Tracing the origin of magnetic fields in galaxies

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• Sergio Martin
• Wednesday 30 October 2019, 13:45-14:15
• Sackler Lecture Theatre, IoA.

If you have a question about this talk, please contact Catrina Diener.

Magnetic fields are one of the most fascinating puzzles in the picture of galaxy formation. Recognised important throughout many astrophysical scenarios, they often stand as a major source of uncertainty. In galaxy evolution, one of the major unknowns is which mechanisms generate microGauss magnetic fields in the ISM . Three main alternative pictures stand as possible drivers of their evolution: either magnetic field are of strong primordial origin; amplified by dynamos; or produced by stars or AGN and subsequently fed to the ISM , and possibly further out into the intergalactic medium, polluting the cosmic magnetic field. While each picture appears self-sufficient, current studies struggle to shed light on how these different mechanisms interact or whether one dominates over the others.

I present in this talk our first scientific results using our new algorithm designed to answer these questions by following how magnetic fields from different origins co-evolve. I apply the code to a cosmic zoom-in MHD RAMSES simulation where magnetic fields are sourced simultaneously as an ab-initio primordial field and by magnetised stellar feedback to study the origin of galactic magnetic fields. The two sources are followed separately. I discuss which magnetic source dominates the energy budget in the galaxy and in different parts of its ISM . I review some signatures of these fields and how the stellar-generated field pollutes the primordial magnetic field in the environment.

This talk is part of the Institute of Astronomy Seminars series.

This talk is included in these lists:

• Cambridge Astronomy Talks
• Combined External Astrophysics Talks DAMTP
• Cosmology lists
• Cosmology, Astrophysics and General Relativity
• Institute of Astronomy Seminars
• Institute of Astronomy Talk Lists
• Kavli Institute for Cosmology Talk Lists
• Priscilla
• Sackler Lecture Theatre, IoA

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