91 research outputs found
COVID-19 & privacy: Enhancing of indoor localization architectures towards effective social distancing
Abstract The way people access services in indoor environments has dramatically changed in the last year. The countermeasures to the COVID-19 pandemic imposed a disruptive requirement, namely preserving social distance among people in indoor environments. We explore in this work the possibility of adopting the indoor localization technologies to measure the distance among users in indoor environments. We discuss how information about people's contacts collected can be exploited during three stages: before, during, and after people access a service. We present a reference architecture for an Indoor Localization System (ILS), and we illustrate three representative use-cases. We derive some architectural requirements, and we discuss some issues that concretely cope with the real installation of an ILS in real-world settings. In particular, we explore the privacy and trust reputation of an ILS, the discovery phase, and the deployment of the ILS in real-world settings. We finally present an evaluation framework for assessing the performance of the architecture proposed
An atypical assessment of Ebsteinâs anomaly in an 86-year-old man
We present the echocardiographic analysis of an 86- year-old man affected by Ebsteinâs anomaly. In the natural history of this congenital disease only 5% of patients survive beyond the fifth decade. The patient presented severe right atrial dilatation and right heart failure, and he was referred to our institution for supraventricular tachycardia
The production of ionizing photons in UV-faint z~3-7 galaxies
The demographics of the production and escape of ionizing photons from
UV-faint early galaxies is a key unknown in discovering the primary drivers of
reionization. With the advent of JWST it is finally possible to observe the
rest-frame optical nebular emission from individual sub-L z>3 galaxies to
measure the production of ionizing photons, . Here we study a
sample of 380 z~3-7 galaxies spanning -23 <M < -15.5 (median
M -18) with deep multi-band HST and JWST/NIRCam photometry
covering the rest-UV to optical from the GLASS and UNCOVER JWST surveys. Our
sample includes 109 galaxies with Lyman-alpha emission detected in MUSE
spectroscopy. We use H-alpha fluxes inferred from NIRCam photometry to estimate
the production rate of ionizing photons which do not escape these galaxies
. We find median
, with a broad
intrinsic scatter 0.42 dex, implying a broad range of galaxy properties and
ages in our UV-faint sample. Galaxies detected with Lyman-alpha have ~0.1 dex
higher , which is explained by their higher
H-alpha EW distribution, implying younger ages, higher sSFR and thus more O/B
stars. We find significant trends of increasing
with increasing H-alpha EW, decreasing UV
luminosity, and decreasing UV slope, implying the production of ionizing
photons is enhanced in young, low metallicity galaxies. We find no significant
evidence for sources with very high ionizing escape fraction
(>0.5) in our sample, based on their photometric properties,
even amongst the Lyman-alpha selected galaxies. This work demonstrates that
considering the full distribution of across galaxy
properties is important for assessing the primary drivers of reionization.Comment: 10 pages, 7 figures, submitted to A&
The GLASS-JWST Early Release Science Program. II. Stage I release of NIRCam imaging and catalogs in the Abell 2744 region
We present images and a multi-wavelength photometric catalog based on all of
the JWST NIRCam observations obtained to date in the region of the Abell 2744
galaxy cluster. These data come from three different programs, namely the
GLASS-JWST Early Release Science Program, UNCOVER, and Director's Discretionary
Time program 2756. The observed area in the NIRCam wide-band filters - covering
the central and extended regions of the cluster, as well as new parallel fields
- is 46.5 arcmin in total. All images in eight bands (F090W, F115W, F150W,
F200W, F277W, F356W, F410M, F444W) have been reduced adopting the latest
calibration and reference files available. Data reduction has been performed
using an augmented version of the official JWST pipeline, with improvements
aimed at removing or mitigating defects in the raw images and improving the
background subtraction and photometric accuracy. We obtain a F444W-detected
multi-band catalog, including all NIRCam and available HST data, adopting
forced aperture photometry on PSF-matched images. The catalog is intended to
