Mario Llerena
A5079133036- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Relativity and Gravitational Theory
- Adaptive optics and wavefront sensing
- Black Holes and Theoretical Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Scientific Research and Discoveries
- Nuclear Physics and Applications
- Astrophysics and Cosmic Phenomena
- Impact of Light on Environment and Health
- CCD and CMOS Imaging Sensors
- Spanish Literature and Culture Studies
- Urbanism, Landscape, and Tourism Studies
- Radio Astronomy Observations and Technology
- Advanced Semiconductor Detectors and Materials
- Tribology and Lubrication Engineering
- Glass properties and applications
- Spectroscopy and Laser Applications
- Remote Sensing in Agriculture
- Computational Physics and Python Applications
Astronomical Observatory of Rome
2024-2025
University of La Serena
2020-2024
National Polytechnic School
2016-2020
Consejo Nacional de Investigaciones Científicas y Técnicas
2018
Universidad Nacional de Cuyo
2017-2018
Abstract We spectroscopically confirm the M UV = −20.5 mag galaxy GHZ2/GLASS-z12 to be at redshift z 12.34. The source was selected via NIRCam photometry in GLASS-JWST Early Release Science data, providing first evidence of a surprising abundance bright galaxies ≳ 10. NIRSpec PRISM spectrum shows detections N iv , C He ii O iii and Ne lines detection high Bowen fluorescence line 3133 Å rest frame. prominent with rest-frame equivalent width (EW) ≈ 46 puts GHZ2 category extreme emitters....
The ionizing photon escape fraction (LyC $f_{\rm{esc}}$) of star-forming galaxies is the single greatest unknown in reionization budget. Stochastic sightline effects prohibit direct separation LyC leakers from non-leakers at significant redshift. Here we circumvent this uncertainty by inferring $f_{\rm{esc}}$ with resolved (R>4000) LyA profiles X-SHOOTER survey z=2 (XLS-z2). We select ($f_{\rm{esc}}>20$%) and ($f_{\rm{esc}}<5$%) a representative sample $>0.2 L^{*}$ emitters (LAEs). With...
Far-ultraviolet (FUV; ~1200-2000 angstroms) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The launch JWST will soon usher in new era, pushing the UV spectroscopic frontier higher redshifts than ever before, however, its success hinges comprehensive star populations gas conditions that power observed spectral features. This requires level detail is only...
ABSTRACT The cosmic ionizing emissivity from star-forming galaxies has long been anchored to UV luminosity functions. Here, we introduce an framework based on Lyα emitters (LAEs), which naturally hones in the subset of responsible for background due intimate connection between production and escape LyC photons. Using constraints fractions bright LAEs (LLyα &gt; 0.2L*) at z ≈ 2 obtained resolved profiles, arguing their redshift-invariance, show that: (i) quasars together reproduce...
The resonant scattering interaction between Ly α photons and neutral hydrogen implies that a partially intergalactic medium has the ability to significantly impact detectability of emission in galaxies. Thus, redshift evolution equivalent width distribution galaxies offers key observational probe degree ionization during Epoch Reionization (EoR). Previous in-depth investigations at z ≥ 7 were limited by ground-based instrument capabilities. We present an extensive study from 4.5 < 8.5,...
We present Lyman continuum (LyC) radiation escape fraction $f_{\rm{esc}}$ measurements for 183 spectroscopically confirmed star-forming galaxies in the redshift range $3.11 < z 3.53$ \textit{Chandra} Deep Field South. use ground-based imaging to measure $f_{\rm{esc}}$, and ground- space-based photometry derive galaxy physical properties using spectral energy distribution (SED) fitting. additionally [O III]+H$β$ equivalent widths (that fall observed K band) by including nebular emission...
Abstract The Cosmic Origins Spectrograph (COS) Legacy Archive Spectroscopic SurveY (CLASSY) provides the first high-resolution spectral catalog of 45 local high- z analogs in ultraviolet (UV; 1200–2000 Å) to investigate their stellar and gas properties. Here we present a toolkit UV interstellar medium (ISM) diagnostics, analyzing main emission lines CLASSY spectra (N iv ] λ 1483,87, C λλ 1548,51, He ii 1640, O iii 1661,6, Si 1883,92, 1907,9). Specifically, our aim is provide accurate...
