Matter flows from a Seyfert nucleus.

Matter flow from a Seyfert nucleus

Active galactic nuclei are bright, concentrated sources of energy inhabiting the centers of certain galaxies, the class called Seyfert galaxies particularly. Astrophysicists infer that these active nuclei interact powerfully with their surroundings, spewing out large amounts of fast-moving matter, but until now clear evidence of such an outflow has been lacking, according to Jean W. Goad of the National Optical Astronomy Observatories in Tucson, Ariz.

In the Seyfert galaxy NGC 3516, Goad and John S. Gallagher III, formerly of Kitt Peak National Observatory, now director of the Lowell Observatory in Flagstaff, Ariz., have found such evidence in the form of a pattern of velocities indicating a flow of matter out of the active center of that galaxy.

Many galaxies with active nuclei are accompanied by lobes and "jets' of radio--emitting material with shapes that suggest they are matter spewn out of the galactic nuclei, although as Goad and Gallagher remark in their report in the September ASTRONOMICAL JOURNAL, "actual kinematic measurements are scarce.' Also, the jets and lobes tend to lie at large distances from the galactic nuclei. What Goad and Gallagher have found is an indication of matter fairly close to the center of NGC 3516, flowing away from the center in S-shaped, bipolar pattern.