Interaction of low- and high-velocity systems in the galaxy NGC 1275

Abstract

Published data on gas systems of different velocities in the galaxy NGC 1275 are examined. One of the systems is associated with NGC 1275 (low-velocity system — LV); the other is approaching it at a velocity of 3000 km/sec (high-velocity system — HV). Many of the collected results obtained from spectra and from direct images in the ultraviolet, optical, red, and infrared indicate interaction of these systems. The interaction is exhibited in the same shape and spatial distribution of the gas filaments in both systems, in the elongation of some of them toward the nucleus of the galaxy, and in the increase in brightness of the HV gas near some of the clusters of young stars of the LV system. Gas of the HV system is observed at a distance of O″.5 (170 pc) from the nucleus of the galaxy, while intermediate-velocity gas (IV — 600–1520 km/sec relative to the velocity of NGC 1275) is detected at distances less than 7″ (2.5 kpc). We presume that the rare cases of the detection of IV gas are related to the use of Ha observations primarily: at the velocities of 600–900 km/sec, the Ha line of the IV gas blends with the [NII] 6584A line of the LV gas.