A5077584906- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Astrophysics and Star Formation Studies
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- SAS software applications and methods
- Adaptive optics and wavefront sensing
- Remote Sensing in Agriculture
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Relativity and Gravitational Theory
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Urban Development and Societal Issues
- Advanced Mathematical Theories
- Space Satellite Systems and Control
- Education and Digital Technologies
- Advanced Mathematical Theories and Applications
- Spectroscopy and Laser Applications
- History of Education Research in Brazil
Universidade de São Paulo
2013-2024
Universidade Cidade de São Paulo
2016-2024
Museu de Astronomia e Ciências Afins
2004-2022
Instituto de Geofísica y Astronomía
2017
Laboratório Interinstitucional de e-Astronomia
2013
Laboratoire d’Astrophysique de Marseille
2010
Midwestern University
2010
University College London
2006-2010
University of Naples Federico II
2010
University of Chicago
2010
We present a detailed strong-lensing, weak-lensing and X-ray analysis of Abell 2744 (z= 0.308), one the most actively merging galaxy clusters known. It appears to have unleashed 'dark', 'ghost', 'bullet' 'stripped' substructures, each ∼1014 M⊙. The phenomenology is complex will challenge for numerical simulations reproduce. With new, multiband Hubble Space Telescope (HST) imaging, we identify 34 strongly lensed images 11 galaxies around massive Southern 'core'. Combining this with data from...
The Southern Photometric Local Universe Survey (S-PLUS) is imaging ~9300 deg^2 of the celestial sphere in twelve optical bands using a dedicated 0.8 m robotic telescope, T80-South, at Cerro Tololo Inter-American Observatory, Chile. telescope equipped with 9.2k by e2v detector 10 um pixels, resulting field-of-view 2 plate scale 0.55"/pixel. survey consists four main subfields, which include two non-contiguous fields high Galactic latitudes (8000 |b| > 30 deg) and areas plane bulge (for an...
We use the weak gravitational lensing effect to study mass distribution and dynamical state of a sample 24 X-ray-luminous clusters galaxies (0.05 < z 0.31) observed with FORS1 instrument mounted on VLT-Antu (Unit Telescope 1) under homogeneous sky conditions subarcsecond image quality. The galaxy shapes were measured in combined VIR after deconvolution locally determined point-spread function, while two-dimensional distributions computed using an algorithm based maximum entropy method. By...
We study in detail the photometric redshift requirements needed for tomographic weak gravitational lensing order to measure accurately Dark Energy equation of state. In particular, we examine how ground-based photometry (u,g,r,i,z,y) can be complemented by space-based near-infrared (IR) (J,H), e.g. on board planned DUNE satellite. Using realistic simulations and an artificial neural network photo-z method evaluate Figure Merit parameters $(w_0, w_a)$. consider a DUNE-like broad optical...
The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological to be carried out from Javalambre Observatory in Spain with purpose-built, dedicated 2.5m telescope and 4.7 sq.deg. camera 1.2Gpix. Starting late 2015, J-PAS will observe 8500sq.deg. Northern Sky measure $0.003(1+z)$ photo-z for $9\times10^7$ LRG ELG galaxies plus several million QSOs, sampling an effective volume $\sim 14$ Gpc$^3$ up $z=1.3$ becoming first radial...
We determine the first fossil group luminosity function based on spectroscopy of member galaxies. The RX J1552.2+2013 has 36 confirmed members, it is at a mean redshift 0.136 and velocity dispersion 623 km/s (or 797 if four emission lines galaxies in outskirts distribution are included). J1552.2+2013, measured within inner region system ~1/3 R_vir), range -23.5< M_i'<-17.5, well fitted by Schechter with M*i'=-21.3 +/- 0.4 alpha = -0.6 0.3 or Gaussian centered M_i'= -20.0 sigma=1.29 0.24 i'...
Context. The luminous material in clusters of galaxies exists two forms: the visible and X-ray emitting intra-cluster medium. hot gas is major observed baryonic component clusters, about six times more massive than stellar component. mass contained within approximately 3% dynamical mass.
Defined as X-ray bright galaxy groups with large differences between the luminosities of their brightest and second galaxies, 'fossil groups' are believed to be some oldest systems in Universe. They have therefore been subject much recent research.
We present a weak-lensing and dynamical study of the complex cluster Abell 1758 (A1758, z = 0.278) supported by hydrodynamical simulations. This is composed two main structures, called A1758N A1758S. The Northern structure A1758NW & A1758NE, with lensing determined masses 7.90_{-1.55}^{+1.89} X 10^{14} M_\odot 5.49_{-1.33}^{+1.67} M_\odot, respectively. They show remarkable feature: while in there spatial agreement among weak mass distribution, intracluster medium its brightest galaxy...
We study the properties of fossil cluster RX J1416.4+2315 through g' and i'-band imaging spectroscopy 25 member galaxies. The system is at a mean redshift 0.137 has velocity dispersion 584 km s^-1. Superimposed onto one quadrant field there group five galaxies 0.131, which, if included as part cluster, increases to 846 km/s. central object normal elliptical galaxy, with no cD envelope. luminosity function system, estimated by number counts, statistical background correction, in range...
We have discovered four intergalactic H II regions in Stephan's quintet, which is more than a 25 kpc projected distance from the center of nearest group galaxy, with no apparent optical connection to it. They MB ranging -11.9 -12.5 mag, colors B-R = 0.7-1.1 radial velocities 6565 6651 km s-1, and they are superposed onto I tail east NGC 7319, mean velocity 6610 s-1. In addition, metallicities order 12 + log(O/H) 8.58 ± 0.25, suggests that were formed preenriched material. derive age 4.6 0.6...
