E. Romelli
A5039672603- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Remote Sensing in Agriculture
- History and Developments in Astronomy
- Calibration and Measurement Techniques
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Planetary Science and Exploration
- Impact of Light on Environment and Health
- Statistical and numerical algorithms
- Advanced Vision and Imaging
- Spectroscopy and Laser Applications
- CCD and CMOS Imaging Sensors
- Particle physics theoretical and experimental studies
- Spectroscopy and Chemometric Analyses
- Real-time simulation and control systems
Trieste Astronomical Observatory
2015-2025
University College London
2024
University of Copenhagen
2024
Flatiron Health (United States)
2024
Flatiron Institute
2024
Royal Holloway University of London
2024
University of California, Davis
2024
New York University
2024
Princeton University
2024
Marconi University
2023-2024
Recent cosmic shear studies have shown that higher-order statistics (HOS) developed by independent teams now outperform standard two-point estimators in terms of statistical precision thanks to their sensitivity the non-Gaussian features large-scale structure. The aim Higher-Order Weak Lensing Statistics (HOWLS) project is assess, compare, and combine constraining power ten different HOS on a common set $Euclid$-like mocks, derived from N-body simulations. In this first paper HOWLS series,...
Euclid's photometric galaxy cluster survey has the potential to be a very competitive cosmological probe. The main probe with observations of clusters is their number count, within which halo mass function (HMF) key theoretical quantity. We present new calibration analytic HMF, at level accuracy and precision required for uncertainty in this quantity subdominant respect other sources recovering parameters from Euclid counts. Our model calibrated against suite N-body simulations using...
Aims. We validate a semi-analytical model for the covariance of real-space two-point correlation function galaxy clusters. Methods. Using 1000 PINOCCHIO light cones mimicking expected Euclid sample clusters, we calibrated simple to accurately describe clustering covariance. Then, used this quantify likelihood-analysis response variations in covariance, and investigated impact cosmology-dependent matrix at level statistics survey Results. find that Gaussian with Poissonian shot-noise does not...
This work considers which higher order modeling effects on the cosmic shear angular power spectra must be taken into account for Euclid . We identified relevant terms and quantified their individual cumulative impact cosmological parameter inferences from computed values of these using analytic expressions calculated estimations Fisher matrix formalism. reviewed 24 determined ones that potentially need to accounted for, namely: reduced approximation, magnification bias, source-lens...
ABSTRACT Next-generation telescopes, like Euclid, Rubin/LSST, and Roman, will open new windows on the Universe, allowing us to infer physical properties for tens of millions galaxies. Machine-learning methods are increasingly becoming most efficient tools handle this enormous amount data, because they often faster more accurate than traditional methods. We investigate how well redshifts, stellar masses, star-formation rates (SFRs) can be measured with deep-learning algorithms observed...
Gravitational redshift and Doppler effects give rise to an antisymmetric component of the galaxy correlation function when cross-correlating two populations or different tracers. In this paper, we assess detectability these in spectroscopic survey. We model impact gravitational on observed galaxies Flagship mock catalogue using a Navarro--Frenk--White profile for host haloes. isolate relativistic effects, largely subdominant standard analysis, by splitting into faint bright objects...
In physically realistic, scalar-field-based dynamical dark energy models (including, e.g., quintessence), one naturally expects the scalar field to couple rest of model’s degrees freedom. particular, a coupling electromagnetic sector leads time (redshift) dependence in fine-structure constant and violation weak equivalence principle. Here we extend previous Euclid forecast constraints on this enlarged (but more realistic) parameter space, how well , together with high-resolution...
We investigate the cosmological constraints that can be expected from measurement of cross-correlation galaxies with cosmic voids identified in Euclid spectroscopic survey, which will include information for tens millions over $15\,000$ deg$^2$ sky redshift range $0.9\leq z<1.8$. do this using simulated measurements obtained Flagship mock catalogue, official closely matches properties data set. To mitigate anisotropic selection-bias effects, we use a velocity field reconstruction method to...
The photometric catalogue of galaxy clusters extracted from ESA Euclid data is expected to be very competitive for cosmological studies. Using dedicated hydrodynamical simulations, we present systematic analyses simulating the weak-lensing profiles in a variety dynamic states and wide range redshifts. In order derive cluster masses, use model consistent with implementation within Consortium processing function find that when jointly mass concentration parameter Navarro–Frenk–White halo...
To obtain an accurate cosmological inference from upcoming weak lensing surveys such as the one conducted by Euclid , shear measurement requires calibration using galaxy image simulations. As it typically millions of simulated images and consequently a substantial computational effort, seeking methods to speed up is valuable. We study efficiency different noise cancellation that aim at reducing simulation volume required reach given precision in measurement. The more efficient method is,...
The material composition of asteroids is an essential piece knowledge in the quest to understand formation and evolution Solar System. Visual near-infrared spectra or multiband photometry required constrain asteroids, but we currently have such data, especially wavelengths, for only a limited number asteroids. This significant limitation considering complex orbital structures asteroid populations. Up 150 000 will be visible images upcoming ESA Euclid space telescope, instruments offer visual...
