EXPLOSIVE STELLAR PHENOMENA - 2022/3
Module code: PHYM052
This module aims to provide an advanced level understanding of explosive nuclear astrophysics and the physics of stars. In particular, the course will provide an analytical underpinning of resonant reaction rates, together with the experimental techniques involved in their determination, as well as a theoretical treatment of nuclear reactions and celestial objects.
Mathematics & Physics
LOTAY Gavin (Maths & Phys)
Number of Credits: 15
ECTS Credits: 7.5
Framework: FHEQ Level 7
JACs code: F370
Module cap (Maximum number of students): N/A
Overall student workload
Independent Learning Hours: 100
Lecture Hours: 22
Tutorial Hours: 13
Laboratory Hours: 3
Captured Content: 12
Prerequisites / Co-requisites
This module will assume prior knowledge equivalent to PHY2067 Nuclear and Particle Physics (BSc Physics Year 2). If you have not taken this module, you should consult the module descriptor.
Indicative content includes:
- Introduction to EPAP, overview of nuclear landscape and the importance of stars in the formation of the chemical elements
The Physics of Stars
- Basic observations and stellar parameters – Hertzsprung-Russell diagram, Mass-Luminosity relationship and colour
- Gravitational contraction and hydrostatic equilibrium
- Main Sequence stellar structure
- Late stellar evolution and compact astronomical objects
Explosive Stellar Phenomena
- Classical Novae – Observations (UV/IR spectra and presolar grains), explosive hydrogen burning and novae nuclear reaction networks
- Core-Collapse supernovae and the formation of neutron stars and black holes – Principles of the explosion and the possibility of neutrino driven winds. Heavy element formation and the role of the νp-process.
- Cosmic γ-ray emission
- Concept of isomers and nucleosynthetic complications involved in high temperature environments – example of 26mAl
- X-ray bursts – Observations (XMM-Newton and Chandra satellite missions), “Breakout” from hot CNO cycles and nucleosynthetic path of the rp-process; role of waiting points
Experimental determination of Resonant Stellar Reaction Rates
- Basic overview of nuclear reactions in exploding stars – Energetics: Q-values, reaction cross sections and concept of particle-emission thresholds (Sn, Salpha and Sp)
- Experimental determination of Q-values – Mass measurements with Ion Penning Traps and Heavy-ion Storage Rings
- Resonant reactions with neutrons and charged particles – concept of broad and narrow resonances
- Analytical formalism for narrow and broad resonance contributions to stellar reaction rates – key nuclear physics properties of resonance energy, spin and particle partial widths
- Experimental techniques for the determination of resonant stellar reaction rates –
- Direct methods using recoil mass spectrometers and need for radioactive ion beams. Direct methods using neutrons and time-of-flight facilities: (n,gamma) as well as (n,p) for vp-process.
- Indirect methods: (i) Charge exchange reactions, such as (3He,t), and angular distributions (ii) γ-ray spectroscopy; role of angular distributions, lifetimes and mirror symmetry, (iii) β-delayed particle decay spectroscopy; selection rules and logft values, (iv) Measurements of alpha-particle decay branches using transfer reactions and (iv) Spectroscopic factors from (d,p) and (3He,d) transfer reactions and principles of scattering theory.
- Broad resonance studies and R-Matrix theory: example of 18F(p,alpha) and its role in the destruction of the potential cosmic gamma-ray emitter 18F in novae.
- Nuclear reactions leading to solar neutrinos. Concept of neutrino oscillations and analytical formalism of 2-flavour oscillation probabilities.
- Concept of Dark Matter – current experimental studies for direct dark matter detection (LUX-Zepplin and XENON 1T).
- Basic principles of Dark Energy
|Assessment type||Unit of assessment||Weighting|
|Examination||End of Semester Examination - 2 hours||70|
In the event that a student fails the computational group coursework, they will be reassessed with a take home, open book test, consisting of exam style questions.
The proposed assessment strategy for this module will involve:
30% of group based coursework to produce a final report describing a computational project involving explosive nucleosynthesis yields and/or hydrodynamical stellar simulations, as well as an oral presentation. All students will be marked individually for their contribution to the project based on a peer review process. Open-source numerical codes will be provided. Coursework set in week 6, to be submitted/presented in week 9.
70% for a final, 2 hour closed book examination where students will answer a series of compulsory questions as well as 2 questions from a set of 3 longer questions.
Formative feedback will be given in class tutorial sessions and from assessment of coursework.
- Provide an understanding of the underlying physics behind the formation of stars and stellar evolution.
- Provide an understanding of explosive stellar phenomena, such as novae, supernovae and x-ray bursts, including the underlying nuclear physics processes involved that result in observational data
- Provide an analytical treatment of resonant stellar reaction rates for both narrow and broad resonance contributions, together with a detailed understanding of the modern experimental and theoretical techniques used in obtaining the key nuclear physics information required.
- Provide an understanding of astroparticle physics, such as neutrino oscillations, dark energy and direct dark matter detection
|001||The student will be knowledgeable about current stellar models and will be able to describe how stars of different masses are born and evolve in time. The student will understand the Hertzsprung-Russell diagram. The student will identify the different density and temperature regimes occurring inside stars and will be aware of how dense quantum fluids and extremely hot relativistic gases impact stellar properties.||KC|
|002||The student will be able to describe in detail different explosive stellar phenomena, including the various observational data and the underlying nuclear reaction networks involved.||KC|
|003||The student will be able to perform resonant stellar reaction rate calculations at given temperatures for a variety of reactions. In particular, the student will have a detailed understanding of the importance of the specific microscopic nuclear physics input needed as well as the experimental and theoretical techniques involved in determining these properties.||KC|
|004||The student will obtain an understanding of dark energy, direct dark matter detection research and will be able to reproduce the formalism for 2-flavour neutrino oscillation probabilities||KC|
C - Cognitive/analytical
K - Subject knowledge
T - Transferable skills
P - Professional/Practical skills
Methods of Teaching / Learning
The learning and teaching methods include:
• lectures and tutorials
Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.
Upon accessing the reading list, please search for the module using the module code: PHYM052
Programmes this module appears in
|Physics MSc||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
|Mathematics and Physics MPhys||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
|Mathematics and Physics MMath||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
|Physics with Nuclear Astrophysics MPhys||2||Compulsory||A weighted aggregate mark of 50% is required to pass the module|
|Physics with Astronomy MPhys||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
|Physics with Quantum Technologies MPhys||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
|Physics MPhys||2||Optional||A weighted aggregate mark of 50% is required to pass the module|
Please note that the information detailed within this record is accurate at the time of publishing and may be subject to change. This record contains information for the most up to date version of the programme / module for the 2022/3 academic year.