author={Sonali Sachdeva and Kanak Saha},
  journal={The Astrophysical Journal Letters},
Pure disk galaxies without any bulge component, i.e., bulges that are neither classical nor pseudo, seem to have escaped the effects of merger activity that are inherent to hierarchical galaxy formation models as well as strong internal secular evolution. We discover that a significant fraction (∼15%–18%) of disk galaxies in the Hubble Deep Field ( 0.4 < z < 1.0 ?> ) and in the local universe ( 0.02 < z < 0.05 ?> ) are such pure disk systems (PDSs). The spatial distribution of light in these… 

Growth of Bulges in Disk Galaxies Since z ∼ 1

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Indications of the invalidity of the exponentiality of the disk within bulges of spiral galaxies

Context. A fundamental subject in extragalactic astronomy concerns the formation and evolution of late-type galaxies (LTGs). The standard scenario envisages a two-phase build-up for these systems,

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Structural properties of faint low-surface-brightness galaxies

We study the structural properties of Low Surface Brightness galaxies (LSB) using a sample of 263 galaxies observed by the Green Bank Telescope (Schneider et al 1992). We perform 2D decompositions of

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The Carnegie-Irvine Galaxy Survey. VII. Constraints on the Origin of S0 Galaxies from Their Photometric Structure

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The evolution of disc galaxies with and without classical bulges since z 1

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Secular Evolution and the Formation of Pseudobulges in Disk Galaxies

▪ Abstract The Universe is in transition. At early times, galactic evolution was dominated by hierarchical clustering and merging, processes that are violent and rapid. In the far future, evolution


We present an inventory of galaxy bulge types (elliptical galaxy, classical bulge, pseudobulge, and bulgeless galaxy) in a volume-limited sample within the local 11 Mpc sphere using Spitzer 3.6 μm

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Galactic disks, infall, and the global value of Omega

Stringent limits on the current rate of infall of satellite systems onto spiral galaxies are set on the basis of the thinness and coldness of Galactic disks. For infalling satellites on isotropically

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On the origin of exponential galaxy discs

One of the most important unresolved issues for galaxy formation theory is to understand the origin of exponential galaxy discs. We use a disc galaxy evolution model to investigate whether galaxies

The Growth of Massive Galaxies Since z = 2

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Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies

Gas-rich disks in the early universe are highly turbulent and have giant star-forming clumps. Models suggest that the clumps form by gravitational instabilities, and if they resist disruption by star

The Progenitors of Local Ultra-massive Galaxies Across Cosmic Time: from Dusty Star-bursting to Quiescent Stellar Populations

Using the UltraVISTA catalogs, we investigate the evolution in the 11.4 Gyr since z = 3 of the progenitors of local ultra-massive galaxies (log (Mstar/M☉) ≈ 11.8; UMGs), providing a complete and