Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/8043
Title: Growth of disc-like pseudo-bulges in SDSS DR7 since z = 0.1
Authors: Ankit Kumar
Kataria, Sandeep Kumar
Keywords: Methods: numerical
Galaxies: bulges
Galaxies: evolution
Galaxies: photometry
Issue Date: Aug-2022
Publisher: Oxford University Press on behalf of Royal Astronomical Society
Citation: Monthly Notice of Royal Astronomical Society, Vol. 514, No. 2, pp. 2497–2512
Abstract: Cosmological simulations predict more classical bulges than their observational counterparts in the local Universe. Here, we quantify evolution of the bulges since z = 0.1 using photometric parameters of nearly 39 000 unbarred disc galaxies from SDSS DR7 which are well represented by two components. We adopted a combination of the Sersic ´ index and Kormendy relation to separate classical bulges and disc-like pseudo-bulges. We found that the fraction of pseudo-bulges (classical bulges) smoothly increases (decreases) as the Universe gets older. In the history of the Universe, there comes a point (z ≈ 0.016) when classical bulges and pseudo-bulges become equal in number. The fraction of pseudo-bulges rises with increasing bulge to disc half-light radius ratio until Re/Rhlr ≈ 0.6 suggesting that a concentrated disc is the most favourable place for pseudo-bulge formation. The mean ellipticity of pseudo-bulges is always greater than that of classical bulges and it decreases with decreasing redshift, indicating that the bulges tend to be more axisymmetric with evolution. Also, the massive bulges are progressing towards axisymmetry at steeper rate than the low-mass bulges. There is no tight correlation of bulge Sersic ´ index evolution with other photometric properties of the galaxy. Using the sample of multicomponent fitting of S4G data and N-body galaxy models, we have verified that our results are consistent or even more pronounced with multicomponent fitting and high-resolution photometry.
Description: Restricted Access
URI: http://hdl.handle.net/2248/8043
ISSN: 1365-2966
Appears in Collections:IIAP Publications

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