On March 19, Nicolas Laporte received one of the six “Français à l’Etranger” Trophies, in the “Education” category, at the Ministry of Foreign Affairs in Paris, in the presence of Minister Franck Riester (see picture below). Nicolas was rewarded for his work in research and popularization while a senior fellow at the Kavli Institute for Cosmology at Cambridge University (UK). Since then, Nicolas Laporte has joined the LAM where is pursuing his excellent work in research and science outreach!
English
Installation of the last modules of the PFS spectrograph in Hawaii
The SUBARU Prime Focus Spectrograph (PFS) is a wide-field multi-object spectrograph based on an international collaboration. PFS will carry out three major spectroscopic surveys with scientific objectives in cosmology, galaxy evolution and galactic archaeology.
Each of the international partners is making a contribution under a framework agreement, with the aim of building a 2400-fibre multi-object spectrograph (https://pfs.ipmu.jp/index.html). This new instrument exploits the wide field of the primary focus of the Subaru telescope, which houses the fibre positioner. The 60 m long fibres feed the spectrograph, which is located in a room heated to 5°C on one of the Nasmyth platforms. There are in fact 4 strands of 600 fibres each connected to the 4 spectrograph modules. Each module has 4 spectral channels from 380 to 1260 nm (https://pfs.ipmu.jp/research/parameters.html).
The LAM is responsible for the integration and testing of all the spectrographs, a task carried out within the laboratory. The Assemblies, Integrations and Tests (AIT) adventure, which began in 2015 and has been fraught with pitfalls, will come to an end in 2024 with the installation of all the modules at the Subaru telescope on the summit of Mauna Kea.
Two spectrograph modules with their Blue, Red and Near Infrared cameras had been installed and already tested on the sky before spring 2023. The two remaining spectrograph modules were shipped in 2023 and installed by a team from the LAM.
Performance tests have been carried out on the sky since 2023 and have shown the excellent functionality of all parts of the PFS instrument. However, an anomaly in the spectro-photometric transmission on the sky expected from the instrument has been detected, and after extensive analysis by a ‘tiger team’, the LAM’s PFS team has hypothesised that the PFS optical dispersive gratings may be misaligned, shifting and reducing the peak absolute transmission per band.
A spectrograph module has four channels, i.e. four gratings: three for the low-resolution channels (LR ~2000) in the blue, red and near infrared, and one for the medium-resolution mode (MR ~4500) in the red only.
Additional analyses, studies and tests have been carried out at JHU Baltimore, Bertin Winlight, IPMU Tokyo and at the LAM in 2023 to confirm this hypothesis and then to develop, test and validate a method and tooling that can change the orientation of gratings bonded to their support by 180 degrees. These reversals required special tools to handle the 50kg of optics. The consortium worked together to come up with the best solution in time.
The LAM team intervened in two stages, firstly to turn over the simple (low-resolution) 20kg gratings in the 3 spectral channels of each module in November 2023, and then to turn over the gratings in the 4th medium-resolution spectral channel (50kg optics) in February 2024.
The spectrograph is now almost complete.
The LAM has delivered, installed, aligned and validated the optical performance of all the spectrograph modules in collaboration with the Subaru team on site. However, two of the four near-infrared cameras need work to correct the inefficiency of their detectors. These operations are underway under the responsibility of JHU and Subaru. The telescope is once again operational after a shutdown period of several months, and tests on the PFS sky were carried out at the beginning of March 2024.
Some photographs of the team:
The JWST identifies a transition in the star formation mode of young galaxies.
Most galaxies follow a tight relation between their stellar mass and their star formation rate, implying that they form their stars gradually rather than through violent episodes of starbursts. Constrained up to z=6, when the Universe was 1 billion years old, this relation, called the galaxy main sequence, seems difficult to reconcile with the stochastic star formation of the very first galaxies predicted by simulations. Thanks to JWST data from the JADES extragalactic survey, researchers from LAM have highlighted a transition between these two modes of star formation when the Universe was about 700 million years old. They have used a new approach to reconstruct the star formation history of galaxies in order to study the establishment of the galaxy main sequence in the primordial Universe. In this study, they also showed that the stochasticity of the star formation they measure is not sufficient to explain the excess of very bright UV galaxies at z>10 observed in several studies of the earliest galaxies.
