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 x 10^40 ergs s^-1. The X-ray nebulae are roughly cospatial with the largescale 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 >~10^4 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 (Refer to PDF file for exact formulas).

Publication Date

4-1-1998

Comments

Also archived in: arXiv: astro-ph/9711137 v1 12 Nov 1997 E.J.M.C. thanks Kim Weaver, Michael Dahlem and Martin Elvis for providing information and for helpful discussions and Michael Corcoran for helping with the NASA/HEASARC data archive. E.J.M.C. acknowledges support from the Director’s Office of the Space Telescope Science Institute, NASA grant NAG5-3016, and the National Research Council. S.V. acknowledges the financial support of NASA through grant LTSA 035-97. This research has made extensive use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, Caltech, under contract with NASA. The Digitized Sky Surveys were produced at STScI under U.S. Government grant NAGW-2166. This paper represents a portion of E.J.M.C.’s Ph.D. thesis, submitted in partial fulfillment of the requirements of the Graduate School of the University of Maryland.ISSN:1538-4365 Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

Document Type

Article

Department, Program, or Center

School of Physics and Astronomy (COS)

Campus

RIT – Main Campus

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