Subvenciones relacionadas:
General
El objetivo general del Proyecto es el estudio de la estructura, historia evolutiva y proceso de formación de galaxias a través de sus poblaciones estelares resueltas, tanto a partir de fotometría como espectroscopia. El proyecto puede dividirse en cuatro líneas principales:
I. Historia de formación estelar en el Grupo Local.
El objetivo de esta línea es la caracterización de la estructura espacio-temporal de las galaxias del Grupo Local mediante la observación de sus estrellas individuales. Un objetivo fundamental es la determinación de las historias de la formación estelar (HFE) detalladas y extendidas a toda la historia evolutiva de la galaxia con objeto de determinar el grado de importancia que los procesos cosmológicos (tales como la reionización o self-shielding) o locales (barrido de gas por supernovas, fuerzas de marea, migración estelar) tuvieron en su formación.
II. Multipoblaciones estelares en cúmulos globulares.
De forma contraria al paradigma clásico, hay evidencias de que los cúmulos globulares (CG) albergan más de una población estelar de diferente composición química. Observaciones fotométricas de los CG usando el HST muestran fuertes evidencias de múltiples secuencias principales en el DCM. El objetivo de la línea es caracterizar dichas multipoblaciones en CG.
III. Formación y estructura de la Vía Láctea.
Esta línea tiene como eje principal el estudio de la Vía Láctea a través de los datos que proporcionará GAIA (espacio) y el survey ESO-VVV . Este tipo de datos van a dar una oportunidad única de conocer la historia de formación estelar en el disco y en el bulbo galáctico. En este marco, es necesario adecuar las herramientas desarrolladas por nuestro grupo para el análisis de poblaciones estelares al tipo de datos que está suministrando ambos surveys.
IV. Evolución estelar y diagrama color-magnitud sintético.
Nuestro grupo ha liderado el desarrollo de una nueva librería de evolución estelar. Hay una necesidad en la comunidad científica de mejorar la confianza y exactitud de la computación de modelos estelares mediante la incorporación de las últimas mejoras en el campo de la física tales como la Ecuación de Estado, nuevos cálculos en tablas de opacidades o en secciones nucleares effectivas.
Miembros
Resultados
- Desarrollo de la web http://basti-iac.oa-teramo.inaf.it de la librería BaSTI
- Obtención de fotometría PSF en el IR próximo de la región completa del disco galáctico procedente de VVV (220 grados cuadrados entre 294.7° ≤ l ≤ 350.0° y |b| ≤ 2.25°) en J y K
- Elaboración de una base de datos completa de "mapas cromosómicos", de acceso público, para todos los objetos del "HST Legacy Project on Globular Clusters".
- Determinación de las Historias de Formación Estelar de tres galaxias ultra-débiles (UFD): Bootes I, Canes Venatici II y Leo IV
Actividad científica
Publicaciones relacionadas
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The ACS LCID Project. VI. The Star Formation History of The Tucana dSph and The Relative Ages of the Isolated dSph GalaxiesWe present a detailed study of the star formation history (SFH) of the Tucana dwarf spheroidal galaxy. High-quality, deep HST/ACS data, collected in the framework of the LCID project, allowed us to obtain the deepest color-magnitude diagram to date, reaching the old main-sequence turnoff (F814 ~ 29) with good photometric accuracy. Our analysisMonelli, M. et al.
Fecha de publicación:
102010 -
The ACS LCID Project. V. The Star Formation History of the Dwarf Galaxy LGS-3: Clues to Cosmic Reionization and FeedbackWe present an analysis of the star formation history (SFH) of the transition-type (dIrr/dSph) Local Group galaxy LGS-3 (Pisces) based on deep photometry obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope. Our observations reach the oldest main-sequence turnoffs at high signal to noise, allowing a time resolution at theHidalgo, S. L. et al.