These results are part of a publication in press in A&A and are available in open access (https://arxiv.org/pdf/2309.15720.pdf).
LAM researchers involved in this study are Laure Ciesla, Olivier Ilbert, Véronique Buat, and Rafael Arango-Toro.
Best wishes 2024
All the teams at Laboratoire d’Astrophysique de Marseille would like to wish you the very best for 2024.
Training session for teachers at LAM
As part of the Year of Physics 2023-2024, the LAM welcomed some 50 teachers to the laboratory, in a training session organized with the Aix-Marseille education authority and the CNRS.
The program included introductory remarks by director Stéphane Arnouts, lectures by Stéphanie Escoffier, Alexandre Santerne and Annie Zavagno, and an afternoon tour of the laboratory to help participants discover the scientific themes, latest news and instrumental resources that enable us to push back the frontiers of astrophysical knowledge!
Webb reveals that galaxy mergers are the solution to early Universe mystery
One of the key missions of the NASA/ESA/CSA James Webb Space Telescope is to probe the early Universe. Now, the unmatched resolution and sensitivity of Webb’s NIRCam instrument have revealed, for the first time, what lies in the local environment of galaxies in the very early Universe. This has solved one of the most puzzling mysteries in astronomy — why astronomers detect light from hydrogen atoms which should have been entirely blocked by the pristine gas that formed after the Big-Bang. These new Webb observations have found small, faint objects surrounding the very galaxies that show the ‘inexplicable’ hydrogen emission. In conjunction with state-of-the-art simulations of galaxies in the early Universe, the observations have shown that the chaotic merging of these neighbouring galaxies is the source of this hydrogen emission.
Light travels at a finite speed (300 000 kilometres per second), which means that the further away a galaxy is, the longer it has taken the light from it to reach our Solar System. As a result, not only do observations of the most distant galaxies probe the far reaches of the Universe, but they also allow us to study the Universe as it was in the past. In order to study the very early Universe, astronomers require exceptionally powerful telescopes that are capable of observing very distant — and therefore very faint — galaxies. One of Webb’s key capabilities is its ability to observe those very distant galaxies, and hence to probe the early history of the Universe. An international team of astronomers have put Webb’s amazing capacity to excellent use in solving a long-standing mystery in astronomy.
The very earliest galaxies were sites of vigorous and active star formation, and as such were rich sources of a type of light emitted by hydrogen atoms called Lyman-α emission. However, during the epoch of reionisation an immense amount of neutral hydrogen gas surrounded these areas of active star formation (also known as stellar nurseries). Furthermore, the space between galaxies was filled by more of this neutral gas than is the case today. The gas can very effectively absorb and scatter this kind of hydrogen emission, so astronomers have long predicted that the abundant Lyman-α emission released in the very early Universe should not be observable today. This theory has not always stood up to scrutiny, however, as examples of very early hydrogen emission have previously been observed by astronomers. This has presented a mystery: how is it that this hydrogen emission — that should have long since been absorbed or scattered — is being observed? Researcher at the University of Cambridge and principal investigator on the new study Callum Witten elaborates:
“One of the most puzzling issues that previous observations presented was the detection of light from hydrogen atoms in the very early Universe, which should have been entirely blocked by the pristine neutral gas that was formed after the Big-Bang. Many hypotheses have previously been suggested to explain the great escape of this ‘inexplicable’ emission.”
The team’s breakthrough came thanks to Webb’s extraordinary combination of angular resolution and sensitivity. The observations with Webb’s NIRCam instrument were able to resolve smaller, fainter galaxies that surround the bright galaxies from which the ‘inexplicable’ hydrogen emission had been detected. In other words, the surroundings of these galaxies appear to be a much busier place than we previously thought, filled with small, faint galaxies. Crucially, these smaller galaxies were interacting and merging with one another, and Webb has revealed that galaxy mergers play an important role in explaining the mystery emission from the earliest galaxies. Nicolas Laporte, team member from Aix-Marseille University, adds:
“Where Hubble was seeing only a large galaxy, Webb sees a cluster of smaller interacting galaxies, and this revelation has had a huge impact on our understanding of the unexpected hydrogen emission from some of the first galaxies.”
The team then used state-of-the-art computer simulations to explore the physical processes that might explain their results. They found that the rapid build-up of stellar mass through galaxy mergers both drove strong hydrogen emission and facilitated the escape of that radiation via channels cleared of the abundant neutral gas. So the high merger rate of the previously unobserved smaller galaxies presented a compelling solution to the long-standing puzzle of the ‘inexplicable’ early hydrogen emission.
