Grants related:
General
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
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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Basic parameters of three star clusters in the Small Magellanic Cloud: Kron 11, Kron 63 and NGC 121We present observations for three star clusters, Kron 11, Kron 63 and NGC 121, in the Small Magellanic Cloud. We have studied their structure and derived their fundamental parameters by means of their luminosity functions, their colour magnitude diagrams and the Padova suite of isochrones. NGC 121 is a well-studied object, for which we confirmBaume, G. et al.
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112008 -
The stellar population of the star-forming region G61.48+0.09Context: We present the results of a near-infrared photometric and spectroscopic study of the star-forming region G61.48+0.09. Aims: The purpose of this study is to characterize the stellar content of the cluster and to determine its distance, extinction, age, and mass. Methods: The stellar population was studied by using color-magnitude diagramsMarín-Franch, A. et al.
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82009 -
The Star Formation History of M32We use deep Hubble Space Telescope Advanced Camera for Surveys/High Resolution Channel observations of a field within M32 (F1) and an M31 background field (F2) to determine the star formation history (SFH) of M32 from its resolved stellar population. We find that 2-5 Gyr old stars contribute ~40% ± 17% of M32's mass, while ~55% ± 21% of M32's massMonachesi, Antonela et al.
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12012 -
The Recent Star Formation History of NGC 5102We present Hubble Space Telescope photometry of young stars in NGC 5102, a nearby gas-rich post-starburst S0 galaxy with a bright young stellar nucleus. We use the IAC-pop/MinnIAC algorithm to derive the recent star formation history in three fields in the bulge and disk of NGC 5102. In the disk fields, the recent star formation rate has declinedBeaulieu, Sylvie F. et al.
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32010 -
The Nature of Starbursts. II. The Duration of Starbursts in Dwarf GalaxiesThe starburst phenomenon can shape the evolution of the host galaxy and the surrounding intergalactic medium. The extent of the evolutionary impact is partly determined by the duration of the starburst, which has a direct correlation with both the amount of stellar feedback and the development of galactic winds, particularly for smaller mass dwarfMcQuinn, Kristen B. W. et al.
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112010 -
The Nature of Starbursts. I. The Star Formation Histories of Eighteen Nearby Starburst Dwarf GalaxiesWe use archival Hubble Space Telescope observations of resolved stellar populations to derive the star formation histories (SFHs) of 18 nearby starburst dwarf galaxies. In this first paper, we present the observations, color-magnitude diagrams (CMDs), and the SFHs of the 18 starburst galaxies, based on a homogeneous approach to the data reductionMcQuinn, Kristen B. W. et al.
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92010 -
NEOWISE Observations of Near-Earth Objects: Preliminary ResultsWith the NEOWISE portion of the Wide-field Infrared Survey Explorer (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 μm, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whetherMainzer, A. et al.
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122011 -
The Impact of Enhanced He and CNONa Abundances on Globular Cluster Relative Age-Dating MethodsThe impact that unrecognized differences in the chemical patterns of Galactic globular clusters (GGCs) have on their relative age determinations is studied. The two most widely used relative age-dating methods, horizontal and vertical, together with the more recent relative MS-fitting method, were carefully analyzed on a purely theoretical basisMarín-Franch, A. et al.
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52010 -
Photometric Properties of the M33 Star Cluster SystemWe present a catalog of 2990 extended sources in a 1° × 1° area centered on M33 using the MegaCam camera on the 3.6 m Canada-France-Hawaii Telescope. The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1969 likely background galaxies, and 218 unknown extended objects. We present ugriz integrated magnitudes ofSan Roman, Izaskun et al.
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92010 -
IAC-pop: Finding the Star Formation History of Resolved GalaxiesIAC-pop is a code designed to solve the star formation history (SFH) of a complex stellar population system, like a galaxy, from the analysis of the color-magnitude diagram (CMD). It uses a genetic algorithm to minimize a χ2 merit function comparing the star distributions in the observed CMD and the CMD of a synthetic stellar population. AAparicio, Antonio et al.
