The Complex Nature of the Interacting System NGC 7592
Abstract
In this paper we present a detailed analysis of the physical conditions and of the kinematical and dynamical properties of the system of interacting galaxies NGC 7592, the western component of which shows signs of Seyfert activity. Medium resolution long-slit spectra taken at different position angles along the nuclei show that the H α, H β, [O III] λλ 4959, 5007, [N II] λλ 6548,6583, [S II] λλ 6716,6731, and [O II] λλ3726,3729 emission lines are spatially extended over a size comparable to the size of the system. The aspect and the kinematics of the galaxies suggest that a prograde encounter between the eastern and the western component of the system is occurring. The large Hα luminosity indicates that all galaxies are undergoing a strong burst of star formation, with a very large global star formation rate (~ 20M_sun_ yr^-1^). In the spectra of the nuclear and circumnuclear regions of the western component, the high ionization lines are redshifted by {DELTA}_r_~ 50 km s^-1^ with respect to the low ionization lines, and their ratios indicate the simultaneous presence of thermally and nonthermally ionized gas. This is interpreted in terms of coexistence in the nucleus of the western component of Seyfert and Starburst activity, the last one being responsible for ~75% of the Hα line luminosity. In the contact region between the eastern and the western component of NGC 7592, the presence of gas whose radial velocity increases approaching the Seyfert nucleus has been revealed. We suggest that this could be due to gas stripped from the eastern component, and which is infalling on the Seyfert nucleus.
- Publication:
-
The Astronomical Journal
- Pub Date:
- March 1992
- DOI:
- 10.1086/116098
- Bibcode:
- 1992AJ....103..743R
- Keywords:
-
- Emission Spectra;
- Globular Clusters;
- H Alpha Line;
- Seyfert Galaxies;
- Star Formation;
- Charge Coupled Devices;
- H Ii Regions;
- Novae;
- Red Shift;
- Stellar Luminosity;
- Astrophysics;
- GALAXIES: INTERACTIONS;
- GALAXIES: ABUNDANCES