We present a study designed to measure the average LyC escape fraction ($\langle f_{\rm esc}\rangle$) of star-forming galaxies at z=3.5. assemble sample 148 from VANDELS survey $3.35\leq z_{\rm spec}\leq3.95$, selected minimize line-of-sight contamination their photometry. For this sample, we use ultra-deep, ground-based, $U-$band imaging and HST $V-$band robustly distribution $\mathcal{R_{\rm obs}}$ $=(L_{\rm LyC}/L_{\rm UV})_{\rm obs}$. then model as function $\langle esc}\rangle$,...
We spectroscopically confirm the $M_{\rm UV} = -20.5$ mag galaxy GHZ2/GLASS-z12 to be at redshift $z=12.34$. The source was selected via NIRCam photometry in GLASS-JWST Early Release Science data, providing first evidence of a surprising abundance bright galaxies $z \gtrsim 10$. NIRSpec PRISM spectrum is remarkable and unlike any local analog. It shows significant detections N IV, C He II, O III, Ne III lines, detection high-redshift object Bowen fluorescence line 3133 {\AA} rest-frame....
Finding reliable indicators of Lyman continuum (LyC) photon leakage from galaxies is essential in order to infer their escape fraction the epoch reionisation, where direct measurements LyC flux are impossible. To this end, here we investigate whether strong C IV $\lambda \lambda 1548,1550$ emission rest-frame UV spectra traces conditions ripe for ample production and photons. We compile a sample 19 star-forming redshift range $z=3.1-4.6$ VANDELS survey that exhibit emission, producing...
Abstract The COS Legacy Archive Spectroscopic SurveY (CLASSY) is designed to provide the community with a spectral atlas of 45 nearby star-forming galaxies that were chosen cover similar properties those seen at high z ( > 6). prime high-level science product CLASSY accurately coadded UV spectra, ranging from ∼1000 2000 Å, derived combination archival and new data obtained HST’s Cosmic Origins Spectrograph (COS). This paper details multistage technical processes creating this...
We selected 35 low-mass SFGs (7.9<log(M$_*$/M$_{\odot}$)<10.3) from deep spectroscopic surveys based on their CIII]1908 emission. used follow-up NIR observations to examine rest-optical emission lines and identify ionized outflow signatures through broad wings detected after Gaussian modeling of [OIII]4959,5007 profiles. characterized the galaxies' gas-phase metallicity carbon-to-oxygen (C/O) abundance using a Te-based method via OIII]1666/[OIII]5007 ratio photoionization models. find line...
The galaxy-integrated star formation rate (SFR) surface density measurement (Σ SFR ) has been proposed as a valuable diagnostic of the mass accumulation in galaxies given it is more tightly related to physics and stellar feedback than other indicators. In this work, we assembled statistical sample 230 observed with JWST GLASS CEERS spectroscopic surveys estimate Balmer line-based dust attenuations SFRs (i.e., from H α , β γ ), along UV rest-frame effective radii. We studied evolution galaxy...
Abstract Ultraviolet (UV; rest-frame ∼1200–2000 Å) spectra provide a wealth of diagnostics to characterize fundamental galaxy properties, such as their chemical enrichment, the nature stellar populations, and amount Lyman-continuum (LyC) radiation. In this work, we leverage publicly released JWST data construct UV-to-optical composite spectrum sample 63 galaxies at 5.6 < z 9, spanning wavelength range from 1500 5200 Å. Based on spectrum, derive an average dust attenuation <mml:math...
We present the Cosmic Evolution Early Release Science (CEERS) Survey, a 77.2 hour Director's Discretionary Program. CEERS demonstrates, tests, and validates efficient extragalactic surveys using coordinated, overlapping parallel observations with JWST instrument suite, including NIRCam MIRI imaging, NIRSpec low (R~100) medium (R~1000) resolution spectroscopy, slitless grism (R~1500) spectroscopy. targets Hubble Space Telescope-observed region of Extended Groth Strip (EGS) field, supported by...
Compact, star-forming galaxies with high star formation rate surface densities ($\Sigma_{\text{SFR}}$) are often efficient Lyman continuum (LyC) emitters at $z\leq 4.5$, likely as intense stellar feedback creates low-density channels that allow photons to escape. Irregular or disturbed morphologies, such those resulting from mergers, can also facilitate LyC escape by creating anisotropic gas distributions. We investigate the influence of galaxy morphology on production and redshifts $5 \leq...
