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
For the case of an Imaging Fabry-Perot, each image
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
The Electronic Universe Project