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
Stockholm Observatory
Stockholm University
T. Izumi
University of Tokyo
Alessandro Romeo
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
S. Martin
Institut de Radioastronomie Millimétrique (IRAM)
M. Imanishi
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
E. Hatziminaoglou
European Southern Observatory (ESO)
Susanne Aalto
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
D. Espada
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Atacama Large Millimeter-submillimeter Array (ALMA)
K. Kohno
University of Tokyo
Research Center for the Early Universe
Melanie Krips
Institut de Radioastronomie Millimétrique (IRAM)
S Matsushita
Academia Sinica
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
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1088/2041-8205/806/2/L34