Major mergers between massive clusters have a profound effect in the intracluster gas, which may be used as probe of dynamics structure formation at high end mass function. An example such merger is observed northern component Abell 1758, comprising two sub-clusters separated by approximately 750 kpc. One exhibits an offset dark matter and gas. We aim to determine whether it possible reproduce specific morphological features this cluster means major merger. perform dedicated SPH (smoothed...
We determine a K-band luminosity-metallicity (L-Z) relation for dwarf irregular galaxies over large range of magnitudes, -20.5 < MK -13.5, using combination K photometry from either the Two Micron All Sky Survey or recent study Vaduvescu et al., and metallicities derived mainly with Te-method, several different studies. then use this newly relation, together published Ks our new spectra objects in field HCG 31, to discuss nature possible tidal group. catalog member namely, "R," situated ∼50...
Cosmic shear requires high precision measurement of galaxy shapes in the presence observational Point Spread Function (PSF) that smears out image. The PSF must therefore be known for each to a accuracy. However, several reasons, is usually wavelength dependent, differences between spectral energy distribution observed objects introduces further complexity. In this paper we investigate effect wavelength-dependence PSF, focusing on instruments which size dominated by diffraction-limit...
We present new Gemini spectra of 14 objects found within the HI tails Hickson Compact Groups 92 and 100. Nine them are GALEX Far-UV (FUV) Near-UV (NUV) sources. The confirm that these members compact groups have metallicities close to solar, with an average value 12+log(O/H)~8.5. They FUV luminosities 7 x 10^40 erg/s, very young ages (< 100 Myr) two resemble tidal dwarf galaxies (TDGs) candidates. suggest they were created gas clouds ejected during galaxy-galaxy interactions into...
We present a stacked weak lensing analysis of 27 richness selected galaxy clusters at $0.40 \leqslant z 0.62$ in the CODEX survey. The fields were observed 5 bands with CFHT. measure surface mass density profile $14\sigma$ significance radial range $0.1 < R\ Mpc\ h^{-1} 2.5$. is well described by halo model, main term following an NFW and including off-centring effect. select background sample using conservative colour-magnitude method to reduce potential systematic errors contamination...
We analyse the structures of all clusters in DAFT/FADA survey for which XMM-Newton and/or a sufficient number galaxy redshifts cluster range is available, with aim detecting substructures and evidence merging events. These properties are discussed framework standard cold dark matter cosmology.XMM-Newton data were available 32 clusters, we derive X-ray luminosity global temperature 25 them. For 23 able to fit emissivity beta-model subtract it detect gas. A dynamical analysis based on SG...
The galaxy cluster Abell~3376 is a nearby (z=0.046) dissociative merging surrounded by two prominent radio relics and showing an X-ray comet-like morphology. merger system comprised of the subclusters A3376W & A3376E. Based on new deep multi-wavelength large-field images published redshifts, we bring insights about history this merger. Despite difficulty applying weak lensing technique at such low redshift, successfully recovered mass distribution in field. Moreover, with application...
We analyze the mass content of massive strong-lensing cluster Abell 586 (z = 0.17). use optical data (imaging and spectroscopy) obtained with Gemini Multi-Object Spectrograph (GMOS) mounted on 8 m North telescope, together publicly available X-ray taken Chandra space telescope. Employing different techniques—velocity distribution galaxies, weak gravitational lensing, spatially resolved spectroscopy—we derive velocity dispersion estimates from each them. All agree well other, within a 68%...
We present a catalogue of galaxy groups and clusters selected using friends-of-friends (FoF) algorithm with dynamic linking length from the 2dF-SDSS LRG QSO (2SLAQ) luminous red survey. The parameters for code are chosen through an analysis simulated 2SLAQ haloes. resulting includes 313 containing 1152 galaxies. have average velocity dispersion km s−1 size Mpc h−1. Galaxies regions 1 deg2 centred on were downloaded Sloan Digital Sky Survey Data Release 6. Investigating photometric redshifts...
We aim to use multi-band imaging from the Phase-3 Verification Data of J-PLUS survey derive accurate photometric redshifts (photo-z) and look for potential new members in surroundings nearby galaxy clusters A2589 (z=0.0414) & A2593 (z=0.0440), using redshift probability distribution functions. The ultimate goal is demonstrate usefulness a 12-band filter system study large-scale structure local universe. present an optimized pipeline estimation photo-z galaxies. tested our with sample 296...
The impending Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS) will be first wide-field survey ≳ 8500 deg2 to reach 'stage IV' category. Because redshift resolution afforded by 54 narrow-band filters, J-PAS is particularly suitable for cluster detection in range z<1. photometric dispersion estimated only ∼0.003 with few outliers ≲4 per cent galaxies brighter than i ∼ 23 AB, because sensitivity narrow band imaging absorption and emission lines. Here, we evaluate...
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands square degrees northern extragalactic sky with a unique set $56$ optical filters from dedicated $2.55$m telescope, JST, at Javalambre Observatory. Before arrival final instrument (a 1.2 Gpixels, 4.2deg$^2$ field-of-view camera), JST was equipped an interim camera (JPAS-Pathfinder), composed one CCD 0.3deg$^2$ and resolution 0.23 arcsec pixel$^{-1}$. To demonstrate scientific...