A5055987077- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Advanced Combustion Engine Technologies
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- Molecular Spectroscopy and Structure
- Complex Systems and Time Series Analysis
- Planetary Science and Exploration
- Fluid Dynamics and Turbulent Flows
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Atmospheric Ozone and Climate
- Atomic and Molecular Physics
- Vibration and Dynamic Analysis
- Ionosphere and magnetosphere dynamics
- Pickering emulsions and particle stabilization
- Optical Polarization and Ellipsometry
Scuola Normale Superiore
2020-2024
Foundation for Research and Technology Hellas
2018-2024
University of Crete
2018-2023
CEA Paris-Saclay
2014-2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013-2019
Centre National de la Recherche Scientifique
2014-2019
Institut de Recherche sur les Lois Fondamentales de l'Univers
2013-2019
Délégation Paris 7
2014-2019
Université Paris Cité
2014-2019
Astrophysique, Instrumentation et Modélisation
2014-2019
Spiral galaxies, including the Milky Way, have large-scale magnetic fields with significant energy densities. The dominant theory attributes these to a dynamo. We review current status of dynamo and discuss various numerical simulations designed either explain particular aspects problem or reproduce galactic globally. Our main conclusions can be summarized as follows: ▪Idealized direct produce mean fields, whose saturation density tends decline increasing Reynolds number. This is still an...
Stellar winds and supernova (SN) explosions of massive stars (‘stellar feedback’) create bubbles in the interstellar medium (ISM) insert newly produced heavy elements kinetic energy into their surroundings, possibly driving turbulence. Most this is thermalized immediately removed from ISM by radiative cooling. The rest available for dynamics. In work we estimate amount feedback retained as when bubble walls have decelerated to sound speed ambient medium. We show that most star outweighs less...
We present the first Bayesian method for tomographic decomposition of plane-of-sky orientation magnetic field with use stellar polarimetry and distance. This standalone inversion presents an important step forward in reconstructing magnetized interstellar medium (ISM) three dimensions within dusty regions. develop a model which polarization signal from ISM is described by thin layers at various distances, working assumption should be satisfied small-angular circular apertures. Our modeling...
The study of gas-phase metallicity and its spatial distribution at high redshift is crucial to understand the processes that shaped growth evolution galaxies in early Universe. Here we spatially resolved three systems z ∼ 6 − 8, namely A2744-YD4, BDF-3299, COSMOS24108, with JWST NIRSpec IFU low-resolution ( R 100) spectroscopic observations. These are among highest- sources which gradients have been probed so far. Each these hosts several components process merging within a few kiloparsecs,...
The study of gas-phase metallicity and its spatial distribution at high redshift is crucial to understand the processes that shaped growth evolution galaxies in early Universe. Here we spatially resolved three systems $z\sim6-8$, namely A2744-YD4, BDF-3299, COSMOS24108, with JWST NIRSpec IFU low-resolution ($R\sim100$) spectroscopic observations. These are among highest-$z$ sources which gradients have been probed so far. Each these hosts several components process merging within a few kpc,...
The expansion and collision of two wind-blown superbubbles is investigated numerically. Our models go beyond previous simulations molecular cloud formation from converging gas flows by exploring this process with realistic flow parameters, sizes timescales. are blown time-dependent winds supernova explosions, calculated population synthesis models. They expand into a uniform or turbulent diffuse medium. We find that dense, cold clumps filaments form naturally in the compressed zone...
This work aims at improving the current understanding of interaction between H ii regions and turbulent molecular clouds. We propose a new method to determine age large sample OB associations by investigating development their associated in surrounding medium. Using analytical solutions, one-dimensional (1D), three-dimensional (3D) simulations, we constrained expansion ionized bubble depending on level parent cloud. A grid 1D simulations was then computed order build isochrone curves for...
Herschel surveys of Galactic clouds support a paradigm for low-mass star formation in which dense filaments play crucial role. The detailed fragmentation properties star-forming remain poorly understood, however, and the validity filament high-mass regime is still unclear. To investigate density/velocity structure region NGC6334, we conducted ALMA observations 3mm continuum N2H+(1-0) line at ~3arcsec resolution. was detected both tracers. We identified 26 cores 5 velocity-coherent fiber-like...
In this chapter we review recent advances in understanding the roles that magnetic fields play throughout star formation process, gained through observations and simulations of molecular clouds, dense, star-forming phase magnetised, turbulent interstellar medium (ISM). Recent results broadly support a picture which clouds transition from being gravitationally sub-critical near equipartition with turbulence low-density cloud envelopes, to energetically sub-dominant unstable cores. Magnetic...
Context: Filamentary structures in nearby molecular clouds have been found to exhibit a characteristic width of 0.1 pc, as observed dust emission. Understanding the origin this universal has become topic central importance study cloud structure and early stages star formation. Aims: We investigate how recovered widths filaments depend on distance from observer, by using previously published results Herschel Gould Belt Survey. Methods: obtained updated estimates distances with recent based 3D...
We present the analysis of magnetic field ($B$-field) structure galaxies measured with far-infrared (FIR) and radio (3 6 cm) polarimetric observations. use first data release Survey on extragALactic magnetiSm SOFIA (SALSA) 14 nearby ($<20$ Mpc) resolved (5 arcsec-18 arcsec; $90$ pc--$1$ kpc) imaging observations using HAWC+/SOFIA from $53$ to $214$ \um. compute pitch angle ($\Psi_{B}$) profiles as a function galactrocentric radius. introduce new alignment parameter ($\zeta$) estimate...
