# Milky Way and Nearby Galaxies

Start year
1994
End year
2021
Organizational Unit
Organizing institutions
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.

Principal investigator
Project staff
Collaborators
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.
K. Freeman
Dr.
E. Kirby
Dr.
J. M. Carrrasco
Dr.
T. Mineikis
Dr.
A. Monachesi
Dr.
S. Okamoto
Dr.
A. Piatti
Dr.
V. Nascimbeni
Dr.
G. Piotto
Dr.
E. Skillman
Dr.
A. del Pino

### Milestones

1. Development of the web site http://basti-iac.oa-teramo.inaf.it for the BaSTI stellar evolution library
2. 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
3. Computation of a open access data base of "cromosomic maps" for all the object of the "HST Legacy Project on Globular Clusters".
4. Determination of the star formation history of three Ultra-fain Dwarfs (UFD): Bootes I, Canes Venatici II y Leo IV

### Related publications

• Internal rotation of Milky Way dwarf spheroidal satellites with Gaia Early Data Release 3

We present an analysis of the kinematics of 14 satellites of the Milky Way (MW). We use proper motions (PMs) from the Gaia Early Data Release 3 (EDR3) and line-of-sight velocities (vlos) available in the literature to derive the systemic 3D motion of these systems. For six of them, namely the Carina, Draco, Fornax, Sculptor, Sextans, and Ursa Minor

Martínez-García, Alberto Manuel et al.

8
2021
• Constraining the solar neighbourhood age-metallicity relation from white dwarf-main sequence binaries

The age-metallicity relation (AMR) is a fundamental tool for constraining the chemical evolution of the Galactic disc. In this work, we analyse the observational properties of this relation using binary stars that have not interacted consisting of a white dwarf (WD) - from which we can derive the total age of the system - and a main sequence (MS)

Rebassa-Mansergas, A. et al.

8
2021
• Exploring nine simultaneously occurring transients on April 12th 1950

Nine point sources appeared within half an hour on a region within ∼? 10 arcmin of a red-sensitive photographic plate taken in April 1950 as part of the historic Palomar Sky Survey. All nine sources are absent on both previous and later photographic images, and absent in modern surveys with CCD detectors which go several magnitudes deeper. We

Villarroel, Beatriz et al.

0
2021
• The Cluster HEritage project with XMM-Newton: Mass Assembly and Thermodynamics at the Endpoint of structure formation. I. Programme overview

The Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE) is a three-mega-second Multi-Year Heritage Programme to obtain X-ray observations of a minimally-biased, signal-to-noise-limited sample of 118 galaxy clusters detected by Planck through the Sunyaev-Zeldovich effect. The

CHEX-MATE Collaboration et al.

6
2021
• Interactions between large-scale radio structures and gas in a sample of optically selected type 2 quasars

Context. The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient ionised gas. Aims: We investigate this interaction in a sample of 13 optically selected type 2 quasars

Villar Martín, M. et al.

6
2021
• A Case against a Significant Detection of Precession in the Galactic Warp

Recent studies of warp kinematics using Gaia DR2 data have produced detections of warp precession for the first time, which greatly exceeds theoretical predictions of models. However, this detection assumes a warp model derived for a young population (few tens of megayears) to fit velocities of an average older stellar population of the thin disk

Chrobáková, Ž. et al.

5
2021
• Exact Semianalytical Calculation of Rotation Curves with Bekenstein-Milgrom Nonrelativistic MOND

Astronomers derive MOdified Newtonian Dynamics (MOND) rotation curves using the simple algebraic rule of calculating the acceleration as equal to the Newtonian acceleration (a) divided by some factor μ(a). However, there are velocity differences between this simple rule and the calculation derived from more sophisticated MOND versions such as AQUAL

López-Corredoira, M. et al.

3
2021
• Multiple Populations in Low-mass Globular Clusters: Palomar 13

Since the discovery of chemically peculiar stars in globular clusters in the last century, the study of multiple populations has become increasingly important, given that chemical inhomogeneity is found in almost all globular clusters. Despite various proposed theories attempting to explain this phenomenon, fitting all the observational evidence in

Tang, Baitian et al.

2
2021
• Updated BaSTI Stellar Evolution Models and Isochrones. II. α-enhanced Calculations

This is the second paper of a series devoted to presenting an updated release of the BaSTI (a Bag of Stellar Tracks and Isochrones) stellar model and isochrone library. Following the publication of the updated solar-scaled library, here we present the library for an α-enhanced heavy element distribution. These new α-enhanced models account for all

2
2021
• PSR B0656+14: the unified outlook from the infrared to X-rays

We report detection of PSR B0656+14 with the Gran Telescopio Canarias in narrow optical F657, F754, F802, and F902 and near-infrared JHKs bands. The pulsar detection in the Ks band extends its spectrum to 2.2 $\mu$ m and confirms its flux increase towards the infrared. We also present a thorough analysis of the optical spectrum obtained by us with

Zharikov, S. et al.

