional structure of the system and the "cosmic dance" of the satellite galaxies around the quasar. Credits: Decarli/INAF/A&A 2024

Federica Loiacono, astrophysicist, research fellow and postdoc working at INAF, enthusiastically comments on the results: "Thanks to NIRSpec, for the first time we can study in the PJ308-21 system the optical band, rich in precious diagnostic data on properties of the gas near the black hole in the galaxy hosting the quasar and in the surrounding galaxies. We can see, for example, the emission of hydrogen atoms and compare it with the chemical elements produced by the stars to establish how rich the gas in galaxies is in metals. The experience in reducing and calibrating these data, some of the first collected with NIRSpec in integral field spectroscopy mode, has ensured a strategic advantage for the Italian community in managing similar data from other programs". Federica Loiacono is the Italian contact person for NIRSpec data reduction at the INAF JWST Support Center.

She adds: “Thanks to the sensitivity of the James Webb Space Telescope in the near and medium infrared, it was possible to study the spectrum of the quasar and companion galaxies with unprecedented precision in the distant universe. Only the excellent 'view' offered by JWST, with its unparalleled capabilities, can ensure these observations". The work represented a real "emotional rollercoaster", Decarli continues, "with the need to develop innovative solutions to overcome the initial difficulties in data reduction".

This transformative impact of the James Webb Space Telescope's onboard instruments underscores its crucial role in advancing astrophysical research: “Until a couple of years ago, data on the enrichment of metals (essential for understanding the chemical evolution of galaxies) were almost beyond our reach, especially at these distances. Now we can map them in detail with just a few hours of observation, even in galaxies observed when the universe was in its infancy", Decarli concludes.

Related journal article: "A quasar-galaxy merger at z ∼ 6.2: rapid host growth via accretion of two massive satellite galaxies”, by Roberto Decarli, Federica Loiacono, Emanuele Paolo Farina, Massimo Dotti, Alessandro Lupi, Romain A. Meyer, Marco Mignoli, Antonio Pensabene, Michael A. Strauss, Bram Venemans, Jinyi Yang, Fabian Walter, Julien Wolf, Eduardo Bañados, Laura Blecha, Sarah Bosman, Chris L. Carilli, Andrea Comastri, Thomas Connor, Tiago Costa, Anna-Christina Eilers, Xiaohui Fan, Roberto Gilli, Hyunsung D. Jun, Weizhe Liu, Madeline A. Marshall, Chiara Mazzucchelli, Marcel Neeleman, Masafusa Onoue, Roderik Overzier, Maria Anne Pudoka, Dominik A. Riechers, Hans-Walter Rix, Jan-Torge Schindler, Benny Trakhtenbrot, Maxime Trebitsch, Marianne Vestergaard, Marta Volonteri, Feige Wang, Huanian Zhang, Siwei Zou. Forthcoming in: Astronomy & Astrophysics.

Contacts:

INAF Press Office - Marco Galliani, +39 335 1778428, ufficiostampa@inaf.it

With these objectives in mind, the National Institute for Astrophysics has won an ESO international call for proposals aimed at producing forecasts of optical turbulence (OT) and the main atmospheric parameters to optimise astronomical observations of the VLT and all the instruments with which it is equipped. The selected project, called FATE (Forecasting Atmosphere and Turbulence for ESO sites) sees the collaboration of the CNR/Regione Toscana consortium LaMMA (Laboratorio di Monitoraggio e Modellistica Ambientale per lo sviluppo sostenibile), which also provides meteo services for the Italian Civil Protection.

The FATE project began in November 2022 and entered the commissioning phase in September - December 2023, with tests to verify the technical and operational specifications. Once completed, it will enter in the operational phase in which ESO will be able to optimise observing strategies for the VLT and start planning those for ELT, which is currently scheduled to come into operation in 2028.

"The commissioning lasted four months and was aimed at verifying the robustness of the prediction system and compliance with the technical specifications required by ESO, i.e. the accuracy of the predictions of the different parameters at different time scales," says Elena Masciadri, INAF researcher and principal investigator of the FATE project. "The spatio-temporal fluctuations of optical turbulence have much smaller typical scales than those of classical atmospheric parameters and therefore the prediction of optical turbulence is a much more difficult objective to achieve. ESO's technical specifications are also quite stringent, as one would naturally expect, considering that the VLT is undoubtedly one of the most prestigious telescopes in the world, but also one of the most complex, consisting of four 8.2-metre diameter telescopes plus four 1.8-metre auxiliary telescopes, with a great variety of instrumentation and therefore observing possibilities. We can say that we are satisfied with the commissioning,' continues Masciadri, 'as it has allowed us to demonstrate the robustness and reliability of the system, and at the same time to better define the margins for improving the accuracy of the predictions where we will concentrate in the second phase of the project.

