Gemini South Helps Discover

Galactic Jet in Spiral Galaxy

Gemini South Assistant Astronomer Dr. Michael Ledlow has helped confirm the existence of a giant, subatomic particle jet streaming from a spiral galaxy similar to the Milky Way.

Though long known to be associated with elliptical and merging galaxies, the discovery of such jets streaming from a spiral galaxy raises significant questions about current theories on jet production.

The discovery was made possible by the combination of radio, optical and infrared observations. The findings were reported at the American Astronomical Society's meeting in Seattle.

Dr. Ledlow's infrared work at Gemini South was instrumental in complementing research by the team leader, Dr. William Keel with the University of Alabama, and Dr. Frazer Owen with the National Radio Astronomy Observatory. The galaxy, known as 0313-192, first came to the attention of Dr. Owen more than 20 years ago during a galaxy survey he conducted using the Very Large Array (VLA).

Spiral Galaxy 0313-192

Spiral Galaxy 0313-192

Gemini South's infrared images complemented optical images of the galaxy taken by the Hubble Space Telescope in the spring of 2002. The Gemini images penetrated deep into the galactic dust to confirm the spiral nature of the galaxy.

"The Gemini South data are the first clear detection of the dust lane from a ground-based telescope," said Dr. Ledlow.

"All previous ground-based imaging was of insufficient resolution to see any structure at all in the disk. In this image, we can see lots of structure, evidence of a warped disk and have a better measure of the strength of the nucleus.

"Since Gemini's near-infrared imaging is able to probe deeper through the disk than the optical imaging, these data have provided a very nice complement to the Hubble optical images at nearly the same resolution for studying the structure of the disk," Dr. Ledlow said.

Dr. Ledlow's image of 0313-192, shown here, was obtained at Gemini South using Flamingos-I, a near-infrared imager and spectrograph loaned to Gemini by the University of Florida. The image is a J,H,K-short composite. Integration time was 15 minutes total at each band. The final IQ was 0.37" on average.

For more information, see NRAO's press release.