The team are planning follow up observations with galaxies at various stages of merging, in order to continue to develop their understanding of how the hydrogen emission is ejected from these changing systems. Ultimately, this will enable them to improve our understanding of galaxy evolution.
These findings have been published today in Nature Astronomy.
New Astronomy Finding Uncovers the Mystery of Star Formation at the Edge of Galaxies
International research team led by Stony Brook Professor Jin Koda and including Samuel Boissier from LAM uncovers the Mystery of star formation at the edge of Galaxies
The mystery of star formation in galaxies continues to intrigue astronomers worldwide. Yet a key question remains just how and why and where do stars form in the Universe? A new discovery from an international team of astronomers
provides a significant clue to star formation.
The research team used the Atacama Large Millimeter/submillimeter Array (ALMA) and investigated the far edge of the spiral galaxy M83, at a distance of 15 million light years from earth. They uncovered 23 concentrations of a dense molecular gas called “molecular clouds,” which are evidence of the birthing region of stars.
Molecular clouds are a typical site for star formation in the inner parts of galaxies. When it comes to the far edges of many galaxies, scientists had yet to understand how and why stars form because they could not pinpoint their formation sites. Yet, a surprising number of very young stars are known to exist at the far edges of many galaxies. The discovery of these 23 molecular clouds appears different from their counterparts in the typical star-forming sites in
galaxies. The large bodies of these clouds were not visible like “normal” molecular clouds—only their star-forming dense cores, the “hearts” of the clouds, were observed. This new research finding opens the door to a better understanding of the process of star formation in the Universe in general.
Additionally, the molecular cloud discovery uncovered a key link to the large reservoir of the diffuse atomic gas within the clouds. Normally, the atomic gas condenses into dense molecular clouds, where even denser cores develop and form stars. This process of conversion from atomic to molecular gas occurs even at the galaxy edges, but the conversion turned out to be very inefficient.
Koda and colleagues presented their findings in the 243rd meeting of the American Astronomical Society (AAS) in New Orleans on January 8. The AAS presentation included a confirmation of the hypothesis presented in a 2022 paper, titled “First Detection of the Molecular Cloud Population in the Extended Ultraviolet Disk of M83,” published in The Astrophysical Journal , along with new findings by way of the Jansky Very Large Array (VLA) and Green Bank Telescope (GBT).
Samuel Boissier contributed to the discovery of star formation at galaxy edges 18 years ago by the NASA’s GALEX satellite in so-called XUV galaxies, such as M83 . “This type of star formation at galaxy edges have been a nagging mystery since their discovery” says Koda, lead researcher. “Astronomers are eager to understand how stars form, and our discovery provides a clue to star formation processes.” Koda and co-authors write that “these molecular clouds are likely the main drivers of the star formation activity in galaxy edges.” They further explain: “We hypothesized that these clouds share, on average, the same common structure (mass distribution) as molecular clouds in the Milky Way, such as Orion, and have star-forming dense cores embedded in thick layers of bulk molecular gas. However, their envelopes are invisible.”
The revelation of these molecular clouds uncovered a link to a large reservoir of diffuse atomic gas, another discovery by this research. Normally, atomic gas condenses into dense molecular clouds, within which even denser cores develop and form stars. This process is in operation even at galaxy edges, but the conversion of this atomic gas to molecular clouds was not evident, for reasons that are unresolved.
Koda and colleagues came to their conclusion by using data collected using several instruments including the Atacama Large Millimeter/submillimeter Array (ALMA), the Karl G. Jansky Very Large Array (VLA), and the Green Bank Telescope (GBT), as well as with the National Astronomical Observatory of Japan’s (NAOJ) Subaru Telescope and the NASA Galaxy Evolution Explorer (GALEX).
Amanda Lee, who was an undergraduate student on Koda’s research team at Stony Brook University, processed GBT & VLA data for these findings. Through this, she discovered the atomic gas reservoir at the galaxy edge.
“We still do not understand why this atomic gas does not efficiently become dense molecular clouds and form stars,” adds Lee, who is now pursuing her Ph.D. in astronomy at UMass Amherst. “As often is the case in astronomy, pursuing answers to one mystery can often lead to another. That’s why research in astronomy is exciting.”
