lag_esom

The LISA Mission was adopted by ESA in January, as the next L-class mission, with a launch date in 2035. LISA will detect GWs in the milliHertz regime, where we observe the coalescence of supermassive galaxies up to very high redshift as well as thousands of compact binaries in the Milky Way and many other sources. The LISA mission is an international collaboration between ESA, its member states, and NASA. It will consist of three identical spacecraft forming a near equilateral triangle that exchange laser beams over the 2.5 × 106 km long arms. LISA will use precision laser interferometry to compare separations between test masses that are protected by the spacecraft from non-gravitational disturbances. LISA will coherently measure spacetime strain variations as a function of time, including frequency, phase, and polarisation, forming a continuous, all-sky observatory sensitive to all sources simultaneously.

LISA’s science objectives cover a wide range of outstanding questions in astrophysics, fundamental physics and cosmology. LISA is unique in that it will be sensitive to Massive Black Hole mergers across the Universe, directly probing the origin of Massive Black Holes and their growth and important role in galaxy evolution. Some of these sources will have signal-to-noise ratios as large as 1000, providing exquisite tests of General Relativity and the nature of event horizons. Multi-messenger observations will provide additional information about matter surrounding the mergers and a test of the propagation of gravitational waves. Stellar mass compact objects surrounding Massive Black Holes give rise to extreme mass-ratio inspiral signals, unique for LISA, that probe the stellar population in the central regions of galaxies and measure the mass and spin of the Massive Black Hole. They are also outstanding sources to map the detailed structure of the spacetime metric of the central Massive Black Hole, allowing tests of the no-hair theorem, the existence of additional fields and other alternative Gravity theories. LISA is guaranteed to detect a large number of Galactic sources, consisting of binary and multiple compact objects, which will give detailed insight into the final stages of stellar binary evolution, into the physics of tides and mass transfer, and can be used as independent probes of Galactic structure. Stellar-mass Black Hole binaries can be detected in the nearby Universe and can evolve from the LISA measurement band into that of the ground-based detectors, potentially yielding multi-band gravitational wave sources. Because gravitational waves provide a direct distance measurement of the source, LISA will determine the expansion of the Universe in a complementary way to Euclid and other cosmological probes. Finally, there are several potential stochastic signals from collective phenomena in the Early Universe, such as first-order phase transitions, that, if detected, would provide the unique direct measurement of the first seconds after the Big Bang.

France is a major contributor to LISA, including the responsibility for the coordination of the data analysis, though the Distributed Data Processing Center (DDPC). The Observatoire de la Côte d'Azur is responsible for the pipelines creating the final data products (e.g. catalogs). For any question, contact Astrid Lamberts (co-PI LISA-Frace, Coordinator of the DDPC catalog production).

news lamberts LISA waves 23102024

L'ANR MOSAIC dans laquelle le Laboratoire Lagrange et l'équipe P2S constitue un des partenaires est acceptée

Nardetto Nicolas Team Leader (Directeur de Recherche, CNRS)

Nicolas NARDETTO Team Leader

CR - CNRS
+33 (0)4 92 00 19 68
nicolas.nardetto at oca.eu
Location : PES - Mont Gros
Research: distance scale (Araucaria Project) with cepheids and eclipsing binaries (VEGA, SPICA/CHARA)
Webpage

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Former Ph.D. & Postdocs

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Staff (Alphabetical order)

	Philippe Bendjoya Professor +33 (0)4 92 00 19 63 philippe.bendjoya at unice.fr Location: Fizeau - Valrose Research : Asteroids and evolved stars, Astrobiology (Master Mauca - M2)
	Lionel Bigot CR CNRS +33 (0)4 92 00 30 56 lbigot at oca.eu Location : PES - Mont Gros Research : 3D MHD, seismology, dynamo of Sun & star, exoplanet detection (OCA-PLATO)

