A5031216717- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Enzyme Structure and Function
- Astrophysics and Cosmic Phenomena
- Phase Equilibria and Thermodynamics
- Geophysics and Sensor Technology
- Methane Hydrates and Related Phenomena
- Radio Astronomy Observations and Technology
- SAS software applications and methods
- Mass Spectrometry Techniques and Applications
- Scientific Research and Discoveries
- Molecular Spectroscopy and Structure
- Superconducting and THz Device Technology
- Geomagnetism and Paleomagnetism Studies
- Image Processing and 3D Reconstruction
- Nuclear physics research studies
Osservatorio di Astrofisica e Scienza dello Spazio
2023-2025
Osservatorio astronomico di Bologna
2025
Stockholm University
2015-2024
AlbaNova
2016-2024
University of Geneva
2021-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2024
Global Social Observatory
2023
University of Massachusetts Amherst
2020-2021
We present the clump populations detected in 18 lensed galaxies at redshifts 1 to 8.5 within lensing cluster field SMACS0723. The recent JWST Early Release Observations of this poorly known region sky have revealed numerous point-like sources and surrounding their host galaxies, undetected shallower HST images. use multiband photometry model galaxy estimate intrinsic sizes magnitudes stellar clumps. derive optical restframe effective radii from $<$10 100s pc masses ranging $\sim10^5$ $10^9$...
Abstract The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z ≈ 10.2 (ref. 1 ). However, it an intrinsically ultraviolet faint galaxy, in range of those now thought to drive reionization Universe 2–4 . Hitherto smallest features resolved a galaxy comparable are between few hundreds tens parsecs (pc) 5,6 Here we report JWST observations Gems. light into five star clusters located region smaller than 70 pc. They exhibit minimal dust attenuation low...
We report the large effort which is producing comprehensive high-level young star cluster (YSC) catalogues for a significant fraction of galaxies observed with Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. present methodology developed to extract positions, verify their genuine nature, produce multiband photometry (from NUV NIR), and derive physical properties via spectral energy distribution fitting analyses. use nearby spiral galaxy NGC628 as test case demonstrating...
Context. Recent James Webb Space Telescope (JWST) spectroscopic observations of the z = 10.6 galaxy GN-z11 have revealed a very peculiar UV spectrum exhibiting intense emission lines nitrogen, which are not typically detected in spectra. This observation indicates super-solar N/O abundance ratio at low metallicity, only resembles abundances seen globular cluster (GC) stars. discovery suggests that we might be seeing proto-GCs formation or possibly even signatures supermassive Aims. To...
ABSTRACT We study the populations of stellar clumps in three high-redshift galaxies, at z = 4.92, 4.88, and 4.03, gravitationally lensed by foreground galaxy clusters MS1358, RCS0224, MACS0940, respectively. The galaxies consist multiple counter-images with large magnifications, mostly above $\mu &gt; 5$ some cases reaching 20$. use rest-frame UV observations from HST to extract analyse their clump populations, counting 10, 3, 11 unique sources, Most have derived effective radii range...
ABSTRACT We present a sample of 1956 individual stellar clumps at redshift $0.7\lt z\lt 10$, detected with JWST/NIRCam in 476 galaxies lensed by the galaxy cluster Abell2744. The magnifications ranging between $\mu$ = 1.8 and 300. perform simultaneous size-photometry estimates 20 median broad-band filters from 0.7 to 5 $\mu$m. Spectral energy distribution (SED) fitting analyses enable us recover physical properties clumps. majority are spatially resolved have effective radii range $\rm {\it...
We present a detailed JWST/NIRSpec and NIRCam analysis of gravitationally lensed galaxy ( μ = 17 − 21) at redshift 6.14 magnified by the Hubble Frontier Field cluster MACS J0416. The target is typical compact UV-faint M UV −17.8) Lyman- α emitter, yet large magnification allows characterization structures on sub-galactic scales (down to few parsecs). Prominent optical H , β [O III ] λλ 4959, 5007 lines are spatially resolved with high-spectral-resolution grating (G395H, R 2700), equivalent...
