Lison Malo

Canada-France-Hawaii Telescope Resident Astronomer and iREx Alumni

Lison Malo

Since 2014, Lison is a Resident Astronomer for Canada-France-Hawaii Telescope (CFHT), which is located on the Big Island of Hawaii, in the United States. As a Resident Astronomer, she prepares observations made with the various instruments of the telescope (the infrared and optical cameras WIRCam and MegaCam and the spectrograph-polarimeter ESPaDOnS), she establishes a contact between the user and the observatory, and she optimizes the observations to reach the user’s scientific goals. She is also the scientific lead for the project GRACES at CFHT. This ambitious project will allow in 2015 to analyse with ESPaDOnS photons collected by CFHT’s neighbour telescope Gemini North, using a 270 meters optical fiber. This projects requires the development of a new reduction pipeline, OPERA, on which Lison is actively working.

Lison also continues to work on diverse research projects. Interested by the identification of young stars of the solar neighborhood, she is working on the selection and characterization of the star sample that will be observed with SPIRou, an instrument that will be installed on CFHT in 2018. She is also interested by the characterization of stars that host brown dwarf of exoplanetary companions, and of binary star systems.

 

Depuis 2014, Lison travaille comme astronome résidente au Télescope Canada-France-Hawaii (TCFH), situé sur la grande île d’Hawaii, aux États-Unis. Son travail d’astronome résidente consiste à préparer les observations effectuées avec différents instruments (les caméras infrarouge, optique WIRCam et MegaCam et le spectrographe-polarimètre ESPaDOnS), à établir un contact entre l’utilisateur et l’observatoire et à rendre la prise des données optimale pour l’atteinte des objectifs scientifiques de l’usager. Dans le cadre de ses fonctions, Lison est responsable scientifique du projet GRACES au TCFH, un projet d’envergure qui permettra en 2015 d’analyser avec l’instrument ESPaDOnS les photons collectés par le télescope Gemini Nord à l’aide d’une fibre optique de 270 mètres. Ce projet nécessite le développement d’un nouveau programme de réduction des données, OPERA, auquel Lison participe activement.

D’autre part, Lison continue de travailler sur de multiples projets de recherche. Intéressée par l’identification d’étoiles jeunes dans le voisinage solaire, elle participe à l’élaboration et la caractérisation de l’échantillon d’étoiles qui seront observées par l’instrument SPIRou en 2018. Elle s’intéresse aussi à la caractérisation des paramètres fondamentaux d’étoiles hôtes, ainsi qu’à l’étude de systèmes binaires.

 

For her PhD thesis (2010-2014) and her master thesis (2007-2009), under the supervision of René Doyon and in collaboration with David Lafrenière and Étienne Artigau, Lison searched for young, low-mass stars in the solar neighbourhood. Nearly 70% of stars in the galaxy have a mass of less than 0.8 solar-mass. However, because these stars are faint and difficult to observe, this statistic does not reflect the current survey of the population of young or old low-mass stars in the solar neighbourhood. Low-mass stars are excellent targets to search for exoplanets with various techniques (direct imaging, radial velocity, transit). In addition, the characterization of exoplanets depends on our knowledge of their basic parameters, i.e. their bolometric luminosity, effective temperature, radius and age.

The main objective of my doctoral research is searching for and characterizing young, low-mass stars. The first part is devoted to developing the statistical method combining Bayesian inference and empirical models of several observable parameters for confirmed members of 7 groups of stars (8-120 million years old). This part of the research led to the development of a tool called BANYAN. Using this tool we can predict the probability of association, the radial velocity and trigonometric distance of a star as a member of a given association.

The second part consists of measuring the radial velocity of stars with a high probability of association, and studying the behaviour of X-ray luminosity, as an indicator of youth for low-mass stars.

The last part consists of determining a star’s fundamental parameters in order to deduce its exact age. This step calls for comparison between the fundamental properties and the latest theoretical evolutionary models, including processing the magnetic field. The scope of this work is discussed in connection with current astronomical projects, including the Gaia Space Telescope and SPIRou, an instrument to be deployed on the Canada-France-Hawaii Telescope in 2017.

 

Contact

Email: malo@cfht.hawaii.edu

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