Bibcode
Wilson, C. D.; Warren, B. E.; Israel, F. P.; Serjeant, S.; Bendo, G.; Brinks, E.; Clements, D.; Courteau, S.; Irwin, J.; Knapen, J. H.; Leech, J.; Matthews, H. E.; Mühle, S.; Mortier, A. M. J.; Petitpas, G.; Sinukoff, E.; Spekkens, K.; Tan, B. K.; Tilanus, R. P. J.; Usero, A.; van der Werf, P.; Wiegert, T.; Zhu, M.
Bibliographical reference
The Astrophysical Journal, Volume 693, Issue 2, pp. 1736-1748 (2009).
Advertised on:
3
2009
Journal
Citations
95
Refereed citations
85
Description
We present large-area maps of the CO J = 3-2 emission obtained at the
James Clerk Maxwell Telescope for four spiral galaxies in the Virgo
Cluster. We combine these data with published CO J = 1-0, 24 μm, and
Hα images to measure the CO line ratios, molecular gas masses, and
instantaneous gas depletion times. For three galaxies in our sample (NGC
4254, NGC 4321, and NGC 4569), we obtain molecular gas masses of 7
× 108 - 3 × 109 M sun and
disk-averaged instantaneous gas depletion times of 1.1-1.7 Gyr. We argue
that the CO J = 3-2 line is a better tracer of the dense star-forming
molecular gas than the CO J = 1-0 line, as it shows a better correlation
with the star formation rate surface density both within and between
galaxies. NGC 4254 appears to have a larger star formation efficiency
(smaller gas depletion time), perhaps because it is on its first passage
through the Virgo Cluster. NGC 4569 shows a large-scale gradient in the
gas properties traced by the CO J = 3-2/J = 1-0 line ratio, which
suggests that its interaction with the intracluster medium is affecting
the dense star-forming portion of the interstellar medium directly. The
fourth galaxy in our sample, NGC 4579, has weak CO J = 3-2 emission
despite having bright 24 μm emission; however, much of the central
luminosity in this galaxy may be due to the presence of a central active
galactic nucleus.
Related projects
![The moderately-inclined spiral galaxy NGC 4536 features two very-well defined arms, sparsely populated by star forming regions. Right above its yellow core, made up mostly of old stars, two dust lanes appear to intersect forming an 'X' shape. Project Image](/sites/default/files/styles/crop_square_2_2_to_320px/public/images/project/imagen-jhk.jpg?itok=fuDqntc5)
Spiral Galaxies: Evolution and Consequences
Our small group is well known and respected internationally for our innovative and important work on various aspects of the structure and evolution of nearby spiral galaxies. We primarily use observations at various wavelengths, exploiting synergies that allow us to answer the most pertinent questions relating to what the main properties of
Johan Hendrik
Knapen Koelstra