Mathematics – Logic
Scientific paper
Jul 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...430..142r&link_type=abstract
The Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 430, no. 1, p. 142-162
Mathematics
Logic
88
Brightness, Disk Galaxies, Spiral Galaxies, Star Formation, Surface Properties, Astronomical Photometry, H Alpha Line, Stellar Mass
Scientific paper
We present some results of a major new multiband imaging survey of 34 nearby southern spiral galaxies. Images in V, I, H-alpha, and the adjacent red continuum have been obtained using a CCD and focal reducer on the 1.0 and 2.3 m telescopes at Siding Spring Observatory. Surface photometry using the GASP software package is used first to derive the disk orientation parameters, then to provide deprojected radial surface brightness profiles for each galaxy in V and I, as well as the continuum-subtracted H-alpha, which traces the present-day rate of massive star formation. In the outer disk, the H-alpha profile can be reasonably well fitted by an exponential disk, but with a scale length much longer than the V scale length, which itself tends to be sligtly longer than the I scale length. An almost universal relationship is observed in the disk between the H-alpha surface brightness and the I-band surface brightness at a given radius, with any residual offset from the mean trend being a weak function of the morphological type. Thus the rate of massive star formation per unit area in the disk is closely related to the old stellar mass surface density at each radius, and to the mean H I surface density in the disk as a whole. This forms the basis for a law of (or rather, a consistent on) massive star formation in the disks of spiral galaxies, one that has a surprising degree of independence from both galactic dynamics and molecular gas content.
Dopita Michael A.
Ryder Stuart D.
No associations
LandOfFree
The relationship between past and present star formation in galactic disks from CCD surface photometry does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The relationship between past and present star formation in galactic disks from CCD surface photometry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The relationship between past and present star formation in galactic disks from CCD surface photometry will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1253260