Examinando por Autor "Demarco, Ricardo"
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Ítem CHANCES, the Chilean Cluster Galaxy Evolution Survey: Selection and initial characterisation of clusters and superclusters(EDP Sciences, 0025) Sifón, Cristóbal; Finoguenov, Alexis; Haines, Christopher P; Jaffé, Yara; Amrutha B.M.; Demarco, Ricardo; Lima E.V.R; Lima-Dias, Ciria; Méndez-Hernández, Hugo; Merluzzi, Paola; Monachesi, Antonela; Teixeira, Gabriel S. M.CHANCES, the CHileAN Cluster galaxy Evolution Survey, will study the evolution of galaxies in and around 100 massive galaxy clusters from the local Universe out to z = 0.45, and two superclusters at z ∼ 0.05 that contain roughly 25 Abell clusters each. CHANCES will use the new 4MOST Spectroscopic Survey Facility on the VISTA 4m telescope to obtain spectra for ∼500 000 galaxies with magnitudes rAB < 20.4, providing comprehensive spectroscopic coverage of each cluster out to 5r200. Its wide and deep scope will trace massive and dwarf galaxies from the surrounding filaments and groups to the cores of galaxy clusters. This will enable the study of galaxy preprocessing and of the role of the evolving environment on galaxy evolution. In this paper, we present and characterise the sample of clusters and superclusters to be targeted by CHANCES. We used literature catalogues based on X-ray emission and the Sunyaeva-Zel'dovich effect to define the cluster sample in a homogeneous way, with attention to cluster mass and redshift, as well as the availability of ancillary data. We calibrated literature mass estimates from various surveys against each other and provide an initial mass estimate for each cluster, which we used to define the radial extent of the 4MOST coverage. We also present an initial assessment of the structure surrounding these clusters based on the redMaPPer red-sequence algorithm as a preview of some of the science CHANCES will enable. © The Authors 2025Ítem Galaxy evolution in compact groups: II. Witnessing the influence of major structures in their evolution(EDP Sciences, 2025-04) Montaguth, Gissel P.; Monachesi, Antonela; Torres-Flores, Sergio; Gómez, Facundo A.; Lima-Dias, Ciria; Cortesi, Arianna; Mendes De Oliveira, Claudia; Telles, Eduardo; Panda, Swayamtrupta; Grossi, Marco; Lopes, Paulo A. A.; O'Mill, Ana Laura; Hernandez-Jimenez, Jose A.; Olave-Rojas, Daniela E.; Demarco, Ricardo; Kanaan, Antonio; Ribeiro, Tiago; Schoenell, WilliamCompact groups (CGs) of galaxies are an extreme environment for the morphological transformations and the cessation of star formation in galaxies. However, despite initially being conceived as isolated systems, it is now widely recognised that many of them are not as isolated as expected. Our objective is to understand the dynamics of CGs, as well as how the environment surrounding CGs impacts their morphological and physical properties. To achieve this, we selected a sample of 316 CGs in the Stripe 82 region, with a total of 1011 galaxies, and a sample of 2281 field galaxies as a control sample. We find that at least 41% of our sample of CGs are part of major structures, i.e. non-isolated CGs. We find a bimodality in the effective radius (Re)-Sérsic index (n) plane for all transition galaxies (those with (u - r) > 2:3 and n < 2:5) in CGs. Additionally, transition galaxies in isolated CGs populate more densely the Re-n plane for n < 1:75. In contrast, transition galaxies in non-isolated CGs show a bimodal distribution in the Re-n plane, with the n values smoothly increasing towards higher values, and 62% of these galaxies having n > 1:5. This indicates that the majority of these galaxies have already undergone a morphological transformation and primarily contribute to the population of more compact galaxies in the Re-n plane. We find that galaxies in our sample of CGs have a lower mean specific star formation rate (sSFR) compared to the control sample, with