The research that led to team’s findings was supported in part by National Science Foundation grant AST-20006600 and by NASA grant NNX14AF74G.
LAM women in the spotlight
Because they represent the LAM and make science shine, whether they are researchers, teacher-researchers, engineers, technicians or administrators, we have decided to honor them through a mosaic in which a number of women have agreed to take part.
This panorama illustrates that an astronomy laboratory is open to all. A particularly important message for young girls wondering about their future! At the LAM, women make up around a quarter of the workforce, and are present in all the professions that make up astronomy: female researchers study the solar system, planets, galaxies or astronomical instrumentation. But there are also women engineers and technicians working in all fields: optics, mechanics, administration, IT… Some of them have also won prestigious prizes and are helping to spread a taste for science among the younger generation. Well done, and thank you.
The LAM prepares for the launch of Euclid, carrying the NISP instrument made in Marseille
On Saturday July 1, the Euclid satellite will be launched at 5:11 pm (Marseille time) and propelled towards its trajectory to reach the Lagrange L2 point one month later. Lift-off will take place from Cape Canaveral, aboard the SpaceX/Falcon 9 rocket. After ten years of development in which the LAM has played a leading role, as prime contractor for one of the two instruments, the NISP, this is a key phase in the project. You can find out more about this instrument on the project’s dedicated web page: https://www.lam.fr/projets/euclid-nisp/
Work on Euclid at the LAM is not yet finished. We will continue to work on data processing, and finally in a few months’ time on scientific analysis. Euclid will map the distribution of galaxies on large scales, giving us crucial new information on dark matter and dark energy in the universe.
You can follow the event live on several of the sites listed below.
SPACE X (English):
Space X broadcast: https://www.spacelaunchschedule.com/launch/falcon-9-block-5-euclid/
ESA (English only):
ESA broadcast: https://www.youtube.com/watch?v=1zcmH5aESHo
CNES/CNRS with the Stardust channel (in French)
Stardust : https://www.youtube.com/watch?v=rxczLEzzKrE
A new Tatooine-type multi-planetary system identified
An international team of astronomers has announced the second discovery of a multi-planetary circumbinary system. Circumbinary systems are unusual in that they contain planets that orbit two central stars rather than just one, as in our own solar system. The researchers involved in this team come from the University of Birmingham and the Laboratoire d’Astrophysique de Marseille (OSU Institut Pythéas / CNRS, AMU, CNES). This discovery is presented in the Monday 12 June 2023 issue of the journal Nature Astronomy.
Astronomy Festival of Provence : the end !
The 1st edition of the Festival of Astronomy of Provence was held as planned from May 6 to 12, 2023. At the end of a week rich in events, and in spite of the climatic hazards, we were able to ensure the almost integrality of the scientific program, except for the final evening of open air observations (cancelled because of rain). With about 40 astrophysicists from the LAM and about 30 volunteers from partner associations, supported by the CNRS, Aix-Marseille University and the French Astronomy and Astrophysics Society, the organizing committee welcomed more than 1500 people on the sites of the Historical Astronomical Observatory of Longchamp and of the LAM at Chateau-Gombert, as well as in the conference rooms lent by the cities of Marseille, Allauch and Plan-de-Cuques. Thanks to all and see you soon for new adventures!
Laure Ciesla, price for young researcher from SF2A 2023.
The SF2A board has awarded the 2023 young researcher prize to Laure Ciesla from the LAM. Laure Ciesla has been a researcher at the LAM since 2018. Her research focuses on the evolution of galaxies, guessing their history by using their spectral energy distribution and modelling it with the CIGALE code, in which she integrates, for example, the emission of supermassive black holes at the centre of galaxies, or is interested in the contribution of artificial intelligence to this subject. She is very involved in the PRIMA project (Probe far-infrared mission for Astrophysics), under discussion between NASA and CNES. She is also co-leader of the GECO team, and has organised a meeting at the LAM between young students and women in astrophysics, to fight against gender bias.
New Results for PAPYRUS at OHP!
PAPYRUS is an Adaptive Optics bench developed and put on sky by the LAM and ONERA at the Observatoire de Haute Provence (OHP). Since its release in June 2022, it has successfully corrected turbulence on multiple objects: single stars, double stars and extended object (Mars). These data feed abundantly the research in Adaptive Optics in order to provide better performing instruments to the community. Thus PAPYURS is a unique platform in France and in Europe allowing to test on the sky the new ideas and the new components developed by the scientific teams.