enable early scientific investigations and is optimized for the study of faint
galaxies; it contains 24389 sources, with a 5 limiting magnitude in the
F444W band ranging from 28.5 AB to 30.5 AB, as a result of the varying exposure
times of the surveys that observed the field. We publicly release the reduced
NIRCam images, associated multi-wavelength catalog and code adopted for
noise removal with the aim of aiding users to familiarize themselves with JWST
NIRCam data and identify suitable targets for follow-up observations.Comment: Accepted for publication in The Astrophysical Journal. Revised
analysis with updated comparison
Deliverable D6.4: Assessment report: Experimenting with CONNECT in Systems of Systems, and Mobile Environments
The core objective of WP6 is to evaluate the CONNECT technologies under realistic situations. To achieve this goal, WP6 concentrated a significant amount of its 4th year effort on the finalization of the implementation of the GMES scenario defined during the 3rd year. The GMES scenario allows the consortium to assess the validity of CONNECT claims and to investigate the exploitation of CONNECT technologies to deal with the integration of real systems. In particular, GMES requires the connection of highly heterogeneous and independently built systems provided by the industry partners. WP6 contributed also in providing mobile collaborative applications and case studies showing the exploitation of CONNECTORs on mobile devices
Near-infrared emission line diagnostics for AGN from the local Universe to redshift 3
Optical rest-frame spectroscopic diagnostics are usually employed to
distinguish between star formation and AGN-powered emission. However, this
method is biased against dusty sources, hampering a complete census of the AGN
population across cosmic epochs. To mitigate this effect, it is crucial to
observe at longer wavelengths in the rest-frame near-infrared (near-IR), which
is less affected by dust attenuation and can thus provide a better description
of the intrinsic properties of galaxies. AGN diagnostics in this regime have
not been fully exploited so far, due to the scarcity of near-IR observations of
both AGNs and star-forming galaxies, especially at redshifts higher than 0.5.
Using Cloudy photoionization models, we identify new AGN - star formation
diagnostics based on the ratio of bright near-infrared emission lines, namely
[SIII] 9530 Angstrom, [CI] 9850 Angstrom, [PII] 1.188 , [FeII] , and [FeII] to Paschen lines (either Pa or
Pa), providing simple, analytical classification criteria. We apply
these diagnostics to a sample of 64 star-forming galaxies and AGNs at 0 < z <
1, and 65 sources at 1 < z < 3 recently observed with JWST-NIRSpec in CEERS. We
find that the classification inferred from the near-infrared is broadly
consistent with the optical one based on the BPT and the [SII]/H ratio.
However, in the near-infrared, we find more AGNs than in the
optical (13 instead of 8), with 5 sources classified as 'hidden' AGNs, showing
a larger AGN contribution at longer wavelengths, possibly due to the presence
of optically thick dust. The diagnostics we present provide a promising tool to
find and characterize AGNs from z=0 to z=3 with low and medium-resolution
near-IR spectrographs in future surveys.Comment: Paper accepted for publication in A&A on 05/09/2023. Three public
Github repositories include: (1) a table with emission line measurements for
the paper sample : https://github.com/Anthony96/Line_measurements_nearIR ,
Cloudy emission line predictions for star-forming galaxies and AGN models :
https://github.com/Anthony96/star-forming_models ,
https://github.com/Anthony96/AGN_model
Early Results from GLASS-JWST. XIX: A High Density of Bright Galaxies at in the Abell 2744 Region
We report the detection of a high density of redshift galaxies
behind the foreground cluster Abell 2744, selected from imaging data obtained
recently with NIRCam onboard {\it JWST} by three programs -- GLASS-JWST,
UNCOVER, and DDT\#2756. To ensure robust estimates of the lensing magnification
, we use an improved version of our model that exploits the first epoch of
NIRCam images and newly obtained MUSE spectra, and avoids regions with
where the uncertainty may be higher. We detect seven bright
galaxies with demagnified rest-frame mag,
over an area of sq. arcmin. Taking into account photometric
incompleteness and the effects of lensing on luminosity and cosmological
volume, we find that the density of galaxies in the field is
about () larger than the average at mag reported so far. The density is even higher when considering only