non-isolated CGs showing even lower sSFR values, indicating that dense environments suppress star formation. Additionally, non-isolated CGs have a higher fraction of quenched galaxies relative to isolated CGs and the control sample. Based on our results, we propose an evolutionary scenario where the major structures in which the CGs are embedded accelerate the morphological transformations of their galaxy members, and also facilitates preprocessing. Our findings highlight the importance of considering the larger structures in which CGs may be located, when analysing the properties of their galaxy members, as this can significantly affect the evolution of CGs and their galaxies. © The Authors 2025.Ítem Gemini Observations of Galaxies in Rich Early Environments (GOGREEN) I: Survey description(Oxford University Press, 2017-10) Balogh, Michael L.; Gilbank, David G.; Muzzin, Adam; Rudnick, Gregory; Cooper, Michael C.; Lidman, Chris; Biviano, Andrea; Demarco, Ricardo; McGee, Sean L.; Nantais, Julie B.; Noble, Allison; Old, Lyndsay; Wilson, Gillian; Yee, Howard K.C.; Bellhouse, Callum; Cerulo, Pierluigi; Chan, Jeffrey; Pintos-Castro, Irene; Simpson, Rane; van der Burg, Remco F.J.; Zaritsky, Dennis; Ziparo, Felicia; Alonso, María Victoria; Bower, Richard G.; Lucia, Gabriella De; Finoguenov, Alexis; Lambas, Diego Garcia; Muriel, Hernan; Parker, Laura C.; Rettura, Alessandro; Valotto, Carlos; Wetzel, AndrewWe describe a new Large Program in progress on the Gemini North and South telescopes: Gemini Observations of Galaxies in Rich Early Environments (GOGREEN). This is an imaging and deep spectroscopic survey of 21 galaxy systems at 1 < z < 1.5, selected to span a factor >10 in halo mass. The scientific objectives include measuring the role of environment in the evolution of low-mass galaxies, and measuring the dynamics and stellar contents of their host haloes. The targets are selected from the SpARCS, SPT, COSMOS, and SXDS surveys, to be the evolutionary counterparts of today's clusters and groups. The newred-sensitive Hamamatsu detectors on GMOS, coupled with the nod-and-shuffle sky subtraction, allow simultaneous wavelength coverage over λ ~ 0.6-1.05 μm, and this enables a homogeneous and statistically complete redshift survey of galaxies of all types. The spectroscopic sample targets galaxies with AB magnitudes z' < 24.25 and [3.6] μm < 22.5, and is therefore statistically complete for stellar masses M* ≳ 1010.3M⊙, for all galaxy types and over the entire redshift range. Deep, multiwavelength imaging has been acquired over larger fields for most systems, spanning u through K, in addition to deep IRAC imaging at 3.6 μm. The spectroscopy is ~50 per cent complete as of semester 17A, and we anticipate a final sample of ~500 new cluster members. Combined with existing spectroscopy on the brighter galaxies from GCLASS, SPT, and other sources, GOGREEN will be a large legacy cluster and field galaxy sample at this redshift that spectroscopically covers a wide range in stellar mass, halo mass, and clustercentric radius. © 2017 The Authors.Ítem The GOGREEN Survey: Evidence of an Excess of Quiescent Disks in Clusters at 1.0(IOP Publishing Ltd, 2021-10-10) Chan, Jeffrey C. C.; Wilson, Gillian; Balogh, Michael; Rudnick, Gregory; van der Burg, Remco F. J.; Muzzin, Adam; Webb, Kristi A.; Biviano, Andrea; Cerulo, Pierluigi; Cooper, M. C.; De Lucia, Gabriella; Demarco, Ricardo; Forrest, Ben; Jablonka, Pascale; Lidman, Chris; McGee, Sean L.; Nantais, Julie; Old, Lyndsay; Pintos-Castro, Irene; Poggianti, Bianca; Reeves, Andrew M. M.; Vulcani, Benedetta; Yee, Howard K. C.; Zaritsky, DennisWe present the results of the measured shapes of 832 galaxies in 11 galaxy clusters at 1.0 < z < 1.4 from the GOGREEN survey. We measure the axis ratio (q), the ratio of the minor to the major axis, of the cluster galaxies from near-infrared Hubble Space Telescope imaging using Sersic