A5020051803- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Statistical and numerical algorithms
- Solar and Space Plasma Dynamics
- Impact of Light on Environment and Health
- Remote Sensing in Agriculture
- Advanced Optical Sensing Technologies
- Space Science and Extraterrestrial Life
- Toxoplasma gondii Research Studies
- Color perception and design
- Computer Graphics and Visualization Techniques
- Inorganic and Organometallic Chemistry
- Astrophysics and Cosmic Phenomena
- Crystal Structures and Properties
- Planetary Science and Exploration
- Pulsars and Gravitational Waves Research
Universidad Andrés Bello
2015-2024
Max Planck Institute for Astronomy
2021-2024
Pontificia Universidad Católica de Chile
2010-2019
Millennium Institute of Astrophysics
2011-2018
University of Florida
2006-2014
Millennium Institute
2014
University of Washington
2009
University of Virginia
2009
Instituto de Astrofísica de Canarias
2009
Universidad de La Laguna
2009
Context. The fraction of binary stars is an important ingredient to interpret globular cluster dynamical evolution and their stellar population.
The ACS Survey of Galactic Globular Clusters is a Hubble Space Telescope (HST) Treasury program designed to provide new large, deep and homogeneous photometric database. Based on observations from this program, we have measured precise relative ages for sample 64 globular clusters by comparing the position clusters' main sequence turn offs, using main-sequence fitting cross-compare within sample. This method provides formal precision 2-7%. We demonstrate that calculated are independent...
Context. The ESO public survey VISTA variables in the Vía Láctea (VVV) started 2010. VVV targets 562 sq. deg Galactic bulge and an adjacent plane region is expected to run for about five years.
We report the discovery of 158 previously undetected dwarf galaxies in Fornax cluster central regions using a deep coadded $u, g$ and $i$-band image obtained with DECam wide-field camera mounted on 4-meter Blanco telescope at Cerro Tololo Interamerican Observatory as part {\it Next Generation Survey} (NGFS). The new have quasi-exponential light profiles, effective radii $0.1\!<\!r_e\!<\!2.8$ kpc average surface brightness values $22.0\!<\!\mu_i\!<\!28.0$ mag arcsec$^{-2}$. confirm existence...
Photometry with the Hubble Space Telescope Advanced Camera for Surveys (HST ACS) reveals that subgiant branch (SGB) of globular cluster NGC 1851 splits into two well-defined branches. If split is due only to an age effect, SGBs would imply star formation episodes separated by ~1 Gyr. We discuss other anomalies in could be interpreted terms a double stellar population. Finally, we compare case globulars known host multiple populations, and show all three clusters differ several important respects.
We have combined optical and near-infrared data of known RR Lyrae (RRL) stars in the bulge order to study spatial distribution its metal-poor component by measuring precise reddening values distances 7663 fundamental-mode RRL with high-quality photometry. obtain a distance Galactic center R0 = 8.33 ± 0.05 0.14 kpc. find that differs from structures traced predominantly metal-rich red clump (RC) stars. Unlike RC stars, do not trace strong bar, but more spheroidal, centrally concentrated...
We present the first stellar density profile of Milky Way bulge reaching latitude $b=0^\circ$. It is derived by counting red clump stars within colour\--magnitude diagram constructed with new PSF-fitting photometry from VISTA Variables in V\'\i a L\'actea (VVV) survey data. The map covers area between $|l|\leq 10^\circ$ and $|b|\leq 4.5^\circ$ unprecedented accuracy, allowing to establish direct link kinematics Giraffe Inner Bulge Spectroscopic Survey (GIBS) mass distribution. In particular,...
An analysis of ages, metallicities, and [ α/Fe] ratios globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized Puzia et al. (2004, A&A, 415, 123, Paper I this series). In the light calibration measurement uncertainties, age-metallicity degeneracy, relative dynamic range indices, as well systematics introduced by abundance ratio variations (in particular ratios), we find that most reliable age indicator for our dataset a combination...
VISTA Variables in the V\'{\i}a L\'actea (VVV) is one of six ESO Public Surveys operating on new 4-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV scanning Milky Way bulge an adjacent section disk, where star formation activity high. One principal goals to find clusters different ages. In order trace early epochs cluster we concentrated our search directions those known regions, masers, radio, infrared sources. The disk area covered by was visually inspected using...
We have used observations obtained as part of the Hubble Space Telescope/ACS Survey Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models extrapolate from our cluster behavior. The these are well matched by power laws turnoff, ≈0.8 M☉, 0.2–0.3 M☉ on lower main sequence. slopes those power-law fits, α, been correlated with an extensive set intrinsic and extrinsic properties investigate which parameters may influence...
