A5010197403- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Bariatric Surgery and Outcomes
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Scientific Research and Discoveries
- Diet and metabolism studies
- CCD and CMOS Imaging Sensors
- Impact of Light on Environment and Health
- Pulsars and Gravitational Waves Research
- Metabolism and Genetic Disorders
- Geophysics and Gravity Measurements
- Diabetes Treatment and Management
- Clinical Nutrition and Gastroenterology
- Adipokines, Inflammation, and Metabolic Diseases
- Calibration and Measurement Techniques
- Cosmology and Gravitation Theories
- Electrolyte and hormonal disorders
- Cardiovascular Disease and Adiposity
University of Malta
2016-2025
Erie County Medical Center
1981-2019
Williams (United States)
2006-2019
University at Buffalo, State University of New York
1981-2018
Instituto de Astrofísica de Andalucía
2018
University of Leicester
2018
Leibniz Institute for Astrophysics Potsdam
2013-2017
Synergy University
2017
Yale University
2016
University of Oxford
2010-2014
Thomson optical depth τ measurements from Planck provide new insights into the reionization of universe. In pursuit model-independent constraints on properties ionizing sources, we determine empirical evolution cosmic emissivity. We use a simple two-parameter model to map out in emissivity at z ≳ 6 measurements, provided by quasar absorption spectra and prevalence Lyα emission ∼ 7–8 galaxies. find redshift required observations be ( for flat prior), largely independent assumed clumping...
We observed the Hubble Deep Field South with new panoramic integral field spectrograph MUSE that we built and just commissioned at VLT. The data cube resulting from 27 hours of integration covers one arcmin^2 view an unprecedented depth a 1 sigma emission line surface brightness limit 1x$10^{-19}$ erg/s/cm$^2$/arcsec$^2$ contains ~90,000 spectra. present combined calibrated cube, perform first-pass analysis sources detected in HDF-S imaging. measured redshifts 189 up to magnitude F814W =...
We present a reduction and analysis of the \textit{James Webb Space Telescope} (JWST) SMACS~0723 field using new post-launch calibrations to conduct search for ultra-high-redshift galaxies ($z > 9$) within Epoch Reionisation. this by modelling photometric redshifts in several ways all sources applying conservative magnitude cuts ($m_{\rm F200W} < 28$) identify strong Lyman breaks greater than 1 magnitude. find four $z 9$ candidate which have not previously been identified, with one object at...
We present early results regarding the morphological and structural properties of galaxies seen with James Webb Space Telescope at $z > 3$ in Early Release Observations SMACS 0723, a galaxy cluster $z=0.39$. investigate, for first time, optical morphologies significant number accurate photometric redshifts this field to determine form structure relatively universe. use visual \textsc{Morfometryka} measures perform quantitative morphology measurements, both parametric light profile fitting...
Abstract We present results on the morphological and structural evolution of a total 3956 galaxies observed with JWST at 1.5 < z 6.5 in CEERS observations that overlap CANDELS EGS field. This is biggest visually classified sample yet, ∼20 times larger than previous studies, allows us to examine detail how galaxy structure has changed over this critical epoch. All sources were by six individual classifiers using simple classification scheme aimed producing disk/spheroid/peculiar...
Abstract We present an analysis of the quenching star formation in massive galaxies ( M * > 10 9.5 ⊙ ) within first 0.5–3 Gyr Universe’s history utilizing JWST-CEERS data. utilize a combination advanced statistical methods to accurately constrain intrinsic dependence multidimensional and intercorrelated parameter space. Specifically, we apply random forest classification, area statistics, partial correlation First, identify key testable predictions from two state-of-the-art cosmological...
Abstract We develop a photometric search method for identifying smouldering galaxies at 5 &lt; z 8, which are defined to have weak emission lines and thus generally low specific star formation rates may even be in state of (temporary) quiescence. The deep NIRCam imaging (∼29.5 AB mag, 5σ) from the JADES second data release is essential finding these systems, as they faint, relatively quiescent dwarf (M* ∼ 108–9 M⊙) Epoch Reionisation (EoR). Moreover, medium band key, enabling clear...
