Astronomy and Astrophysics – Astrophysics
Scientific paper
May 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...445l..15i&link_type=abstract
Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X), vol. 445, no. 1, p. L15-L18
Astronomy and Astrophysics
Astrophysics
21
Cosmology, Dwarf Galaxies, Faint Objects, Luminous Intensity, Magnitude, Populations, Elliptical Galaxies, Galactic Evolution, Galactic Structure, Hubble Space Telescope, Luminosity
Scientific paper
The axis ratio distribution of faint galaxies observed by the Hubble Space Telescope (HST) as part of the Medium Deep Survey (MDS) key project suggests that a very large fraction of the total population at magnitudes I greater than or equal to 20 mag consists of a class of galaxies with luminosity profile, axis ratio distribution, angular size, and color that resemble local dwarfs. We find that galaxies with exponential light profiles and small angular sizes (half-light radius less than 0.6 sec) have an axis ratio distribution that is incompatible with their being intrinsically flattened objects and is instead consistent with local elliptical galaxies. We call these objects 'Small Exponential Ellipticals.' They are most likely dwarf galaxies, and they are numerous enough that, together with irregular galaxies, they can account for most if not all of the excess in the number counts at I approximately 20-21 mag with respect to the standard no-evolution models. This may suggest that the excess number counts are best explained by dwarf-rich models with strong luminosity evolution of the dwarf galaxies. Our data also supports a very mild luminosity evolution of the giant galaxy populations, which contributes little to the excess number counts.
Casertano Stefano
Griffiths Richard E.
Im Myungshin
Ratnatunga Kavan U.
No associations
LandOfFree
The axis ratio distribution of faint galaxies: Evidence for a populatin of dwarfgalaxies at I approximately 20.5 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 axis ratio distribution of faint galaxies: Evidence for a populatin of dwarfgalaxies at I approximately 20.5, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The axis ratio distribution of faint galaxies: Evidence for a populatin of dwarfgalaxies at I approximately 20.5 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1059424