ALMA observationsof warm dense gas in NGC 1614-breaking of the star formation law in the central kiloparsec
Journal article, 2015
We present ALMA Cycle-0 observations of the CO (6-5) line emission and of the 435 mu m dust continuum emission in the central kiloparsec of NGC 1614, a local luminous infrared galaxy at a distance of 67.8 Mpc (1 '' = 329 pc). The CO emission is well resolved by the ALMA beam (0.'' 26x0.'' 20) into a circumnuclear ring, with an integrated flux of f(C O(6-5)) = 898 (+/- 153) Jy km s(-1), which is 63(+/- 12)% of the total CO (6-5) flux measured by Herschel. The molecular ring, located between 100 pc < r < 350 pc from the nucleus, looks clumpy and includes seven unresolved (or marginally resolved) knots with median velocity dispersion of similar to 40 km s(-1). These knots are associated with strong star formation regions with Sigma(SFR) similar to 100M(circle dot) yr(-1) kpc(-2) and Sigma(Gas) similar to 10(4) M-circle dot pc(-2). The nondetections of the nucleus in both the CO (6-5) line emission and the 435 mu m continuum rule out, with relatively high confidence, a Compton-thick active galactic nucleus in NGC 1614. Comparisons with radio continuum emission show a strong deviation from an expected local correlation between Sigma(Gas) and Sigma(SFR), indicating a breakdown of the Kennicutt-Schmidt law on the linear scale of similar to 100 pc.
galaxies: general
galaxies: starburst
galaxies: evolution
submillimeter: galaxies
galaxies: ISM
galaxies: active
galaxies: interactions
galaxies: nuclei
galaxies: magnetic fields
Author
C. K. Xu
California Institute of Technology (Caltech)
C. F. Cao
California Institute of Technology (Caltech)
Shandong University
Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment
N. Lu
California Institute of Technology (Caltech)
Y. Gao
Chinese Academy of Sciences
T. Diaz-Santos
California Institute of Technology (Caltech)
R. Herrero-Illana
Institute of Astrophysics of Andalusia (IAA)
R. Meijerink
Leiden University
G. Privon
University of Virginia
Y. H. Zhao
Chinese Academy of Sciences
California Institute of Technology (Caltech)
A. S. Evans
University of Virginia
National Radio Astronomy Observatory
Sabine Konig
Institut de Radioastronomie Millimétrique (IRAM)
J. Mazzarella
California Institute of Technology (Caltech)
Susanne Aalto
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
P. Appleton
California Institute of Technology (Caltech)
L. Armus
California Institute of Technology (Caltech)
V. Charmandaris
National Observatory of Athens
University of Crete
Paris Observatory
J. Chu
University of Hawaii
S. Haan
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
H. Inami
National Optical Astronomy Observatory
E. J. Murphy
California Institute of Technology (Caltech)
D. B. Sanders
University of Hawaii
B. Schulz
California Institute of Technology (Caltech)
P. van der Werf
Leiden University
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 799 1 11Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1088/0004-637x/799/1/11