profile fitting and compare them with a field sample. We find that the median q of both star-forming and quiescent galaxies in clusters increases with stellar mass, similar to the field. Comparing the axis ratio distributions between clusters and the field in four mass bins, the distributions for star-forming galaxies in clusters are consistent with those in the field. Conversely, the distributions for quiescent galaxies in the two environments are distinct, most remarkably in where clusters show a flatter distribution, with an excess at low q. Modelling the distribution with oblate and triaxial components, we find that the cluster and field sample difference is consistent with an excess of flattened oblate quiescent galaxies in clusters. The oblate population contribution drops at high masses, resulting in a narrower q distribution in the massive population than at lower masses. Using a simple accretion model, we show that the observed q distributions and quenched fractions are consistent with a scenario where no morphological transformation occurs for the environmentally quenched population in the two intermediate-mass bins. Our results suggest that environmental quenching mechanism(s) likely produce a population that has a different morphological mix than those resulting from the dominant quenching mechanism in the field.Ítem GOGREEN: A critical assessment of environmental trends in cosmological hydrodynamical simulations at z ≈ 1(Oxford University Press, 2023-01-01) Kukstas, Egidijus; Balogh, Michael L.; McCarthy, Ian G.; Bahé, Yannick M.; De Lucia, Gabriella; Jablonka, Pascale; Vulcani, Benedetta; Baxter, Devontae C.; Biviano, Andrea; Cerulo, Pierluigi; Chan, Jeffrey C.; Cooper, M. C.; Demarco, Ricardo; Finoguenov, Alexis; Font, Andreea S.; Lidman, Chris; Marchioni, Justin; McGee, Sean; Muzzin, Adam; Nantais, Julie; Old, Lyndsay; Pintos-Castro, Irene; Poggianti, Bianca; Reeves, Andrew M. M.; Rudnick, Gregory; Sarron, Florian; van der Burg, Remco; Webb, Kristi; Wilson, Gillian; Yee, Howard K. C.; Zaritsk, DennisRecent observations have shown that the environmental quenching of galaxies at z ∼1 is qualitatively different to that in the local Universe. However, the physical origin of these differences has not yet been elucidated. In addition, while low-redshift comparisons between observed environmental trends and the predictions of cosmological hydrodynamical simulations are now routine, there have been relatively few comparisons at higher redshifts to date. Here we confront three state-of-the-art suites of simulations (BAHAMAS+MACSIS, EAGLE+Hydrangea, IllustrisTNG) with state-of-the-art observations of the field and cluster environments from the COSMOS/UltraVISTA and GOGREEN surveys, respectively, at z ∼1 to assess the realism of the simulations and gain insight into the evolution of environmental quenching. We show that while the simulations generally reproduce the stellar content and the stellar mass functions of quiescent and star-forming galaxies in the field, all the simulations struggle to capture the observed quenching of satellites in the cluster environment, in that they are overly efficient at quenching low-mass satellites. Furthermore, two of the suites do not sufficiently quench the highest mass galaxies in clusters, perhaps a result of insufficient feedback from AGN. The origin of the discrepancy at low stellar masses (M* ≲ 1010 M⊙), which is present in all the simulations in spite of large differences in resolution, feedback implementations, and hydrodynamical solvers, is unclear. The next generation of simulations, which will push to significantly higher resolution and also include explicit modelling of the cold interstellar medium, may help us to shed light on the low-mass tension.