idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Grafik: idw-Logo

idw - Informationsdienst
Wissenschaft

idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
02/09/2026 14:16

Stellar remnants solve the mystery of missing mass in galaxy clusters

Johannes Seiler Dezernat 8 - Hochschulkommunikation
Rheinische Friedrich-Wilhelms-Universität Bonn

    +++ RESEARCH TICKER UNIVERSITY OF BONN: Astrophysics +++
    Under the leadership of the University of Bonn, a research team led by Prof. Dr. Pavel Kroupa from the Helmholtz Institute for Radiation and Nuclear Physics has discovered that galaxy clusters are about twice as heavy as previously assumed. The additional mass comes mainly from neutron stars and stellar black holes and also explains the observed quantities of heavy elements.

    WHAT IS IT ABOUT?
    Galaxy clusters are the largest gravitationally bound structures in the universe, but their mass and composition have not yet been fully researched. A new study led by Prof. Dr. Kroupa investigated how stellar populations and matter are distributed in the clusters. Using the Integrated Galaxy-wide Initial Mass Function (IGIMF) theory developed in Bonn, realistic star populations were calculated and the total masses of the clusters were determined.

    WHAT IS THE MOST IMPORTANT FINDING?
    The study shows that galaxy clusters are about twice as heavy as previously assumed. The newly determined masses are in good agreement with the predictions of Milgrom's theory of gravity (MOND). Newton's theory with dark matter, on the other hand, does not provide correct results, as the amount of dark matter required for this is only about half as much as previously assumed.

    WHAT WAS THE CHALLENGE?
    For the study, the researchers had to compile a large amount of observational data on numerous galaxy clusters, including data from gravitational lens measurements and detailed information about the individual galaxies. On this basis, the star populations of each galaxy had to be recalculated in order to finally determine the total mass of the clusters.

    IS THERE AN APPLICATION?
    No, this is purely basic research. However, the results provide a new understanding of the connection between space-time and matter, which could potentially lead to new technologies in the future.

    WHO WAS INVOLVED?
    In addition to the Helmholtz Institute for Radiation and Nuclear Physics at the University of Bonn, the Astronomical Institute of Charles University in Prague and the Institute for Advanced Studies in Basic Sciences (IASBS) at the University of Zanjan, Iran, were also involved in the study.


    Contact for scientific information:

    Prof. Dr. Pavel Kroupa
    Helmholtz Institute for Radiation and Nuclear Physics
    University of Bonn
    Tel. 0228/73-6140
    Email: pkroupa@uni-bonn.de


    Original publication:

    Dong Zhang, Akram Hasani Zonoozi, and Pavel Kroupa: Revisiting the missing mass problem in MOND for nearby galaxy clusters, Physical Review D (PRD), DOI: https://doi.org/10.1103/mp3f-q5dc, advance copy via arXiv: https://arxiv.org/abs/2602.06082


    Images

    Criteria of this press release:
    Journalists, all interested persons
    Physics / astronomy
    transregional, national
    Research results, Scientific Publications
    English


     

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).