A5027232356- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Spectroscopy and Laser Applications
- Nonlinear Waves and Solitons
- Gamma-ray bursts and supernovae
- Mathematics and Applications
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Relativity and Gravitational Theory
- Pulsars and Gravitational Waves Research
- Quantum Mechanics and Applications
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Elasticity and Wave Propagation
- Advanced Mathematical Theories and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Fluorescence Microscopy Techniques
- History and Developments in Astronomy
- Noncommutative and Quantum Gravity Theories
- Quantum Electrodynamics and Casimir Effect
- Geophysics and Gravity Measurements
- Advanced Mathematical Theories
- Advanced Differential Geometry Research
Scuola Normale Superiore
2019-2025
Alzahra University
2015-2017
Institute for Advanced Studies in Basic Sciences
1997
We study the formation and evolution of a sample Lyman Break Galaxies in Epoch Reionization by using high-resolution ($\sim 10 \,{\rm pc}$), cosmological zoom-in simulations part SERRA suite. In SERRA, we follow interstellar medium (ISM) thermo-chemical non-equilibrium evolution, perform on-the-fly radiative transfer radiation field (ISRF). The simulation outputs are post-processed to compute emission far infrared lines ([CII], [NII], [OIII]). At $z=8$, most massive galaxy, `Freesia', has an...
ABSTRACT A tight relation between the [C ii] 158 $\mu$m line luminosity and star formation rate is measured in local galaxies. At high redshift (z > 5), though, a much larger scatter observed, with considerable (15–20 per cent) fraction of outliers being ii]-deficient. Moreover, surface brightness ($\Sigma_{\rm [C\, \small {II}]}$) these sources systematically lower than expected from relation. To clarify origin such ii]-deficiency, we have developed an analytical model that fits data has...
ALMA observations have revealed that [CII] 158$\mu$m line emission in high-z galaxies is ~2-3$\times$ more extended than the UV continuum emission. Here we explore whether surface brightness dimming (SBD) of responsible for reported deficit, and large $L_{\rm [OIII]}/L_{\rm [CII]}$ luminosity ratio measured early galaxies. We first analyse archival images nine z>6 observed both [OIII]. After performing several uv-tapering experiments to optimize identification emission, detect whole sample,...
We study the kinematical properties of galaxies in Epoch Reionization via [CII] 158$\mu$m line emission. The profile provides information on kinematics as well structural such presence a disk and satellites. To understand how these are encoded profile, first we develop analytical models from which identify inclination gas turbulent motions key parameters affecting profile. gain further insights, use "Althaea", highly-resolved ($30\, \rm pc$) simulated prototypical Lyman Break Galaxy,...
We introduce SERRA, a suite of zoom-in high-resolution ($\sim 10\,\rm pc$) cosmological simulations including non-equilibrium chemistry and on-the-fly radiative transfer. The outputs are post-processed to derive galaxy UV+FIR continuum emission line properties. Results compared with available multi-wavelength data constrain the physical properties (e.g., star formation rates, stellar/gas/dust mass, metallicity) high-redshift $6 \lesssim z 15$ galaxies. This flagship paper focuses on $z=7.7$...
The recent JWST tentative discovery of a population super-early (redshift $z> 10$), relatively massive (stellar mass $M_* = 10^{8-9} M_{\odot}$) and evolved (metallicity $Z \approx 0.1 Z_{\odot}$) galaxies, which nevertheless show blue ($\beta \simeq -2.6$) spectra, very small dust attenuation ($A_{\rm V} \leq 0.02$), challenges our interpretation these systems. To solve the puzzle we propose two solutions in is either (a) ejected by radiation pressure, or (b) segregated with respect to...
Context. Theoretical models struggle to reproduce dynamically cold disks with significant rotation-to-dispersion support ( V rot / σ ) observed in star-forming galaxies the early Universe at redshift z > 4. Aims. We aim explore possible emergence of cosmological simulations and understand whether different kinematic tracers can help reconcile tension between theory observations. Methods. used 3218 from S ERRA suite zoom-in simulations, 8 ≤ log( M ⋆ ⊙ 10.3 star formation rates SFR 128 /yr,...
ABSTRACT We investigate the contribution of clumps and satellites to galaxy mass assembly. analysed spatially resolved HubbleSpace Telescope observations (imaging slitless spectroscopy) 53 star-forming galaxies at z ∼ 1–3. created continuum emission line maps pinpointed residual ‘blobs’ detected after subtracting disc. Those were separated into compact (unresolved) extended (resolved) components. Extended components have sizes ∼2 kpc comparable stellar age as discs, whereas are 1.5 dex less...
Context. The characterization of the dynamical state galaxies up to z ∼ 7 is crucial for constraining mechanisms that drive mass assembly in early Universe. However, it unclear whether data quality typical observations obtained with current and future facilities sufficient perform a solid analysis at these redshifts. Aims. This paper defines angular resolution signal-to-noise ratio (S/N) required robust Epoch Reionization. final aim help design spatially resolved surveys targeting emission...
Context. Spatially resolved studies of the kinematics galaxies provide crucial insights into their assembly and evolution, enabling one to infer properties dark matter halos, derive impact feedback on interstellar medium (ISM), as well measure characterize outflow motions. To date, most kinematic at z = 0.5 − 3.5 have been obtained using emission lines tracing warm, ionized gas (e.g., H α , [OII], [OIII]). However, whether these an exhaustive or only a partial view dynamics ISM is still...
