Stellar feedback and the energy budget of late-type Galaxies: missing baryons and core creation

Katz, H.; Desmond, H.; Lelli, F.; McGaugh, S.; Di Cintio, A.; Brook, C.; Schombert, J.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 480, Issue 4, p.4287-4301

Advertised on:
11
2018
Number of authors
7
IAC number of authors
2
Citations
9
Refereed citations
7
Description
In a ΛCDM cosmology, galaxy formation is a globally inefficient process: it is often the case that far fewer baryons are observed in galaxy discs than expected from the cosmic baryon fraction. The location of these `missing baryons' is unclear. By fitting halo profiles to the rotation curves of galaxies in the SPARC data set, we measure the `missing baryon' mass for individual late-type systems. Assuming that haloes initially accrete the cosmological baryon fraction, we show that the maximum energy available from supernovae is typically not enough to completely eject these `missing baryons' from a halo, but it is often sufficient to heat them to the virial temperature. The energy available from supernovae has the same scaling with galaxy mass as the energy needed to heat or eject the `missing baryons', indicating that the coupling efficiency of the feedback to the ISM may be constant with galaxy virial mass. We further find that the energy available from supernova feedback is always enough to convert a primordial cusp into a core and has magnitude consistent with what is required to heat the `missing baryons' to the virial temperature. Taking a census of the baryon content of galaxies with 109 < Mvir/M⊙ < 1012 reveals that {˜ }86{{ per cent}} of baryons are likely to be in a hot phase surrounding the galaxies and possibly observable in the X-ray, {˜ }7{{ per cent}} are in the form of cold gas, and {˜ }7{{ per cent}} are in stars.
Related projects
Project Image
Numerical Astrophysics: Galaxy Formation and Evolution

How galaxies formed and evolved through cosmic time is one of the key questions of modern astronomy and astrophysics. Cosmological time- and length-scales are so large that the evolution of individual galaxies cannot be directly observed. Only through numerical simulations can one follow the emergence of cosmic structures within the current

Claudio
Dalla Vecchia
Project Image
Numerical Astrophysics: Galaxy Formation and Evolution

How galaxies formed and evolved through cosmic time is one of the key questions of modern astronomy and astrophysics. Cosmological time- and length-scales are so large that the evolution of individual galaxies cannot be directly observed. Only through numerical simulations can one follow the emergence of cosmic structures within the current

Claudio
Dalla Vecchia
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology

We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.

Ignacio
Martín Navarro