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Title: THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE

Abstract

We present deep radio images of the inner ∼50 kpc of Centaurus A, taken with the Karl G. Jansky Very Large Array at 90 cm. We focus on the Transition Regions between the inner galaxy—including the active nucleus, inner radio lobes, and star-forming disk—and the outer radio lobes. We detect previously unknown extended emission around the Inner Lobes, including radio emission from the star-forming disk. We find that the radio-loud part of the North Transition Region (NTR), known as the North Middle Lobe, is significantly overpressured relative to the surrounding interstellar medium. We see no evidence for a collimated flow from the active galactic nucleus through this region. Our images show that the structure identified by Morganti et al. as a possible large-scale jet appears to be part of a narrow ridge of emission within the broader, diffuse, radio-loud region. This knotty radio ridge is coincident with other striking phenomena: compact X-ray knots, ionized gas filaments, and streams of young stars. Several short-lived phenomena in the NTR, as well as the frequent re-energization required by the Outer Lobes, suggest that energy must be flowing through both Transition Regions at the present epoch. We suggest that the energy flow is in the form ofmore » a galactic wind.« less

Authors:
 [1];  [2];  [3]
  1. NASA's Goddard Space Flight Center, Laboratory for Observational Cosmology, Mail Code 665, Greenbelt, MD 20771 (United States)
  2. Physics Department, New Mexico Tech, Socorro, NM 87801 (United States)
  3. National Radio Astronomy Observatory, P.O. Box O,  Socorro, NM 87801 (United States)
Publication Date:
OSTI Identifier:
22522524
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 802; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC RADIO SOURCES; FILAMENTS; GALAXIES; GALAXY NUCLEI; IMAGES; INTERSTELLAR SPACE; JETS; STAR EVOLUTION; STARS; STELLAR WINDS; STREAMS; X RADIATION

Citation Formats

Neff, Susan G., Eilek, Jean A., and Owen, Frazer N., E-mail: susan.g.neff@nasa.gov. THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE. United States: N. p., 2015. Web. doi:10.1088/0004-637X/802/2/87.
Neff, Susan G., Eilek, Jean A., & Owen, Frazer N., E-mail: susan.g.neff@nasa.gov. THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE. United States. doi:10.1088/0004-637X/802/2/87.
Neff, Susan G., Eilek, Jean A., and Owen, Frazer N., E-mail: susan.g.neff@nasa.gov. Wed . "THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE". United States. doi:10.1088/0004-637X/802/2/87.
@article{osti_22522524,
title = {THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE},
author = {Neff, Susan G. and Eilek, Jean A. and Owen, Frazer N., E-mail: susan.g.neff@nasa.gov},
abstractNote = {We present deep radio images of the inner ∼50 kpc of Centaurus A, taken with the Karl G. Jansky Very Large Array at 90 cm. We focus on the Transition Regions between the inner galaxy—including the active nucleus, inner radio lobes, and star-forming disk—and the outer radio lobes. We detect previously unknown extended emission around the Inner Lobes, including radio emission from the star-forming disk. We find that the radio-loud part of the North Transition Region (NTR), known as the North Middle Lobe, is significantly overpressured relative to the surrounding interstellar medium. We see no evidence for a collimated flow from the active galactic nucleus through this region. Our images show that the structure identified by Morganti et al. as a possible large-scale jet appears to be part of a narrow ridge of emission within the broader, diffuse, radio-loud region. This knotty radio ridge is coincident with other striking phenomena: compact X-ray knots, ionized gas filaments, and streams of young stars. Several short-lived phenomena in the NTR, as well as the frequent re-energization required by the Outer Lobes, suggest that energy must be flowing through both Transition Regions at the present epoch. We suggest that the energy flow is in the form of a galactic wind.},
doi = {10.1088/0004-637X/802/2/87},
journal = {Astrophysical Journal},
number = 2,
volume = 802,
place = {United States},
year = {Wed Apr 01 00:00:00 EDT 2015},
month = {Wed Apr 01 00:00:00 EDT 2015}
}