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82009 -
Evidence for Blue Straggler Stars Rejuvenating the Integrated Spectra of Globular ClustersIntegrated spectroscopy is the method of choice for deriving the ages of unresolved stellar systems. However, hot stellar evolutionary stages, such as hot horizontal branch stars and blue straggler stars (BSSs), can affect the integrated ages measured using Balmer lines. Such hot, ``noncanonical'' stars may lead to overestimation of the temperatureCenarro, A. Javier et al.
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122008 -
Young Stellar Populations and Star Clusters in NGC 1705We present Hubble Space Telescope (HST) photometry of the late-type dwarf galaxy NGC 1705 observed with the Wide-Field Planetary Camera 2 (WFPC2) in the F380W and F439W bands and with the Advanced Camera for Surveys/High-Resolution Channel (HRC) in the F330W, F555W, and F814W broad-band filters. We cross-correlate these data with previous onesAnnibali, F. et al.
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72009 -
The star formation history and dust content in the far outer disc of M31We present a detailed analysis of two fields located 26 kpc (˜5 radial scalelengths) from the centre of M31 along the south-west semimajor axis of the disc. One field samples the major axis populations - the Outer Disc field - while the other is offset by ˜18 arcmin and samples the warp in the stellar disc - the warp field. The colour-magnitudeBernard, Edouard J. et al.
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32012 -
The magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clustersWe present new measurements of the magnitude of the main sequence turn off and the red giant branch bump in the luminosity function of a sample of Galactic globular clusters with updated estimates of [Fe/H] and [α/Fe], employing photometric data collected with the Advanced Camera for Survey onboard the HST. We compare measured and predicted valuesCassisi, S. et al.
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32011 -
The Carina Project. V. The Impact of NLTE Effects on the Iron ContentWe have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R˜38,000) collected with UVES at ESO/VLT either in slit mode (five RGs) or in fiber mode (39 RGs, FLAMES/GIRAFFE-UVES). The sample is more than a factor of 4 larger than any previousFabrizio, M. et al.
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62012 -
The Carina Project. IV. Radial Velocity DistributionWe present new and accurate radial velocity (RV) measurements of luminous stars of all ages (old horizontal branch, intermediate-age red clump, and young blue plume, as well as red giants of a range of ages: 20.6 ≤ V ≤ 22 ) in the Carina dwarf spheroidal galaxy, based on low-resolution spectra collected with the FORS2 multiobject slit spectrographFabrizio, M. et al.
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42011 -
Strömgren Photometry of Galactic Globular Clusters. II. Metallicity Distribution of Red Giants in ω CentauriWe present new intermediate-band Strömgren photometry based on more than 300 u, v, b, y images of the Galactic globular cluster ω Cen. Optical data were supplemented with new multiband near-infrared (NIR) photometry (350 J, H, Ks images). The final optical-NIR catalog covers a region of more than 20 × 20 arcmin squared across the cluster center. WeCalamida, A. et al.
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122009 -
On the ΔV bump HB Parameter in Globular ClustersWe present new empirical estimates of the ΔV bump HB parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data. Together with similar evaluations available in the literature, we ended up with a sample of 62 GGCs covering a very broad range in metal content (-2.16 dexDi Cecco, A. et al.
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32010 -
On the White Dwarf Cooling Sequence of the Globular Cluster ω CentauriWe present deep and precise photometry (F435W, F625W, F658N) of ω Cen collected with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). We have identified ~6500 white dwarf (WD) candidates, and the ratio of WD to main-sequence (MS) star counts is found to be at least a factor of 2 larger than the ratio of CO-core WDCalamida, A. et al.
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12008 -
On the Stellar Content of the Starburst Galaxy IC10We investigate the stellar content of the starburst dwarf galaxy IC10 using accurate and deep optical data collected with the Advanced Camera for Surveys and with the Wide Field Planetary Camera 2 onboard the Hubble Space Telescope. The comparison between theory and observations indicates a clear change in age distribution when moving from theSanna, N. et al.
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72009