Related papers: Forming Young Bulges within Existing Disks: Statis…
We study the color structure of disk galaxies in the Groth strip at redshifts 0.1<z<1.2. Our aim is to test formation models in which bulges form before/after the disk. We find smooth color distributions with gentle outward blueing across…
Recent ground-based photometric investigations suggest that central regions of late-type spirals are closely coupled to the inner disk and probably formed via secular evolution. Evidence presented in support of this model includes the…
It is an observational fact that bulges of spiral galaxies contain a high fraction of old and metal-rich stars. Following this observational fact, we have investigated colors of 21 bulges hosted by a selected sample of high surface…
ABRIDGED: We use HSTACS and NICMOS imaging to study the structure and colors of a sample of nine late-type spirals. We find: (1) A correlation between bulge and disks scale-lengths, and a correlation between the colors of the bulges and…
We present line strengths in the bulges and inner disks of 38 galaxies in the local universe, including several galaxies whose bulges were previously identified as being disk-like in their colors or kinematics, to see if their spectral…
Bulges are a major galaxy component in the nearby universe, and are one of the primary features that differentiates and defines galaxies. The origin of bulges can be directly probed in part by examining distant galaxies to search for high…
A new idea is proposed for the origin of bulges in spiral galaxies. Numerical simulations for the protogalactic collapse suggest strongly that galactic bulges have been assembled from massive clumps formed in the galactic disks in their…
Observational and theoretical evidence that internal, slow ("secular") evolution reshapes galaxy disks is reviewed in Kormendy & Kennicutt (2004, ARAA, 42, 603). This update has three aims. First, I emphasize that this evolution is very…
It is widely accepted that within the framework of LCDM a significant fraction of giant-disk galaxies has recently experienced a violent galactic merger. We present numerical simulations of such major mergers of gas-rich pure disk galaxies,…
Recent observations with the James Webb Space Telescope (JWST) have begun to reveal a surprising morphological diversity in galaxies within the first billion years after the Big Bang, including indications of structural maturity previously…
We analyse colours of the nuclear regions of intermediate redshift disk galaxies, with the aim of obtaining empirical information of relative ages of bulges and disks at 0.1 < z < 1.3. We work with an apparent-diameter limited parent sample…
We analyze central surface brightness mu_0, nuclear and global colors of intermediate redshift disk galaxies. On an apparent-diameter limited sample of 398 galaxies from ACS/HST Great Observatories Origins Deep Survey North (GOODS-N), we…
We review internal processes of secular evolution in galaxy disks, concentrating on the buildup of dense central features that look like classical, merger-built bulges but that were made slowly out of disk gas. We call these pseudobulges.…
We review internal secular evolution in galaxy disks -- the fundamental process by which isolated disks evolve. We concentrate on the buildup of dense central features that look like classical, merger-built bulges but that were made slowly…
We analyze a volume-limited sample of massive bulge-dominated galaxies with data from both the Sloan Digital Sky Survey and the Galaxy Evolution Explorer (GALEX) satellite. The galaxies have central velocity dispersions greater than 100…
Gas-rich disks in the early universe are highly turbulent and have giant star-forming clumps. Models suggest the clumps form by gravitational instabilities, and if they resist disruption by star formation, then they interact, lose angular…
Galaxy evolution is in transition from an early universe dominated by hierarchical clustering to a future dominated by secular processes. These result from interactions involving collective phenomena such as bars, oval disks, spiral…
The origins of the bulge and disc components of galaxies are of primary importance to understanding galaxy formation. Here bulge-disc decomposition is performed simultaneously in B- and R-bands for 922 bright galaxies in 8 nearby (z < 0.06)…
The role of disk instabilities, such as bars and spiral arms, and the associated resonances, in growing bulges in the inner regions of disk galaxies have long been studied in the low-redshift nearby Universe. There it has long been probed…
More than half of nearby disc galaxies have pseudobulges instead of classical bulges that are though to be end-products of galaxy mergers. Pseudobulges are presumed to develop overtime as a result of secular evolution of galaxy discs. We…