The Papyrus project allows to prepare and validate technological bricks which will come to equip the future instruments of the VLT and the ELT.
At the beginning of January, all the PAPYRUS team was gathered at the OHP for a week of observations and tests.
Among all the tested novelties, one of them concerned the acceleration of the Adaptive Optics loop to correct the effects of the turbulence up to 1500 times per second! The results are convincing as you can see on the attached animation.
Without the correction provided by PAPYRUS, the image of a star (on the left) is about 3 arcseconds, but thanks to the Adaptive Optics of PAPYRUS, the light is concentrated on less than 0.1 arcseconds. A gain of a factor 30 on the angular resolution! And above all a demonstration of the robustness of PAPYRUS to « erase » the effects of the atmosphere.
Congratulations to all the teams involved, and stay tuned for more great results to come!
Workshop on tele-work at LAM
On 30 January, a “co-construction workshop” was held on telework at the LAM, and more specifically on “how to respond to the problems raised by the results of the survey sent to staff on this subject”. Several topics were discussed (how to welcome a newcomer in hybrid mode, how to encourage inter-service and inter-team exchanges, how to maintain group cohesion, etc.). The objective was to draft a telework charter and to put in place effective actions to improve this system, using a “Word café” method (a creative process which aims to facilitate constructive dialogue and the sharing of knowledge and ideas) around several questions to be addressed, a reflection on our values, and a brainstorming session on the actions to be developed and the ideas to be included in the charter.
All staff were involved, ensuring that there was at least one teleworker and one non-teleworker per team and department. The participants were all motivated and there were many relevant ideas. This will lead to the drafting of a charter and the study of possible actions by the laboratory council.
LAM general assembly
On 16 January, the LAM’s traditional general meeting took place, an opportunity for all the staff to discover the Henri Fabre trophy, awarded by the Marseille Academy of Sciences, Arts and Letters to the whole laboratory, but also to thank Jean-Luc Beuzit, director of the LAM since 2018, who will now be the director of the OSU Pythéas. Samuel Boissier, formerly deputy director, is now acting director of the LAM until 1 January 2024.
It was also an opportunity to enjoy a piece “galette” in a good mood and in a friendly atmosphere
Click to know the new graduate students at LAM
The new graduate students starting their thesis this autumn are listed here:
Brieuc COLLET, started September 1st in GSP (ED 352 funds),
Supervisor: Laurent Lamy.
Title: In situ analysis of Jovian auroral decametric emissions with Juno
Lisa ALTINIER, starting October 1st in GRD (ERC funds).
Supervisors: Arthur Vigan and Elodie Choquet.
Title: Development of image processing methods for the detection of exoplanets in reflected light with the NASA Roman Space Telescope.
Alizée AMSLER, starting October 1st in GSP (AMU funds).
Supervisors: Olivier Mousis and Alexis Bouquet.
Title: Physico-chemical evolution of ice moon hydrospheres.
Rafael ARANGO-TORO, starting October 1st in GECO (ED 352 funds).
Supervisors: Laure Ciesla and Olivier Ilbert.
Title: Star Formation Histories of galaxies from deep multi-color images.
Houda BELLAHSENE, starting October 1st in GRD (LabCom NanoPTov ANR funds).
Supervisors: Yannick Guari (Institut Charles Gerhardt Montpellier, Montpellier) and Marc Ferrari.
Title: Optimization of surface chemistry processes for hyper-polished mirrors.
Loris BERTHELOT, starting Dec 1st in the GECO at LAM and QARMA at LIS (Interdisciplinary, CNRS 80PRIME fellowship).
Supervisors: Annie Zavagno (LAM) et Thierry Artières (LIS)
Title: Big Data et Apprentissage automatique pour l’étude de la formation stellaire Galactique
Salomé GROUFFAL, starting October 1st in GSP (CNES – Institut Origines funds).
Supervisor: Alexandre Santerne.
Title: Characterization of transiting exoplanets in the habitable zone.
Ny-Avo RAKOTONDRAINIBE, starting October 1st in GECO (AMU funds).
Supervisor: Véronique Buat.
