A5032869766- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Remote Sensing in Agriculture
- Astrophysics and Star Formation Studies
- Dark Matter and Cosmic Phenomena
- Advanced Vision and Imaging
- Impact of Light on Environment and Health
- Scientific Research and Discoveries
- Space Science and Extraterrestrial Life
- CCD and CMOS Imaging Sensors
- Plant Water Relations and Carbon Dynamics
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- Advanced Mathematical Theories and Applications
- Historical and socio-economic studies of Spain and related regions
- Multidisciplinary Science and Engineering Research
- Earth Systems and Cosmic Evolution
- Nuclear physics research studies
- Historical Art and Architecture Studies
Consejo Nacional de Investigaciones Científicas y Técnicas
2013-2024
National University of San Juan
2013-2024
Centro Científico Tecnológico - San Juan
2007-2018
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio
2012
Universidad Nacional de Córdoba
2002-2009
Argentine National Observatory
2002-2009
University of La Serena
2009
We study galaxy pairs (GPs) in the field selected from 100-K public release of Two Degree Field (2dF) redshift survey. Our analysis provides a well-defined sample 1258 GPs, large data base suitable for statistical studies interactions local Universe, z≤ 0.1. GPs were by radial velocity (ΔV) and projected separation (rp) criteria determined analysing star-formation activity within neighbours. have excluded high-density regions removing galaxies groups clusters. analyse as function both...
We perform a statistical analysis of active galactic nucleus (AGN) host characteristics and nuclear activity for AGNs in pairs without companions. Our study concerns sample derived from the Sloan Digital Sky Survey Data Release 4 data by Kauffmann et al. pair galaxies obtained same set Alonso An eye-ball classification images 1607 close (rp < 25 kpc h−1, ΔV 350 km s−1) according to evidence interaction through distorted morphologies tidal features provides us with more confident assessment...
We assess the effects of galaxy–galaxy interactions on star formation (SF) by analysing pairs in groups and clusters galaxies with virial masses range 1013–1015 M⊙ extracted from 2dF Galaxy Redshift Survey (2dFGRS). find that galaxy relative separation rp < 15 h−1 kpc show significant SF activity comparison other group member galaxies. Similar results were found for field (rp 25 kpc) so nature driven is nearly independent environment, spite general lower level systems The above reflect, one...
Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed inner Galactic bulge and adjacent southern disk from 2009–2015. Upon its conclusion, complementary VVV extended (VVVX) has expanded both temporal as well spatial coverage of original area, widening it 562 to 1700 sq. deg., providing additional epochs JHK s filters 2016–2023. Aims. With completion VVVX observations during first semester 2023, we present here observing strategy, a description data quality access,...
Aims: With the aim of assessing effects bars on disc galaxy properties, we present an analysis different characteristics spiral galaxies with strong, weak and without bars. Method: We identified barred from Sloan Digital Sky Survey. By visual inspection, classified face-on brighter than g<16.5 mag into strong-bar, weak-bar unbarred. In order to provide appropiate quantification influence also constructed a suitable control sample unbarred similar redshift, magnitude, morphology, bulge sizes,...
We analyse star formation rates derived from photometric and spectroscopic data of galaxies in pairs different environments using the 2dF Galaxy Redshift Survey (2dFGRS) Sloan Digital Sky (SDSS). The two samples comprise several thousand pairs, suitable to explore into detail dependence activity on orbital parameters global environment. use projected galaxy density fifth nearest neighbour each galaxy, with convenient luminosity thresholds characterise environment both surveys a consistent...
We analyse the environment of low redshift, z < 0.2, SDSS quasars using spectral and photometric information galaxies from Sloan Digital Sky Survey Third Data Release (SDSS-DR3). compare quasar neighbourhoods with field high density environments through an analysis on samples typical groups. compute surrounding surface number finding that systematically avoid regions. Their mean correspond to galaxy enhancements similar those galaxies. have also explored several properties in these...
In February 1997, the Japanese radio astronomy satellite HALCA was launched to provide space-bourne element for VLBI Space Observatory Programme (VSOP) mission. Approximately twenty-five percent of mission time dedicated VSOP Survey bright compact Active Galactic Nuclei (AGN) at 5 GHz. This paper, fifth in series, presents images and models remaining 140 sources not included Paper III, which contained 102 sources. For most sources, plots uv-coverage, visibility amplitude versus uv-distance,...
With the aim of assessing effects bars on active galactic nuclei (AGN), we present an analysis host characteristics and nuclear activity AGN galaxies with without selected from Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). By visual inspection SDSS images classified hosts face-on spiral brighter than g < 16.5 into barred or unbarred. purpose providing appropriate quantification bars, also constructed a suitable control sample unbarred similar redshift, magnitude, morphology, bulge...
We explore properties of barred active spiral galaxies in groups selected from the SDSS-DR7, with aim assessing effects bars on AGN and role high density environment. identified that reside SDSS-DR7 group catalog. To provide a suitable quantification bars, reliable control sample unbarred environments similar redshift, magnitude, morphology, bulge size distributions was constructed. found fraction (~ 38 %) is higher than those total ( ~ 28 %), indicating are more likely to be field. also...
ABSTRACT The standard paradigm for the formation of Universe suggests that large structures are formed from hierarchical clustering by continuous accretion less massive galaxy systems through filaments. In this context, filamentary play an important role in properties and evolution galaxies connecting high-density regions, such as nodes, being surrounded low-density cosmic voids. availability filament critical point catalogues extracted disperse illustris TNG300-1 hydrodynamic simulation...
