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High resolution observations of protoplanetary disks by ALMA have brought up the possibility of modeling disks in detail. For instance, the maximum size of the particles within the disk and the opacity as a function of the wavelength can be derived if a model for the grains is assumed.
Historically, only spherical grains have been used in these models, just because of simplicity: the scattering matrix and the thermal emission can be easily, analytically derived. Just a few new results have been obtained by using spheroids, which are significantly different from those referred to spheres. Furthermore, to our knowledge, all radiative transfer model for disks available (Polaris, SKIRT and MCFOST) only accept spherical particles as radio emitters and scatterers.
Non-spherical particles have been widely proved to give radically different results in radiative transfer in different astrophysical scenarios, such as planetary atmospheres and cometary comae.
The aim of this project is to definitely demonstrate the need for non-spherical grains in modeling protoplanetary disks, and the implementation or adaptation of a radiative transfer model code that include realistic irregular particles. A second objective is the extension of such model to the study of aerosols in atmospheres.
The thesis project will be developed within the Light Scattering Group of the Department of Solar System at the Instituto de Astrofísica de Andalucía – CSIC (Spain), where we conduct a national project entitled “Laboratory Experiments, Observations and modeling of cometary Dust: A new Strategy (LEONIDAS)”. Studies extend from cometary tails, including exploitation of OSIRIS and Giada-Rosetta data and participation in upcoming missions such as Comet Interceptor to circumstellar disks. The student will also benefit from our collaborations in Mexico and Belgium. Our group operates the world-class facility COsmic DUst LABoratory (CODULAB), and instrument that produces light scattering matrices by non-spherical particles. Existing and future measurements by CODULAB could now be applied to a new field of: disks. The use of these matrices in a radiative transfer model for disks and the instant transfer of the vast body of knowledge on light scattering by non-spherical particles to the study of protoplanetary disks would revolutionize that field.
Requirements:
• Programming skills: Python or Fortran.
• Background: Physics or Engineering.
Tasks:
• Use of available approximations for the generation of light scattering matrices of a collection of spherical, non-spherical and irregular particles matching some properties of the grains in protoplanetary disks. Codes are already made but their use implies a deep knowledge on light scattering and an intensive computation that will require the usage of supercomputers.
• Development of a new radiative transfer model or adaptation of an existing one in order to introduce radio emission and scattering by non-spherical particles in protoplanetary disks.
• Extension of the model to model to atmospheres.
The student would work based at the IAA and would have access to the CODULAB. The student would receive training on light scattering and radiative transfer models within our group, and training on protoplanetary disks by our collaborator Carlos Carrasco at IRyA (UNAM, Mexico). The student will make stays in centers with which we collaborate, (Mexico and France) and will attend relevant astronomical schools and will participate each year in international astronomical meetings to present research results.
Group Leaders
1. Title: Dr.
2. Full name: Olga Muñoz, Fernando Moreno Danvila
3. Email: olga@iaa.es, fernando@iaa.es
4. Research project/ Research Group website (Url): https://www.iaa.csic.es/scattering/
5. Website description: Webpage of the Amsterdam-Granada Scattering database and
homepage of the Cosmic Dust Laboratory (CODULAB). This webpage works as an open- access repository of experimental measurements of the scattering matrix of cosmic dust analogs and of atmospheric aerosols performed at CODULAB. A description of the CODULAB apparatus and the theoretical background behind scattering matrix measurement techniques can also be found in this webpage, as well as a list of peer- reviewed publications of the group and of links to other databases and webpages of international collaborators.
Additional websites
1. Url: https://www.iaa.csic.es/en
2. Website description: Webpage of the Andalusian Institute of Astrophysics (Instituto de
Astrofísica de Andalucía, IAA). IAA is the leading Astronomy institute of the Spanish Research Council (Consejo Superior de Investigaciones Científicas, CSIC). The webpage describes research and technical activities carried out by the four Scientific Departments and the Instrumental and Technological Development Unit, including laboratory research facilities like CODULAB. It also provides information about space missions with involvement of IAA-CSIC, and the two Observatories run by the institute (Observatorio de Sierra Nevada and Observatorio de Calar Alto).
IAA is an equal opportunity institution. Applications to this program by female scientists are particularly encouraged.
Should you need any further information or assistance concerning the application, please contact the IAA at severoochoa[at]iaa.es