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Fabry-Perot Images of Galaxies

Some Fabry-Perot Images of Galaxies

On these pages we present a subset of some observational data that was acquired with an Imaging Fabry-Perot and CCD detector. The Imaging Fabry-Perot is capable of producing some of the best kinematic data on galaxies. Basically, an image of the galaxy is taken in the light of an emission line, in this case, the light from H-alpha from regions of ionized hydrogen known as H II regions. These regions are ionized by hot young stars and are a ubiquitous tracer of star formation in spiral and irregular galaxies. H II regions are good tracers of spiral structure as can be seen in this H-alpha image of M33. For the case of an Imaging Fabry-Perot, each image or channel is taken with a bandpass of 2 Angstroms in width which and the step size is about 1 Angstrom or about 50 km/s at the wavelength of H-alpha. Hence, several images, spaced by an angstrom or so, are taken to cover the full rotation of a galaxy.

Each data point in the image then is characterized by a different intensity as a function of filter bandpass. When you sum all the images up into a data cube, each pixel is actually defined by 10-20 different wavelength bands, which represent different velocities. The bandpass which corresponds to the highest intensity represents the velocity at that pixel location. In this manner, a two dimensional velocity map can be generated.

Several Examples of this process is in the links to various Fabry-Perot programs that we are engaged in. Much of this data were acquired at the Cerro Tololo Interamerican Observatory in Northern Chile.

Warning, some of these pages have many images on them and hence may be slow to load.

Ultraluminous IRAS Galaxies

Normal and Barred Spirals

Starburst Dwarfs; NGC 1560 and NGC 3310

FP Images of Interacting Galaxies

The Electronic Universe Project
e-mail: nuts@moo.uoregon.edu