The Response of Galactic Gas Disks to A The Response of Galactic Gas Disks to A Spiral Density-wave PotentialSpiral Density-wave Potential

Speaker : Hsiang-Hsu WangSpeaker : Hsiang-Hsu WangCollaborator: Dr. Chi YuanCollaborator: Dr. Chi Yuan

Institute of Astronomy and Astrophysics, Academia Sinica, Taiwan, R.O.C.

EANAM 2006EANAM 2006

JHK band

near IR (3.4um, Spitzer)

M81 M51

Galactic Shock and star formation

visible light

visible light

spiral potential galactic shockgas response

Chaotic structureChaotic structure

Near IR image (8um, Spitzer)Near IR image (Spitzer)

Rayleigh shear instability

M81

M51

Simulation

Higher order responseHigher order response

Density response on disk plane Azimuthal cut at different radius: 7.3, 12, 16, 18 kpc

ILR = 3.03 kpcCR = 12.25 kpcOLR = 21.22 kpc4:1 resonance: 7.35/17.14 kpc6:1 resonance: 8.71/15.8 kpc

With self-gravityWith self-gravity