Title: Multi-wavelength analysis from X-rays to the optical domain for the characterization of gamma-ray bursts and the galaxies that host them: the SVOM/COLIBRI synergy.
Théo SIEG-LETESSIER, starting October 1st in GRD (LabCom NanoPTov ANR funds).
Supervisors: Marc Ferrari and Ray Barret (European Synchrotron Radiation Facility, Grenoble)
Title: Metrology of large optical components with sub-nanometric accuracy.
Paolo SUIN, starting October 1st in GECO (ED 352 funds).
Supervisor: Annie Zavagno.
Title: High mass stars’ feedback impact on star formation properties.
Simon HANS, Starting November 1st in GRD (CNES – Thales Alenia Space funds)
Supervisors: Frédéric Zamkotsian and Guillaume Demésy (Institut Fresnel)
Title: Nanostructured blazed gratings for efficient and compact spectro-imagers in space.
Romain MAYER, Starting November 1st at Laboratoire Lagrange & LAM-GRD (Region Sud and ACRI-ST funds).
Supervisors: David Mary (Lagrange) & Elodie Choquet.
Title: Detection of exoplanets in high-contrast images using statistical learning.
Arnaud STRIFFLING, Starting November 1st in GRD.
Supervisors: Jeff Sauvage and Alexis Carlotti (IPAG)
Title: .Coupling adaptive optics and a high contrast instrument: ultimate performance of the pyramid analyzer.
Tom BENEST, will start in December 1st in GSP,
Supervisor: Olivier Mousis
Title: Study of the formation conditions of the Jupiter system.
Francisco OYAZUN, Starting December 1st in GRD.
Supervisors: Benoit Neichel, Thierry Fusco & Jean-Luc Gach
Title: Innovative detectors for high-performance Adaptive Optics. Application to exoplanet detection.
Jordi ROUBICHOU, starting December. 1st in GRD (CIFRE Thales Land & Air Systems funds).
Supervisor: Jean-Luc Beuzit; Advisors: Jean-Luc Gach (LAM) & Jean-Luc Reverchon (TLAS)
Title: Study of new types of SWIR detectors: extension of the operating band beyond 1.7μm
Crédit illustration: Image by pch.vector on Freepik
When a star metamorphoses into a black hole
On Sunday 9 October 2022, at precisely 13:16:50, the most energetic flare ever observed on Earth was detected by the US satellites FERMI and SWIFT. This flare, called GRB 221009A (GRB stands for Gamma Ray Burst), is the signature of the gravitational collapse of a very massive star (over 20 to 30 times the mass of the Sun) into a black hole.
But this gamma-ray burst is absolutely exceptional because it released photons with an energy of 18 teraelectronvolts (an 18 followed by 12 zeros!), even leading to a disruption of long-range communications on Earth. Considering that this event was emitted at a distance of 1.9 billion light-years from Earth, in a galaxy located in the constellation of the Arrow, this makes GRB 221009A one of the most violent astrophysical phenomena since the formation of the Universe.
This phenomenon immediately triggered a rather remarkable observation campaign, involving considerable resources. Researchers from the Laboratoire d’Astrophysique de Marseille (LAM) actively contributed to this campaign, in particular thanks to the observation facilities of the Observatoire de Haute-Provence (OHP), the T193 with the MISTRAL instrument and the T120. Thanks to excellent coordination between the LAM and OHP teams, it was possible to follow this remarkable phenomenon for several days.
This observation prefigures the many discoveries to come from the SVOM satellite and its follow-up telescope, COLIBRI. The latter will have the task of detecting and studying these remarkable objects, namely the super gamma-ray bursts, from the middle of 2023. The LAM and the OHP, as co-leaders of SVOM and COLIBRI, will thus be able to continue to play a key role in this hunt, in which the MISTRAL instrument of T193 will naturally have its place.
Contacts :
Stéphane BASA : stephane.basa@lam.fr
Christophe ADAMI: christophe.adami@lam.fr
“Fête de la Science” event
Staff from the LAM participated extensively in this year’s science festival. In particular, the laboratory hosted “unusual visits” from the CNRS on October 12th. A video report by a journalist from La Provence who followed the visit is available here: https://www.laprovence.com/actu/en-direct/6931020/video-au-coeur-du-laboratoire-dastrophysique-de-marseille.html
The laboratory also had a stand on the site of the Marseille Science Festival which welcomed nearly 7000 visitors during the weekend. We were able to discuss with the public, show models, one of the first images of the James Web Space Telescope, or even make a model of a comet nucleus live in front of young and old. And we made some great encounters!