The magnificent Milky Way stretching over the Very Large Telescope (VLT) at ESO’s Paranal Observatory, demonstrating the astounding level of detail visible in the night sky from this remote site in the Chilean Atacama Desert. Credit: P. Horálek/ESO

Modern telescopes are now equipped with interchangeable instruments that have specific conditions of use, which also depend on the atmospheric conditions prevailing during observations. Some of these instruments are not very sensitive to, for example, a high concentration of humidity in the air, while others are almost completely 'blinded' by it. For certain types of scientific programmes, it is very important to collect data in the presence of a weak optical turbulence, for example in all observations requiring a high level of detail in small portions of the sky that exploit the benefits of adaptive optics, such as in the search for exoplanets. In general, knowledge of optical turbulence is crucial in all observations supported by adaptive optics.  The ELT will be a facility supported 100 per cent by adaptive optics, so the prediction of optical turbulence is certainly crucial for next generation astronomy.

Beside to the prediction above the VLT of a number of atmospheric parameters such as temperature, wind strength and direction, relative humidity, water vapour and cloud cover, the FATE project will also be concerned with the prediction of so-called astroclimatic parameters at night, including the so-called seeing, a parameter indicating the level of the atmospheric perturbation in the quality of astronomical images. But what is the optical turbulence? Temperature fluctuations in the air generate fluctuations in the refractive index, which in turn perturbs the wavefront of light from the celestial objects observed. This wavefront is thus 'imperfect' and the image collected by the telescope looses details accuracy, thus limiting the potential of the instrumentation used. Adaptive optics techniques aim to correct for these perturbations, but their performance depends on the state of the turbulence, which is why an accurate prediction of the optical turbulence is essential.

A forecasting system such as the one envisaged in the FATE project is based on hydrodynamic models that are defined as 'mesoscale': the model is applied to a limited region of the Earth, achieving a higher resolution than a forecast on a global scale could provide. This forecast is made using, as initialisation data, those produced by general circulation models, i.e. applied to the entire globe by the European Centre for Medium Range Weather Forecast (ECMWF), the centre acting on behalf of the entire European community.

INAF's experience in the field of optical turbulence forecasting for astronomy acquired over the years was fundamental in arriving at the FATE project: "We developed a model for forecasting optical turbulence, called Astro-Meso-NH in the 1990s, and since then the system has evolved, it has been applied to several among the best observatories in the world and more recently has been automated, making the model usable in operational mode and not just for research purposes", recalls Elena Masciadri "the development of modern 'assimilation data' techniques and more generally the statistical techniques of spatial filtering have guaranteed us levels of accuracy that were inconceivable only a decade ago. INAF,' concludes Masciadri, 'has the scientific responsibility for the FATE project, taking care of the development of the automatic operational forecasting system, the study and development of the algorithms required to obtain the technical specifications of the forecasting system, and all the activities necessary to improve performance that will be implemented during the first years of the operational phase. The LaMMA has the operational responsibility to manage and monitor the forecast system, both on a daily basis and over longer time intervals, and thus to ensure optimal coverage of the system”. “Software for the OT forecasts is operational in LaMMA and use High Performance Computing ressources (HPC) that are expressely dedicated to FATE and have been purchased thanks also to a contribution from the Tuscany Region. The role of LaMMA in the project is based mainly on trustworthiness of its data center that, since  more than 20 years has shown reliability in terms of strenghtness and resilience in the field of the meteo service done for the Tuscany Region – says Alberto Ortolani, LaMMA researcher and responsible of the LaMMA unit – the deep scientific comptences of INAF in the field of the OT forecast and the long-time experience del LaMMA in the management of operational meteo services lead to the win of the international call opened by ESO. The fact that a tuscany proposal won this international competition make us very proud”.

Wednesday, 21 February 2024: The first MeerKAT+ antenna was today handed over in a festive ceremony in the Karoo region in South Africa. This marks another important step towards the SKA Observatory’s (SKAO) mid-frequency telescope, into which the 14 antennas of the MeerKAT extension will be integrated in the next few years. In addition to representatives of the members Max Planck Society (MPG), the South African Radio Astronomy Observatory (SARAO) and the Istituto Nazionale di Astrofisica (INAF) which are jointly financing these 14 antennas, invited guests from the partner countries involved and the SKAO took part in the handover ceremony.

In their welcoming remarks, Angus Paterson, Deputy CEO of the National Research Foundation in South Africa, Takalani Nemaungani, Chief Director for the Astronomy portfolio of the Department of Science and Innovation, Enrico Brandt, Deputy Ambassador of the German Embassy in South Africa, and Michael Kramer, Director at the Max Planck Institute for Radio Astronomy in Bonn, Germany, highlighted the importance of the event for the future of radio astronomy.

Together with Pontsho Maruping, Managing Director of the South African Radio Astronomy Observatory (SARAO), Michael Kramer addressed the development of the MeerKAT extension (MeerKAT+) antenna and the excellent collaboration throughout the entire process. “It is incredibly impressive to see what has already been achieved with the MeerKAT telescope, and even greater results could be expected with the expansion,” he said. The highlight of the ceremony was a trip to the antenna field, where the MeerKAT+ antenna was officially handed over by Fabrice Scheid, Managing Director of the Mainz location of OHB Digital Connect.