Fecha de publicación:
32011 -
The ACS LCID Project. IV. Detection of the Red Giant Branch Bump in Isolated Galaxies of the Local GroupWe report the detection and analysis of the red giant branch (RGB) luminosity function bump in a sample of isolated dwarf galaxies in the Local Group. We have designed a new analysis approach comparing the observed color-magnitude diagrams (CMDs) with theoretical best-fit CMDs derived from precise estimates of the star formation histories of eachMonelli, M. et al.
Fecha de publicación:
82010 -
The ACS LCID Project. III. The Star Formation History of the Cetus dSph Galaxy: A Post-reionization FossilWe use deep HST/ACS observations to calculate the star formation history (SFH) of the Cetus dwarf spheroidal (dSph) galaxy. Our photometry reaches below the oldest main-sequence turnoffs, which allows us to estimate the age and duration of the main episode of star formation in Cetus. This is well approximated by a single episode that peaked roughlyMonelli, M. et al.
Fecha de publicación:
92010 -
The ACS LCID Project. II. Faint Variable Stars in the Isolated Dwarf Irregular Galaxy IC 1613We present the results of a new search for variable stars in the Local Group (LG) isolated dwarf galaxy IC 1613, based on 24 orbits of F475W and F814W photometry from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope. We detected 259 candidate variables in this field, of which only 13 (all of them bright Cepheids) wereBernard, E. J. et al.
Fecha de publicación:
42010 -
The ACS LCID Project. I. Short-Period Variables in the Isolated Dwarf Spheroidal Galaxies Cetus and TucanaWe present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSphs) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the Advanced Camera for Surveys in the F475W and F814W bands, we identified 180 and 371 variables in Cetus and Tucana, respectively. The vast majority are RR Lyrae starsBernard, Edouard J. et al.
Fecha de publicación:
72009 -
Seven young star clusters in the inner region of the Small Magellanic CloudWe present CCD photometry in the Washington system C and T1 passbands down to T1 ~ 22 in the fields of L35, L45, L49, L50, L62, L63 and L85, seven poorly studied star clusters in the inner region of the Small Magellanic Cloud (SMC). We measured T1 magnitudes and C - T1 colours for a total of 114826 stars distributed throughout cluster areas of 13.7Piatti, Andrés E. et al.
Fecha de publicación:
92008 -
Revised Bolometric Corrections and Interstellar Extinction Coefficients for the ACS and WFPC2 Photometric SystemsWe present extensive tables of bolometric corrections and interstellar extinction coefficients for the WFPC2 and ACS (both WFC and HRC) photometric systems. They are derived from synthetic photometry applied to a database of spectral energy distributions covering a large range of effective temperatures, surface gravity, and metal content. CarbonGirardi, Léo et al.
Fecha de publicación:
52008 -
Proper Motions of Local Group Dwarf Spheroidal Galaxies I: First Ground-Based Results for FornaxIn this article we present in detail the methodology and the first results of a ground-based program to determine the absolute proper motion of the Fornax dwarf spheroidal galaxy. The proper motion was determined using bona fide Fornax star members measured with respect to a fiducial at-rest background spectroscopically confirmed quasar, QSO J0240Méndez, René. A. et al.
Fecha de publicación:
72010 -
Outside-In Disk Evolution in the Large Magellanic CloudFrom the analysis of the color-magnitude diagrams and color functions of four wide LMC fields located from ~=2 to 6 kpc from the kinematic center of the LMC we present evidence that, while the oldest population is coeval in all fields, the age of the youngest component of the dominant stellar population gradually increases with galactocentricGallart, Carme et al.
Fecha de publicación:
82008 -
On the Extended Structure of the Phoenix Dwarf GalaxyWe present the star formation history (SFH) and its variations with galactocentric distance for the Local Group dwarf galaxy of Phoenix. They have been derived from a (F555W, F814W) color-magnitude diagram obtained from WFPC2@HST data, which reaches the oldest main-sequence turnoffs. The IAC-star and IAC-pop codes and the MinnIAC suite have beenHidalgo, Sebastian L. et al.
