Jupiter photographed by Christopher Go on the day of the ALMA observations (March 22, 2017). The bright regions indicate HCN emission, which is concentrated at the planet limb. The HCN depletion is observed in the northern and southern auroral regions. A small region of very high altitude HCN production is localized inside the southern aurora.

Credits: T. Cavalié and C. Go

The impacts of comet Shoemaker-Levy 9 with Jupiter's atmosphere in 1994 produced new species in its stratosphere, above the cloud deck which is usually observed in the visible. These species, like carbon monoxide (CO) and hydrogen cyanide (HCN) are stable in Jupiter's atmosphere, because they have a very long chemical lifetime. More than 20 years after the impacts of the comet, these species should have contaminated all the latitudes and longitudes of the planet.

Spectral maps of these species obtained with ALMA show however that while CO follows the expected trend, it is not the case for HCN. In the auroral regions and at surrounding latitudes, Cavalié et al. 2023 have observed a depletion of HCN in the middle stratosphere, which indicates that this species is destroyed in these regions and at these altitudes. They believe that organic aerosols which are produced in the aurorae are responsible for this depletion, by adsorbing HCN onto their surfaces. The data reveal even more unexpectedly a region of very high-altitude production of HCN inside Jupiter's aurorae. The energy deposited by the magnetosphere in the aurorae is a serious candidate to explain this very localized production.

Sylvia Adscheid

Sylvia is a PhD student at the University of Bonn, Germany. Since October 2022, she is a member of the German ARC Node, where currently her main duty is being a contact scientist.

Sylvia's main research interest is in high-redshift galaxies. She works with large volumes of ALMA archival data to perform statistical analyses on populations of high-redshift galaxies, their evolution and physical properties, with a focus on their (sub-)mm dust emission.

Dr. Łukasz Tychoniec

Łukasz joined the ESO ARC in Garching as an ESO Fellow in September 2021. As parth of his duties, he is involved in helpdesk triage for the EU ARC, as well as a contact scientist for ALMA projects for PIs from ESO. He also participates in the ALMA development study - BRAIN (Bayesian Adaptive Interferometric Image Reconstruction Methods) led by Dr. Fabrizia Guglielmetti for which he test algorithms for the imaging of ALMA data using Bayesian inference methods.

Łukasz's research interests focus on studies of early stages of star formation. This involves ALMA observations of both dust that forms planet-forming disks as well as gas, especially launched in protostellar outflows and jets. He also uses the James Webb Space Telescope (JWST) to study mid-IR properties of protostars and is very keen on exploring synergies between ALMA and JWST.

ALMA poll of the month

ALMA poll results June 2023

Radio 2023

The conference will provide an insight into the activities of German radio astronomy and point out future challenges, but also opportunities. An important aspect besides radio astronomy is the management of the enormous amounts of data by the national data centres. The conference also provides a platform to communicate the assessment of the operators of these data centres regarding the technical requirements and ultimately the feasibility of future projects on a national level.

Abstract submission deadline: 01 October 2023

Conference: 14-17 November 2023; Ruhr-University Bochum

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