Water on Mars
Studies carried out in part by the GSP team at the LAM and the Origins Institute has provided the first global, high-resolution map of the so-called ‘hydrated’ minerals on the surface of Mars. These minerals have the particularity of having been formed by chemical interaction between Martian rock and liquid water, and they often contain water trapped in their structure. They are thus excellent tracers of the ancient aqueous environments of Mars and exobiological targets of prime importance.
This global mapping, which took more than 10 years to build, highlights several hundred thousand sites of aqueous alteration on Mars, compared with about a thousand known previously. Most importantly, it reveals that the oldest surface of Mars (older than 3.7 Ga) is altered by water almost everywhere, changing our view of ancient Mars. Many of the mineralogical sites discovered in this way are being studied in greater depth because of their high scientific potential, particularly in the context of in-situ exploration of Mars. For example, the Oxia Planum landing site for the ESA ExoMars rover was discovered.
On Earth, certain hydrated minerals such as clays (phyllosilicates) or salts (sulphates) are known for their potential to sequester and preserve organic matter, particularly in sedimentary geological contexts. The identification of sites on Mars from orbit with similar composition and geology make them important candidates for the exploration of organic matter on Mars and its exobiological potential.
Ultimately, this mineral map will be used to better constrain the amount of Martian water trapped in its rocks today, in order to answer a key question about the history of Mars: did the planet ‘drink’ most of its water in its rocks? Another long-term objective is to propose landing sites for future human missions where these mineral deposits will allow the use of in-situ resources via the extraction of volatiles (including water) and as construction materials.
ESA Press Release:
https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/New_water_map_of_Mars_will_prove_invaluable_for_future_exploration
Contact:
John Carter
Marseille Astrophysics Laboratory (LAM / CNRS / Aix-Marseille University)
john.carter .at. lam.fr
Adoption of the Comet Interceptor space exploration mission
The Comet Interceptor space mission has been adopted by the European Space Agency (ESA) as the next mission to explore the solar system. Developed in collaboration with the Japanese space agency (JAXA), several national space agencies and research centres in Europe, including CNES and CNRS, Comet Interceptor will be the first space mission to visit a comet from the farthest reaches of the Solar System, or even outside the Solar System. A unique feature of this space mission will be that it will wait in the Solar System before merging with the comet. Such a comet may not be discovered for a few years and potentially after Comet Interceptor leaves Earth.
The Comet Interceptor space exploration mission, proposed by the European scientific community and pre-selected by ESA in 2019 to study its feasibility, was adopted on 8 June 2022 by ESA. It will be implemented in the coming years for launch in 2029.
Comet Interceptor can be seen as a descendant of ESA’s pioneering cometary missions Giotto and Rosetta. It is different, however, because it will provide the first simultaneous observations – from three different points – of an object outside the Earth’s environment, and because it will target a comet visiting the inner Solar System for the first time – probably from the large Oort cloud surrounding the outer reaches of the Solar System. This type of comet can only be observed a few years before it enters the inner Solar System, so one of the singularities of the Comet Interceptor mission is that its target has not yet been discovered, even though it has already begun its journey towards us.
Comet Interceptor will consist of three space probes. The composite spacecraft will wait patiently at a point in the Solar System (the Lagrange point L2) for a suitable target comet, and then travel together before the three space probes split up a few weeks before intercepting the comet. Its three spacecraft will then make simultaneous observations around the comet. Each spacecraft will be equipped with specific scientific instruments that will provide complementary information about the comet’s nucleus and its gas, dust and plasma environment, to understand the nature of a primitive comet interacting with the ever-changing solar wind environment. They will create the first 3D profile of a comet from the Oort cloud, containing material that has survived since the formation of the Sun and planets.
CNRS and CNES are fully involved in the Comet Interceptor mission through contributions to four on-board instruments, two of which are directly under French responsibility. CNRS is also responsible for coordinating the scientific modelling, which is crucial for the selection of the target comet. Astrophysicists from 10 French laboratories (LPC2E in Orleans; IRAP and LAPLACE in Toulouse; LAM in Marseille; LAB in Bordeaux; LGLTPE in Lyon; Lagrange in Nice; IMCCE, LESIA, LATMOS in Paris) are currently involved in the mission. The French contributions to Comet Interceptor illustrate the strong scientific and technical heritage acquired by the French scientific community with the successful previous cometary space mission Rosetta.