	Andrea Chiavassa CR - CNRS +33 (0)4 92 00 30 27 andrea.chiavassa at oca.eu Location : PES - Mont Gros Research : Stellar spectroscopy and convection, Interferometry, Exoplanet atmospheres, 3D models (OPTIM3D) webpage
	Thierry Corbard Astronome adjoint +33 (0)4 92 00 30 49 thierry.corbard at oca.eu Location : PES - Mont Gros Research : Helioseismology, Solar weather & Physics, Inversion (MeteoSpace) webpage
	Orlagh Creevey Astronome Adjoint +33 (0)4 92 00 30 41 orlagh.creevey at oca.eu Location : Fizeau - Valrose Research : Stellar and planetary fundamental parameters, stellar populations (Gaia)
	Armando Domiciano de Souza Astronome adjoint +33 (0)4 92 00 19 71 armando.domiciano at oca.eu Location : Fizeau - Valrose Research: High angular and high spectral resolution of massive stars - Rotation, mass loss, environnement (CHARRON, HDUST, FRACS, ESTER codes). AMHRA/MOIO/JMMC coordinator.
	Marianne Faurobert Professor +33 (0)4 92 00 63 46 marianne.faurobert at oca.eu Location : Fizeau - Valrose Research : Solar magnetic fields, non-LTE radiative transfer of polarized radiation, High angular resolution observations.
	Eric Lagadec Astronome adjoint +33 (0)4 92 00 19 79 eric.lagadec at oca.eu Location : PES - Mont Gros Research : environment of evolved stars (SPHERE/VLT, DUSTY)
	Astrid Lamberts CR - CNRS astrid.lamberts at oca.eu Location : Fizeau - Valrose + Mt Gros - Maison Jumelles Research: compact binaries, gravitationnal waves predictions
	Anthony Meilland CR - CNRS +33 (0)4 92 07 19 74 anthony.meilland at oca.eu Location : Fizeau - Valrose Research : Interferometry - Massive stars - mass loss & Environments (MATISSE/VLTI)
	Djamel Mékarnia CR - CNRS +33 (0)4 92 00 19 73 djamel.mekarnia at oca.eu Location : PES - Mont Gros Research : ASTEP project
	Florentin Millour Astronome adjoint +33 (0)4 92 00 30 68 florentin.millour at oca.eu Location : Fizeau - Valrose Research : Imaging & Long-baseline interferometry, AMBER, MATISSE, Massive stars webpage
	Denis Mourard Astronome +33 (0)4 92 00 19 59 denis.mourard at oca.eu Location : Fizeau - Valrose Research : PI of VEGA and SPICA/CHARA interferometric instruments, hypertelescopes
	Gilles Niccolini Assistant professor +33 (0)4 92 04 19 74 or +33 (0)4 92 00 19 74 gilles.niccolini at oca.eu Location : Fizeau - Valrose Research : L3 coordinator, environment of evolved stars (FRACS code)
	Philippe Stee DR CNRS - Head of Lagrange Laboratory +33 (4) 92 00 31 17 Philippe.Stee at oca.eu Location : Fizeau-Valrose / PES-Mont Gros Research: Massive stars : winds, optical interferometry, radiative transfert. webpage

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Postdocs

	Mathis Houlle Postdoc (start Automn 2022 / ANR ExoVLTI) Mathis.Houlle at oca.eu Location : Valrose Research: Gravity+
	Roxanne Ligi Postdoc (start Automn 2022 / ERC ISSP) Roxanne.Ligi at oca.eu Location : Valrose Research : SPICA (Exoplanet Host Stars)
	Romina Ibanez Postdoc (start Automn 2022 / ERC ISSP) Romina.Ibanez at oca.eu Location : Valrose Research : SPICA (Surface-Brightness Color Relations)
	Shanika Galaudage Postdoc (start Automn 2022 / ANR COSMERGE) Shanika.Galaudage at oca.eu Location : Valrose Research : Progenitors of Gravitational Waves

