Showing papers by "R. Cid Fernandes published in 2022"

The miniJPAS survey: The role of group environment in quenching the star formation

Abstract: The miniJPAS survey has observed ∼ 1 deg 2 on the AEGIS field with 60 bands (spectral resolution of R ∼ 60) in order to demonstrate the scientific potential of the Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) that will map ∼ 8000 deg 2 of the northern sky during the upcoming years. In particular, this paper shows the potential of J-PAS to detect groups with mass up to 10 13 M (cid:12) and the characterisation of their galaxy populations up to z ∼ 1. The parametric code BaySeAGal is used to derive the stellar population properties by fitting the J-PAS spectral energy distribution (SED) of the galaxy members in 80 groups at z ≤ 0 . 8 previously detected by the AMICO code, as well as for a galaxy field sample retrieved from the whole miniJPAS down to r < 22 . 75 (AB). Blue, red, quiescent, and transition (blue quiescent or green valley) galaxy populations are identified through their rest-frame (extinction corrected) ( u − r ) int colour, galaxy stellar mass ( M (cid:63) ), and specific star formation rate (sSFR). We measure the abundance of these galaxies as a function of M (cid:63) and environment to investigate the role that groups play in quenching the star formation. We find: (i) The fraction of red and quiescent galaxies in groups increases with M (cid:63) and it is always higher in groups (28 % on average) than in the field (5 %). (ii) The quenched fraction excess (QFE) in groups shows a strong dependence with M (cid:63) , and increases from a few percent for galaxies with M (cid:63) < 10 10 M (cid:12) , to higher than 60 % for galaxies with M (cid:63) > 3 × 10 11 M (cid:12) . (iii) The abundance excess of transition galaxies in groups shows a modest dependence with M (cid:63) , being 5–10 % for galaxies with M (cid:63) < 10 11 M (cid:12) . (iv) The fading time scale, defined as the time that galaxies in groups spend in the transition phase, is very short ( < 1 . 5 Gyr), indicating that the star formation of galaxies in groups declines very rapidly. (v) The evolution of the galaxy quenching rate in groups shows a modest but significant evolution since z ∼ 0 . 8. The result is compatible with the expected evolution with constant QFE = 0 . 4, which has been previously measured for satellites in the nearby Universe, as traced by SDSS. Further, this evolution is consistent with a scenario where the low-mass star-forming galaxies in clusters at z = 1–1 . 4 are environmentally quenched, as previously reported by other surveys. groups

The miniJPAS survey. Galaxy populations in the most massive cluster in miniJPAS: mJPC2470-1771

Abstract: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a photometric survey that is poised to scan several thousands of square degrees of the sky. It will use 54 narrow-band filters, combining the benefits of low-resolution spectra and photometry. Its offshoot, miniJPAS, is a 1 deg2 survey that uses J-PAS filter system with the Pathfinder camera. In this work, we study mJPC2470-1771, the most massive cluster detected in miniJPAS. We survey the stellar population properties of the members, their star formation rates (SFR), star formation histories (SFH), the emission line galaxy (ELG) population, spatial distribution of these properties, and the ensuing effects of the environment. This work shows the power of J-PAS to study the role of environment in galaxy evolution. We used a spectral energy distribution (SED) fitting code to derive the stellar population properties of the galaxy members: stellar mass, extinction, metallicity, (u− r)res and (u− r)int colours, mass-weighted age, the SFH that is parametrised by a delayed-τ model (τ, t0), and SFRs. We used artificial neural networks for the identification of the ELG population via the detection of the Hα, [NII], Hβ, and [OIII] nebular emission. We used the Ew(Hα)-[NII] (WHAN) and [OIII]/Hα-[NII]/Hα (BPT) diagrams to separate them into individual star-forming galaxies and AGNs. We find that the fraction of red galaxies increases with the cluster-centric radius; and at 0.5 R200 the red and blue fractions are both equal. The redder, more metallic, and more massive galaxies tend to be inside the central part of the cluster, whereas blue, less metallic, and less massive galaxies are mainly located outside of the inner 0.5 R200. We selected 49 ELG, with 65.3 % of the them likely to be star-forming galaxies, dominated by blue galaxies, and 24 % likely to have an AGN (Seyfert or LINER galaxies). The rest are difficult to classify and are most likely composite galaxies. These latter galaxies are red, and their abundance decreases with the cluster-centric radius; in contrast, the fraction of star-forming galaxies increases outwards up to R200. Our results are compatible with an scenario in which galaxy members were formed roughly at the same epoch, but blue galaxies have had more recent star formation episodes, and they are quenching out from within the cluster centre. The spatial distribution of red galaxies and their properties suggest that they were quenched prior to the cluster accretion or an earlier cluster accretion epoch. AGN feedback or mass might also stand as an obstacle in the quenching of these galaxies.

The DIVING$^{3D}$ Survey -- Deep IFS View of Nuclei of Galaxies -- I. Definition and Sample Presentation

Abstract: We present the Deep Integral Field Spectrograph View of Nuclei of Galaxies (DIVING3D) survey, a seeing-limited optical 3D spectroscopy study of the central regions of all 170 galaxies in the Southern hemisphere with B < 12.0 and |b | > 15◦. Most of the observations were taken with the Integral Field Unit of the Gemini Multi-Object Spectrograph, at the Gemini South telescope, but some are also being taken with the Southern Astrophysical Research Telescope (SOAR) Integral Field Spectrograph. The DIVING3D survey was designed for the study of nuclear emission-line properties, circumnuclear (within scales of hundreds of pc) emission-line properties, stellar and gas kinematics and stellar archaeology. The data have a combination of high spatial and spectral resolution not matched by previous surveys and will result in significant contributions for studies related to, for example, the statistics of low-luminosity active galactic nuclei, the ionization mechanisms in Low-Ionization Nuclear Emission-Line Regions, the nature of transition objects, among other topics.

Photometric and Morphological Analysis of Fornax Galaxies through S-PLUS

Abstract: The photometric and morphological analysis of galaxies in clusters provides invaluable information regarding the evolutionary stage of the cluster itself. In addition, it helps to understand how the environment affects the properties of the galaxies and, as a consequence, their evolutionary path. In this contribution we present the first steps on the photometric and morphological analysis of galaxies in the Fornax cluster using SPLUS data. We expect that the S-PLUS novel filter set and wide field coverage allow us to obtain new information about Fornax and its galaxy population.

Falas e Comensalidade: políticas e coletivos em um acampamento de retomada entre os Kaingang da TI Queimadas (Ortigueira/PR)

Abstract: Em 2018, os Kaingang da TI Queimadas (Ortigueira/PR) realizavam ampla mobilização, ocupando uma área que havia sido retirada deles há mais de 70 anos. Em retomada, acampamentos eram levantados e casas ocupadas, visando à acomodação, à pernoite e às refeições. Ainda, um contingente significativo de indígenas se encontrava em fluxo e refluxo diários entre a sede da Terra Indígena e a área de retomada. Trata-se de contexto aqui analisado no recorte etnológico da guerra: na produção de coletivos e de lideranças/ chefes. Abordamos, assim, o cotidiano da guerra nesse acampamento de retomada a partir de dois eixos principais: pronunciamentos e registros audiovisuais pautados por duas lideranças indígenas principais, nos quais emergem “chefes”, “povo”, “a gente” e não indígenas; e os fogos dos acampamentos, nos quais se opera a distribuição de comida e a comensalidade. A partir desses referenciais, visamos à contribuição sobre a configuração de coletivos e lideranças/chefes entre os Kaingang, haja vista a relevância da guerra.