1 / 34

SELECTED TOPICS on GRAVITATIONAL LENSES

SELECTED TOPICS on GRAVITATIONAL LENSES. September 2006 Bogdan Popescu. Gravitational Lens Timeline.

shandi
Télécharger la présentation

SELECTED TOPICS on GRAVITATIONAL LENSES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SELECTED TOPICS on GRAVITATIONAL LENSES September 2006 Bogdan Popescu

  2. Gravitational Lens Timeline -18th Century - JOHN MICHELL , LAPLACE and CAVENDISH - deflection of light by a body, assuming the corpuscular theory of light and Newton’s law of gravitation. -1915 - EINSTEIN - General Relativity - gravitational deflection of the light -1919 - OLIVER LODGE - proposal of gravitational lens -1919 - EDDINGTON - first experimental proof -1924 - CHWOLSON - “Chwolson Rings” (now “Einstein Rings”…) -1936 - EINSTEIN - confirm existence of “Einstein Rings” -1937 - ZWICKY - affirm that is possible to detect the images -1937-1979 - a lot of theoretical work -1979 - DENNIS WALSH , R.F.CARSWELL and R.J.WEYMANN – discover first double quasar (0957 + 561 A, B ) proved as multiple images of the same object. September 2006 Bogdan Popescu

  3. Deflection of the Light Sir HENRY CAVENDISH (1784) September 2006 Bogdan Popescu

  4. Q 0957+561 A, B – The First Gravitational Lens September 2006 Bogdan Popescu Image credit : ****** http://antwrp.gsfc.nasa.gov

  5. Q 0957+561 A, B – The First Gravitational Lens The first gravitationally lensed object ever discovered, Q0957+561 is a quasar whose image is split into two by the gravity of a foreground galaxy. In this image, the two star like objects are the split images of the quasar. The fuzzy object near top quasar image is the foreground galaxy. The quasar lies at a redshift of 1.41. The foreground galaxy lies at a redshift of 0.39. In optical light, Q0957+561 appears as two point images of roughly 17 mag separated by 6.1 arcseconds. *** Image credit : Walsh, D. and Carswell, R.F. and Weyman, R.J. 1979, "0957+561 A,B: twin quasistellar objects or gravitational lens?" Nature, 279, 381 September 2006 Bogdan Popescu

  6. Gravitational Lens Optics September 2006 Bogdan Popescu

  7. Images **,****,***** Image credit : http://cassfos02.ucsd.edu/public/tutorial/GLens.html http://www.iam.ubc.ca/~newbury/lenses/research.html http://zebu.uoregon.edu/~soper/Mass/gravlens.html September 2006 Bogdan Popescu

  8. Images * Image credit : http://www-ra.phys.utas.edu.au/~jlovell/simlens/ September 2006 Bogdan Popescu

  9. Images – “Strong” and “Weak” Lenses 3 Image credit : Jetzer, P. – Gravitational Lensing – in Modern Cosmology, edited by Bonometto, S. et al, 2002 September 2006 Bogdan Popescu

  10. Dark Matter September 2006 Bogdan Popescu

  11. Dark Matter ***** Image credit : http://zebu.uoregon.edu/~soper/Mass/gravlens.html September 2006 Bogdan Popescu

  12. Mass Distribution from Gravitational Lenses This animation shows a galaxy cluster with two mass concentrations (the pink shading indicates the projected mass density) lensing a background field of faint blue galaxies. The magnitude of this shear pattern can be used to determine the mass contained within the cluster. Abell 2218 and CL2244-02 are clusters with tangential arcs. ***** Image credit : http://zebu.uoregon.edu/~soper/Mass/gravlens.html September 2006 Bogdan Popescu

  13. Weak Gravitational Lenses (WL) ***** Image credit : Schneider, P - astro-ph/0509252 September 2006 Bogdan Popescu

  14. Weak Gravitational Lenses (WL) (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  15. Weak Gravitational Lenses (WL) (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  16. Mass Reconstruction Three principal methods for determining the mass of galaxy clusters are in use: - Dynamical mass estimates - Assuming virial equilibrium, the observed velocity distribution of galaxies in clusters can be converted into a mass estimate, employing the virial theorem; this method typically requires assumptions about the statistical distribution of the anisotropy of the galaxy orbits. - X-ray mass determination of clusters - The hot intra-cluster gas, as visible through its Bremsstrahlung in X-rays, traces the gravitational potential of the cluster. Under certain assumptions (relaxed clusters), the mass profile can be constructed from the X-ray emission. - Weak and strong gravitational lensing probes the projected mass profile of clusters, with strong lensing confined to the central regions of clusters, whereas weak lensing can yield mass measurements for larger radii. September 2006 Bogdan Popescu

  17. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  18. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  19. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  20. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  21. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  22. Mass Reconstruction – Multiple Lens 1,5 Image credit : 1 Bernadeau, F – Gravitational Lensing : From Micro-Lensing to Cosmic Shear Experiments – in Frontiers of Cosmology, edited by Blanchard, A. and Signore, M., 2005; 5 Schneider, P et all – Gravitational Lenses, 1999 September 2006 Bogdan Popescu

  23. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  24. Mass Reconstruction - Ellipticities (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  25. The Galaxy-Galaxy Lensing Signal (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  26. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  27. Mass Reconstruction (astro-ph/0509252 - P. Schneider) September 2006 Bogdan Popescu

  28. Mass Reconstruction - Dark Matter (astro-ph/0608408 – Bradac et al) September 2006 Bogdan Popescu

  29. Mass Reconstruction - Dark Matter (astro-ph/0608408 – Bradac et al) September 2006 Bogdan Popescu

  30. Mass Reconstruction - Dark Matter (astro-ph/0608408 – Bradac et al) September 2006 Bogdan Popescu

  31. Mass Reconstruction - Dark Matter (astro-ph/0608408 – Bradac et al) September 2006 Bogdan Popescu

  32. References 1. Bernadeau, F – Gravitational Lensing : From Micro-Lensing to Cosmic Shear Experiments – in Frontiers of Cosmology, edited by Blanchard, A. and Signore, M., 2005 2. Bradac, M. et al - astro-ph/0608408 3. Jetzer, P. – Gravitational Lensing – in Modern Cosmology, edited by Bonometto, S. et al, 2002 4. Schneider, P - astro-ph/0509252 5. Schneider, P et all – Gravitational Lenses, 1999 Images : * http://www-ra.phys.utas.edu.au/~jlovell/simlens/ ** http://cassfos02.ucsd.edu/public/tutorial/GLens.html *** Walsh, D. and Carswell, R.F. and Weyman, R.J. 1979, "0957+561 A,B: twin quasistellar objects or gravitational lens?" Nature, 279, 381 **** http://www.iam.ubc.ca/~newbury/lenses/research.html ***** http://zebu.uoregon.edu/~soper/Mass/gravlens.html ****** http://antwrp.gsfc.nasa.gov/ September 2006 Bogdan Popescu

  33. Link http://www.physics.uc.edu/~popescu/ September 2006 Bogdan Popescu

  34. September 2006 Bogdan Popescu

More Related