We report the detection of extended Lyα emission around individual star-forming galaxies at redshifts z = 3−6 in an ultradeep exposure Hubble Deep Field South obtained with MUSE on ESO-VLT. The data reach a limiting surface brightness (1σ) ~1 × 10-19 erg s-1 cm-2 arcsec-2 azimuthally averaged radial profiles, order magnitude improvement over previous narrowband imaging. Our sample consists 26 spectroscopically confirmed Lyα-emitting, but mostly continuum-faint (mAB ≳ 27) galaxies. In most...
Following our previous spectroscopic observations of $z>7$ galaxies with Gemini/GNIRS and VLT/XSHOOTER, which targeted a total 8 objects, we present here results from deeper larger VLT/FORS2 sample Wide Field Camera 3 selected candidate galaxies. With FORS2 setup cover the 737-1070nm wavelength range, enabling search for Lyman-$\alpha$ in redshift range spanning 5.06 - 7.80. We target 22 $z$-band dropouts find no evidence emission, exception tentative detection ($<5\sigma$, is adopted...
Direct Ly $\alpha$ imaging of intergalactic gas at $z\sim2$ has recently revealed giant cosmological structures around quasars, e.g. the Slug Nebula (Cantalupo et al. 2014). Despite their high luminosity, detection rate such systems in narrow-band and spectroscopic surveys is less than 10%, possibly encoding crucial information on distribution quasars quasar emission properties. In this study, we use MUSE integral-field instrument to perform a blind survey for nebulae 17 bright radio-quiet...
The acquisition of deep Near-IR imaging with Wide Field Camera 3 on the Hubble Space Telescope has provided opportunity to study very-high redshift Universe. For galaxies up $z\approx 7.7$ sufficient wavelength coverage exists probe rest-frame ultraviolet (UV) continuum without contamination from either Lyman-$α$ emission or break. In this work we use measure UV colours at $4.7
ABSTRACT Galaxies represent one of the preferred candidate sources to drive reionization universe. Even as gains are made in mapping galaxy UV luminosity density <?CDATA $z\gt 6$?> , significant uncertainties remain regarding conversion implied ionizing emissivity. The relevant unknowns Lyman-continuum (LyC) photon production efficiency ${\xi }_{\mathrm{ion}}$?> and escape fraction f esc . As we show here, first these is directly measurable z = 4–5 galaxies based on impact H α line has...
The Lyman alpha (lya) line of Hydrogen is a prominent feature in the spectra star-forming galaxies, usually redshifted by few hundreds km/s compared to systemic redshift. This large offset hampers follow-up surveys, galaxy pair statistics and correlations with quasar absorption lines when only lya available. We propose diagnostics that can be used recover redshift directly from properties profile. use spectroscopic observations Lyman-Alpha Emitters (LAEs) for which precise measurement Our...
We present a first instalment of the MUSE-Wide survey, covering an area 22.2 arcmin$^2$ (corresponding to $\sim$20% final survey) in CANDELS/Deep Chandra Deep Field South. use MUSE integral field spectrograph at ESO VLT conduct full-area spectroscopic mapping depth 1h exposure time per 1 pointing. searched for compact emission line objects using our newly developed LSDCat software based on 3-D matched filtering approach, followed by interactive classification and redshift measurement...
We present the MUSE-Wide survey, a blind, 3D spectroscopic survey in CANDELS/GOODS-S and CANDELS/COSMOS regions. The final will cover 100 × 1 arcmin 2 MUSE fields. Each pointing has depth of one hour hence targets more extreme luminous objects over ten times area MUSE-Deep legacy value lies providing “spectroscopy everything” without photometric pre-selection. describe data reduction, post-processing PSF characterization first 44 pointings released with this publication. Using matched...
