Large-Scale Outflows in Edge-on Seyfert Galaxies. III. Kiloparsec-Scale Soft X-Ray Emission
Abstract
We present ROSAT PSPC and HRI images of eight galaxies selected from a distance-limited sample of 22 edge-on Seyfert galaxies. Kiloparsec-scale soft X-ray nebulae extend along the galaxy minor axes in three galaxies (NGC 2992, NGC 4388, and NGC 5506). The extended X-ray emission has 0.2-2.4 keV X-ray luminosities of 0.4-3.5 × 1040 ergs s-1. The X-ray nebulae are roughly cospatial with the large-scale radio emission, suggesting that both are produced by large-scale galactic outflows. Assuming pressure balance between the radio and X-ray plasmas, the X-ray filling factor is >~104 times larger than the radio plasma filling factor, suggesting that large-scale outflows in Seyfert galaxies are predominantly winds of thermal X-ray-emitting gas. We favor an interpretation in which large-scale outflows originate as active galactic nucleus-driven jets that entrain and heat gas on kiloparsec scales as they make their way out of the galaxy. Active galactic nucleus- and starburst-driven winds are also possible explanations in cases where the winds are oriented along the rotation axis of the galaxy disk.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1998
- DOI:
- 10.1086/305417
- arXiv:
- arXiv:astro-ph/9711137
- Bibcode:
- 1998ApJ...496..786C
- Keywords:
-
- GALAXIES: ACTIVE;
- GALAXIES: KINEMATICS AND DYNAMICS;
- GALAXIES: SEYFERT;
- X-RAYS: GALAXIES;
- Galaxies: Active;
- Galaxies: Kinematics and Dynamics;
- Galaxies: Seyfert;
- X-Rays: Galaxies;
- Astrophysics
- E-Print:
- 24 pages, 7 ps figures, AASTEX 4.0, accepted for ApJ April 1, 1998