We use JWST Near-Infrared Spectrograph (NIRSpec) observations from the Cosmic Evolution Early Release survey (CEERS), GLASS-JWST ERS (GLASS), and Advanced Deep Extragalactic Survey (JADES) to measure rest-frame optical emission-line ratios of 90 galaxies at z>4. The stacked spectra with without a broad-line feature reveal difference in [OIII]$\lambda$ 4363 H$\gamma$ ratios. This motivated our investigation [OIII]/H$\gamma$ vs [NeIII]/[OII] diagram. define two AGN/SF classification lines...
Abstract Over twenty years ago, Type Ia Supernovae (SNIa) observations revealed an accelerating Universe expansion, suggesting a significant dark energy presence, often modelled as cosmological constant, Λ. Despite its pivotal role in cosmology, the standard ΛCDM model remains largely underexplored redshift range between distant SNIa and Cosmic Microwave Background (CMB). This study harnesses James Webb Space Telescope’s advanced capabilities to extend Hubble flow mapping across...
We study the mean properties of a large representative sample 217 galaxies showing CIII] emission at $2<z<4$, selected from parent $\sim$750 main-sequence star-forming in VANDELS survey. These emitters have broad range UV luminosities, thus allowing detailed stacking analysis to characterize their stellar mass, star formation rate (SFR) and metallicity, as function line ratios, EWs, carbon-to-oxygen (C/O) abundance ratio. Reliable detections represent $\sim$30% sample. Extreme...
The resonant scattering interaction between Ly$\alpha$ photons and neutral hydrogen implies that a partially IGM can significantly impact the detectability of emission in galaxies. redshift evolution equivalent width distribution galaxies thus offers key probe degree ionization during Epoch Reionization (EoR). Previous in-depth investigations at $z$ $\geq$ 7 were limited by ground-based instrument capabilities. We present an extensive study from 4 < 8.5, observed CEERS JADES surveys JWST...
Context. Extreme emission line galaxies (EELGs) are typically characterized by high equivalent widths (EWs) which driven elevated specific star formation rates (sSFRs) in low-mass with subsolar metallicities and little dust. Such extreme systems exceedingly rare the local universe, but number density of EELGs increases increasing redshift. starburst currently strongly presumed to be main drivers hydrogen reionization over 5.5 < z 15, serves motivate many searches for high- EELGs. Aims. We...
In the local universe, galaxies in clusters show different properties compared to more isolated systems. Understanding how this difference originates and whether it is already place at high redshift still a matter of debate. Thanks uniquely deep optical spectra from VANDELS survey, we investigate environmental effects on stellar mass-metallicity relation (MZR) for sample ~1000 star-forming 2<z<4. We complement our dataset with MOSFIRE follow-up 21 study dependence gas-phase MZR. Robust gas...
Abstract GHZ2/GLASS-z12, one of the most distant galaxies found in JWST observations, has been recently observed with both NIRSpec and MIRI spectrographs, establishing a spectroscopic redshift z spec = 12.34 making it first system at > 10 complete coverage from rest-frame UV to optical wavelengths. This galaxy is identified as strong C iv λ 1549 emitter (EW 46 Å) many other detected emission lines, such N ] 1488 , He ii 1640 O iii 1661,1666 1750 1907,1909 [O 3726,3729 [Ne 3869 4959,5007 H...
Gaseous flows inside and outside galaxies are key to understanding galaxy evolution, as they regulate their star formation activity across cosmic time. We study the ISM kinematics of 330 CIII or HeII emitters, using far-UV absorption lines detected in VANDELS spectra. These span a broad range stellar masses M$_\ast$ from $10^8$ $10^{11}$ M$_\odot$, SFRs 1 500 M$_\odot$/yr, redshift between 2 5. find that bulk velocity v$_{ism}$ is globally outflow, with -60 $\pm$ 10 km/s for low ionization...
GHZ2/GLASS-z12 has been recently observed by JWST with both NIRSpec and MIRI spectrographs, making it the most distant galaxy ($z_{spec}=12.34$) complete spectroscopic coverage from rest-frame UV to optical. It is identified as a strong CIV$_{1549}$ emitter many other detected emission lines (NIV], HeII, OIII], NIII], CIII], [OII], [NeIII], [OIII], H$\alpha$), including remarkable OIII$_{1333}$ Bowen fluorescence line. We analyze in this paper joint NIRSpec+MIRI spectral data set. Combining...