CAS News and Highlights

An international group of astrophysicists, led by MPE scientists Marta Obolentseva, Alexei Ivlev, Kedron Silsbee, and Paola Caselli, have revisited the long-standing problem of evaluating the rate at which cosmic rays ionize gas in the interstellar medium. By combining available observational data for diffuse molecular clouds with novel developments in understanding the dust and gas distribution in these regions and applying numerical modeling, the scientists were able to compute the cosmic-ray ionization rate (or its upper limit) for a dozen nearby clouds. They showed that earlier estimates were a factor of ten too high. more

Using the JWST, a team of researchers including Paola Caselli, Barbara Michela Giuliano and Basile Husquinet from MPE, have probed deep into dense cloud cores, revealing details of interstellar ice that were previously unobservable. The study focuses on the Chamaeleon I region, using JWST’s NIRCam to measure spectroscopic lines towards hundreds of stars behind the cloud. more

In a groundbreaking study, the James Webb Space Telescope (JWST) observed the early stages of the growth of dust grains in the dense Chamaeleon I cloud. These cold dust grains have accumulated molecular solids on their surface early in the process leading to star formation, challenging previous assumptions on where and when grain growth occurs. The findings indicate that the growth of these „icy grains” begins even before the protostellar phase. This not only sheds light on the intricacies of grain evolution before the birth of stars and planets but also poses challenges for chemical abundance determination due to the deformation of observed profiles. more

A recent study led by researchers at the Max Planck Institute for Extraterrestrial Physics challenges conventional notions of star formation by revealing the intricate connection between streamers and filaments. Focusing on the star-forming region Barnard 5, the study traces the journey of material from larger scales to protostellar disks, uncovering a remarkable relationship between elongated filaments and gas streamers. In particular, the team discovered a sizeable streamer, which suggests that young stars can receive additional material even after the so-believed main accretion phase. more

Astronomers excited by first JWST spectra of planetary cradles showing a rich and diverse chemistry more

Liquid water is one of the most important ingredients for the emergence of life as we know it on Earth. Researchers of the ORIGINS Cluster and the Max Planck Institute for Extraterrestrial Physics from the fields of astrophysics, astrochemistry and biochemistry have now determined the necessary properties that allow moons around free-floating planets to retain liquid water for a sufficiently long time and thus enable life. more

James Webb Space Telescope unveils the dark side of pre-stellar ice chemistry more

High-resolution ALMA observations of the system IRAS 16293-2422 have revealed localized hot spots in the dusty material of the young stellar system. The study led by the Max Planck Institute of Extraterrestrial Physics indicates that these are most likely due to local shocks caused by fast gas motions rather than illumination from the protostars. This suggests that heat produced in shocks is an important factor during the early stages of the formation of protostars and the planetary disks around them. Such shocks could be caused by localized accretion of material from the surrounding envelope or by local fragmentation due to gravitational instabilities. more

The German Astronomical Society (AG) has awarded MPE scientist Dr. Tommaso Grassi with the Astrophysical Software Award for the development of the astrochemistry package KROME. The award ceremony will take place at the University of Bremen during the annual AG meeting from 12th to 16th of September 2022. more

Astronomers at the Max Planck Institute for Extraterrestrial Physics have found evidence that just before star formation, in the central region of a pre-stellar cloud, practically all heavy molecules freeze out on top of dust grains. The ALMA observations of the L1544 cloud in the constellation Taurus showed not only a central concentration of dust grains, but also revealed that molecules containing nitrogen as well those containing carbon, oxygen and all elements heavier than helium, are stored in thick icy mantles around the dust grains. These icy mantles are rich in water and organic molecules, precursors of pre-biotic molecules. The abundances are similar to those observed in leftover objects from the formation of our Solar System. more