arXiv subjects

Erik V. R. Lima

Publications and source records attributed to Erik V. R. Lima.

3 recordsLinked to original sources

arXiv2026

Star formation and morphological trends in the Antlia cluster: Probing environmental influence out to 5R200

Galaxy evolution in dense environments such as clusters is strongly affected by environmental processes that can alter both morphology and star formation activity. We investigate these effects in the Antlia cluster out to 5R200 using Southern Photometric Local Universe Survey (S-PLUS) data. We derive H-alpha-based star formation rates from the J0660 band and Sersic indices with GALFITM. Our analysis focuses on 154 spectroscopically confirmed galaxies brighter than mr = 16. We classify galaxies as early- or late-type systems using colour and Sersic index, and as quenched or star-forming using specific star formation rate. We examine their dependence on clustercentric distance, projected phase-space, substructure, and local density. We find that star-forming galaxies dominate from 1 to 5R200, while quenched galaxies are more common within 1R200. Early- and late-type galaxies show similar radial trends, with comparable fractions within 1R200 and a higher late-type fraction at larger radii. Quenched galaxies dominate at log(Sigma10 [Mpc^-2]) >= 1.5, whereas late-type galaxies dominate at log(Sigma10 [Mpc^-2]) <= 1.0. We identify substructures extending from the cluster centre to the outskirts. Substructures outside the central region are dominated by star-forming and late-type galaxies, with fractions similar to those of galaxies not associated with detected substructures. However, when the massive central structure is included, the fraction of star-forming galaxies in substructures decreases, indicating a more environmentally processed population in the central region. Altogether, the presence of a massive central substructure together with additional substructures detected out to 5R200 indicates that Antlia is still undergoing mass assembly through group accretion, consistent with a dynamically active and young cluster that is still assembling its galaxy population.

astro-ph.GA↗

arXiv2025

Targeting cluster galaxies for the 4MOST CHANCES Low-z sub-survey with photometric redshifts

The evolution of galaxies is shaped by both internal processes and their external environments. Galaxy clusters and their surroundings provide ideal laboratories to study these effects, particularly mechanisms such as quenching and morphological transformation. The Chilean Cluster galaxy Evolution Survey (CHANCES) Low-z sub-survey is part of the CHileAN Cluster galaxy Evolution Survey, a 4MOST community survey designed to uncover the relationship between the formation and evolution of galaxies and hierarchical structure formation as it happens, through deep and wide multi-object spectroscopy. We present the target selection strategy followed to select galaxy cluster candidate members for the CHANCES low-z sub-survey, in and around 50 clusters and two superclusters at z<0.07, out to (5XR200) and down to mr= 20.4. Combining public photometric redshift estimates from the DESI Legacy Imaging Survey and T80S/S-PLUS iDR5, with custom photometric redshifts, we identify likely galaxy cluster candidate members whose photometric redshifts are consistent with being at the known redshift of the cluster and measure the average deviations of their photometric redshifts with respect to the spectroscopic redshift measurements σNMAD. We have successfully compiled our CHANCES-low-redshift catalogues, split into three different sub-surveys: low-z bright (mr<18.5), low-z faint (18.5<=mr<20.4) and low-z faint supplementary, by selecting>= 500,000 galaxy cluster candidate members and including confirmed spectroscopic galaxy cluster members, from which we expect to obtain 4MOST low-resolution (R~6500) spectra for ~320,000 galaxies. The CHANCES Low-z target catalogues form a statistically robust sample for spectroscopic follow-up, allowing studies of galaxy evolution and environmental effects in nearby cluster and supercluster environments.

astro-ph.GA↗

arXiv2024

The Fourth S-PLUS Data Release: 12-filter photometry covering $\sim3000$ square degrees in the southern hemisphere

The Southern Photometric Local Universe Survey (S-PLUS) is a project to map $\sim9300$ sq deg of the sky using twelve bands (seven narrow and five broadbands). Observations are performed with the T80-South telescope, a robotic telescope located at the Cerro Tololo Observatory in Chile. The survey footprint consists of several large contiguous areas, including fields at high and low galactic latitudes, and towards the Magellanic Clouds. S-PLUS uses fixed exposure times to reach point source depths of about $21$ mag in the $griz$ and $20$ mag in the $u$ and the narrow filters. This paper describes the S-PLUS Data Release 4 (DR4), which includes calibrated images and derived catalogues for over 3000 sq deg, covering the aforementioned area. The catalogues provide multi-band photometry performed with the tools \texttt{DoPHOT} and \texttt{SExtractor} -- point spread function (\PSF) and aperture photometry, respectively. In addition to the characterization, we also present the scientific potential of the data. We use statistical tools to present and compare the photometry obtained through different methods. Overall we find good agreement between the different methods, with a slight systematic offset of 0.05\,mag between our \PSF and aperture photometry. We show that the astrometry accuracy is equivalent to that obtained in previous S-PLUS data releases, even in very crowded fields where photometric extraction is challenging. The depths of main survey (MS) photometry for a minimum signal-to-noise ratio $S/N = 3$ reach from $\sim19.5$ for the bluer bands to $\sim21.5$ mag on the red. The range of magnitudes over which accurate \PSF photometry is obtained is shallower, reaching $\sim19$ to $\sim20.5$ mag depending on the filter. Based on these photometric data, we provide star-galaxy-quasar classification and photometric redshift for millions of objects.

astro-ph.GA↗