We present a comprehensive study of the flaring mode transitional millisecond pulsar (tMSP) PSR J1023+0038 during its X-ray sub-luminous state, using strictly simultaneous X-ray, UV, optical, and radio observations. The flares exhibit UV optical counterparts coincide with brightest flare observed in past decade, reaching 1.2,mJy at 6,GHz lasting ∼1,hour. During flare, polarisation drops from ≃1.4% to ≃0.5%, indicating emergence an unpolarised component. propose that thickening disc, which...
We present a study correlating the spatial locations of young star clusters with those molecular clouds in NGC~5194, order to investigate timescale over which separate from their birth clouds. The cluster catalogues are Legacy ExtraGalactic UV Survey (LEGUS) and Plateau de Bure Interefrometer Arcsecond Whirpool (PAWS). find that younger spatially closer than older clusters. median ages for associated is 4~Myr whereas it 50~Myr sufficiently separated cloud be considered unassociated. After...
We present an investigation of the relationship between giant molecular cloud (GMC) properties and associated stellar clusters in nearby flocculent galaxy NGC 7793. combine star cluster catalogue from HST LEGUS (Legacy ExtraGalactic UV Survey) programme with 15 pc resolution ALMA CO(2–1) observations. find a strong spatial correlation young GMCs such that all still GMC are younger than 11 Myr display median age 2 Myr. The distribution increases gradually as cluster–GMC distance increases,...
We present a study of the effective (half-light) radii and other structural properties systematically selected sample young, massive star clusters (YMCs, $\geq$$5\times10^3$ M$_{\odot}$ $\leq$200 Myr) in two nearby spiral galaxies, NGC 628 1313. use Hubble Space Telescope WFC3/UVIS archival ACS/WFC data obtained by Legacy Extragalactic UV Survey (LEGUS), an HST Treasury Program. measure with GALFIT, two-dimensional image-fitting package, new technique to estimate from concentration index...
Abstract We present a study of the hierarchical clustering young stellar clusters in six local (3–15 Mpc) star-forming galaxies using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from Treasury Program LEGUS (Legacy ExtraGalactic Survey). identified 3685 likely associations, each visually classified by their morphology, we use angular two-point correlation function to these systems. find that spatial distribution associations are clustered with respect other, forming...
We present a study of the spatial distribution stellar cluster populations in star-forming galaxy NGC 628. Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from Treasury Program LEGUS (Legacy ExtraGalactic Survey), we have identified 1392 potential young ( Myr) clusters within using combination visual inspection automatic selection. investigate clustering these quantify strength change with scale two-point correlation function. also how image boundary conditions dust...
We present the Hubble imaging Probe of Extreme Environments and Clusters (HiPEEC) survey. fit HST NUV to NIR broadband H$\alpha$ fluxes, derive star cluster ages, masses, extinctions determine formation rate (SFR) 6 merging galaxies. These systems are excellent laboratories trace under extreme gas physical conditions, rare in local universe, but typical for star-forming galaxies at cosmic noon. detect clusters with ages 1-500 Myr masses that exceed $10^7$ M$_\odot$. The recent history their...
We present the star cluster catalogs for 17 dwarf and irregular galaxies in $HST$ Treasury Program "Legacy ExtraGalactic UV Survey" (LEGUS). Cluster identification photometry this subsample are similar to that of entire LEGUS sample, but special methods were developed provide robust with accurate fluxes due low statistics. The colors ages largely consistent two widely used aperture corrections, a significant fraction clusters more compact than average training cluster. However, ensemble...
We present JWST/Near Infrared Spectrograph (NIRSpec) integral field spectroscopy (IFS) of a lensed Population III candidate stellar complex (dubbed Lensed And Pristine 1, LAP1), with lensing-corrected mass ≲10 4 M ⊙ and an absolute luminosity UV > −11.2 ( m 35.6), confirmed at redshift 6.639 ± 0.004. The system is strongly amplified μ ≳ 100) by straddling critical line the Hubble Frontier Field galaxy cluster MACS J0416. Although continuum currently not detected in Camera (NIRCam) Near...
