Bibcode
Beckman, J. E.; Fathi, K.; Piñol, N.; Hernandez, O.; Carignan, C.; Pérez, I.
Referencia bibliográfica
Memorie della Societa Astronomica Italiana Supplement, v.18, p.35 (2011)
Fecha de publicación:
2011
Número de citas
0
Número de citas referidas
0
Descripción
The Tremaine-Weinberg method is a well-known model-independent technique
for measuring density wave pattern speeds in spiral galaxies. Here we
show how it can be applied to the data cubes (maps of surface brightness
and velocity) obtained in Halpha emission using a Fabry-Perot
spectrometer. One of the main difficulties, the discontinuity of the
Halpha emission, is resolved using the neighbouring stellar continuum
delivered by the data cube. We argue from symmetry that the motions not
associated with the density wave should cancel. We show that our pattern
speeds are reasonable by computing corotation radii, and comparing them
to measured bar lengths. Simulations including star forming gas also add
credibility to our results. Nevertheless it will be necessary to compare
them with results using the spectra of the stellar components to
quantify any systematic deviations from valid pattern speed values.