The recent availability of high-resolution far-infrared (FIR) polarization observations galaxies using HAWC+/SOFIA has facilitated studies extragalactic magnetic fields in the cold and dense molecular disks.We investigate if any significant structural differences are detectable kpc-scale field grand design face-on spiral galaxy M51 when traced within diffuse (radio) interstellar medium (ISM). Our analysis reveals a complex scenario where radio FIR do not necessarily trace same structure. We...
We present the first data release of Survey on extragALactic magnetiSm with SOFIA (SALSA Legacy Program) a set 14 nearby ($<20$ Mpc) galaxies resolved imaging polarimetric observations using HAWC+ from $53$ to $214$ $\mu$m at resolution $5-18$" ($90$ pc $-$ $1$ kpc). introduce definitions and background extragalactic magnetism, scientific motivation sample selection program. Here, we focus general trends in emissive polarization fraction. Far-infrared trace thermal polarized emission...
PASIPHAE (the Polar-Areas Stellar Imaging in Polarization High-Accuracy Experiment) is an optopolarimetric survey aiming to measure the linear polarization from millions of stars, and use these create a three-dimensional tomographic map magnetic field threading dust clouds within Milky Way. This will provide invaluable information for future CMB B-mode experiments searching inflationary gravitational waves, providing unique regarding line-of-sight integration effects. Optical observations...
Context. The filamentary structure of the molecular interstellar medium and potential link this morphology to star formation have been brought into focus recently by high resolution observational surveys. An especially puzzling matter is that local filaments appear same thickness, independent their column density. This requires a theoretical understanding process physics governs evolution.
We describe the data processing of Survey on extragALactic magnetiSm with SOFIA (SALSA Legacy Program). This first release presents 33% (51.34h out 155.7h, including overheads) total awarded time taken from January 2020 to December 2021. Our observations were performed using newly implemented on-the-fly mapping (OTFMAP) technique in polarimetric mode. present pipeline steps obtain homogeneously reduced high-level products maps galaxies for use scientific analysis. approach has a general...
Recent Herschel observations of nearby clouds have shown that filamentary structures are ubiquitous and most prestellar cores form in filaments. Probing the density ($n$) velocity ($V$) structure filaments is crucial for understanding star formation process. To characterize both $n$ $V$ field a fragmenting filament, we mapped NGC2024. 13CO, C18O, H13CO+ trace filament seen $N_{H_2}$ data. The radial profile from data shows $D_{HP}$~0.081 pc, which similar to findings. $D_{HP}$ 13CO C18O...
Abstract The structure of magnetic fields in galaxies remains poorly constrained, despite the importance magnetism evolution galaxies. Radio synchrotron and far-infrared (FIR) polarization polarimetric observations are best methods to measure galactic scale properties beyond Milky Way. We use synthetic a simulated galaxy identify quantify regions, scales, interstellar medium (ISM) phases probed at FIR radio wavelengths. Our studied suite magnetohydrodynamical cosmological zoom-in simulations...
Context. The connection between the prestellar core mass function (CMF) and stellar initial (IMF) lies at heart of all star formation theories, but it is inherently observationally unreachable. Aims. In this paper we aim to elucidate earliest phases with a series high-resolution numerical simulations that include sinks from high-density clumps. particular, focus on transition cores sink particles within massive molecular filament, work towards identifying factors determine shape CMF IMF....
Galactic bars are frequent in disk galaxies and they may support the transfer of matter towards central engine active nuclei. The barred galaxy NGC 1097 has magnetic forces controlling gas flow at several kpc scales, which suggest that fields (B-fields) dynamically important along bar nuclear ring. However, effect B-field on flows scale not been characterized. Using thermal polarized emission $89$ $\mu$m with HAWC+/SOFIA, here, we measure flux is spatially located contact regions outer-bar...
Herschel observations have emphasized the role of molecular filaments in star formation. However, origin and evolution these are not yet well understood, partly because lack kinematic information. To examine whether B211/B213 filament is accreting background gas due to its gravitational potential, we produced a toy accretion model compared predictions 12CO(1--0) 13CO(1--0) velocity patterns. We also examined spatial distributions Halpha, 857 GHz continuum, HI emission search for evidence...
Dense, star-forming gas is believed to form at the stagnation points of large-scale interstellar medium flows, but observational examples this process in action are rare. We here present a giant molecular cloud (GMC) sandwiched between two colliding Milky Way supershells, which we argue shows strong evidence having formed from material accumulated collision zone. Combining 12CO, 13CO, and C18O(J = 1–0) data with new high-resolution, three-dimensional hydrodynamical simulations discuss origin...
Dark Matter (DM) halos with masses below $\sim10^{8}$ $M_{\odot}$, which would help to discriminate between DM models, may be detected through their gravitational effect on distant sources. The same applies primordial black holes, considered as an alternative scenario particle models. However, there is still no evidence for the existence of such objects. With aim finding compact objects in mass range $\sim$ 10$^{6}$ -- 10$^{9}$$M_{\odot}$, we search strong lenses milli (mas)-arcseconds...
Mergers are thought to be a fundamental channel for galaxy growth, perturbing the gas dynamics and magnetic fields (B-fields) in interstellar medium (ISM). However, mechanisms that amplify dissipate B-fields during merger remain unclear. We characterize morphology of ordered multi-phase ISM closest two spiral galaxies, Antennae galaxies. compare inferred using $154~\mu$m thermal dust $11$ cm radio synchrotron emission polarimetric observations. find more across galaxies than B-fields. The...