• Next SFB 1601 colloquium

    Next SFB 1601 colloquium

    The next SFB-colloquium will be on July 15 at 3 pm in lecture hall III of the physics institutes in Cologne. Bérenger Gans from the Institut des Sciences Moléculaires d’Orsay, CNRS & University of Paris-Saclay will talk about Investigation of interstellar radical photoionization by VUV photoelectron spectroscopy.

  • Next Astronomy on Tap event in Cologne

    Next Astronomy on Tap event in Cologne

    Join us at our season finale of SoSe 2024! Program below. 

    • Eine kurze Geschichte der Schwarzen Löcher: von Einstein bis in die Gegenwart” (auf Deutsch) by Daniel Vieira

    Die allgemeine Relativitätstheorie sagt die Existenz von Singularitäten in der Raumzeit voraus. Diese Singularitäten sind keine mathematische Kuriositäten sondern die beschreiben echte Objekte in der Universum: schwarze Löcher!

    • How many eyes does it take to see dusty young protostars?” (in English) by Dr. Bethany Jones

    What goes on in the birthplaces of the most massive stars? The creation of young stars much more massive than the sun can be seen with ALMA, a telescope in the Atacama Desert in Chile made of 66 smaller telescopes that see different light to human eyes, which tells us enough about their chemistry to work out where they come from – important, as they provide almost all of the UV radiation in a galaxy!

    More information about Astronomy on Tap can be found here: https://sfb1601.astro.uni-koeln.de/events/aot-2/

  • Science Communication Seminar

    Science Communication Seminar

    Our science is often not visible to the public because we don’t know how to present in properly. 
    With the help of the UoC press department we are aiming to change that. 

    A first seminar about science communication will be on Monday, June 24 at 3 pm (regular colloquium time). All PH1 or SFB1601-members are invited to join, there is no registration necessary.

  • An unexpected observed orbital pattern of candidate Young Stellar Objects close to the supermassive black hole

    An unexpected observed orbital pattern of candidate Young Stellar Objects close to the supermassive black hole

    High-speed baby stars circle the supermassive black hole Sgr A* like a swarm of bees.

    Publication Highlight from Florian Peißker
    A&A news: https://www.aanda.org/2024-press-releases
    UoC-article: https://portal.uni-koeln.de

    The Near- and Mid-infrared observation of dusty sources in the S cluster, which harbors the supermassive black hole in the center of our galaxy, Sgr A*, is accompanied by a discussion about their nature. The current study, published today in A&A, aims to explore the Keplerian parameters of these dusty S cluster members orbiting Sgr A* and analyze their orbital distribution. The results indicate a clear disk-like pattern following the arrangements of the main-sequence cluster members, suggesting a common formation process for the young dusty sources. Based on the multi-wavelength photometric analysis, the study found strong indications that suggest that the dusty sources have a stellar nature consistent with the spectral energy distribution of Young Stellar Objects. The nature of the dusty sources and their organized arrangement around Sgr A* are unexpected and shed light on unexplored star formation processes in the high energetic radiation environment of the supermassive black hole.

    Published in A&A (2024)

    Context: The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. Until now, the question of the origin of these two populations is vague, although all explanations favor migration processes for the individual cluster members.
    Aims: This work revisits the S-cluster and its dusty members orbiting the supermassive black hole Sgr A* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a non-random distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources.
    Methods: Based on the photometric analysis, we estimated the individual H − K and K − L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a Young Stellar Object Class I model. We obtained the position angle from the Keplerian fit results, and additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node.
    Results: The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and mid-infrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of Sgr A* are much shorter (≪ 2 years) than the epochs covered by the observations (≈15 years). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process.
    Conclusions: The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and the longitudes of the ascending node, strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share the common formation history or migrated with a similar formation channel in the vicinity of Sgr A*. Alternatively, the gravitational influence of Sgr A* in combination with a massive perturber, such as a putative IMBH in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement.

  • Astronomy on Tap Bonn

    Astronomy on Tap Bonn

    Join us next Tuesday, 23rd of April, at 19:00 at Fiddlers, Frongasse 9, Endenich for a new event of Astronomy on Tap Bonn!

    The event will be featuring

    1) Arunima Dutta: A Pulsar and its Mysterious Companion[en]

    2) David Ohse: Warum sind wir hier? [de]

  • Julian Rohrhuber & Volker Ossenkopf-Okada: Leuchtstoffraum 2, Kleinmann-Low 16.1 channel sound installation

    Julian Rohrhuber & Volker Ossenkopf-Okada: Leuchtstoffraum 2, Kleinmann-Low 16.1 channel sound installation

    AUSSTELLUNG
    DÜSSELDORF — WELTKUNSTZIMMER 
    Öffnungszeiten: Do–So 14–18 h
    Eintritt frei 
    Eröffnung • 18. April 2024 / Donnerstag / 19.00 h

    The Kleinmann-Low nebula in the Orion is a location of intense star formation with a complex spatial and chemical dynamic. Its radiation originates from finely distributed atoms and molecules, which in the light of the young stars emit a characteristic spectrum. The piece „Leuchtstoffraum“ is informed by the unusually precise measurements of the Herschel space telescope from 2010. It is based on the simple principle that the natural laws are the same on earth as in the nebula 1300 light years away. We hear the structure of electromagnetic radiation of a minute point in the sky whose frequencies may be partitioned into series of molecule spectra, known from the laboratory. Leuchtstoffraum 2 is an outcome of a collaboration between Julian Rohrhuber, professor at the Robert Schumann Hochschule Düsseldorf, with the astro-physicist PD Dr. Volker Ossenkopf-Okada, who teaches at I. Physikalische Institut of the University, Cologne.

    www.JulianRohrhuber
    wertlos.org/~rohrhuber
    youtube:VolkerOssendorf-Okada

  • Colloquium program for Summer 2024

    Colloquium program for Summer 2024

    The colloquium program for summer semester 2024 is online. https://sfb1601.astro.uni-koeln.de/events/sfb1601-colloquium/

    We welcome you every Monday at 3 pm at the University of Cologne, Physics Institutes (Zülpicher Str. 77) in Lecture Hall III.
    The colloquia will start off with a coffee/tea reception at 02:45 pm in front of the lecture hall.

  • Gastvortrag in der Volkssternwarte von Stefanie Walch-Gassner

    Gastvortrag in der Volkssternwarte von Stefanie Walch-Gassner

    Am 22. März um 20:00 Uhr im Theaterkeller des Schiller-Gymnasiums

  • Training offers at the FZJ

    Jülich Supercomputing Centre offers a training programme of about 25 HPC-relevant courses per year. The courses comprise lectures and hands-on training on programming languages, usage of HPC systems, parallel environments, MPI, hybrid programming, GPU programming, deep learning, and – in the near future – quantum computing.

    https://sfb1601.astro.uni-koeln.de/events/trainings/