Abstract It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the bulge. High stellar density combined with high and differential interstellar reddening are two major problems for finding located We use deep near-IR photometry VISTA Variables in Vía Láctea (VVV) Survey search projected bulge, hereby report discovery 22 new candidate clusters. These objects, detected as regions our maps bulge red giants, confirmed cluster candidates by their...
Abstract We present the physical characterization of FSR 1758, a new large, massive object very recently discovered in Galactic Bulge. The combination optical data from 2nd Gaia Data Release and DECam Plane Survey near-IR VISTA Variables Vía Láctea Extended led to clean sample likely members. Based on this integrated set, position, distance, reddening, size, metallicity, absolute magnitude, proper motion (PM) are measured. estimate following parameters: α = 17:31:12, δ −39:48:30 (J2000), D...
The inner regions of the Galaxy are severely affected by extinction, which limits our capability to study stellar populations present there. Vista Variables in Via Lactea (VVV) ESO Public Survey has observed this zone at near-infrared wavelengths where reddening is highly diminished. By exploiting high resolution and wide field-of-view VVV images we aim produce a deep, homogeneous, complete database sources that cover innermost Galaxy. To better deal with crowding surveyed areas, have used...
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,...
Context. The Milky Way (MW) bulge is a fundamental Galactic component for understanding the formation and evolution of galaxies, in particular our own. ESO Public Survey VISTA Variables Vía Láctea deep near-IR survey mapping southern plane. Particularly area, VVV covering ~315 deg2. Data taken during 2010 2011 covered entire area JHKs bands.
Context: It is not known how many globular clusters may have been left undetected towards the Galactic bulge. Aims: One of aims VISTA Variables in Via Lactea (VVV) Survey to accurately measure physical parameters inner regions Milky Way and search for new ones, hidden large extinction. Methods: Deep near infrared images give deep JHKs-band photometry a region surrounding cluster UKS 1 reveal low-mass candidate that we name VVV CL001. Results: We use horizontal branch red clump order...
VISTA Variables in the V\'ia L\'actea (VVV) is one of six ESO Public Surveys using 4 meter Visible and Infrared Survey Telescope for Astronomy (VISTA). The VVV survey covers Milky Way bulge an adjacent section disk, principal objectives to search new star clusters within previously unreachable obscured parts Galaxy. primary motivation behind this work discover analyze direction inner Galactic disk bulge. Regions covered by were visually inspected composite JHKs color images select cluster...
Interstellar extinction towards the Galactic Center is large and significantly differential. Its reddening dimming effects in red clump stars Bulge can be exploited to better constrain law innermost Galaxy. By virtue of a deep complete catalog more than 30 million objets at $|l|\le2.7\deg$ $|b|\le1.55\deg$ obtained from VVV survey observations, we apply method infer selective-to-total ratios $Z$, $Y$, $J$, $H$ $K_s$ broadband near-infrared filters. The measured values are smaller previously...
We use deep multi-epoch near-IR images of the VISTA Variables in V\'ia L\'actea (VVV) Survey to search for RR Lyrae stars towards Southern Galactic plane. Here we report discovery a group close together VVV tile d025. Inspection and PSF photometry reveals that most these are likely belong globular cluster, matches position previously known star cluster FSR\,1716. The stellar density map field yields $>100$ sigma detection this candidate is centered at equatorial coordinates...
Abstract We present a photometric study of the dwarf galaxy population in core region (≲ r vir /4) Fornax cluster based on deep u ′ g i photometry from Next Generation Cluster Survey . All imaging data were obtained with Dark Energy Camera mounted 4 m Blanco telescope at Cerro Tololo Interamerican Observatory. identify 258 candidates luminosities −17 ≲ M −8 mag, corresponding to typical stellar masses <?CDATA $9.5\gtrsim \mathrm{log}{{ \mathcal }}_{\star }/{M}_{\odot }\gtrsim 5.5$?> ,...
Context . High reddening near the Galactic plane hampers observations and proper characterization of globular clusters (GCs) located toward inner regions Milky Way. Aims The VISTA Variables in Vía Láctea (VVV) survey observed bulge adjacent disk for several years, providing multi-epoch, near-infrared images 41 GCs. Detecting RR Lyrae variable stars belonging to these GCs will aid their accurate parameterization. Methods By fully leveraging astrometric, photometric, variability VVV catalogs,...