Fast, Collimated Outflow in the Western Nucleus of Arp 220
Journal article, 2018
We present the first spatially and spectrally resolved image of the molecular outflow in the western nucleus of Arp 220. The outflow, seen in HCN (1-0) by the Atacama Large millimeter/sub-millimeter Array, is compact and collimated, with an extension ≲120 pc. Bipolar morphology emerges along the minor axis of the disk, with redshifted and blueshifted components reaching a maximum inclination-corrected velocity of km s -1 . The outflow is also seen in CO and continuum emission, the latter implying that it carries significant dust. We estimate a total mass in the outflow of , a dynamical time of ∼10 5 yr, and mass outflow rates of yr -1 and yr -1 for the northern and southern lobes, respectively. Possible driving mechanisms include supernovae energy and momentum transfer, radiation pressure feedback, and a central AGN. The latter could explain the collimated morphology of the HCN outflow; however, we need more complex theoretical models, including contributions from supernovae and AGN, to pinpoint the driving mechanism of this outflow.
galaxies: starburst
galaxies: active
galaxies: interactions
galaxies: individual (Arp220)
Author
Loreto Barcos-Munoz
Atacama Large Millimeter-submillimeter Array (ALMA)
National Radio Astronomy Observatory
Susanne Aalto
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Todd A. Thompson
Ohio State University
K. Sakamoto
Academia Sinica
Sergio Martín
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
Adam K. Leroy
Ohio State University
G. Privon
University of Florida
Pontificia Universidad Catolica de Chile
A. S. Evans
National Radio Astronomy Observatory
University of Virginia
Amanda Kepley
National Radio Astronomy Observatory
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 853 2 L28Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Theoretical Chemistry
DOI
10.3847/2041-8213/aaa28d