91 research outputs found

    COVID-19 & privacy: Enhancing of indoor localization architectures towards effective social distancing

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    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 Ebstein’s anomaly in an 86-year-old man

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    We present the echocardiographic analysis of an 86- year-old man affected by Ebstein’s 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

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    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, ξion\xi_\mathrm{ion}. Here we study a sample of 380 z~3-7 galaxies spanning -23 <MUV_\mathrm{UV} < -15.5 (median MUV≈_\mathrm{UV}\approx -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 ξion(1−fesc)\xi_\mathrm{ion}(1-f_\mathrm{esc}). We find median log⁡10ξion(1−fesc)=25.33±0.47\log_{10}\xi_\mathrm{ion}(1-f_\mathrm{esc})=25.33\pm 0.47, 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 ξion(1−fesc)\xi_\mathrm{ion}(1-f_\mathrm{esc}), 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 ξion(1−fesc)\xi_\mathrm{ion}(1-f_\mathrm{esc}) 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 (fescf_\mathrm{esc}>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 ξion\xi_\mathrm{ion} 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

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    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 arcmin2^2 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 5σ\sigma 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 1/f1/f 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

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    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

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    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 Οm\mu m, [FeII] 1.257Οm1.257 \mu m, and [FeII] 1.64Οm1.64 \mu m to Paschen lines (either Paγ\gamma or Paβ\beta), 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]/Hι\alpha ratio. However, in the near-infrared, we find ∟60%\sim 60 \% 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 z≈10z\approx10 in the Abell 2744 Region

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    We report the detection of a high density of redshift z≈10z\approx 10 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 μ\mu, 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 μ>5\mu>5 where the uncertainty may be higher. We detect seven bright z≈10z\approx 10 galaxies with demagnified rest-frame −22≲MUV≲−19-22 \lesssim M_{\rm UV}\lesssim -19 mag, over an area of ∼37\sim37 sq. arcmin. Taking into account photometric incompleteness and the effects of lensing on luminosity and cosmological volume, we find that the density of z≈10z\approx 10 galaxies in the field is about 10×10\times (3×3\times) larger than the average at MUV≈−21 (−20)M_{UV}\approx -21~ (-20) 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 MUV<−20M_{\rm UV}< -20 mag having a projected separation of only 16 kpc. These findings suggest the presence of a z≈10z\approx 10 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

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    We present the spectroscopic confirmation of a protocluster at z=7.88z=7.88 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 >20×>20\times greater than a random volume, they do not show strong Lyman-alpha emission. We place 2-σ\sigma upper limits on the rest-frame equivalent width <16<16-2828AA. 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 xHI>0.45x_{\rm HI} > 0.45 (68% CI). Using an empirical MUVM_{\rm UV}-MhaloM_{\rm halo} relation for individual galaxies, we estimate that the total halo mass of the system is ≳4×1011 M⊙\gtrsim 4\times10^{11}\,M_\odot. Likewise, the line of sight velocity dispersion is estimated to be 1100±2001100 \pm 200km/s. Using an empirical relation, we estimate the present-day halo mass of A2744-z7p9OD to be ∼2×1015 M⊙\sim2\times10^{15}\,M_\odot, 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 <20<20hrs 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

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    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~μ\mum), enabling us to measure the effective radii (ReffR_{\rm{eff}}) and S\'{e}rsic indexes of these SFGs at rest-frame 6.2 and 7.7 μ\mum, 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 ReffR_{\rm{eff}} of galaxies in the PAH-band are slightly smaller (∼\sim10\%) than those in F160W for galaxies with M∗≳109.5 M⊙\rm{M_*\gtrsim10^{9.5}~M_\odot} at z≤1.2z\leq1.2, but the PAH-band and F160W have a similar fractions of light within 1 kpc. In contrast, the ReffR_{\rm{eff}} of galaxies in the NUV-band are larger, with lower fractions of light within 1 kpc compared to F160W for galaxies at z≤1.2z\leq1.2. Using the MIRI data to estimate the SFRIR\rm{SFR_{\rm{IR}}} surface density, we find the correlation between the SFRIR\rm{SFR_{\rm{IR}}} surface density and stellar mass has a steeper slope than that of the SFRUV\rm{SFR_{\rm{UV}}} 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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