Summary
The Unidentified Infrared (UIR) bands are discrete emission features observed in the interstellar medium (ISM), circumstellar regions, galactic and extragalactic sources. The UIR bands are very characteristic for the C=C and C-H vibrational modes of Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are thought to occur in the ISM either in the neutral, cationic, protonated, hydrogenated, dehydrogenated or substituted forms. In spite of many theoretical and experimental investigations for several decades, the exact form of PAHs or the group of PAHs responsible for the emission of the UIR bands still remains a major challenge in astronomy. Observations reveal that large PAHs (with 30 to 100 carbon atoms) harbors 10–15% of elemental carbon in the ISM. These PAHs are suggested to play an important role in the ionization and energy balance of interstellar gas. Fullerene, C60 has also been identified in the ISM through its infrared bands and its electronic transitions. Observations have revealed that the abundance of C60 increases rapidly while the abundance of PAHs decreases close to stars. This has been attributed to photochemical fragmentation and isomerization processes under the influence of the strong UV radiation field but the details of this are not at all understood. This project focuses on larger (>20 C, >30 C) and compact PAHs that have the high photo-stability to withstand the intense UV radiations in space and hence could be present at high abundances in the ISM. I propose to study the photo-fragmentation pattern of astrophysically relevant PAHs using the “Instrument for photo-dynamics of PAHs (i-PoP)” housed at the University of Leiden. I would further extend this research to record the infrared spectra of the PAH ions stored in a 22-pole cryogenic ion-trap at FELion using intense and tunable Free Electron Laser for Infrared eXperiments (FELIX) facility. The data obtained in this project will be timely for the upcoming James Webb Space Telescope.
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| Web resources: | https://cordis.europa.eu/project/id/101062984 |
| Start date: | 01-09-2022 |
| End date: | 31-08-2024 |
| Total budget - Public funding: | - 187 624,00 Euro |
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Original description
The Unidentified Infrared (UIR) bands are discrete emission features observed in the interstellar medium (ISM), circumstellar regions, galactic and extragalactic sources. The UIR bands are very characteristic for the C=C and C-H vibrational modes of Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are thought to occur in the ISM either in the neutral, cationic, protonated, hydrogenated, dehydrogenated or substituted forms. In spite of many theoretical and experimental investigations for several decades, the exact form of PAHs or the group of PAHs responsible for the emission of the UIR bands still remains a major challenge in astronomy. Observations reveal that large PAHs (with 30 to 100 carbon atoms) harbors 10–15% of elemental carbon in the ISM. These PAHs are suggested to play an important role in the ionization and energy balance of interstellar gas. Fullerene, C60 has also been identified in the ISM through its infrared bands and its electronic transitions. Observations have revealed that the abundance of C60 increases rapidly while the abundance of PAHs decreases close to stars. This has been attributed to photochemical fragmentation and isomerization processes under the influence of the strong UV radiation field but the details of this are not at all understood. This project focuses on larger (>20 C, >30 C) and compact PAHs that have the high photo-stability to withstand the intense UV radiations in space and hence could be present at high abundances in the ISM. I propose to study the photo-fragmentation pattern of astrophysically relevant PAHs using the “Instrument for photo-dynamics of PAHs (i-PoP)” housed at the University of Leiden. I would further extend this research to record the infrared spectra of the PAH ions stored in a 22-pole cryogenic ion-trap at FELion using intense and tunable Free Electron Laser for Infrared eXperiments (FELIX) facility. The data obtained in this project will be timely for the upcoming James Webb Space Telescope.Status
SIGNEDCall topic
HORIZON-MSCA-2021-PF-01-01Update Date
09-02-2023
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