Ítem GOGREEN: A critical assessment of environmental trends in cosmological hydrodynamical simulations at z ≈ 1(Oxford University Press, 2023-01) Kukstas, Egidijus; Balogh, Michael L.; Mccarthy, Ian G.; Bahe, Yannick M.; De Lucia, Gabriella; Jablonka, Pascale; Vulcani, Benedetta; Baxter, Devontae C.; Biviano, Andrea; Cerulo, Pierluigi; Chan, Jeffrey C.; Cooper M.C.; Demarco, Ricardo; Finoguenov, Alexis; Font, Andreea S.; Lidman, Chris; Marchioni, Justin; Mcgee, Sean; Muzzin, Adam; Nantais, Julie; Old, Lyndsay; Pintos-Castro, Irene; Poggianti, Bianca; Reeves, Andrew M. M.; Rudnick, Gregory; Sarron, Florian; Van Der Burg, Remco; Webb, Kristi; Wilson, Gillian; Yee, Howard K. C.; Zaritsky, DennisRecent observations have shown that the environmental quenching of galaxies at z ∼1 is qualitatively different to that in the local Universe. However, the physical origin of these differences has not yet been elucidated. In addition, while low-redshift comparisons between observed environmental trends and the predictions of cosmological hydrodynamical simulations are now routine, there have been relatively few comparisons at higher redshifts to date. Here we confront three state-of-the-art suites of simulations (BAHAMAS+MACSIS, EAGLE+Hydrangea, IllustrisTNG) with state-of-the-art observations of the field and cluster environments from the COSMOS/UltraVISTA and GOGREEN surveys, respectively, at z ∼1 to assess the realism of the simulations and gain insight into the evolution of environmental quenching. We show that while the simulations generally reproduce the stellar content and the stellar mass functions of quiescent and star-forming galaxies in the field, all the simulations struggle to capture the observed quenching of satellites in the cluster environment, in that they are overly efficient at quenching low-mass satellites. Furthermore, two of the suites do not sufficiently quench the highest mass galaxies in clusters, perhaps a result of insufficient feedback from AGN. The origin of the discrepancy at low stellar masses (M* ≲ 1010 M⊙), which is present in all the simulations in spite of large differences in resolution, feedback implementations, and hydrodynamical solvers, is unclear. The next generation of simulations, which will push to significantly higher resolution and also include explicit modelling of the cold interstellar medium, may help us to shed light on the low-mass tension. © 2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.Ítem Ionized gas kinematics of cluster AGN at z ∼0.8 with KMOS(Oxford University Press, 2021-09-01) Paillalef, Marcela G.; Flores, Hector; Demarco, Ricardo; Rettura, Alessando; Jaffé, Yara; Lidman, Chris; Nantais, Julie; Puech, Mathieu; Rosati, PieroWe present an integral field spectroscopy study of two active galactic nuclei (AGN) in the galaxy cluster RXJ0152-137 at z = 0.84. We have combined integrated and 3D spectra with HST images to perform a complete morpho-kinematical analysis of each galaxy. For G557, we detect narrow and broad H α and [N ii] emission. The broad H α component is redshifted by v ∼939 km s-1 concerning the narrow component. The kinematics analysis and VLT/FORS2 data indicate that G557 presents evidence of radial outflows. For G300, it was possible to detect only the broad H α emission. The spectral properties of both galaxies are equivalent to those of local AGN. We also compare the results obtained for each AGN with their location within the cluster. We found a possible connection of the environment with the properties inferred for each of them, and the possible interaction of G557 with an unconfirmed neighboring galaxy, for which a bridge-like structure is observed in the HST images. This work shows evidence of how the same type of AGN can show differences in their spectroscopic properties depending on the region of the cluster in which they develop, which is important to understand how the environment affects AGN and, consequently, the evolution of galaxies. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.