The Role of Magnetic Fields in The Evolution of Galaxies. (arXiv:1811.04401v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Tabatabaei_F/0/1/0/all/0/1">Fatemeh S. Tabatabaei</a>
Magnetic fields constitute an energetic component of the interstellar medium
in galaxies and hence can affect the formation of galactic structures.
Sensitive resolved radio continuum observations together with statistical
studies in galaxy samples are performed to investigate the origin and the
impact of the magnetic fields. The JVLA cloud-scale survey of the local group
galaxy, M33, unveils strong tangled magnetic field along the spiral arms and in
the galaxy center indicating amplification due to compression and local shear
in molecular clouds. Studying a sample of non-cluster, non-interacting
galaxies, we find that the large-scale ordered magnetic field scales with the
rotation speed of galaxies. The total and disordered magnetic fields scales
with the star formation rate in normal star forming galaxies. On the other
hand, a strong magnetic field in the center of NGC 1097 — a massive galaxy
undergoing quenching — is found responsible for decelerating its massive star
formation. Putting these results together, it is deduced that 1) the Universe
was highly magnetized short after the peak of the massive star birth at about 1
Gyr after the Big Bang and 2) the strong magnetic field has possibly acted as
back reaction after this time, quenching the massive star formation and
stimulating the creation of low-mass stars in massive galaxies.
Magnetic fields constitute an energetic component of the interstellar medium
in galaxies and hence can affect the formation of galactic structures.
Sensitive resolved radio continuum observations together with statistical
studies in galaxy samples are performed to investigate the origin and the
impact of the magnetic fields. The JVLA cloud-scale survey of the local group
galaxy, M33, unveils strong tangled magnetic field along the spiral arms and in
the galaxy center indicating amplification due to compression and local shear
in molecular clouds. Studying a sample of non-cluster, non-interacting
galaxies, we find that the large-scale ordered magnetic field scales with the
rotation speed of galaxies. The total and disordered magnetic fields scales
with the star formation rate in normal star forming galaxies. On the other
hand, a strong magnetic field in the center of NGC 1097 — a massive galaxy
undergoing quenching — is found responsible for decelerating its massive star
formation. Putting these results together, it is deduced that 1) the Universe
was highly magnetized short after the peak of the massive star birth at about 1
Gyr after the Big Bang and 2) the strong magnetic field has possibly acted as
back reaction after this time, quenching the massive star formation and
stimulating the creation of low-mass stars in massive galaxies.
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