(Back to the menu - click here.)


“Interstellar ices in dark molecular clouds: structure and chemical complexity"





  Thursday, 10 June 2021

    Video-Recording for any system with MP4-support

   - Video.mp4  (ca. 203 Mb)

   - Video_with_eng_sub.mp4  (ca. 207 Mb)


 15:15 – 16:05





Dust particles covered by icy mantles play a crucial role in the formation of

molecules in the Interstellar Medium (ISM). These icy mantles are mainly

composed of water but many other chemical species are also contained in these ices.

The structure of this ice mantle plays in important role in the capacity to hold

other species, promote reactions, and take up energy. It further can be used as

a diagnostic tool, since the spectroscopy varies with ice structure.

Although amorphous solid water (ASW) is widely studied and is generally

well characterized by different techniques, energetically-induced structural changes,

such as ion, electron and photon irradiation, in these materials are less well

understood. Selective pumping of specific infrared (IR) vibrational modes can aid

in understanding the role of vibrations in restructuring of hydrogen bonding

networks. I will present the experimental results on hydrogen bonding changes

in ASW induced by mid-IR free-electron laser (FEL) radiation.

Upon resonant irradiation, a modification in IR absorption band profile of ASW is

observed which is analysed in terms of hydrogen bonding donors and acceptors

and the experiments are complimented with Molecular Dynamics simulations

to constrain the effect at the molecular level. I will further present work on the

formation of complex molecules such as glycine in ASW at low temperatures

and without UV light.


Speaker today:  Herma Cuppen  (Radboud University & University of Amsterdam)


                              <<<<<<  Denna sida ändrades, den 7 oktober 2021 kl.22:51:31    >>>>>>