Speaker
Dr
Sunil Kumar Sudhakaran
(Max-Planck-Institut für Kernphysik)
Description
One of the long-standing mysteries in astronomy is the origin of the interstellar absorption features that are observed in the visible to near infrared range and dubbed as the diffuse interstellar bands (DIBs). Despite the observation of several hundred lines, none of them has been unambiguously attributed to a chemical species. A potential candidate believed to be responsible for some of these absorption features is C60+ [1,2] for which no laboratory gas-phase spectra exist. Our objective is to carry out the first gas-phase spectroscopy of C60+ using a cryogenic ion-beam trap [3]. The stored molecular ions will be subject to excitation by near-infrared laser light spanning the range of the suggested absorption features of C60+. At resonance, the absorbed energy is expected to be re-distributed among the vibrational modes of the molecule followed by the delayed emission of mid-infrared radiation [4]. A significant fraction of the emitted light will be guided onto highly sensitive blocked impurity band (BIB) detectors which feature extremely low dark current and high sensitivity. After the proof-of-principle experiments with C60+, this novel spectroscopy scheme should also be applicable to a wide range of other complex organic molecular ions like, e.g., polycyclic aromatic hydrocarbons. The measurement scheme, preparatory work toward its implementation, and the current state of the experimental setup will be presented.
References
[1] B. H. Foing and P. Ehrenfreund, A&A 317 (1997) L59.
[2] O. Berné, G. Mulas, and C. Joblin, A&A 550 (2013) L4.
[3] M. Lange, M. Froese, S. Menk, et al., Rev. Sci. Instrum. 81 (2010) 055105.
[4] L. J. Allamandola, A. G. Tielens, and J. R. Barker, Astrophys. J., Suppl. Ser. 71 (1989) 733.
Authors
Dr
Holger Kreckel
(Max-Planck-Institut für Kernphysik)
Dr
Sebastian George
(Max-Planck-Institut für Kernphysik)
Dr
Sunil Kumar Sudhakaran
(Max-Planck-Institut für Kernphysik)
Co-authors
Mr
Bastian Kern
(Karlsruher Institut für Technologie)
Mr
Christian Breitenfeldt
(Ernst-Moritz-Arndt-Universität Greifswald)
Mr
Christian Meyer
(Max-Planck-Institut für Kernphysik)
Dr
Dmitry Strelnikov
(Karlsruher Institut für Technologie)
Dr
Gaël Rouillé
(Max-Planck-Institut für Astronomie)
Mr
Jonas Karthein
(Max-Planck-Institut für Kernphysik)
Mr
Jürgen Göck
(Max-Planck-Institut für Kernphysik)
Prof.
Klaus Blaum
(Max-Planck-Institut für Kernphysik)
Dr
Peter Bizenberger
(Max-Planck-Institut für Astronomie)
Prof.
Thomas Henning
(Max-Planck-Institut für Astronomie)
Dr
Ulrich Grözinger
(Max-Planck-Institut für Astronomie)
Prof.
Wolf Andreas
(Max-Planck-Institut für Kernphysik)