Ítem The GOGREEN Survey: A deep stellar mass function of cluster galaxies at 1.0 < z < 1.4 and the complex nature of satellite quenching(EDP Sciences, 2020-06-01) van der Burg, Remco F. J.; Rudnick, Gregory; Balogh, Michael L.; Muzzin, Adam; Lidman, Chris; Old, Lyndsay J.; Shipley, Heath; Gilbank, David; McGee, Sean; Biviano, Andrea; Cerulo, Pierluigi; Chan, Jeffrey C. C.; Cooper, Michael; De Lucia, Gabriella; Demarco, Ricardo; Forrest, Ben; Gwyn, Stephen; Jablonka, Pascale; Kukstas, Egidijus; Marchesini, Danilo; Nantais, Julie; Noble, Allison; Pintos-Castro, Irene; Poggianti, Bianca; Reeves, Andrew M. M.; Stefanon, Mauro; Vulcani, Benedetta; Webb, Kristi; Wilson, Gillian; Yee, Howard; Zaritsky, DennisWe study the stellar mass functions (SMFs) of star-forming and quiescent galaxies in 11 galaxy clusters at 1.0 < z < 1.4 drawn from the Gemini Observations of Galaxies in Rich Early ENvironments (GOGREEN) survey. Based on more than 500 h of Gemini/GMOS spectroscopy and deep multi-band photometry taken with a range of observatories, we probe the SMFs down to a stellar mass limit of 109.7 M (109.5 M for star-forming galaxies). At this early epoch, the fraction of quiescent galaxies is already highly elevated in the clusters compared to the field at the same redshift. The quenched fraction excess (QFE) represents the fraction of galaxies that would be star-forming in the field but are quenched due to their environment. The QFE is strongly mass dependent, and increases from ∼30% at M? = 109.7 M to ∼80% at M? = 1011.0 M . Nonetheless, the shapes of the SMFs of the two individual galaxy types, star-forming and quiescent galaxies, are identical between cluster and field to high statistical precision. Nevertheless, along with the different quiescent fractions, the total galaxy SMF is also environmentally dependent, with a relative deficit of low-mass galaxies in the clusters. These results are in stark contrast with findings in the local Universe, and therefore require a substantially different quenching mode to operate at early times. We discuss these results in light of several popular quenching models.Ítem The stellar mass function of quiescent galaxies in 2 < z < 2.5 protoclusters(Oxford University Press, 2024-01) Edward, Adit H.; Balogh, Michael L.; Bahe, Yannick M.; Cooper M.C.; Hatch, Nina A.; Marchioni, Justin; Muzzin, Adam; Noble, Allison; Rudnick, Gregory H; Vulcani, Benedetta; Wilson, Gillian; De Lucia, Gabriella; Demarco, Ricardo; Forrest, Ben; Hirschmann, Michaela; Castignani, Gianluca; Cerulo, Pierluigi; Finn, Rose A.; Hewitt, Guillaume; Jablonka, Pascale; Kodama, Tadayuki; Maurogordato, Sophie; Nantais, Julie; Xie, LizhiWe present an analysis of the galaxy stellar mass function (SMF) of 14 known protoclusters between 2.0 < z < 2.5 in the COSMOS field, down to a mass limit of 109.5 M. We use existing photometric redshifts with a statistical background subtraction, and consider star-forming and quiescent galaxies identified from (NUV - r) and (r - J) colours separately. Our fiducial sample includes galaxies within 1 Mpc of the cluster centres. The shape of the protocluster SMF of star-forming galaxies is indistinguishable from that of the general field at this redshift. Quiescent galaxies, however, show a flatter SMF than in the field, with an upturn at low mass, though this is only significant at ∼2σ. There is no strong evidence for a dominant population of quiescent galaxies at any mass, with a fraction <15 per cent at 1σ confidence for galaxies with log M∗/M < 10.5. We compare our results with a sample of galaxy groups at 1 < z < 1.5, and demonstrate that a significant amount of environmental quenching must take place between these epochs, increasing the relative abundance of high-mass () quiescent galaxies by a factor 2. However, we find that at lower masses (), no additional environmental quenching is required. © 2023 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.