*Please note that this seminar is at 7pm ET on Thursday, April 13th*

Hosted by Kanji Mori (Fukuoka University, Japan)

Hosted by Erin Good (Michigan State University)

The n-process is a neutron-capture process activated in Core-Collapse Supernovae (CCSNe), when the Supernova shock is passing through the deepest He-rich layers of the massive star progenitor. The peak neutron density generated is typically larger than 1018 neutrons cm-3, and the dominant neutron source is the Ne22(alpha,n)Mg25 reaction where the Ne22 available was left in the ashes of the hydrostatic convective He shell.

Understanding the behavior of white dwarfs in interacting binary systems is critical to determining the rates, distributions, and chemical contributions from transients such as novae and type Ia supernovae. In this talk I will be presenting results from my recent work on novae, which combines population synthesis (binary_c) and galactic chemical evolution modeling (OMEGA+).

Understanding how the heavy elements came into being in the universe presents one of the greatest challenges in nuclear physics and astrophysics.  For some time we have known that elements beyond iron on the periodic table must have been made through neutron-induced reactions, but the environments where they are made and what they can tell us about this history of our galaxy remain a mystery.

Carbon is produced in stars mainly via the triple-alpha process where three helium nuclei fuse to form an excited state of carbon-12 known as the Hoyle state. This is a nuclear resonance (an excited form of a nucleus) that has properties that guide the rate that the triple alpha process takes place. Primarily, the key property is how often the Hoyle state is able to lose energy and end up in the ground state of carbon-12 – known as the radiative width.

Gamma rays from nuclear lines are the most-direct astronomical messenger for the occurrence of nuclear reactions in cosmic sites, next to neutrinos.

Characteristic lines from radioactive decays have been measured with space-borne telescopes, most-recently with ESA’s INTEGRAL mission, for the isotopes 56Ni, 57Ni, 44Ti, 26Al, and 60Fe.