12 research outputs found
VizieR Online Data Catalog: COSMOS field variability-selected AGN nuclei (De Cicco+, 2015)
The VLT Survey Telescope (VST) is located at Cerro Paranal Observatory; it is a joint venture between the European Southern Observatory (ESO) and the INAF-Osservatorio Astronomico di Capodimonte (OAC) in Napoli. The telescope is 2.65m in diameter and is equipped with the single focal plane detector OmegaCAM: a mosaic of 32 CCD detectors made up of 268 megapixels in total, corresponding to a 26cmx26cm area and a 1°x1° FoV, the resolution being 0.214"/pixel. The VST is dedicated to surveys in the wavelength range 0.3-1.0um. The survey provides data in the g, r, and i bands, with an observing frequency of approximately ten days for the g and i bands and three days for the r band, depending on the various observational constraints. We discuss here the analysis of 28 epochs in the r band, for which we have the best temporal sampling. The observations cover the period from December 2011 to May 2012. (1 data file)
VizieR Online Data Catalog: SUDARE-VOICE variability-selection of AGN (Falocco+, 2015)
This work is based on data in the r band from the SUDARE-VOICE survey performed with the VST telescope (Botticella et al., 2013Msngr.151...29B; Cappellaro et al., in prep.; Vaccari et al., in prep.). The data are centred on the Chandra Deep Field South, covering an area of 2deg2, in the u, g, r, i bands. (1 data file)
VizieR Online Data Catalog: SUDARE VST-OmegaCAM search supernova rates (Cappellaro+, 2015)
The SUDARE SN survey was performed using the VLT Survey Telescope (VST) equipped with the OmegaCAM camera, that started regular operations in October 2011 at ESO Paranal (Chile). The VST has a primary mirror of 2.6m and a f/5.5 modified Ritchey-Chretien optical layout that is designed to deliver a large, uniform focal plane. SUDARE is a four-year programme and this paper is devoted to analysing the first two observing seasons for VOICE-CDFS and one season for COSMOS. We are currently completing the monitoring of both fields for the two subsequent seasons. (1 data file)
First Results from Supernova Diversity and Rate Evolution (SUDARE) Survey at VST
Despite the key role played by Supernovae (SNe) in discovering the accelerating expansion of the Universe, there are still fundamental questions to answer about their progenitor systems and explosion mechanisms. Furthermore the discovery of a significant number of both exceptionally bright and extremely faint SNe, as well as peculiar events, suggests the existence of an unexpected diversity. Important clues on the SN progenitors can be derived by examining the rate of type Ia and core collapse SNe. With this goal in mind we started the SUpernova Diversity And Rate Evolution (SUDARE) programme currently running at the VLT Survey Telescope (VST). We present a measurement of the volumetric SN rates as a function of redshift for the first 2 years of data from SUDARE
Il sistema agro-alimentare dell’Emilia-Romagna, Rapporto 2014
Il Rapporto 2014 sul Sistema Agroalimentare dell'Emilia-Romagna rappresenta un importante contributo alla conoscenza di un settore fondamentale dell'economia regionale, un utile strumento per gli operatori e una guida per le politiche degli enti locali. Il Rapporto si apre con due capitoli che descrivono da un lato, lo scenario internazionale e, dall'altro le politiche comunitarie e nazionali, per il settore agroalimentare, che modificano lo scenario nel quale gli operatori saranno chiamati a muoversi dal 2014 al 2020. I principali cambiamenti congiunturali del sistema agroalimentare regionale occupano la parte central del Rapporto, con Quattro capitol dedicati all'agricoltura. Successivamente vengono affrontati gli altri aspetti rilevanti del sistema agro-alimentare regionale partendo dall'industria alimentare, con le dinamiche congiunturali e alcuni approfondimenti strutturali dell'occupazione
Chasing Gravitational Waves with the Chereknov Telescope Array
Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)2310.07413International audienceThe detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA
Chasing Gravitational Waves with the Chereknov Telescope Array
Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)2310.07413International audienceThe detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA
Performance of a proposed event-type based analysis for the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the field of very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics. Classically, data analysis in the field maximizes sensitivity by applying quality cuts on the data acquired. These cuts, optimized using Monte Carlo simulations, select higher quality events from the initial dataset. Subsequent steps of the analysis typically use the surviving events to calculate one set of instrument response functions (IRFs). An alternative approach is the use of event types, as implemented in experiments such as the Fermi-LAT. In this approach, events are divided into sub-samples based on their reconstruction quality, and a set of IRFs is calculated for each sub-sample. The sub-samples are then combined in a joint analysis, treating them as independent observations. This leads to an improvement in performance parameters such as sensitivity, angular and energy resolution. Data loss is reduced since lower quality events are included in the analysis as well, rather than discarded. In this study, machine learning methods will be used to classify events according to their expected angular reconstruction quality. We will report the impact on CTA high-level performance when applying such an event-type classification, compared to the classical procedure
Chasing Gravitational Waves with the Chereknov Telescope Array
Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)2310.07413International audienceThe detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA
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Risk of COVID-19 after natural infection or vaccinationResearch in context
Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health