LOCAL INSTABILITY SIGNATURES IN ALMA OBSERVATIONS OF DENSE GAS IN NGC 7469
Journal article, 2015
We present an unprecedented measurement of the disk stability and local instability scales in the luminous infrared Seyfert 1 host, NGC 7469, based on ALMA observations of dense gas tracers and with a synthesized beam of 165 × 132 pc. While we confirm that non-circular motions are not significant in redistributing the dense interstellar gas in this galaxy, we find compelling evidence that the dense gas is a suitable tracer for studying the origin of its intensely high-mass star-forming ringlike structure. Our derived disk stability parameter $\mathcal{Q}$ accounts for a thick disk structure, and its value falls below unity at the radii in which intense star formation is found. Furthermore, we derive the characteristic instability scale ${\lambda }_{c}$ and find a striking agreement between our measured scale of ~180 pc and the typical sizes of individual complexes of young and massive star clusters seen in high-resolution images.
Author
K. Fathi
Stockholms universitet
Stockholm Observatory
T. Izumi
University of Tokyo
Alessandro Romeo
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
S. Martin
IRAM Institut de RadioAstronomie Millimetrique
M. Imanishi
Sokendai Graduate University for Advanced Studies
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
E. Hatziminaoglou
European Southern Observatory
Susanne Aalto
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
D. Espada
Atacama Large Millimeter-submillimeter Array
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
Sokendai Graduate University for Advanced Studies
K. Kohno
University of Tokyo
Research Center for the Early Universe
Melanie Krips
IRAM Institut de RadioAstronomie Millimetrique
S Matsushita
Institute of Astrophysics and Astronomy, Academia Sinica Taiwan
D. S. Meier
New Mexico Institute of Mining and Technology
N. Nakai
Faculty of Pure and Applied Sciences
Y. Terashima
Ehime University
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 806 2 L34 (6pp)- L34Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1088/2041-8205/806/2/L34