57 8 v 1 25 J un 2 00 4 A UNIFIED PICTURE OF DISK GALAXIES WHERE BARS , SPIRALS AND WARPS RESULT FROM THE SAME FUNDAMENTAL CAUSES

Content Provider	Semantic Scholar
Author	Pfenniger, Daniel Revaz, Yves
Copyright Year	2004
Abstract	Bars and spiral arms have played an important role as constra i t on the dynamics and on the distribution of dark matter in the optical p arts of disk galaxies. Dynamics linked to the dissipative nature of gas, and it s transformation into stars provide clues that spiral galaxies are driven by d issipation close to a state ofmarginal stability with respect to the dynamics in the galaxy plane. Here we present numerical evidences that warps play a simila r role but in the transverse direction. N-body simulations show that typica l galactic disks are also marginally stable with respect to a bending instabilit y leading to typical observed warps. The frequent occurrence of warps and asymmetr ies in the outer galactic disks give therefore, like bars in the inner disks, new constraints on the dark matter, but this time in the outer disks. If disks are mar ginally stable with respect to bending instabilities, our models suggest that t he mass within the HI disks must be a multiple of the detected HI and stars, i.e., di sks must be heavier than seen. But the models do not rule out a traditional thick h alo with a mass within the HI disk radius similar to the total disk mass.
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://cds.cern.ch/record/746361/files/0406578.pdf
Alternate Webpage(s)	http://arxiv.org/pdf/astro-ph/0406578v1.pdf
Language	English
Access Restriction	Open
Subject Keyword	Alo Alveolar rhabdomyosarcoma Coat of arms Dark Matter Decompression Sickness Galaxy Numerical analysis Ploidies Simulation Star Wars Galaxies Stars, Celestial Transverse wave Typica WARP (information security) Wild Arms 3 newton
Content Type	Text
Resource Type	Article