scholarly journals A direct test of density wave theory in a grand-design spiral galaxy

2018 ◽  
Vol 3 (2) ◽  
pp. 178-182 ◽  
Author(s):  
Thomas G. Peterken ◽  
Michael R. Merrifield ◽  
Alfonso Aragón-Salamanca ◽  
Niv Drory ◽  
Coleman M. Krawczyk ◽  
...  
Keyword(s):  
Spiral Galaxy ◽  
Density Wave ◽  
Wave Theory ◽  
Direct Test ◽  
Grand Design ◽  
Density Wave Theory ◽  
Design Spiral

scholarly journals 5.19. A high resolution CO map of the inner region of M51

1998 ◽  
Vol 184 ◽  
pp. 249-250
Author(s):  
S. Aalto ◽  
S. Hüttemeister ◽  
N. Scoville ◽  
P. Thaddeus
Keyword(s):  
High Resolution ◽  
Spiral Galaxy ◽  
Density Wave ◽  
Linear Size ◽  
Structural Studies ◽  
Spiral Density Wave ◽  
Systemic Velocity ◽  
Grand Design ◽  
Inner Region ◽  
Design Spiral

M51, the Whirlpool Galaxy, at a distance of ≈ 9,6 Mpc and a systemic velocity of 465 km s−1, is the closest “Grand Design” spiral galaxy. Its low inclination (20°) makes it an excellent target for structural studies, e.g. the formation of arms in response to a spiral density wave causing gas streaming motions. We have obtained a high resolution, sensitive map of the inner 2.5′ of M51 using the Caltech six-element OVRO array. The map consists of a 19-field mosaic, taken using three different telescope configurations. The resolution is 2.5″, (corresponding to 115 pc linear size) and 3.5” for the robustly and naturally weigthed maps, respectively.

scholarly journals Star Formation in M81

1987 ◽  
Vol 115 ◽  
pp. 626-626
Author(s):  
Frank Bash ◽  
Michele Kaufman
Keyword(s):  
Shock Wave ◽  
Star Formation ◽  
Interstellar Medium ◽  
Thermal Radiation ◽  
Spiral Galaxy ◽  
Density Wave ◽  
Wave Theory ◽  
Hii Regions ◽  
Radio Continuum ◽  
Density Wave Theory

VLA observations of the spiral galaxy M81 in the radio continuum at wavelengths of 6 and 20-cm have been used to check the predictions of the density wave theory. The non-thermal radiation from the arms has been detected and the arms are found to be broader than the predictions of the classical density wave theory. Their width does seem to agree with that predicted by models which take the clumpy nature of the interstellar medium into account. These data are also able to separate giant HII regions from the non-thermal arms. Collaborators have furnished optical Hα data on the HII regions and HI 21-cm data, from the VLA, which will be used to find and measure the location of the HII regions with respect to the spiral shock wave and to measure the visual extinction in the disk of M81.

scholarly journals The Dynamics of the Spiral Galaxy M81

1978 ◽  
Vol 77 ◽  
pp. 105-112 ◽  
Author(s):  
H.C.D. Visser
Keyword(s):  
Spiral Galaxy ◽  
Atomic Hydrogen ◽  
Density Wave ◽  
Angular Size ◽  
Wave Model ◽  
Wave Theory ◽  
Line Of Sight ◽  
Surface Photometry ◽  
Radio Observations ◽  
Density Wave Theory

The spiral galaxy M81 is a challenging object for testing a density-wave theory. It is of large angular size and favourably inclined to the line of sight; radio observations of neutral atomic hydrogen showing well defined spiral arms with noncircular motions are available (Rots and Shane 1975), and there is evidence from surface photometry for density waves in the old disk population (Schweizer 1976). Can these observations be unified in one density-wave model?

scholarly journals Topological defects in crystals: A density-wave theory

1988 ◽  
Vol 10 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
M Raj Lakshmi ◽  
H R Krishna-Murthy ◽  
T V Ramakrishnan
Keyword(s):  
Density Wave ◽  
Topological Defects ◽  
Wave Theory ◽  
Defects In Crystals ◽  
Density Wave Theory

scholarly journals Fitting the Lin–Shu-type density-wave theory for our own Galaxy★

2013 ◽  
Vol 433 (3) ◽  
pp. 2511-2516 ◽  
Author(s):  
Evgeny Griv ◽  
Chow-Choong Ngeow ◽  
Ing-Guey Jiang
Keyword(s):  
Density Wave ◽  
Wave Theory ◽  
Density Wave Theory

scholarly journals Lifetime of density waves and classification of spirals

1979 ◽  
Vol 84 ◽  
pp. 155-156
Author(s):  
J. V. Feitzinger ◽  
Th. Schmidt-Kaler
Keyword(s):  
Density Wave ◽  
Wave Theory ◽  
Density Waves ◽  
Spiral Arms ◽  
Density Wave Theory

Checking the density-wave theory against observations of our own Galaxy has proven very difficult, as witnessed also at this Symposium. Less ambiguous results, however, are obtained for other galaxies. These results involve a) calculating convincing models for a sample of 25 fairly well observed spirals (Roberts et al. 1975) and b) locating the compression zones on the inner edges of the spiral arms.

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