The VSOP mission is a Japanese-led project to study radio sources with sub-milliarcsec resolution using an orbiting 8 m telescope, HALCA, along global arrays of Earth-based telescopes. Approximately 25% the observing time devoted survey compact AGN which are stronger than 1 Jy at 5 GHz-the Survey. This paper, third in series, presents results from analysis first 102 Survey sources. We present high images and plots visibility amplitude versus projected baseline length. In addition, model-fit...
We analyse interacting galaxy pairs with evidence of tidal features in the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7).The were selected within z < 0.1 by requiring a projected separation r p 50 h -1 kpc and relative radial velocity ∆V 500 km s .We complete spectroscopic using galaxies photometric redshifts considering phot 6800 , taking into account mean redshift uncertainty.We classify visual inspection spirals co-rotating counter-rotating systems.For subsample non-AGN galaxies,...
Suzaku and Chandra X-ray observations detected a new cluster of galaxies, J1759-3450, at redshift z=0.13. It is located behind the Milky Way, high Galactic dust extinction renders it nearly invisible optical wavelengths. We attempt here to confirm galaxy with near-infrared imaging observations, characterize its central member galaxies. Images from VVV survey were used detect candidate galaxies J1759-3450 within region cluster, up 350 kpc peak emission. Color-magnitude color-color diagrams...
We analyse different properties of the small-scale environment Seyfert 2 for two samples selected according to accretion rate parameter , |${\cal R}$|, from Sloan Digital Sky Survey, Data Release 7 survey. compare results with control non-active galaxies that cover same redshift range, luminosity, colours, morphology, age and stellar mass content. Our study shows both high low subsamples reside in bluer lower density environments than samples. However, we find this difference is at least...
The ESO public survey VISTA Variables in the V\'ia L\'actea (VVV) surveyed inner Galactic bulge and adjacent southern disk from $2009-2015$. Upon its conclusion, complementary VVV eXtended (VVVX) has expanded both temporal as well spatial coverage of original area, widening it $562$ to $1700$ sq. deg., providing additional epochs $JHK_{\rm s}$ filters $2016-2023$. With completion VVVX observations during first semester 2023, we present here observing strategy, a description data quality...
We analyse the relation between AGN host properties and large scale environment for a representative red blue galaxy sample selected from DR4 SDSS. A comparison is made with two carefully constructed control samples of non-active galaxies, covering same redshift range color baseline. The cross-correlation functions show that density distribution neighbours almost identical either active, or non-active. Although active galaxies inhabit environments less dense compared to both reside in...
The main goal of this work is to investigate the influence environment at different scales on properties galaxies in systems with a low number members. To end we used catalogue small galaxy comprising compact and locally isolated pairs, triplets groups four up six galaxies. We consider fixed aperture estimators found that lower than 5 Mpc pairs are associated density environments groups. Moreover nearest neighbour approach highlights prefer denser slightly less dense When considering...
Aims: We present a statistical analysis of different characteristics ringed spiral galaxies with the aim assessing effects rings on disk galaxy properties. Methods: built catalog from Sloan Digital Sky Survey Data Release 14 (SDSS-DR14). Via visual inspection SDSS images, we classified face-on brighter than $g < 16.0$ mag into with: an inner ring, outer nuclear both and pseudo-ring. In addition to rings, recorded morphological types existence bars, lenses, pair companions or without...
Aims. With the aim of performing an analysis orientations galaxy pair systems with respect to underlying large-scale structure, we study alignment between axis connecting galaxies and host cosmic filament where resides. In addition, analyze dependence amplitude on morphology members as well properties. Methods. We build a catalog requiring $r_p < 100\kpc$ $\Delta V 500 \kms $ within redshift $z<0.1$ from Sloan Digital Sky Survey (SDSS). divided taking into account morphological...
We aim at defining homogeneous selection criteria of small galaxy systems in order to build catalogues suitable compare main properties pairs, triplets, and groups with four or more members. To this end we use spectroscopic photometric SDSS data identify a low number study global these the their member galaxies finding that are systematically redder lower star formation activity indicators than pairs which have higher fraction forming galaxies. Triplet present intermediate trends between...
This paper presents a large sample of intermediate- to high-redshift galaxy groups and clusters detected using fully automated search in the Cosmic Evolution Survey field. The detection algorithm is based on density peak extraction from distribution sampled Voronoi tessellation within overlapping slices photometric redshift space. cluster catalogue contains 1780 structures covering range 0.2 < z 3.0, spanning three orders magnitude luminosity (10 8 L4 5 × 10 11 L ⊙ ) richness eight hundreds...
Aims. With the aim of performing a suitable comparison internal process galactic bars with respect to external effect interactions on driving gas toward inner most region galaxies, we explored efficiency both mechanisms central nuclear activity in active nuclei (AGN) spiral galaxies. Methods. We selected samples barred AGN and objects residing pair systems, derived from Sloan Digital Sky Survey (SDSS). In order carry out reliable (AGNs hosts isolation galaxy pairs), galaxies similar...
We study the properties of a sample 3967 low-ionization nuclear emission-line region (LINER) galaxies selected from SDSS-DR7, with respect to their proximity galaxy groups. The host LINERs have been analysed and compared well-defined control 3841 non-LINER matched in redshift, luminosity, colour, morphology, age stellar mass content. find no difference between LINER terms colour population as function virial distance geometric centre group. However, we that are more likely populate...
Context. The Ophiuchus cluster of galaxies, located at low latitudes in the direction Galactic bulge, has been relatively poorly studied comparison with other rich galaxy clusters, such as Coma, Virgo, and Fornax, despite being second brightest X-ray sky. Aims. Our aim is perform a study hidden population massive Zone Avoidance. Methods. Deep near-infrared images photometry from VISTA Variables Vía Láctea eXtended (VVVX) survey were used to detect member candidates up 2 Mpc cD 2MASX...