4
2021
• HST Survey of the Orion Nebula Cluster in the H<SUB>2</SUB>O 1.4 μm Absorption Band. III. The Population of Substellar Binary Companions

We present new results concerning the substellar binary population in the Orion Nebula Cluster (ONC). Using the Karhunen-Loève Image Projection algorithm, we have reprocessed images taken with the IR channel of the Wide Field Camera 3 mounted on the Hubble Space Telescope to unveil faint, close companions in the wings of the stellar point-spread

Strampelli, Giovanni M. et al.

6
2020
• Statistical analysis of Galactic globular cluster type properties

The analysis of pseudo-colour diagrams, the so-called chromosome maps, of Galactic globular clusters (GCs) permits to classify them into type I and type II clusters. Type II GCs are characterized by an above-the-average complexity of their chromosome maps and some of them are known to display star-to-star variations of slow neutron-capture reaction

Simioni, M. et al.

4
2020
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XX. Ages of Single and Multiple Stellar Populations in Seven Bulge Globular Clusters

In the present work we analyzed seven globular clusters (GCs) selected from their location in the Galactic bulge and with metallicity values in the range -1.30 ≲ [Fe/H] ≲ -0.50. The aim of this work is first to derive cluster ages assuming single stellar populations and second to identify the stars from first (1G) and second generations (2G) from

Oliveira, R. A. P. et al.

3
2020
• The star formation history of the Sculptor dwarf spheroidal galaxy

We present the star formation history (SFH) of the Sculptor dwarf spheroidal galaxy based on deep g, r photometry taken with Dark Energy Camera at the Blanco telescope, focusing our analysis on the central region of the galaxy extended up to ˜3 core radii. We have investigated how the SFH changes radially, subdividing the sampled area into four

Bettinelli, M. et al.

8
2019
• Mapping the stellar age of the Milky Way bulge with the VVV. II. Deep JKs catalog release based on PSF photometry

Context. The bulge represents the best compromise between old and massive Galactic components, and as such its study is a valuable opportunity to understand how the bulk of the Milky Way formed and evolved. In addition, being the only bulge in which we can individually resolve stars in all evolutionary sequences, the properties of its stellar

Surot, F. et al.

9
2019
• Mapping the stellar age of the Milky Way bulge with the VVV. I. The method

Context. Recent observational programs are providing a global view of the Milky Way bulge that serves as a template for detailed comparison with models and extragalactic bulges. A number of surveys (VVV, GIBS, GES, ARGOS, BRAVA, APOGEE) are producing comprehensive and detailed extinction, metallicity, kinematics, and stellar density maps of the

Surot, F. et al.

3
2019
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters - XVII. Public Catalogue Release

In this paper, we present the astrophotometric catalogues of 56 globular clusters and one open cluster. Astrometry and photometry are mainly based on images collected within the HST Legacy Survey of Galactic Globular Clusters: Shedding UV Light on Their Populations and Formation' (GO-13297, PI: Piotto), and the ACS Survey of Galactic Globular

Nardiello, D. et al.

12
2018
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XV. The Dynamical Clock: Reading Cluster Dynamical Evolution from the Segregation Level of Blue Straggler Stars

The parameter A +, defined as the area enclosed between the cumulative radial distribution of blue straggler stars (BSSs) and that of a reference population, is a powerful indicator of the level of BSS central segregation. As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters (GCs), here we present the BSS population

Ferraro, F. R. et al.

6
2018
• The Updated BaSTI Stellar Evolution Models and Isochrones. I. Solar-scaled Calculations

We present an updated release of the BaSTI (a Bag of Stellar Tracks and Isochrones) stellar model and isochrone library for a solar-scaled heavy element distribution. The main input physics that have been changed from the previous BaSTI release include the solar metal mixture, electron conduction opacities, a few nuclear reaction rates, bolometric

Hidalgo, S. L. et al.

4
2018
• The Hubble Space Telescope UV Legacy Survey of Galactic globular clusters - XIII. ACS/WFC parallel-field catalogues

As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters, 110 parallel fields were observed with the Wide Field Channel of the Advanced Camera for Surveys, in the outskirts of 48 globular clusters, plus the open cluster NGC 6791. Totalling about 0.3 deg2 of observed sky, this is the largest homogeneous Hubble Space

Simioni, M. et al.