IRS2020 - PhD position - Cosmic Rays Irradiation of Interstellar and Planetary Matter

This job offer has expired

    Idex université Grenoble Alpes
    First Stage Researcher (R1)
    Recognised Researcher (R2)
    Established Researcher (R3)
    Leading Researcher (R4)
    19/06/2020 00:00 - Europe/Brussels
    France › Grenoble


IDEX PROJECT TITLE: Cosmic Rays Irradiation of Interstellar and Planetary Matter

PhD SUBJECT TITLE: Cosmic Rays Irradiation of Interstellar and Planetary Matter

SCIENTIFIC DEPARTMENT (LABORATORY’S NAME):  Institut de Planétologie et Astrophysique de Grenoble (IPAG)

DOCTORAL SCHOOL’S: ED Terre Univers Environement

SUPERVISOR’S NAME: Eric Quirico & Aurore Bacmannn



The project consists in characterizing the effects of cosmic rays on ices, with implications on the chemical evolution stages of matter from the interstellar medium and the very first phases of star formation down to surfaces of planetary bodies. To this effect, the doctoral student will have to run cosmic-ray analogue irradiation experiments at ion accelerators such as GANIL or GSI. He/she will be in charge of analyzing the data obtained during the irradiation of the ice sample: extract sputtering yields for the different ice types and ice mixtures from the quadrupole mass spectrometer data, and identify and quantify new species formed in the ice by radiolysis using in situ infrared spectroscopy. Further analysis of the refractory residual after long irradiations will be collected and brought back to IPAG to be analyzed at very high mass resolutions with the Orbitrap mass spectrometer. This work will be carried He/she is expected to use the experimentally-derived sputtering yields and radiolysis cross-sections to interpret gas-phase astrophysical observations of prestellar cores, addressing both the simple molecules (like those in the experimental ice samples, e.g. H2CO, CH3OH, CO) and more complex molecules like methyl formate and dimethyl ether, the presence of which remains unexplained at very low temperatures. The observations are multi-transition maps, which will be modelled using state-of-the-art radiative transfer codes in order to reconstruct molecular abundance profiles as a function of position in the astrophysical source. The derived sputtering yields and formation rates of more complex molecules by radiolysis will be incorporated into an existing chemical model (Hily-Blant et al. 2018), giving expected molecular abundances as a function of density. The outcome of the comparison between the observations and the models will be whether cosmic rays can quantitatively account for both the observed ice desorption and synthesis of complex organic molecules from simple ices. Another application of the experiments is the understanding of the carrier and origin of the red color of a fraction of the Trans-Neptunian population, and to get clues whether they result from chemical processes before accretion, or from the radiolysis of the surface over 4.55 Gyrs.

Funding category: Contrat doctoral

PHD title: Cosmic Rays Irradiation of Interstellar and Planetary Matter

PHD Country: France

More Information

Offer Requirements

Specific Requirements



Academic background:

Applicants must hold a Master's degree (or be about to earn one) or have a university degree equivalent to a European Master's (5-year duration).

Expected skills:

Astrophysics, Planetary Sciences, Chemical physics. Programming. Data treatment.

Desired professional experience:

Experience with laboratory experiments or radio-observations reduction and analysis would be appreciated.

Applications process :

Applicants will have to send:

- Their CV

- An application letter in English

- Their last diploma

- Letters of recommendation are welcome.

Work location(s)
1 position(s) available at
Idex université Grenoble Alpes

EURAXESS offer ID: 526368
Posting organisation offer ID: 92242


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