Current observations favour that the massive ultraviolet-bright clumps with a median stellar mass of $\sim 10^7~M_{\odot}$, ubiquitously observed in $z\sim 1-3$ galaxies, are star-forming regions formed in-situ galaxies. It has been proposed they result from gas fragmentation due to gravitational instability gas-rich, turbulent, high-redshift discs. We bring support this scenario by reporting new discovery giant molecular clouds (GMCs) strongly lensed, clumpy, main-sequence galaxy,...
Abstract We investigate the emergence phase of young star clusters in nearby spiral galaxy NGC 628. use JWST NIRCam and MIRI observations to create spatially resolved maps Pa α 1.87 μ m Br 4.05 hydrogen recombination lines, as well 3.3 7.7 emission from polycyclic aromatic hydrocarbons (PAHs). extract 953 compact H ii regions analyze PAH morphology at ∼10 pc scales associated photodissociation regions. While remain compact, radial profiles help us define three morphological classes: (∼42%),...
The nearby dwarf starburst galaxy NGC 5253 hosts a number of young, massive star clusters, the two youngest which are centrally concentrated and surrounded by thermal radio emission (the "radio nebula"). To investigate role these clusters in energetics, we combine new archival Hubble Space Telescope images with wavelength coverage from 1500 Å to 1.9 μm 13 filters. These include Hα, Pβ, Pα, imaging Treasury Program LEGUS (Legacy Extragalactic UV Survey). extraordinarily well-sampled spectral...
It has recently been established that the properties of young star clusters (YSCs) can vary as a function galactic environment in which they are found. We use cluster catalogue produced by Legacy Extragalactic UV Survey (LEGUS) collaboration to investigate spiral galaxy M51. analyse population galactocentric distance and arm inter-arm regions. The mass exhibits similar shape at all radial bins, described power law with slope close $-2$ an exponential truncation around $10^5\ \rm{M}_{\odot}$...
Recently acquired WFC3 UV (F275W and F336W) imaging mosaics under the Legacy Extragalactic Survey (LEGUS) combined with archival ACS data of M51 are used to study young star cluster (YSC) population this interacting system. Our newly extracted source catalogue contains 2834 candidates, morphologically classified be compact uniform in colour, for which ages, masses extinction derived. In first work we main properties YSC whole galaxy, considering a mass-limited sample. Both luminosity mass...
We present an analysis of the positions and ages young star clusters in eight local galaxies to investigate connection between age difference separation cluster pairs. find that do not form uniformly but instead are distributed such increases with pair 0.25-0.6 power, maximum size over which formation is physically correlated ranges from ~200 pc ~1 kpc. The observed trends suggest hierarchical both space time: close each other more similar than born further apart. temporal correlations...
One of the main theories for explaining formation spiral arms in galaxies is stationary density wave theory. This theory predicts existence an age gradient across arms. We use stellar cluster catalogues NGC 1566, M51a, and 628 from Legacy ExtraGalactic UV Survey (LEGUS) program. In order to test possible sequence arms, we quantified azimuthal offset between star clusters different ages our target galaxies. found that a grand-design galaxy with bisymmetric strong bar, shows significant appear...
Young galaxies, potentially responsible for the last major phase-transition of Universe, appear brighter than expected and go through rapid bursty phases where copious amounts ionizing radiation feedback are produced. However, stellar components majority these reionization--era galaxies remain spatially unresolved. In this letter, we report direct discovery young massive star clusters in strongly lensed galaxy SPT0615-JD1 (dubbed Cosmic Gems arc) at redshift $z\sim10.2_{-0.2}^{+0.2}$ when...
Abstract We analyze the far-ultraviolet (1130−1770 Å rest frame) spectroscopy of 20 young (<50 Myr) and massive (>10 4 M ⊙ ) star clusters (YSCs) in 11 nearby star-forming galaxies. probe interstellar gas intervening along line sight, detecting several metal absorption lines a wide range ionization potentials, from 6.0 to 77.5 eV. Multiple-component Voigt fits are used study kinematics gas. find that nearly all targets sample feature outflowing 30 up 190 km s −1 , often both neutral...