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Emeritus/Benevoles

	Pierre Morel Astronomer +33 (0)4 92 00 xx xx Pierre.Morel at oca.eu Location : Research : Stellar structure and evolution (star evolution code CESAM) webpage
	Janine Provost Astronomer +33 (0)4 92 00 30 79 janine.provost at oca.eu Location : PES - Mont Gros
	Rabbia Yves Astronomer emeritus yves.rabbia at oca.eu Location : Fizeau - Valrose
	Frédéric Thévenin DR - CNRS frederic.thevenin at oca.eu Location : Fizeau - Valrose Research: radiative transfer, NLTE, interferometry, asterosismology
	Alain Chelli Astronome +33 (0)4 92 00 19 66 Chelli at oca.eu Location : PES - Mont Gros Research : Interferometry, catalogues of angular diameters, ...
	Farrokh Vakili Astronome Farrokh.vakili at oca.eu Location : PES - Mont Gros Research : Interferometry, Be, wind, P Cyg
	Eric Fossat Astronome Eric.Fossat at oca.eu Location : PES - Mont Gros Research : Heliosismology

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PhD students

	Maria Chiara MAIMONE PhD. supervisor A. Chiavassa (defense: 2022) mmaimone -at- oca.eu Location: PES - Mont Gros Atmosphere of exoplanets and host stars by high spectral resolution
	Dinil Bose Palakkatharappil PhD. supervisor O. Creevey (defense: 2022) dinil-bose.palakkatharappil -at- oca.eu Location: PES - Mont Gros Age of stars. Asteroseismology. TESS/PLATO.
	Cyril Pannetier PhD. supervisor D. Mourard & F. Cassing (ONERA) (defense: 2022) Cyril.Pannetier -at- oca.eu Location: Fizeau - Valrose Development of CHARA/SPICA instrument. Fringe-Tracker (SPICA-FT) characterization
	Jérémy Perdigon PhD. supervisor M. Faurobert & G. Niccolini (defense: 2022) Jeremy.Perdigon -at- oca.eu Location: Fizeau - Valrose Radiative transfer in circumstellar environment
	Julien Drevon PhD. supervisor P. Cruzalebes & F. Millour (defense: 2023) Julien.Drevon -at- oca.eu Location: PES - Mont Gros Research: Evolved stars with MATISSE/VLTI
	Rahul Srinivasan PhD. supervisor A. Lamberts & Marie-Anne Bizouard (defense: 2023) Rahul.Srinivasan - at - oca.eu Location: Valrose - Mont Gros Research: Stellar Black Holes in Universe
	Bruel Tristan PhD. supervisor A. Lamberts (defense: 2024 / ANR COSMERGE) Tristan.Bruel - at - oca.eu Location: Valrose Research: Study of black hole binaries formation channels
	Margaux Abello PhD. supervisors A. Domiciano and A. Meilland (defense: 2025 / ANR MASSIF) Margaux.Abello - at - oca.eu Location: Valrose Research: Study of massive stars, interferometry
	Elysabeth Beguin PhD. supervisors A. Chiavassa (defense: 2025 / ANR PEPPER) Elysabeth Beguin - at - oca.eu Location: Valrose/PES Research: Study of evolved stars: magnetism, convection, mass loss
	Juraj Jonak PhD. supervisor D. Mourard (defense: 2025 / ERC ISSP) Juraj.Jonak - at - oca.eu Location: Valrose/PES Research: Study of binaries with SPICA