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,...
High-redshift galaxies are expected to be more turbulent than local because of their smaller size and higher star formation thus stronger feedback from formation, frequent mergers events, gravitational instabilities. However, this scenario has recently been questioned by the observational evidence a few at z~4-5 with gas velocity dispersion similar what is observed in population. Our goal determine whether first Gyrs Universe have already formed dynamically cold rotating disk counterparts....
ABSTRACT We exploit moderately resolved [O $\scriptstyle \rm III$], [C II$] and dust continuum ALMA observations to derive the gas density (n), gas-phase metallicity (Z), deviation from Kennicutt–Schmidt (KS) relation (κs) on $\approx \, sub-kpc$ scales in interstellar medium (ISM) of five bright Lyman Break Galaxies at Epoch Reionization (z ≈ 7). To do so, we use GLAM, a state-of-art, physically motivated Bayesian model that links II$]and III$]surface brightness (Σ[CII], Σ[OIII]) SFR...
<title>Abstract</title> Early galaxy formation, initiated by the dark matter and gas assembly, evolves through frequent mergers feedback processes into dynamically hot, chaotic structures<sup>1</sup>. In contrast, cold, smooth rotating disks have been observed in massive evolved galaxies merely 1.4 billion years after Big~Bang<sup>2</sup>, suggesting rapid morphological dynamical evolution early Universe. Probing this mechanism necessitates studies of young galaxies, yet efforts hindered...
We study the structure of spatially resolved, line-of-sight velocity dispersion for galaxies in Epoch Reionization (EoR) traced by [CII] $158\mu\rm{m}$ line emission. Our laboratory is a simulated prototypical Lyman-break galaxy, "Freesia", part SERRA suite. The analysis encompasses redshift range 6 < z 8, when Freesia very active assembling phase. build maps three dynamically distinct evolutionary stages (Spiral Disk at z=7.4, Merger z=8.0, and Disturbed z=6.5) using hyperspectral data...
ALMA observations have revealed that many high redshift galaxies are surrounded by extended (10-15 kpc) [CII]-emitting halos which not predicted even the most advanced zoom-in simulations. Using a semi-analytical model, in previous work we suggested such produced starburst-driven, catastrophically cooling outflows. Here, further improve model and compare its predictions with data from 7 star-forming ($10\lesssim \rm SFR/ M_\odot yr^{-1}<100$) at z=4-6, observed ALPINE survey. We find (a)...
Context. Observations at UV and optical wavelengths have revealed that galaxies z ∼ 1 − 4 host star-forming regions, dubbed “clumps”, which are believed to form due the fragmentation of gravitationally unstable, gas-rich disks. However, detection parent molecular clouds give birth such clumps is still possible only in a minority galaxies, mostly 1. Aims. We investigated [C II] dust morphology 3.4 lensed galaxy hosting four detected continuum. aimed observe emission individual that, unlike...
Recent attempts to detect [OIII] 88$\mu$m emission from super-early ($z>10$) galaxy candidates observed by JWST have been unsuccessful. By using zoom-in simulations, we show that these galaxies are faint, and mostly fall below the local metal-poor $\rm [OIII]-SFR$ relation as a result of their low ionization parameter, $U_{\rm ion}\lesssim 10^{-3}$. Such ion}$ values found in an early assembly stage, whose stars still embedded high-density natal clouds. However, most luminous our sample...
Near- to mid-infrared observations (from Spitzer and JWST) have revealed a hidden population of galaxies at redshift $z=3$--$6$ called optically dark objects, which are believed be massive dusty star-formers. They contribute substantially the cosmic star-formation rate (SFR) density $z (up $30$--$40<!PCT!>$). While sources widely recognized as significant component stellar mass function, history their assembly (and evolution interstellar medium) remains unexplored. However, they...
In this paper we are concerned with the effects of an anisotropic pressure on boundary conditions Lane–Emden equation and homology theorem. Some new exact solutions derived. Then some theorems governing Newtonian perfect fluid star extended, taking into account.
We investigate the spatially-resolved morphology of galaxies in early Universe. consider a typical redshift z = 6 Lyman Break galaxy, "Althaea" from SERRA hydrodynamical simulations. create mock rest-frame ultraviolet, optical, and far-infrared observations, perform two-dimensional morphological analysis to de-blend galaxy disk substructures (merging satellites or star-forming regions). find that [CII]158um emitting region has an effective radius 1.5 - 2.5 times larger than optical one,...
A sizable fraction of the heavy elements synthesized by stars in galaxies condenses into sub-micron-sized solid-state particles, known as dust grains. Dust produces a wavelength-dependent attenuation, $A_\lambda$, galaxy emission, thereby significantly altering its observed properties. Locally, $A_\lambda$ is general sum power-law and UV feature ('bump') produced small, carbon-based However, scant information exists regarding evolution across cosmic time. Here, leveraging data from 173 James...
Abstract A sizable fraction of the heavy elements synthesized by stars in galaxies condenses into sub-micron-sized solid-state particles, known as dust grains^1, 2. Dust produces a wavelength-dependent attenuation, Aλ, galaxy emission, thereby significantly altering its observed properties^3. Locally, Aλ is general sum power-law and UV feature (’bump’)^4 produced small, carbon-based grains^5. However, scant information exists regarding evolution across cosmic time. Here, leveraging data from...