Browsing by Author "Peletier, Reynier"

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    Galaxy populations in the Hydra I cluster from the VEGAS survey I. Optical properties of a large sample of dwarf galaxies
    (2022) La Marca, Antonio; Peletier, Reynier; Iodice, Enrichetta; Paolillo, Maurizio; Challapa, Nelvy Choque; Venhola, Aku; Forbes, Duncan A.; Cantiello, Michele; Hilker, Michael; Rejkuba, Marina; Arnaboldi, Magda; Spavone, Marilena; D'Ago, Giuseppe; Raj, Maria Angela; Ragusa, Rossella; Mirabile, Marco; Rampazzo, Roberto; Spiniello, Chiara; Mieske, Steffen; Schipani, Pietro
    Context. Due to their relatively low stellar mass content and diffuse nature, the evolution of dwarf galaxies can be strongly affected by their environment. Analyzing the properties of the dwarf galaxies over a wide range of luminosities, sizes, morphological types, and environments, we can obtain insights about their evolution. At similar to 50 Mpc, the Hydra I cluster of galaxies is among the closest cluster in the z similar or equal to 0 Universe, and an ideal environment to study dwarf galaxy properties in a cluster environment.
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    Galaxy populations in the Hydra I cluster from the VEGAS survey II. The ultra-diffuse galaxy population
    (2022) La Marca, Antonio; Iodice, Enrichetta; Cantiello, Michele; Forbes, Duncan A.; Rejkuba, Marina; Hilker, Michael; Arnaboldi, Magda; Greggio, Laura; Spiniello, Chiara; Mieske, Steffen; Venhola, Aku; Spavone, Marilena; D'Ago, Giuseppe; Raj, Maria Angela; Ragusa, Rossella; Mirabile, Marco; Rampazzo, Roberto; Peletier, Reynier; Paolillo, Maurizio; Challapa, Nelvy Choque; Schipani, Pietro
    In this work, we extend the catalog of low-surface brightness (LSB) galaxies, including ultra-diffuse galaxy (UDG) candidates, within approximate to 0.4R(vir) of the Hydra I cluster of galaxies based on deep images from the VST Early-type GAlaxy Survey (VEGAS). The new galaxies were found by applying an automatic detection tool and carrying out additional visual inspections of g and r band images. This led to the detection of 11 UDGs and 8 more LSB galaxies. For all of them, we assessed the cluster membership using the color-magnitude relation derived for early-type giant and dwarf galaxies in Hydra I. The UDGs and new LSB galaxies found in Hydra I span a wide range of central surface brightness (22.7 less than or similar to mu(0.g) less than or similar to 26.5 mag arcse(-2)), effective radius (0.6 less than or similar to R-e less than or similar to 4.0 kpc), and color (0.4 <= g-r <= 0.9 mag), and have stellar masses in the range similar to 5 x 10(6)-2 x 10(8) M-circle dot. The 2D projected distribution of both galaxy types is similar to the spatial distribution of dwarf galaxies, with over-densities in the cluster core and north of the cluster center. They have similar color distribution and comparable stellar masses to the red dwarf galaxies. Based on photometric selection, we identify a total of nine globular cluster (GC) candidates associated to the UDGs and four to the LSB galaxies, with the highest number of candidates in an individual UDG being three. We find that there are no relevant differences between dwarfs, LSB galaxies, and UDGs: the structural parameters (i.e., surface brightness, size, color, and n-index) and GC content of the three classes have similar properties and trends. This finding is consistent with UDGs being the extreme LSB tail of the size-luminosity distribution of dwarfs in this environment.
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    The CAVITY project: The spatially resolved stellar population properties of galaxies in voids
    (2024) Conrado, Ana M.; Delgado, Rosa M. Gonzalez; Garcia-Benito, Ruben; Perez, Isabel; Verley, Simon; Ruiz-Lara, Tomas; Sanchez-Menguiano, Laura; Puertas, Salvador Duarte; Jimenez, Andoni; Dominguez-Gomez, Jesus; Espada, Daniel; Argudo-Fernandez, Maria; Alcazar-Laynez, Manuel; Blazquez-Calero, Guillermo; Bidaran, Bahar; Zurita, Almudena; Peletier, Reynier; Torres-Rios, Gloria; Florido, Estrella; Rodriguez Martinez, Monica; del Moral-Castro, Ignacio; van de Weygaert, Rien; Falcon-Barroso, Jesus; Lugo-Aranda, Alejandra Z.; Sanchez, Sebastian F.; van der Hulst, Thijs; Courtois, Helene M.; Ferre-Mateu, Anna; Sanchez-Blazquez, Patricia; Roman, Javier; Aceituno, Jesus
    The Universe is shaped as a web-like structure, formed by clusters, filaments, and walls that leave large low number-density volumes in between named voids. Galaxies in voids have been found to be of a later type, bluer, less massive, and to have a slower evolution than galaxies in denser environments (filaments and walls). However, the effect of the void environment on their stellar population properties is still unclear. We aim to address this question using 118 optical integral field unit datacubes from the Calar Alto Void Integral-field Treasury surveY (CAVITY), observed with the PMAS/PPaK spectrograph at the 3.5 m telescope at the Calar Alto Observatory (Almer & iacute;a, Spain). We fitted their spectra from 3750 & Aring; to 7000 & Aring; with the non-parametric full spectral fitting code STARLIGHT to estimate their stellar population properties: stellar mass, stellar mass surface density, age, star formation rate (SFR), and specific star formation rate (sSFR). We analysed the results through the global properties, assessing the behaviour of the whole galaxy, and the spatially resolved information, by obtaining the radial profiles from the 2D maps up to the 2 half-light radius of each stellar population property. The results were examined with respect to their morphological type and stellar mass. Then, we compared them with a control sample of galaxies in filaments and walls, selected from the CALIFA survey and analysed following the same procedure. To make a fair comparison between the samples, we selected a twin filament galaxy for each void galaxy of the same morphological type and closest stellar mass, to match the void galaxy sample as much as possible in morphology and mass. Key findings from our global and spatially resolved analysis include void galaxies having a slightly higher half-light radius (HLR), lower stellar mass surface density, and younger ages across all morphological types, and slightly elevated SFR and sSFR (only significant enough for Sas). Many of these differences appear in the outer parts of spiral galaxies (HLR > 1), where discs are younger and exhibit a higher sSFR compared to galaxies in filaments and walls, indicative of less evolved discs. This trend is also found for early-type spirals, suggesting a slower transition from star-forming to quiescent states in voids. Our analysis indicates that void galaxies, influenced by their surroundings, undergo a more gradual evolution, especially in their outer regions, with a more pronounced effect for low-mass galaxies. We find that below a certain mass threshold, environmental processes play a more influential role in galactic evolution.