Hosted by: Denise Piatti (University of Padova)

The LUNA (Laboratory for Underground Nuclear Astrophysics) experiment is located at the LNGS (Laboratori Nazionali del Gran Sasso) in Italy. LUNA is aimed at studying the nuclear reactions that are responsible for the synthesis of the elements and shape the life of stars in the universe. The reduction of the cosmic-rays induced background provided by the 1400 m thick rock overburden at LNGS allows the direct measurement of the cross section in the energy range relevant to astrophysics.

Hosted by: Rob Yates (University of Hertfordshire)

Hosted by: Rob Yates (University of Hertfordshire)

Hosted by: Thibaut Dumont (CNRS Strasbourg)

The groundwork for stellar nucleosynthesis was established over 70 years ago, marking the beginning of a fascinating journey. Since then, substantial progress has unfolded on both theoretical and observational fronts. On the theoretical side, intricate models of stellar evolution and nucleosynthesis have evolved, utilising increasingly precise nuclear data. Simultaneously, the observational realm has witnessed a significant rise in the number of stars analysed.

*THIS SEMINAR HAS BEEN POSTPONED TO FRIDAY, DECEMBER 8th AT 2PM EASTERN TIME*

Hosted by: Rob Yates (University of Hertfordshire)

Hosted by: Jennifer Sanchez Rojo (TRIUMF)

*Please note that this seminar will take place at 10am Eastern Time*

Hosted by: Shun Iimura (Rikkyo University)

Hosted by: Avrajit Bandyopadhyay (University of Florida)

*Due to unforeseen circumstances, this seminar is canceled*

Hosted by: Denise Piatti (University of Padova)

Hosted by: Barbara Paes Ribeiro (TANDAR)

Hosted by Eliana Masha (HZDR, Germany)

*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.

In unresolved galaxies, age, metallicity, α/Fe enhancement of the stellar populations, as well as the IMF and the mass can be constrained via full spectra fitting or via line-strength index analysis. The Lick/IDS system is a prime example of line-strength spectroscopic indices that are sensitive to these parameters in the optical domain. In the Near-Infrared (NIR), where the upcoming generation of telescopes will primarily observe, we lack such a system, and the full spectral fitting technique is not yet reliable.

Abstract: One of the biggest questions in nuclear astrophysics regards how elements are synthesized in stellar environments. Observations of astrophysical phenomena provide us with evidence for different nucleosynthesis processes, and modelling these astrophysical scenarios requires a detailed description of the complex nuclear physics that is involved.