Fecha de publicación:
112009 -
Old Main-Sequence Turnoff Photometry in the Small Magellanic Cloud. II. Star Formation History and its Spatial GradientsWe present a quantitative analysis of the star formation history (SFH) of 12 fields in the Small Magellanic Cloud (SMC) based on unprecedented deep [(B - R), R] color-magnitude diagrams (CMDs). Our fields reach down to the oldest main-sequence turnoff with a high photometric accuracy, which is vital for obtaining accurate SFHs, particularly atNoël, Noelia E. D. et al.
Fecha de publicación:
112009 -
Cepheid Variable Stars in the Pegasus Dwarf Irregular Galaxy: Constraints on the Star Formation HistoryObservations of the resolved stars obtained over a period of 11 years in the Local Group dwarf irregular galaxy Pegasus have been used to search for Cepheid variable stars. Images were obtained in 55 epochs in the V band and in 24 epochs in the I band. We have identified 26 Cepheids and have obtained their light curves and periods. On the basis ofMeschin, I. et al.
Fecha de publicación:
32009 -
The Chemical Enrichment History of the Small Magellanic Cloud and its GradientsWe present stellar metallicities derived from Ca II triplet spectroscopy in over 350 red giant branch stars in 13 fields distributed in different positions in the Small Magellanic Cloud, ranging from ~1° to ~4° from its center. In the innermost fields, the average metallicity is [Fe/H] ~-1. This value decreases when we move away toward outermostCarrera, Ricardo et al.
Fecha de publicación:
92008 -
The Chemical Enrichment History of the Large Magellanic CloudCa II triplet spectroscopy has been used to derive stellar metallicities for individual stars in four Large Magellanic Cloud fields situated at galactocentric distances of 3°, 5°, 6°, and 8° to the north of the bar. Observed metallicity distributions show a well-defined peak, with a tail toward low metallicities. The mean metallicity remainsCarrera, R. et al.
Fecha de publicación:
32008 -
Metallicities, Age-Metallicity Relationships, and Kinematics of Red Giant Branch Stars in the Outer Disk of the Large Magellanic CloudThe outer disk of the Large Magellanic Cloud (LMC) is studied in order to unveil clues about its formation and evolution. Complementing our previous studies in innermost fields (3 kpc lsim RCarrera, R. et al.
Fecha de publicación:
82011 -
Low-resolution spectroscopy of main sequence stars belonging to 12 Galactic globular clusters. I. CH and CN band strength variationsContext. Globular clusters show star-to-star abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, within which two subsequent generations of stars co-exist in globular clusters. Observations of chemical abundances in the main sequence and sub-giant branch starsPancino, E. et al.
Fecha de publicación:
122010 -
Chemical abundance analysis of the open clusters Cr 110, NGC 2099 (M 37), NGC 2420, NGC 7789, and M 67 (NGC 2682)Context. The present number of Galactic open clusters that have high resolution abundance determinations, not only of [Fe/H], but also of other key elements, is largely insufficient to enable a clear modeling of the Galactic disk chemical evolution. Aims: To increase the number of Galactic open clusters with high quality measurements. Methods: WePancino, E. et al.
Fecha de publicación:
22010 -
Chemical abundance analysis of the open clusters Berkeley 32, NGC 752, Hyades, and PraesepeContext. Open clusters are ideal test particles for studying the chemical evolution of the Galactic disc. However, the number and accuracy of existing high-resolution abundance determinations, not only of [Fe/H], but also of other key elements, remains largely insufficient. Aims: We attempt to increase the number of Galactic open clusters that haveCarrera, R. et al.
Fecha de publicación:
112011 -
C and N abundances of main sequence and subgiant branch stars in NGC 1851We present the first chemical analysis of stars on the double subgiant branch (SGB) of the globular cluster NGC 1851. We obtained 48 Magellan IMACS spectra of subgiants and fainter stars covering the spectral region between 3650-6750 Å to derive C and N abundances from the spectral features at 4300 Å (G-band) and at ~3883 Å (CN). We added to ourLardo, C. et al.
Fecha de publicación:
52012