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Former Staff

Eric Chapellier

Astronome, retired
Research : asterosismology, analysis of CoRoT and ASTEP data

	Luc Dessart CR - CNRS +33 (0)4 92 00 30 41 luc.dessart at oca.eu Location : Paris Observatory Research :Supernova, massive stars, white dwarfs, stellar evolution, radiative hydrodynamics & transfer webpage
	Thierry Lanz Astronome +33 (0)4 92 00 19 89 thierry.lanz at oca.eu Location : CION - Mont Gros Research: radiative transfer, atmospheric models, abundances, ...
	Claire Michaut DR - CNRS Claire.Michaut at oca.eu Location : Fizeau - Valrose Research : Laboratory astrophysics
	Olga Suarez Ingenieur de recherche, service éducatif de l'OCA +33 (0)4 92 00 19 61 olga.suarez at oca.eu Location : PES - Mont Gros Research: radio interferometry, water fountains

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Former Ph.D. & Postdocs (since 2010)

	Rabah Ikhlef PhD. 12/2016 (Supervisor T. Corbard) Actual position: CRAAG Research : Solar Physics - Atmospheric turbulence
	Zeinab Khorrami PhD. 2016 Research : Adaptive optics of cluster R136
	Mounir Challouf PhD. 2015 Research : Interferometry - Surface Brightness relations
	Daniel Mac Donald PhD. coSupervisor E. Lagadec (defense: 2018) Research : evolved stars
	Kateryna Kravchenko PhD. supervisor Van Eck (Bruxelles) & A. Chiavassa (defense: 2019) Research: Tomography of convective layers in evolved stars
	Roxanne Ligi Ph.D. (11/2010-10/2013) roxanne.ligi at oca.eu Research : Interferometry, Stellar diameters, surface activity.
	Sergey Lisakov PhD. supervisor L. Dessart (defense: 2018) Research : Core collapse Supernovae and progenitor
	Marc-Antoine Martinod PhD. supervisor D. Mourard & K. Perraut (Grenoble) (defense: 2018) Research: Interferometry - FRIEND instrument
	Thibault Merle PhD. Grant Thales Ariane Space/Région (10/2008-02/2012) PACA (Supervisor L. Bigot & F. Thévenin) Actual position : Postdocs University of Bruxelles ULB (Belgium) Research : NLTE line transfer, stellar atmospheres & populations webpage
	David Salabert Postdoc 2011-2013 CNES (T. Corbard) 2016-2017 CEA, Lagrange 2020 (MATISSE and SPICA) Research : Helio and asteroseismology
	Luca Santoro Ph.D. (F. Thévenin OCA, A. Valenari Padova) Actual position : postdoc Research : stellar evolution and rotation.
	Anthony Soulain PhD. supervisor F. Millour & B. Lopez (defense: 2018) Research: massive stars
	Sophia Sulis PhD. Grant Thales Ariane Space/Région PACA (Supervisor L. Bigot & D. Mary) Actual position : postdoc Research : Stellar noise study & exoplanet detection
	Elisson Saldanha PhD. Supervisor A. Meilland & A. Domiciano (defense: 23/11/2020) Research : massive stars (O, Be, LBV) and circumstellar environment (discs, winds, mass loss) Current position: post-doc at Research Instituto de Física y Astronomía/Universidad de Valparaíso (supervisor: Michel Curé) www.elissondealmeida.com
	Kevin Bouchaud PhD. supervisor A. Domiciano & D. Reese (Paris) (defense: 2019) Research: 2D models of fast rotating stars constrained by interferometry and asterosismology
	Vincent Hocdé PhD. supervisor N. Nardetto & E. Lagadec (defense: 2020) Research: Environment of Cepheids, distance scale Post-Doc in Poland (Araucaria Project) with R. Smolec on evolutionnary model of Cepheids including pulsation and mass loss
	Anthony Salsi PhD. supervisor N. Nardetto & D. Mourard (defense: 2021) Research: Surface-Brigthness color relations, eclipsing binaries, distance scale Find a position at Sophia-Antipolis
	Fabien Patru Postdoc 2019 Research: SPICA finge tracker
	Simone Mastrogiovanni Postdoc (start Automn 2021 / ANR COSMERGE) Simone.Mastrogiovanni at oca.eu Location : Fizeau - Valrose Research: Statistical interpretation of black hole coalescences
	Fabian Menezes Postdoc (start Automn 2021 / ANR PEPPER) Menezes.Fabian at oca.eu Location : PES - mont Gros Research: magneto-hydrodynamic modeling of evolved stars

updated on 2021-12-06

L'équipe accueille cette Automne 1 nouveau thésard:

