Galactic Shocks Research Articles

On the Density-Wave Theory of Galactic Spirals. III. Comparisons with External Galaxies

view Abstract Citations (87) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Density-Wave Theory of Galactic Spirals. III. Comparisons with External Galaxies Shu, Frank H. ; Stachnik, Robert V. ; Yost, Jonathan C. Abstract We undertake a semiempirical study of the spiral patterns of three model galaxies constructed from the observed rotation curves of I33, M51, and M8t. Consistent with the proposal that density waves are initiated in the outer regions of a galaxy, we find a good fit to result for the observed spiral structure if we choose a pattern speed equal to the rotation speed where the distribution of H ii regions is seen to end. The circumferential bands containing the most prominent H ii regions are located in qualitative agreement with a mechanism in which star formation is triggered by spiral galactic shocks. A suggestion is made for M51 for the coexistence of short and long trailing waves traveling with the same pattern speed. Publication: The Astrophysical Journal Pub Date: June 1971 DOI: 10.1086/150976 Bibcode: 1971ApJ...166..465S full text sources ADS | data products NED (3)

Large-scale galactic shock phenomena and the implications on star formation

The possible existence of a stationary two-armed spiral shock pattern for a disk-shaped galaxy, such as our own Milky Way System, is demonstrated. It is therefore suggested that large-scale galactic shock phenomena may very well form the large-scale triggering mechanism for the gravitational collapse of gas clouds, leading to star formation along narrow spiral arcs within a two-armed grand design of spiral structure.

Large-Scale Shock Formation in Spiral Galaxies and its Implications on Star Formation

Two armed spiral galactic shock waves as triggering mechanism for gravitational collapse leading to star formation, considering gaseous disk motion using Schmidt model