The Laboratoire d’Astrophysique de Marseille (Aix Marseille Univ, CNRS, CNES) provides the primary mirror of the CoCa camera. This camera is developed by the University of Bern, Switzerland, and will provide colour images of the nucleus and its close environment during the approach and flyby phase. These images will be used to better understand the origin of this comet and its evolutionary processes.
Contact: Olivier GROUSSIN (olivier.groussin@lam.fr)
Annual meeting of the HARMONI consortium at LAM
The Marseille Astrophysics Laboratory (LAM) hosted the annual meeting of the HARMONI consortium. After two years of health restrictions, about 100 people are gathered to work on the progress of the project.
Europe, through its agency for ground-based astronomy (ESO), is engaged in the construction of the largest telescope ever built, the ELT (Extremely Large Telescope https://elt.eso.org/ – webcam on the construction site https://elt.eso.org/about/webcams/). At 39 metres in diameter, the ELT will answer fundamental questions in astronomy, from the search for and characterisation of extrasolar planets (the ultimate goal being the imaging of exo-terrestrials) to the formation and evolution of the first galaxies in the Universe. In operation by 2027, the ELT will be equipped with six scientific instruments, each optimised to exploit the full potential of this giant telescope.
HARMONI, is the ELT’s first light integral field spectrograph (IFU). It will observe in the visible and near-infrared range (from 0.5 to 2.4 microns) and provide spectral resolution from R=3000 to R=20000. To fully exploit the image quality provided by the ELT (the diffraction limit of a 39 m telescope), HARMONI will be equipped with two adaptive optics (AO) systems. The first is a classical AO system (SCAO: Single Conjugate Adaptive Optics) and the second will be a wide field AO system, assisted by laser stars (LTAO: Laser Tomography Adaptive Optics). The LAM is in charge of the complete design and implementation of these Adaptive Optics systems. In addition, the laboratory is responsible for the assembly, integration and testing of these systems in Europe. It is an assembly with a total mass of 11 tonnes and a volume of 6.6 m x 4.8 m x 5.7 m
Une exoplanète de type Tatooine repérée par un télescope terrestre
A rare exoplanet called Kepler-16b orbiting two stars at once has been detected with a ground-based telescope thanks to a close collaboration between the University of Birmingham and the Astrophysics Laboratory in Marseille. Kepler-16b is located some 245 light years from Earth and, like Luke Skywalker’s planet Tatooine in the Star Wars universe, it would have two sunsets if you could stand on its surface. Until now, the planet has only been observed using the Kepler space telescope. It orbits two stars that also orbit each other, forming a binary star system.
The SOPHIE spectrograph mounted on the 193 cm telescope used for this new observation is based at the Observatoire de Haute-Provence in France. The team was able to detect the planet using the radial velocity method, in which astronomers observe a change in the speed of a star as a planet orbits it. This observation is an important demonstration of the possibility of detecting circumbinary planets using this historic method, which is less expensive than using space satellites. The radial velocity method also makes it possible to measure one of the fundamental properties of a planet: its mass.
The team plans to continue the observations by searching for previously unknown circumbinary planets and to help answer questions about planet formation. The usual model of planet formation in a protoplanetary disc – a mass of dust and gas surrounding a young star – needs to be revised. The presence of the second star disrupts accretion – the clumping of dust that allows planets to form. The migration of planets in the disc is most likely a necessary part of understanding the observations
This discovery shows how ground-based telescopes remain highly relevant to the modern search for exoplanets and can be used for exciting new projects. After the detection of Kepler-16b, analyses will be carried out on data from many other binary star systems to search for new circumambient planets.
For more information
Kepler-16 (AB) b – the first circumbinary planet detected with radial velocities’, Triaud et al (2022), Monthly Notices of the Royal Astronomical Society, in press.
University of Birmingham press release
Contact
Isabelle Boisse
Marseille Astrophysics Laboratory (LAM / CNRS / Aix-Marseille University)
isabelle.boisse .at. lam.fr
Alexandre Santerne
Laboratory of Astrophysics of Marseille (LAM / CNRS / Aix-Marseille University)
alexandre.santerne .at. lam.fr