Related papers: The origin of the red sequence galaxy population i…
We analyze the evolution of red and blue galaxies in different cosmic web environments from redshift $z=3$ to $z=0$ using the IllustrisTNG simulation. We use Otsu's method to classify the red or blue galaxies at each redshift and determine…
We investigate the evolution of the optical and near-infrared colour-magnitude relation in an homogeneous sample of massive clusters from z = 1 to the present epoch. By comparing deep Hubble Space Telescope ACS imaging of X-ray selected…
We investigate the evolution of the galaxy population since redshift 2 with a focus on the colour bimodality and mass density of the red sequence. We obtain precise and reliable photometric redshifts up to z=2 by supplementing the optical…
[Abridged] We assemble a sample of 45 intermediate X-ray luminosity galaxy clusters at low redshifts using SDSS data to conduct a comprehensive investigation into the photometric variation of red sequence modal galaxy colours with…
We compare low-redshift ($z<0.1$) BPT-selected pure optical AGN hosts in SDSS DR7 to colour-selected "green-valley" analogue central galaxies in IllustrisTNG100 and EAGLE Ref-L0100N1504. To reduce cross-dataset systematics, we define the…
We confirm the detection of 3 groups in the Lynx supercluster, at z~1.3, and give their redshifts and masses. We study the properties of the group galaxies as compared to the central clusters, RXJ0849+4452 and RXJ0848+4453, selecting 89…
A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called AGN feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later…
We have investigated the redshift evolution of the colour--cluster-centric-radius relation and the morphology--cluster-centric-radius relation in three redshift bins, $0.02\leq z\leq 0.14$, $0.14< z\leq 0.20$, and $0.20< z\leq 0.30$ using a…
The origin of color gradients in elliptical galaxies is examined by comparing model gradients with those observed in the Hubble Deep Field. The models are constructed so as to reproduce color gradients in local elliptical galaxies either by…
We test cosmological hydrodynamical simulations of galaxy formation regarding the properties of the Blue Cloud (BC), Green Valley (GV) and Red Sequence (RS), as measured on the 4000$\small{ \mathring {\mathrm A}}$ break strength vs stellar…
We use cosmological simulations to study a characteristic evolution pattern of high redshift galaxies. Early, stream-fed, highly perturbed, gas-rich discs undergo phases of dissipative contraction into compact, star-forming systems (blue…
Galaxies broadly fall into two categories: star-forming (blue) galaxies and quiescent (red) galaxies. In between, one finds the less populated ``green valley". Some of these galaxies are suspected to be in the process of ceasing their…
We use new models of stellar population synthesis to estimate the fraction of stars formed during the last major bursts of star formation in E/S0 galaxies in low-redshift clusters ($z\simlt0.4$) from the spectral signatures of…
Galaxy clusters, which underwent a recent ($\leq3$ Gyr) major merger, offer a harsher environment due to the global hydrodynamical disturbance and the merger-shock heated ICM. However, the aftermath of such extreme cluster interactions on…
Several mechanisms for the transformation of blue star-forming to red quiescent galaxies have been proposed, and the green valley (GV) galaxies amid them are widely accepted in a transitional phase. Thus, comparing the morphological and…
Color gradients in elliptical galaxies in distant clusters ($z=0.37-0.56$) are examined by using the archival deep imaging data of Wide Field Planetary Camera 2 (WFPC2) on-board the Hubble Space Telescope (HST). Obtained color gradients are…
In colour-magnitude diagrams most galaxies fall in either the ``blue cloud'' or the ``red sequence'', with the red sequence extending to significantly brighter magnitudes than the blue cloud. The bright-end of the red sequence comprises…
We identify a sample of 324 red and 273 blue face-on spiral galaxies selected from 115 low-redshift (0.014 < z < 0.18) galaxy clusters imaged with CFHT+MegaCam in u- and r-band, KPNO 0.9-meter 2TKA and MOSAIC 8K camera in B and Rc, and…
The galaxies found in optical surveys fall in two distinct regions of a diagram of optical colour versus absolute magnitude: the red sequence and the blue cloud with the green valley in between. We show that the galaxies found in a…
We present a new sample of strong gravitational lens systems where both the foreground lenses and background sources are early-type galaxies. Using imaging from HST/ACS and Keck/NIRC2, we model the surface brightness distributions and show…