Start year
1994
End year
2021
Organizational Unit
Organizing institutions
Grants related:
General
Description
The general aim of the project is to research the structure, evolutionary history and formation of galaxies through the study of their resolved stellar populations, both from photometry and spectroscopy. The group research concentrates in the most nearby objects, namely the Local Group galaxies including the Milky Way and M33 under the hypothesis that they are a good representation of the general population of galaxies in the Universe.
The project can be divided in four research lines:
I. Star formation history in the Local Group.
The goal is to characterise the spatial and temporal structure of the galaxies of the Local Group through the observations of individual stars. The fundamental aim is to derive the detailed star formation history (SFH) of a given galaxy in all its evolutionary stages, in order to determine the impact of cosmological (e.g. reionization, self-shielding) and local processes (e.g. gas sweeping by supernovas, tidal forces, stellar migration).
II. Multiple stellar populations in globular clusters.
At odds of what it is classically predicted, there is evidence that globular clusters (GC) host more than one stellar population with different chemical composition. HST photometric observations of GC show strong evidence of multiple main sequences in the CMDs. The aim of this line is to characterise the aforementioned multiple populations in GC.
III. Structure and formation of the Milky Way.
The main purpose of this research line is to study the Milky Way via by using GAIA data (spacebased), and the ESO-VVV survey (Vista Telescope). These data are going to provide a perfect opportunity to study the star formation history of the Galactic disk and bulge. In order to use GAIA and VVV data we need to adapt the tools developed by our group to study stellar populations.
IV. Stellar evolution and synthetic color-magnitude diagram.
We have developed a new stellar evolutionary library. There is the need in the scientific community to increase the reliability and accuracy in the stellar models computation using the most updated results in Physics, such as the equation of state, new opacities, and nuclear sections.
Members
Principal investigator
Martín
López Corredoira
Project staff
Alfredo Rafael
Rosenberg González
Antonio
Aparicio Juan
Collaborators
Matteo
Monelli
Dr.
Elena Valenti
Dr.
J. Alonso
Dr.
D. Minniti
Dr.
M. Zoccali
Dr.
N. Arimoto
Dr.
S. Beaulieu
Dr.
R. Buonanno
Dr.
S. Cassisi
Dr.
A. Pietrinferni
Dr.
C. Jordi
Dr.
F. Figueras
Dr.
E. Kirby
Dr.
J. M. Carrrasco
Dr.
T. Mineikis
Dr.
A. Monachesi
Dr.
A. Piatti
Dr.
V. Nascimbeni
Dr.
G. Piotto
Dr.
E. Skillman
Dr.
A. del Pino
Results
Milestones
- Development of the web site http://basti-iac.oa-teramo.inaf.it for the BaSTI stellar evolution library
- Obtention of near-infrared PSF photometry of the full VVV disk region (220 sq. deg between 294.7° ≤ l ≤ 350.0° and |b| ≤ 2.25°) in J and Ks bands
- Computation of a open access data base of "cromosomic maps" for all the object of the "HST Legacy Project on Globular Clusters".
- Determination of the star formation history of three Ultra-fain Dwarfs (UFD): Bootes I, Canes Venatici II y Leo IV
Scientific activity
Related publications
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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.
Advertised on:
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.
Advertised on:
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.
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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.
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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.
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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.
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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.
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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.
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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.
Advertised on:
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.
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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.
Advertised on:
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.
Advertised on:
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.
Advertised on:
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.
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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.
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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.
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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.
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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.
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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.
Advertised on:
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.
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52012
