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Spiral galaxies without Lambda Cold Dark Matter

Spiral galaxies without Lambda Cold Dark Matter. Piotr Skindzier Jagiellonian University 15 March, Moriond 2013 Suported by The National Science Centre grant nr. K/PBP/000391. O utline. Introduction Disk Model Vertical Gradient Summary. Introduction. Disk model.

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Spiral galaxies without Lambda Cold Dark Matter

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  1. Spiral galaxies without Lambda Cold Dark Matter PiotrSkindzier Jagiellonian University 15 March, Moriond2013 Suported by The National Science Centre grant nr. K/PBP/000391 VHEPU Moriond 2013

  2. Outline • Introduction • Disk Model • Vertical Gradient • Summary VHEPU Moriond 2013

  3. Introduction VHEPU Moriond 2013

  4. Disk model To determine rotational velocity at a given radius one needs the surface mass density be given also everywhere outside that radius And vice versa, the surface mass density is related to the rotation curve by the formula VHEPU Moriond 2013

  5. Self consistent iteration VHEPU Moriond 2013

  6. Disk model - result VHEPU Moriond 2013

  7. Vertical gradient George H. et al. AJ 647:1018-1029 VHEPU Moriond 2013

  8. Vertical gradient - model Base on the radial force equilibrium and assuming that projection of the orbit on the galactic plane forms a circle or a hyperbolic spiral we can approximate: Here gr(r,z) is a radial component of gravitational acceleration which give: VHEPU Moriond 2013

  9. Vertical gradient - result Rotation curve for NGC 891 for Δz=0.6kpc Vertical gradient velocitie for NGC 891 VHEPU Moriond 2013

  10. Summary • To explain rotation of spiral galaxies we do not need Lambda Cold Dark Matter • To explain vertical gradient of rotation velocityin spiral galaxies we do not need Lambda Cold Dark Matter • Lambda Cold Dark Matter can be introduce in our model but it do not dominate dynamic of stars and gas in spiral galaxies VHEPU Moriond 2013

  11. ''One of the striking conclusion from this models is that the relative contribution of the disk and the halo to the interior mass and circular speed at R0 are very uncertain. ... This degeneracy between the disk and halo parameters has to be resolved by bringing other observation or dynamical argument to bear.'‘ Binney et. all ”Galactic Dymanics” p. 110-118 VHEPU Moriond 2013

  12. VHEPU Moriond 2013

  13. Vera C. Rubin et al. „Rotation of Andromeda Nebula from a spectroscopic survey of emission region” 1970ApJ...159..379R VHEPU Moriond 2013

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