Julien DREVON: Exploitation de l'instrument MATISSE/VLTI: imagerie des étoiles évoluées (encadrants: P. Cruzaleves et F. Millour)

Astrid Lamberts est recrutée au CNRS et intégre l'équipe de Physique Stellaire et Solaire ! Bravo Astrid !

HDUST (A. Carciofi) : Code de transfert radiatif Monte Carlo incluant gaz et poussière. Ce code permet d’obtenir des spectres et des cartes d’intensité en lumière naturelle et/ou polarisée. Ce code a besoin d’une puissance de calcul considérable pour que l’on puisse exploiter pleinement ces capacités. La version parallèle du code HDUST a donc été installée sur le Mésocentre SIGAMM (Simulations Intensives en Géophysique, Astronomie, Mécanique et Mathématiques) pour utilisation par les chercheurs de l’équipe Stellaire. L’accès à ce code très complet a été possible grâce au programme de collaboration internationale PICS France-Brésil.

Création d’une grille de modèles de disques de gaz et poussière autour des étoiles massives. Exemple d’images (cartes d’intensités) calculés en utilisant le mésocentre par A. Domiciano de Souza & A. Carciofi.

images disques HDUST 2fcff

Ces images montrent une étoile chaude centrale (température 20000 K; type spectrale B) entourée d’un disque composé de gaz (hydrogène) et de poussière (composition de silicates avec une distribution de tailles entre 1 a 50 microns). Ce modèle physique d’étoile B[e] a été calculé par un code de transfert radiatif par méthode Monte Carlo (code HDUST). Plusieurs paramètres physiques contrôlent la structure physique du disque. Les images montrées ici ont été calculées pour deux inclinaisons du système par rapport à l’observateur (60° et 85°) et pour des longueurs d’onde dans le visible (de 0.6 à 1.2 microns) et dans l’infra-rouge thermique (entre 10 et 11 microns). On voit des différences dans ces images correspondant à des effets géométriques et aussi physiques dus à des variations des contributions relatives de l’étoile B, de l’émission du gaz ionisé dans la partie centrale, et de la poussière (formée à partir d’une distance limite où la température de la poussière est inférieure à 1500 K).

Ces images basées sur un modèle physique sont essentielles pour interpréter des observations en haute résolution angulaire avec des spectro-interférométres tels que VEGA/CHARA, VLTI/AMBER, VLTI/MIDI, VLTI/MATISSE (instrument de deuxième génération).

Publications

Domiciano de Souza, A. and Carciofi, A.C., «Grid of Supergiant B[e] Models from HDUST Radiative Transfer», Circumstellar Dynamics at High Resolution, Proceedings of a Joint ESP/Brazilian Workshop held at Foz do Iguacu, Brazil, 27 February-2 March, 2012, ASP Conference Series vol. 464, p. 149 (2012) (url)

Olivier’s favourite objects

Novae
Hypergiant stars
...

Afin de rendre hommage à la contribution d'Olivier Chesneau pour la recherche en astronomie,
le laboratoire Lagrange à l'Observatoire de la Côte d'Azur et l'ESO ont décidé de créer un prix à son nom.
Le prix Olivier Chesneau est décerné tous les deux ans depuis 2015
pour la meilleure thèse de doctorat d'astrophysique soutenue les deux années précédentes, dans un institut européen et dans le domaine de la haute résolution angulaire visible/infrarouge (par exemple en interférométrie, optique adaptative...).

lien sur le site The Chesneau Prize

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