Fabry-Perot Images of Starburst Galaxies

Some Fabry-Perot Images of Starburst Galaxies

Starbust galaxies represent those galaxies which are currently experiencing a phase of active star formation which is substantially higher than the time average star formation rate. These galaxies are thus marked by the pridigous production of young stars which readily ionize the gas. In addition, to the ionization these massive stars will ultimately terminate their lives as Supernova . These massive stars and supernovae are able to heat the gas an induce a wind. This wind basically represents mechanical energy input into the gas which causes it to accelerate and blow out away from the galaxy. What we are particularly interested in for the case of low mass starburst galaxies is the possibility that the winds are so severe that the gas is blown completely out of the galactic potential and essentially the starburst is terminal in that respect. A technical discussion of galactic winds and baryonic blowout in the case of low mass galaxies can be found here To investigate this possibility we have selected two extreme starburst galaxies with astounding levels of H-alpha emission. These two galaxies are

NGC 1569:

This low mass galaxy located at a distance of about 2.5 Mpc is extraordinary in most respects. It is home to many so called superstar clusters and has very high levels of H-alpha emission. The first Fabry-Perot (FP) image shows just the very center of the galaxy. As some of the other bands are shown, note the incredible filamentary struture and detailed kinematics of the gas. Note also the suddent appearance of a very bright H II region in the bottom part of the frame. This H II region is labelled.

Here is a sequence of some of the NGC 1569 FP images that were obtained at the Kitt Peak Observatory 4-meter telescope on the night of Dec 21, 1996.

Image of Central Regions

Large Arc of Emission

Filamentary Structure

Channel Map that shows the Large H II region

NGC 3310:

This moderate mass galaxy located at a distance of about 10 Mpc is very likely a merger remnant. It has a large amount of ultraviolet emission but, as seen below, the H-alpha emission extends well beyond where the UV emission is. There is intense, shock like structure in the nuclear regions and a very complex distribution of H II regions outside the main body of the galaxy.

Here is a sequence of some of the NGC 3310 FP images that were obtained at the Kitt Peak Observatory 4-meter telescope on the night of Dec 21, 1996. Each Image is 2 angstroms in bandpass and covers 100 km/s. Features which appear in some channels and dissappear in others are the result of velocity structure in the emitting gas.

Some Detached H II Regions

Detached H II Regions on the Other Side

Zeroing in on the central Velocity of the Detached H II regions

Shock like structure in the Core of NGC 3310

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