the GLASS-JWST data, which are the deepest and the least affected by
magnification and incompleteness. The GLASS-JWST field contains 5 out of 7
galaxies, distributed along an apparent filamentary structure of 2 Mpc in
projected length, and includes a close pair of candidates with mag having a projected separation of only 16 kpc. These findings suggest
the presence of a overdensity in the field. In addition to
providing excellent targets for efficient spectroscopic follow-up observations,
our study confirms the high density of bright galaxies observed in early {\it
JWST} observations, but calls for multiple surveys along independent lines of
sight to achieve an unbiased estimate of their average density and a first
estimate of their clustering.Comment: Accepted for publication in ApJL, 13 pages, 4 figure
Early results from GLASS-JWST. XIV: A spectroscopically confirmed protocluster 650 million years after the Big Bang
We present the spectroscopic confirmation of a protocluster at
behind the galaxy cluster Abell2744 (hereafter A2744-z7p9OD). Using JWST
NIRSpec, we find seven galaxies within a projected radius of 60kpc. Although
the galaxies reside in an overdensity around greater than a random
volume, they do not show strong Lyman-alpha emission. We place 2- upper
limits on the rest-frame equivalent width -AA. Based on the tight
upper limits to the Lyman-alpha emission, we constrain the volume-averaged
neutral fraction of hydrogen in the intergalactic medium to be (68% CI). Using an empirical - relation for
individual galaxies, we estimate that the total halo mass of the system is
. Likewise, the line of sight velocity
dispersion is estimated to be km/s. Using an empirical relation,
we estimate the present-day halo mass of A2744-z7p9OD to be
, comparable to the Coma cluster. A2744-z7p9OD is
the highest redshift spectroscopically confirmed protocluster to date,
demonstrating the power of JWST to investigate the connection between
dark-matter halo assembly and galaxy formation at very early times with
medium-deep observations at hrs total exposure time. Follow-up
spectroscopy of the remaining photometric candidates of the overdensity will
further refine the features of this system and help characterize the role of
such overdensities in cosmic reionization.Comment: The title has been updated to reflect the published numbering; a
minor change has been made to Figure 1 with regard to the MSA shutters on the
rgb stamp image. NASA press release article can be found at:
https://www.nasa.gov/feature/goddard/2023/webb-reveals-early-universe-prequel-to-huge-galaxy-cluste
CEERS: Spatially Resolved UV and mid-IR Star Formation in Galaxies at 0.2 < z < 2.5: The Picture from the Hubble and James Webb Space Telescopes
We present the mid-IR (MIR) morphologies for 64 star-forming galaxies at
0.210^{9}~M_\odot} using JWST MIRI
observations from the Cosmic Evolution Early Release Science survey (CEERS).
The MIRI bands span the MIR (7.7--21~m), enabling us to measure the
effective radii () and S\'{e}rsic indexes of these SFGs at
rest-frame 6.2 and 7.7 m, which contains strong emission from Polycyclic
aromatic hydrocarbon (PAH) features, a well-established tracer of star
formation in galaxies. We define a ``PAH-band'' as the MIRI bandpass that
contains these features at the redshift of the galaxy. We then compare the
galaxy morphologies in the PAH-bands to those in rest-frame Near-UV (NUV) using
HST ACS/F435W or ACS/F606W and optical/near-IR using HST WFC3/F160W imaging
from UVCANDELS and CANDELS, where the NUV-band and F160W trace the profile of
(unobscured) massive stars and the stellar continuum, respectively. The
of galaxies in the PAH-band are slightly smaller (10\%)
than those in F160W for galaxies with at
, but the PAH-band and F160W have a similar fractions of light within
1 kpc. In contrast, the of galaxies in the NUV-band are larger,
with lower fractions of light within 1 kpc compared to F160W for galaxies at
. Using the MIRI data to estimate the surface
density, we find the correlation between the surface
density and stellar mass has a steeper slope than that of the
surface density and stellar mass, suggesting more massive
galaxies having increasing amounts of obscured fraction of star formation in
their inner regions. This paper demonstrates how the high-angular resolution
data from JWST/MIRI can reveal new information about the morphology of
obscured-star formation.Comment: 28 pages, 11 figures, Accepted by Ap
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