We present the deepest study to date of Lya luminosity function (LF) in a blank field using blind integral spectroscopy from MUSE. constructed sample 604 emitters (LAEs) across redshift range 2.91 < z 6.64 automatic detection software Hubble Ultra Deep Field. calculate accurate total fluxes capturing low surface brightness extended emission now known be generic property high-redshift star-forming galaxies. simulated realistic LAEs characterise selection our samples, and performed...
ABSTRACT JWST is set to transform many areas of astronomy, one the most exciting expansion redshift frontier z &gt; 10. In its first year, alone should discover hundreds galaxies, dwarfing handful currently known. To prepare for these powerful observational constraints, we use First Light And Reionization Epoch simulations (flares) predict physical and properties 10 population galaxies accessible JWST. This time such predictions have been made using a hydrodynamical model validated at...
ABSTRACT We present the results of a size and structural analysis 1395 galaxies at 0.5 ≤ z ≲ 8 with stellar masses log (M*/M⊙)&gt; 9.5 within James Webb Space Telescope Public CEERS field that overlaps Hubble Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey EGS observations. use GALFIT to fit single Sérsic models rest-frame optical profile our galaxies, which is mass-selected sample complete redshift mass limit. Our primary result fixed wavelength mass, get progressively...
We analyse the photometric and spectroscopic properties of four galaxies in epoch reionisation (EoR) within SMACS 0723 JWST Early Release Observations field. Given known redshifts these sources, we investigated accuracy with which can be derived using NIRCam photometry alone, finding that F115W imaging is essential to distinguish between z~8 high equivalent width (EW) [O III] {\lambda}5007 emission z~10 Balmer break galaxies. find all sources exhibit strong (\geq 0.6 mag) F356W-F444W...
Abstract We utilize deep JWST Near Infrared Camera (NIRCam) observations for the first direct constraints on Galaxy Stellar Mass Function (GSMF) at z > 10. Our EPOCHS v1 sample includes 1120 galaxy candidates 6.5 < 13.5 taken from a consistent reduction and analysis of publicly available NIRCam data covering Prime Extragalactic Areas Reionization Science, CEERS, GLASS, JADES GOOD-S, NGDEEP, SMACS0723 surveys, totaling 187 arcmin 2 . investigate impact spectral energy distribution...
We present Gemini/GNIRS spectroscopic observations of 4 z-band (z~7) dropout galaxies and VLT/XSHOOTER one 3 Y-band (z~8-9) in the Hubble Ultra Deep Field, which were selected with Wide Field Camera imaging on Space Telescope. find no evidence Lyman-alpha emission a typical 5-sigma sensitivity 5X10^-18erg/cm^2/s, we use upper limits flux broad-band magnitudes to constrain rest-frame equivalent widths for this line emission. Accounting incomplete spectral coverage, survey 3.0 dropouts 2.9...
We present a new integral-field spectroscopic dataset of the central part Orion Nebula (M 42), observed with MUSE instrument at ESO VLT. reduced data public pipeline. The output products are two FITS cubes spatial size ~5.9'x4.9' (corresponding to ~0.76 pc x 0.63 pc) and contiguous wavelength coverage 4595...9366 Angstrom, spatially sampled 0.2". provide versions sampling 1.25 Angstrom 0.85 in dispersion direction. Together variance these files have 75 110 GiB on disk. They represent one...
We present rest-frame Lyα equivalent widths (EW0) of 417 emitters (LAEs) detected with Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) at 2.9 <z< 6.6 in Hubble Ultra Deep Field. Based deep MUSE spectroscopy and ancillary Space (HST) photometry data, we carefully measured EW0 values taking into account extended emission UV continuum slopes (β). Our LAEs reach unprecedented depths, both luminosities absolute magnitudes, from log (LLyα/erg s-1) ~ 41.0 to 43.0 MUV −16...