Detalles de publicación
PP 018008
Precision determination of corotation radii in galaxy disks: Tremaine-Weinberg v. Font-Beckman for NGC 3433
(1) Instituto de Astrofísica de Canarias, c/Vía Láctea, s/n, E38205, La Laguna, Tenerife, Spain; jeb@iac.es,
jfont@iac.es, asborlaff@iac.es, bgarcia@iac.es (2) Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain. (3 )Consejo Superior de Investigaciones Científicas, Spain
Density waves in galaxy disks have been proposed over the years, in a variety of
specific models, to explain spiral arm structure and its relation to the mass distribution,
notably in barred galaxies. An important parameter in dynamical density wave theories
is the corotation radius, the galactocentric distance at which the stars and gas rotate at
the same speed as the quasi-static propagating density wave. Determining corotation,
and the pattern speed of a bar have become relevant to tests of cosmologically based
theories of galaxy evolution involving the dynamical braking of bars by interaction with
dark matter haloes. Here comparing two methods, one of which measures the pattern
speed and the other the radius of corotation, using two instruments (an integral field
spectrometer and a Fabry-Perot interferometer) and using both the stellar and interstellar
velocity fields, we have determined the bar corotation radius, and three further radii of
corotation for the SAB(s)b galaxy NGC3433. The results of both methods, with both
instruments, and with both disk components give excellent agreement. This strengthens
our confidence in the value of the two methods, and offers good perspectives for
quantitative tests of different theoretical models.
specific models, to explain spiral arm structure and its relation to the mass distribution,
notably in barred galaxies. An important parameter in dynamical density wave theories
is the corotation radius, the galactocentric distance at which the stars and gas rotate at
the same speed as the quasi-static propagating density wave. Determining corotation,
and the pattern speed of a bar have become relevant to tests of cosmologically based
theories of galaxy evolution involving the dynamical braking of bars by interaction with
dark matter haloes. Here comparing two methods, one of which measures the pattern
speed and the other the radius of corotation, using two instruments (an integral field
spectrometer and a Fabry-Perot interferometer) and using both the stellar and interstellar
velocity fields, we have determined the bar corotation radius, and three further radii of
corotation for the SAB(s)b galaxy NGC3433. The results of both methods, with both
instruments, and with both disk components give excellent agreement. This strengthens
our confidence in the value of the two methods, and offers good perspectives for
quantitative tests of different theoretical models.