Daniel Siegel

Siegel, Daniel-Small.jpg

Assistant Professor

Contact Information

Telephone: 519-824-4120 x53983

Email: dsiegel@uoguelph.ca

Office: MacN 435C

Education

Ph.D., Max Planck Institute for Gravitational Physics (Albert Einstein Institute) and University of Potsdam, Germany, 2015
Diploma in Physics, University of Freiburg, Germany, 2011

Research

A unifying theme of my research is the pursuit to connect fundamental physics with the cosmos. I am excited about multimessenger and gravitational-wave astronomy with Advanced LIGO and Virgo and its partner facilities in the electromagnetic band and the neutrino/high-energy particle sector. My research interests cover a broad range of topics including gravitational physics, nuclear astrophysics, high-energy astrophysics, and transient astronomy. Much of my research centers around unraveling the fundamental physics and astrophysics of compact binary mergers involving neutron stars and pertains to questions such as

  • What are the physical processes that govern the dynamics of neutron star mergers and that give rise so observable electromagnetic radiation?
  • How do such mergers and other astrophysical systems synthesize heavy elements in the Universe via the rapid neutron capture process (r-process)?
  • What are the broader impacts on nuclear (astro-)physics and cosmology? What do such astrophysical phenomena tell us about how our Universe was chemically assembled?

In order to study these prime targets of multi-messenger astronomy, I perform fully general-relativistic magnetohydrodynamic simulations on supercomputers, including microphysical equations of state, weak interactions, neutrino radiation transport, and nuclear reaction networks, in combination with analytical and semi-analytical modeling. This allows me to obtain self-consistent predictions from first principles that can directly be compared to data from multi-messenger astronomy.

Selected Recent Publications

  • Siegel D. M., Barnes J., Metzger B. D. 2019, Collapsars as a major source of r-process elements, Nature 569, 241
    This paper presents strong evidence that the birth of black holes in the collapse of rapidly rotating stars (‘collapsars’) produces heavy (r-process) elements, which could be the dominant r-process production site for cosmic nucleosynthesis.
  • Siegel D. M. 2019, GW170817—the first observed neutron star merger and its kilonova: implications for the astrophysical site of the r-process, to appear in The European Physical Journal A, arXiv:1901.09044
    This invited contribution to a special issue on GW170817 provides a discussion of the kilonova observations and their implications for r-process nucleosynthesis of the first-ever detected neutron star merger.
  • Siegel D. M., Metzger 2017, Three-Dimensional General-Relativistic Magnetohydrodynamic Simulations of Remnant Accretion Disks from Neutron Star Mergers: Outflows and r-Process Nucleosynthesis, Physical Review Letters 119, 231102 (selected PRL Editor’s Suggestion, selected for a Viewpoint in Physics)
  • Siegel D. M., Metzger 2018, Three-dimensional GRMHD Simulations of Neutrino-cooled Accretion Disks from Neutron Star Mergers, The Astrophysical Journal 858, 52

These papers provide strong evidence that outflows from a remnant accretion disk that forms in the aftermath of a neutron star merger represents the most likely explanation for the origin of the red kilonova and the production of heavy elements in the first-ever detected neutron star merger GW170817 by LIGO and Virgo. In general, they provide strong evidence from first principles for neutron star mergers being an important production site for r-process elements in the Universe.