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Disks in Early-Type Galaxies from NIR observations

Author Affiliations

  • 1Department of Physics, University of Calicut, Malappuram, Kerala, INDIA

Res. J. Recent Sci., Volume 3, Issue (ISC-2013), Pages 420-422, (2014)


We report results from morphological analysis of 54 nearby (z < 0.018) early type galaxies, mainly from field, observed in near infra-red K band. Fitting their surface brightness profile with SÚrsic bulge and exponential disk, we find that majority of the sample galaxies, selected based on the detection of ionized gas, contains significant amounts of disk components. We find that 74% of our early-type galaxies are having a bulge to total luminosity ratio in K band. B/T, less than 0.5 while only 26% of the early-type galaxies are actually bulge dominant. The average value of bulge to total luminosity ratio (B/T) is 0.425 ▒ 0.145. The scale length of disk correlates well with its central surface brightness. We also find that the nature of disks in early-type galaxies resembles that observed in field spirals, and actually is with much lesser scatter, suggesting a much more coherent scenario for formation of disks in different types of galaxies.


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