Author/s: J. R. Bermejo-Climent, G. Battaglia, C. Gallart, A. Di Cintio, C. B. Brook. L. Cicuéndez, M. Monelli, R. Leaman, L. Mayer, J. Peñarrubia, J. I. Read
Reference: 2018 MNRAS 479 1514 | Link
Figure: The images show the gas temperature (red is hot, blue is cold) at different redshift. One can appreciate the
Most of the matter in the Universe is thought to be in the form of non-baryonic matter, possibly made of still to be discovered particles.
If only gravitational interactions were important in the formation and evolution of galaxies, current theories predict that galaxies should be surrounded by dark matter haloes having a distribution with densities increasing steeply towards the centre.
However, consensus has been growing that processes due to the baryonic component of galaxies can alter the dark matter distribution. In principle, the energy from explosions of supernovae type II can repeatedly push the gas outwards, changing the gravitational potential and modifying the distribution of dark matter, which would become less dense in the central regions. In this work, the authors used accurate determinations of the amount of stars formed in the early phases of the life of 16 dwarf galaxies inhabiting our own Local Group to calculate the amount of energy associated to massive stars that are expected to have exploded as supernovae type II.
The authors have concluded that, unless more than 90% of this energy radiates away, the observations support the idea that these processes can induce significant changes in the density of the dark matter halo of the galaxies analysed.
The researchers also forecast which systems among the studied satellites of the Milky Way are the most promising to be studied further, finding that the largest deviations from the initial structure of the dark matter haloes should occur in the Sculptor and Fornax dwarf galaxies, whilst Draco and Ursa Minor should have been those more able to preserve the initial central densities of their haloes.