Sandro Barboza Rembold

NoSOCS in SDSS - III. The interplay between galaxy evolution and the dynamical state of galaxy clusters

Context. We investigate relations between the color and luminosity distributions of cluster galaxies and the evolutionary state of their host clusters. Aims. Our aim is to explore some aspects of cluster galaxy evolution and the dynamical state of clusters as two sides of the same process. Methods. We used 10 721 member galaxies of 183 clusters extracted from the Sloan Digital Sky Survey using a list of NoSOCS and CIRS targets. First, we classified the clusters into two categories, Gaussian and non-Gaussian, according to their velocity distribution measurements, which we used as an indicator of their dynamical state. We then used objective criteria to split up galaxies according to their luminosities, colors, and photometric mean stellar age. This information was then used to evaluate how galaxies evolve in their host clusters. Results. Meaningful color gradients, i.e., the fraction of red galaxies as a function of radius from the center, are observed for both the Gaussian velocity distribution and the non-Gaussian velocity distribution cluster subsamples, which suggests that member galaxy colors change on a shorter timescale than the time needed for the cluster to reach dynamical equilibrium. We also found that larger portions of fainter red galaxies are found, on average, in smaller radii. The luminosity function in Gaussian clusters has a brighter characteristic absolute magnitude and a steeper faint-end slope than it does in the non-Gaussian velocity distribution clusters. Conclusions. Our findings suggest that cluster galaxies experience intense color evolution before virialization, while the formation of faint galaxies through dynamical interactions probably takes place on a longer timescale, possibly longer than the virialization time.

NoSOCS in SDSS – IV. The role of environment beyond the extent of galaxy clusters

We are able to extend the investigation of the color-morphology-density-radius relations, for bright and faint galaxies, to

NoSOCS in SDSS – V. Red disc and blue bulge galaxies across different environments

R gtrsim 3 times R_{200}

SDSS-IV MaNGA: evidence of the importance of AGN feedback in low-mass galaxies

and to very low density regions, probing the transition region between cluster and field galaxies, and finding a smooth variation between these two populations. We investigate the environmental variation of galaxy properties (and their relations), such as color, spectral type and concentration. Our sample comprises 6,415 galaxies that were previously selected as cluster members from 152 systems with

The first 62 AGNs observed with SDSS-IV MaNGA – I. Their characterization and definition of a control sample

z le 0.100

NoSOCS in SDSS – VI. The environmental dependence of AGN in clusters and field in the local Universe

. Our main findings are: (i) The fraction of discs is generally higher than the ones for blue and star-forming galaxies, indicating a faster transformation of color and star-formation compared to structural parameters. (ii) Regarding the distance to the cluster center we find a small variation in the galaxy populations outside the virial radius. Once within that radius the fractions of each population change fast, decreasing even faster within

The first 62 AGN observed with SDSS-IV MaNGA – II. Resolvedstellar populations

R sim 0.3 times R_{200}

Optical substructure and BCG offsets of Sunyaev–Zel’dovich and X-ray-selected galaxy clusters

. (iii) We also find a small increase in the fraction of blue faint galaxies within

Gradient pattern analysis applied to galaxy morphology

R sim 0.4 times R_{200}

Morphology of AGN Emission Line Regions in SDSS-IV MaNGA Survey

, before decreasing again to the most central bin. (iv) Our results do not indicate a significant dependence on cluster mass, except for the disc fraction in the core of clusters. (v) The relations between galaxy properties also point to no dependence on cluster mass, except for the scatter of the color stellar mass relation. Our results corroborate a scenario on which pre-processing in groups leads to a strong evolution in galaxy properties, before they are accreted by large clusters (abridged).