The expansion of the MeerKAT telescope will further deepen the scientific and technological cooperation that has already begun through the close collaboration between SARAO and the Max Planck Society (MPG) in Germany as part of MeerKAT. "The project has started only in 2019 and it is great to see that the first successes of this joint project are now visible," said Pontsho Maruping, adding that "The MeerKAT+ expansion project will significantly improve the sensitivity, angular resolution and image quality of the MeerKAT radio telescope.” The expansion of MeerKAT’s 64 parabolic antennas by at least another 14 dishes will result in a huge virtual telescope that can produce detailed radio images from the observation of weak radio sources.

These capabilities will grow even further when the MeerKAT antennas become part of the huge 197-dish SKA-MID telescope array, currently under construction at the same site.

The MeerKAT INAF team for band 5: Antonio Semola, Andrea Melis, Francesco Schillirò, Corrado Trigilo, Grazia Umana, Gianfranco Fallica, Alessandro Cabras

"The expansion of MeerKAT increases the sensitivity of the receiving systems by around 50%, enabling not only much faster mapping of the sky but also the detection of extremely weak astronomical sources," said Angus Paterson. Dennis Winkelmann, Managing Director of industry partner OHB Digital Connect, was satisfied with the result: "We have proven that the design is excellent, that it works for scientific use and that it is suitable for serial production on an industrial scale."

"This project is another example of the excellent and trusting cooperation between SARAO and MPIfR," said Michael Kramer. "It is fantastic to see this first MeerKAT+ antenna being completed. This is an achievement of partners from science and industry, nationally and internationally. And I can’t wait to see the first data from the antenna along with the rest of the array."

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Background Information

MeerKAT: Built and operated by the South African Radio Astronomy Observatory (SARAO), the 64 dish MeerKAT is the largest radio telescope in the Southern hemisphere and one of two SKA precursor instruments based in South Africa. Located in the Karoo semi- desert, the radio telescope will soon be expanded with an additional number of dishes, in the context of the “MeerKAT+” project, jointly funded in 2019 by SARAO and the Max-Planck- Gesellschaft (MPG) in Germany and since 2020 with the Istituto Nazionale di Astrofisica (INAF). The telescope will later be gradually integrated into SKAO's Mid telescope in South Africa.

SARAO: The South African Radio Astronomy Observatory, a facility of the National Research Foundation, is responsible for managing all radio astronomy initiatives and facilities in South Africa, including the MeerKAT Radio Telescope in the Karoo, and the Geodesy and VLBI activities at the HartRAO facility. SARAO also coordinates the African Very Long Baseline Interferometry Network (AVN) for the eight SKA partner countries in Africa, as well as South Africa’s contribution to the infrastructure and engineering planning for the Square Kilometre Array Radio Telescope (SKA).

MPG: The Max Planck Gesellschaft is a non-profit organisation with 86 institutes and research facilities. Among the society’s institutes is the Max Planck Institute for Radio Astronomy (MPIfR) as a key player in the SKA’s Dish engineering consortium. Together with German industry partners, such as the telescope antenna specialists MT Mechatronics (MTM), and international partners, the Dish consortium is responsible for designing the SKA’s mid-frequency array (SKA-Mid).

SKAO: The SKA Observatory (SKAO) is an intergovernmental organisation bringing together nations from around the world. Its mission is to build and operate cutting-edge radio telescopes to transform our understanding of the Universe, and deliver benefits to society through global collaboration and innovation. The Observatory has a global footprint and consists of the SKAO Global Headquarters in the UK, the SKAO’s two telescopes at radio- quiet sites in South Africa and Australia, and associated facilities to support the operations of the telescopes. Once in operation, the SKAO will be one global observatory operating two telescopes across three continents on behalf of its member states and partners.

INAF: The Istituto Nazionale di Astrofisica is the main Italian research institute for the study of the Universe, founded in 1999. INAF funds and operates seventeen separate research facilities, which in turn employ scientists, engineers and technical staff. The research they perform covers most areas of astronomy, ranging from planetary science to cosmology.

The conference is open to the general public and will be in Italian. It will be moderated by Dr. Massimo Stiavelli, head of the JWST mission office at the Space Telescope Science Institute (Baltimore, United States) since 2012.

This event is organized in collaboration between the Pontifical Academy of Sciences and Sapienza University of Rome, with patronage from the Italian National Institute for Astrophysics (INAF), as part of the workshop “Astrophysics: The James Webb Space Telescope. From first light to new visions of the world", which brings together researchers from all over the world at the Casina Pio IV, Vatican City, between 27 and 29 February, to discuss the first, exciting results of the James Webb space telescope (JWST). In addition to scientific results, the workshop aims to reflect also on what this new knowledge means for science and society.

Launched in 2021, JWST is a phenomenal time machine, capable of photographing the first stars and galaxies that formed shortly after the Big Bang and of studying the atmospheres of extrasolar planets, searching for those most similar to Earth.

For more information:

• Public lecture: https://www.phys.uniroma1.it/fisica/archivionotizie/le-scoperte-del-telescopio-spaziale-james-webb-alla-sapienza
• Science workshop: https://www.pas.va/en/events/2024/astrophysics.html