One-Armed Spiral Waves in Galaxy Simulations with Counter-Rotating Stars

Abstract

Motivated by observations of disk galaxies with counter-rotating stars, we have run two-dimensional, collisionless N-body simulations of disk galaxies with significant counter-rotating components. For all our simulations the initial value of Toomre's stability parameter was Q = 1.1. The percentage of counter-rotating particles ranges from 25% to 50%. A stationary one-arm spiral wave is observed to form in each run, persisting from a few to five rotation periods, measured at the half-mass radius. In one run, the spiral wave was initially a leading arm which subsequently transformed into a trailing arm. We also observed a change in spiral direction in the run initially containing equal numbers of particles orbiting in both directions. The results of our simulations support an interpretation of the one armed waves as due to the two stream instability.

arXiv comment13 pages, 4 figures

References in corpus (6)

• NON-AXISYMMETRIC STRUCTURES IN THE STELLAR DISKS OF GALAXIES
• Lopsided Spiral Galaxies and a Limit on the Galaxy Accretion Rate
• A Counter-rotating Bulge in the Sb Galaxy NGC 7331
• NGC 4138 - A Case Study in Counterrotating Disk Formation
• Two-Stream Instability of Counter-Rotating Galaxies
• One-Armed Spiral Waves in Galaxy Simulations with Counter-Rotating Stars

Cited by in corpus (8)

• Molecular Gas in NUclei of GAlaxies (NUGA) I.The counter-rotating LINER NGC4826
• Lopsided Spiral Galaxies
• Counter-Rotating Accretion Discs
• One-Armed Spiral Waves in Galaxy Simulations with Counter-Rotating Stars
• Disk heating and bending instability in galaxies with counterrotation
• Local stability of self-gravitating fluid disks made of two components in relative motion
• Sloshing in High Speed Galaxy Interactions
• Gravitational Torques from a Lopsided Young Stellar Component Sustain High Black Hole Accretion Rates in NGC 4593