The Euclid mission will conduct an extragalactic survey over 15000 deg$^2$ of the sky. spectroscopic channel Near-Infrared Spectrometer and Photometer (NISP) has a resolution $R\sim450$ for its blue red grisms that collectively cover $0.93$--$1.89 $\micron;range. NISP obtain redshifts $3\times10^7$ galaxies experiments on galaxy clustering, baryonic acoustic oscillations, redshift space distortion. wavelength calibration must be accurate within $5$\AA to avoid systematics in downstream...
Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of distribution galaxies on cosmic scales, by means which we can probe underlying large-scale structure (LSS) Universe. This allow to test concordance model and its extensions. However, precision pushes high levels accuracy in theoretical modelling LSS observables, so no biases introduced into estimation parameters. In particular, effects such as redshift-space distortions...
Verifying the fully kinematic nature of cosmic microwave background (CMB) dipole is fundamental importance in cosmology. In standard cosmological model with Friedman-Lemaitre-Robertson-Walker (FLRW) metric from inflationary expansion CMB should be entirely kinematic. Any non-kinematic component would thus reflect preinflationary structure spacetime probing extent FLRW applicability. Cosmic backgrounds galaxies after matter-radiation decoupling, have identical velocity dipole. Comparing two...
Verifying the fully kinematic nature of long-known cosmic microwave background (CMB) dipole is fundamental importance in cosmology. In standard cosmological model with Friedman–Lemaitre–Robertson–Walker (FLRW) metric from inflationary expansion, CMB should be entirely kinematic. Any non-kinematic component would thus reflect preinflationary structure space-time probing extent FLRW applicability. Cosmic backgrounds galaxies after matter-radiation decoupling have a identical velocity to...
The Complete Calibration of the Color–Redshift Relation survey (C3R2) is a spectroscopic program designed to empirically calibrate galaxy color–redshift relation Euclid depth ( I E = 24.5), key ingredient for success Stage IV dark energy projects based on weak lensing cosmology. A calibration sample that as representative possible galaxies in being collected, selecting from self-organizing map (SOM) representation color space. Here, we present results near-infrared H - and K -band campaign...
Cosmological constraints from key probes of the Euclid imaging survey rely critically on accurate determination true redshift distributions, $n(z)$, tomographic bins. We determine whether mean redshift, $$, ten bins can be calibrated to target uncertainties $σ()<0.002\,(1+z)$ via cross-correlation, with spectroscopic samples akin those Baryon Oscillation Spectroscopic Survey (BOSS), Dark Energy Instrument (DESI), and Euclid's NISP survey. construct mock galaxy Flagship simulation measure...
Context. Comparing theoretical predictions to real data is crucial properly formulate galaxy formation theories. However, this usually done naively considering the direct output of simulations and quantities inferred from observations, which can lead severe inconsistencies. Aims. We present FORECAST, a new flexible adaptable software package that performs forward modeling any cosmological hydrodynamical create wide range realistic synthetic astronomical images, thus providing robust...
Forthcoming imaging surveys will increase the number of known galaxy-scale strong lenses by several orders magnitude. For this to happen, images billions galaxies have be inspected identify potential candidates. In context, deep-learning techniques are particularly suitable for finding patterns in large data sets, and convolutional neural networks (CNNs) particular can efficiently process volumes images. We assess compare performance three network architectures classification strong-lensing...
We present new estimates of the brightness temperatures Jupiter, Saturn, Uranus, and Neptune based on measurements carried in 2009--2013 by PLANCK/LFI at 30, 44, 70 GHz released to public 2018. This work extends results presented 2013 2015 Calibration Papers, data acquired 2009--2011. PLANCK observed each planet up eight times during nominal mission. processed time-ordered from 22 LFI radiometers derive antenna for transit. accounted beam shape, radiometer bandpasses, several systematic...
Aims. We validate a semi-analytical model for the covariance of real-space 2-point correlation function galaxy clusters. Methods. Using 1000 PINOCCHIO light cones mimicking expected Euclid sample clusters, we calibrate simple to accurately describe clustering covariance. Then, use such quantify likelihood analysis response variations covariance, and investigate impact cosmology-dependent matrix at level statistics survey Results. find that Gaussian with Poissonian shot-noise does not...
To obtain an accurate cosmological inference from upcoming weak lensing surveys such as the one conducted by Euclid, shear measurement requires calibration using galaxy image simulations. We study efficiency of different noise cancellation methods that aim at reducing simulation volume required to reach a given precision in measurement. Explicitly, we compared fit with cancellations and method based on responses. used GalSim simulate galaxies both grid random positions larger scenes. Placing...
Extragalactic globular clusters (EGCs) are an abundant and powerful tracer of galaxy dynamics formation, their own formation evolution is also a matter extensive debate. The compact nature means that they hard to spatially resolve thus study outside the Local Group. In this work we have examined how well EGCs will be detectable in images from Euclid telescope, using both simulated pre-launch first early-release observations Fornax cluster. Wide Survey provide high-spatial resolution VIS...