P630 Nuclear Astrophysics Charles Horowitz Charles Horowitz Fall 2002, Indiana University Fall 2002, Indiana University Course Web site: 30/index.html Course Web site: 30/index.html 30/index.html 30/index.html What is the Universe made of? Why is it this way? What is the Universe made of? Why is it this way? Note, nucleosynthesis today, discuss neutrinos later. Note, nucleosynthesis today, discuss neutrinos later.

Supernova Simulation by Burrows and Fox

SN Simulation by E. Marietta. Exploding Star is just above frame and interacts with its binary companion star Exploding Star is just above frame and interacts with its binary companion star

Nuclear Reaction Network Simulation by B. Meyer Burning of Si shell to Ni -> Fe as SN shock passes through Burning of Si shell to Ni -> Fe as SN shock passes through

Vela

Cas A Chandra X-ray Observatory image of the supernova remnant Cassiopeia A shows low, medium and high energy X- rays (red, green and blue) Chandra X-ray Observatory image of the supernova remnant Cassiopeia A shows low, medium and high energy X- rays (red, green and blue) Red is enriched in Fe, bright greenish white region in lower left enriched in silicon and sulfur. Red is enriched in Fe, bright greenish white region in lower left enriched in silicon and sulfur.

Abundances From meteorites and solar spectra From meteorites and solar spectra Meteorites are relatively unchanged since being formed 4.6 B years ago with the solar system. Meteorites are relatively unchanged since being formed 4.6 B years ago with the solar system. Abundances reflect composition of primitive solar nebula at time of formation. Abundances reflect composition of primitive solar nebula at time of formation. Heavy elements made in previous generation stars. Not made in Sun. Heavy elements made in previous generation stars. Not made in Sun.

Most Abundant Nuclei NucleusAbundanceSource H0.706Big Bang 1 H0.706Big Bang 4 He0.275Big Bang, CNO, pp 4 He0.275Big Bang, CNO, pp 16 O0.0096Helium 16 O0.0096Helium 20 Ne0.0015Carbon 20 Ne0.0015Carbon 56 Fe0.0012e-process 56 Fe0.0012e-process 14 N0.0011CNO 14 N0.0011CNO 28 Si0.0007Oxygen 28 Si0.0007Oxygen

Astrophysical Neutrinos Dear Radioactive Ladies and Gentleman, …because of the “wrong” statistics of 14 N and 6 Li nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the “exchange theorem” of statistics and the conservation of energy. Namely the possibility that there exists in nuclei electrically neutral particles, that I call neutrons, which have spin ½… The mass of the neutrons should be of the same order as the electron mass and in any event not larger than 0.01 proton masses. The continuous beta spectrum would then be explained by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the electron and neutron is constant. …because of the “wrong” statistics of 14 N and 6 Li nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the “exchange theorem” of statistics and the conservation of energy. Namely the possibility that there exists in nuclei electrically neutral particles, that I call neutrons, which have spin ½… The mass of the neutrons should be of the same order as the electron mass and in any event not larger than 0.01 proton masses. The continuous beta spectrum would then be explained by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the electron and neutron is constant. I agree that my remedy should seem incredible because one should have seen those neutrons very earlier if they really exist. But only the one who dare can win and the difficult situation… Thus dear radioactive people, look and judge. Unfortunately, I cannot appear in Tubingen since I am indispensable here in Zurich because of a ball on the night of 6/7 December. I agree that my remedy should seem incredible because one should have seen those neutrons very earlier if they really exist. But only the one who dare can win and the difficult situation… Thus dear radioactive people, look and judge. Unfortunately, I cannot appear in Tubingen since I am indispensable here in Zurich because of a ball on the night of 6/7 December. Your humble servant, W. PauliDec. 4, 1930 Your humble servant, W. PauliDec. 4, 1930

Solar Neutrino Spectrum

Sudbury Neutrino Observatory

SNO Under construction excavating a large cavity

Underground neutrino detectors Superkamikonda is a giant tank with tons of very clean water. Superkamikonda is a giant tank with tons of very clean water. This is deep in a mine to protect from cosmic rays. This is deep in a mine to protect from cosmic rays. Very rarely a neutrino will interact and cause a small flash of light in the tank. Very rarely a neutrino will interact and cause a small flash of light in the tank. Phototubes on the walls detect these flashes of light. Phototubes on the walls detect these flashes of light. SK should detect a few thousand neutrinos from a galactic supernova. SK should detect a few thousand neutrinos from a galactic supernova.

20 Events from SN1987A The anti-nu appear to be cooling with time not getting warmer.