Pulsars - History and Morphology

Presentation for my Astrophysics work in 2013.

It is about neutron stars and pulsares.

Transcript

1. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Pulsars History and Morphology D. Bento Department of Physics University of Lisbon - Science Faculty Astrophysics, 2013 Daniel Bento University of Lisbon - Science Faculty Pulsars
2. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
3. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
4. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars What was the question... Unknown sources of radio frequencies Very accurate pulses Daniel Bento University of Lisbon - Science Faculty Pulsars
5. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars Precision? Figure : Periodic Pulsar Pulses Daniel Bento University of Lisbon - Science Faculty Pulsars
6. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars It’s a signal of Life or something else? No one could say, astronomers didn’t had any theory Daniel Bento University of Lisbon - Science Faculty Pulsars
7. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars Life? Figure : They will be always there... Daniel Bento University of Lisbon - Science Faculty Pulsars
8. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The study of Pulsars Far Away Figure : NASA Daniel Bento University of Lisbon - Science Faculty Pulsars
9. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Back to 1932 Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
10. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Back to 1932 The discovery of the neutron nucleon 1920 - Ernest Rutherford conceived the possible existence of the neutron 1932 - James Chadwick discovered it Figure : Proton vs Neutron Daniel Bento University of Lisbon - Science Faculty Pulsars
11. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Back to 1932 The model of a neutron star 1934 - Walter Baade and Fritz Zwicky proposed their existence Collapsed supernovae Small Radius: 20km Dense: 5 × 1017km/m3 Hot: T ∼ 1011K Magnetic Field: 1017G Figure : Neutron Star Daniel Bento University of Lisbon - Science Faculty Pulsars
12. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
13. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey The first pulsar record 1967 - Jocelyn Bell found this strange pulses at 81.5MHz Figure : The first record of a pulsar by Jocelyn Bell Daniel Bento University of Lisbon - Science Faculty Pulsars
14. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Theories and explanations needed It was NOT life: They are found all around Figure : Milky Way’s galactic plane Daniel Bento University of Lisbon - Science Faculty Pulsars
15. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Theories and explanations needed It was NOT a Normal Star: It doesn’t pulse Figure : Milky Way’s galactic plane radio emission Daniel Bento University of Lisbon - Science Faculty Pulsars
16. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Theories and explanations needed It was NOT an Eclipsing Binary: Impossible Figure : Binary System Daniel Bento University of Lisbon - Science Faculty Pulsars
17. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Theories and explanations needed It was NOT a Variable Star: They have Big Periods Figure : Cepheid’s Luminosity Evolution Daniel Bento University of Lisbon - Science Faculty Pulsars
18. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Going to the radio survey Bringing some old and unused proposals Figure : Crab Nebula’s pulsar Daniel Bento University of Lisbon - Science Faculty Pulsars
19. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Size, Period and Temperature Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
20. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Size, Period and Temperature Size and Temperature Figure : Pulsar size compared with Manhattan Island Daniel Bento University of Lisbon - Science Faculty Pulsars
21. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
22. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field Magnetic Field Figure : Magnetic field lines Daniel Bento University of Lisbon - Science Faculty Pulsars
23. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field The basic origin of the B field Using hidrostatic equilibrium we found that P ∼ ρ5 3 So, for the neutron star we have R = 1 M 1 3 mnµ 5 3 n (1) The original magnetic flux is maintained after the colapse, so: Bns ≈ Bwd ( Rwd Rns )2 = 1.3 × 1010T (2) Daniel Bento University of Lisbon - Science Faculty Pulsars
24. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field The basic origin of the B field Using hidrostatic equilibrium we found that P ∼ ρ5 3 So, for the neutron star we have R = 1 M 1 3 mnµ 5 3 n (1) The original magnetic flux is maintained after the colapse, so: Bns ≈ Bwd ( Rwd Rns )2 = 1.3 × 1010T (2) Daniel Bento University of Lisbon - Science Faculty Pulsars
25. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field The basic origin of the B field Using rotational kinetic energy and the equation of energy for a magnetic dipole we get: B = 1 2πR3sin(θ) 3µ0 c3IP ˙ P 2π (3) Daniel Bento University of Lisbon - Science Faculty Pulsars
26. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Magnetic Field Beam Cone and Light Cylinder Cone created by the fast rotating star Electrons fall in the magnetic and electric fields like a syncroton High polarization Figure : Schematic representation of a pulsar Daniel Bento University of Lisbon - Science Faculty Pulsars
27. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Creation and Beyond Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
28. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Creation and Beyond How pulsars begin... Figure : Star evolution Daniel Bento University of Lisbon - Science Faculty Pulsars
29. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Creation and Beyond ... and how they end It’s known that the faster pulsars spins the faster they loose energy ... by neutrino emission ... by radiation Daniel Bento University of Lisbon - Science Faculty Pulsars
30. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The reborn of a pulsar Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
31. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The reborn of a pulsar Understanding the incoming data Super fast pulsars? The data doesn’t match with the knowledge about pulsar evolution Daniel Bento University of Lisbon - Science Faculty Pulsars
32. Motivation History Morphology The life sequence of a Pulsar To the Future Summary The reborn of a pulsar Binary Stars Figure : Binary system with a compact object Daniel Bento University of Lisbon - Science Faculty Pulsars
33. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Further Studies Outline Motivation The study of Pulsars History Back to 1932 Going to the radio survey Morphology Size, Period and Temperature Magnetic Field The life sequence of a Pulsar Creation and Beyond The reborn of a pulsar To the Future Further Studies Daniel Bento University of Lisbon - Science Faculty Pulsars
34. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Further Studies Pulsars against General Relativity Theory Figure : Project LISA detecting gravitational waves Daniel Bento University of Lisbon - Science Faculty Pulsars
35. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Further Studies Pulsars for navigation Figure : Artistic view of Rosetta spacecraft guided by pulsars Daniel Bento University of Lisbon - Science Faculty Pulsars
36. Motivation History Morphology The life sequence of a Pulsar To the Future Summary Summary The are many exotic objects to discover in the Universe. A Pulsar put stress tests on all of our Modern Physics Theories. Hoping a lot of new development on pulsar studies. Daniel Bento University of Lisbon - Science Faculty Pulsars
37. Appendix For Further Reading For Further Reading I Geoff McNamara, Clocks in the Sky - The story of pulsars, Springer Max Camenzind, Compact Objects in Astrophysics - White Drafts, Neutron Stars and Black Holes, Springer Werner Becker, Neutron Stars and Pulsares, Springer V. S. Beskin, A. V. Gurevich and Ya. N. Istomin Physics of the pulsar magnetosphere, Cambridge University Press John H. Seiradakis, Richard Wielebinski Morphology and Characteristics of Radio Pulsars, Astronomy & Astrophysics Review Daniel Bento University of Lisbon - Science Faculty Pulsars
38. Appendix For Further Reading For Further Reading II A. G. Lyne and D. R. Lorimer Vrije Universiteit, Amsterdam, 1971-1975 John Antoniadis et al. A Massive Pulsar in a Compact Relativistic Binary, Science 2013 http://www.atnf.csiro.au/research/pulsar/psrcat/ Daniel Bento University of Lisbon - Science Faculty Pulsars