Search

Xenon dual-phase time projection chambers designed to search for Weakly Interacting Massive Particles have so far shown a relative energy resolution which degrades with energy above $\sim$200 keV. This has limited their sensitivity in the search for rare events like the neutrinoless double-beta decay of $^{136}$Xe at its $Q$-value, $Q_{\beta\beta}\simeq$ 2.46 MeV. For the XENON1T dual-phase time projection chamber, we demonstrate that the relative energy resolution at 1 $\sigma/\mu$ is as low as (0.79$\pm$0.02) % in its one-ton fiducial mass, and for single-site interactions at $Q_{\beta\beta}$. We achieve this by using a signal correction method to rectify the saturation effects of the signal readout system. The very good energy resolution from keV to MeV energies demonstrated in XENON1T opens up new windows for the xenon dual-phase dark matter detectors to simultaneously search for other rare events.

Si existe un eje articulador de los debates religiosos de la era de la revolución rioplatense, es lo que hoy llamamos eclesiología. La preocupación por los problemas eclesiológicos fue una de las varias herencias que el nuevo orden recibió del antiguo en materia político-religiosa. La generación que hizo la revolución, en parte por haberse formado en instituciones en las que esa preocupación latía con fuerza, en parte por haber debido tomar decisiones a menudo impostergables en el terreno de la política eclesiástica, hizo de la eclesiología una veta de reflexión prioritaria. En este artículo se exponen y analizan los principales filones de reflexión eclesiológica que se desplegaron entre 1820 y 1835, período en el que tres temas acapararon la atención de los católicos rioplatenses y encendieron candentes debates entre ellos: el de la reforma eclesiástica, el de la tolerancia de cultos disidentes y el de las primeras relaciones formales con la Santa Sede.

We have compiled the most complete census of High-Mass X-ray Binaries (HMXBs) in the Small Magellanic Cloud with the aim to investigate the formation efficiency of young accreting binaries in its low metallicity environment. In total, we use 127 X-ray sources with detections in our \chandra X-ray Visionary Program (XVP), supplemented by 14 additional (likely and confirmed) HMXBs identified by \cite{2016A&A...586A..81H} that fall within the XVP area, but are not either detected in our survey (9 sources) or matched with any XVP source that has at least one OB counterpart in the OGLE-III catalog (5 sources). Specifically, we examine the number ratio of the HMXBs [N(HMXBs)] to {\it (a)} the number of OB stars, {\it (b)} the local star-formation rate (SFR), and {\it (c)} the stellar mass produced during the specific star-formation burst, all as a function of the age of their parent stellar populations. Each of these indicators serves a different role, but in all cases we find that the HMXB formation efficiency increases as a function of time (following a burst of star formation) up to $\sim$40--60\,Myr, and then gradually decreases. The peak formation efficiency N(HMXB)/SFR is (49 $\pm$ 14) $[10^{-5}~{\rm M_{\odot}/yr}]^{-1}$, in good agreement with previous estimates of the average formation efficiency in the broad $\sim$20--60\,Myr age range. The frequency of HMXBs is a factor of 8$\times$ higher than at $\sim$10\,Myr, and 4$\times$ higher than at $\sim$260\,Myr, i.e. at earlier and later epochs, respectively., 9 pages, 4 figures, submitted to ApJ, comments welcome

Obiettivi: Dalle analisi dei dati degli studi precedenti effettuati in Sicilia sono emerse diverse indicazioni, per cui è stata avviata un’indagine in Sicilia nel 2013 , grazie ad un finanziamento della LILT nazionale, intesa a: valutare la situazione immunologica ed ematochimica e la sieroprevalenza in persone a stretto contatto con i malati (parente di 1 grado o marito/moglie) o parenti affetti dalla stessa patologia; indagare alcuni fattori di rischio con un questionario;effettuare il follow-up dei malati ogni 6-12-18-24 mesi ; individuare un Centro di Riferimento in Sicilia per la diagnosi e cura di questo tumore raro. Materiali e Metodi: Sono stati arruolati 24 Casi (21M/3F) e 27 Controlli familiari (9M/18F), residenti in Sicilia e solo un caso di sesso maschile residente in Calabria. La casistica non include 3 casi maschi perché arruolati per la seconda volta al follow-up ; inoltre 1 caso M e relativo controllo (moglie) è stato escluso in quanto affetto da altro tipo di Sarcoma. I controlli sono stati familiari consanguinei e/o non consanguinei ( moglie, marito, genero ecc..) di casi in cura presso le Università di Catania e Messina oppure già arruolati negli studi precedenti dalla LILT di Ragusa, alcuni dei quali deceduti. Risultati: Dal confronto tra Controlli HHV8 positivi (n°11) vs. Controlli HHV8 negativi (n°16) non sono state individuate differenze significative a eta’, sesso, livello d’istruzione, occupazione e varie esposizione ambientali (età : >64 vs

Gravitational lensing provides a means to measure mass that does not rely on detecting and analysing light from the lens itself. Compact objects are ideal gravitational lenses, because they have relatively large masses and are dim. In this paper we describe the prospects for predicting lensing events generated by the local population of compact objects, consisting of 250 neutron stars, 5 black holes, and approximately 35,000 white dwarfs. By focusing on a population of nearby compact objects with measured proper motions and known distances from us, we can measure their masses by studying the characteristics of any lensing event they generate. Here we concentrate on shifts in the position of a background source due to lensing by a foreground compact object. With HST, JWST, and Gaia, measurable centroid shifts caused by lensing are relatively frequent occurrences. We find that 30-50 detectable events per decade are expected for white dwarfs. Because relatively few neutron stars and black holes have measured distances and proper motions, it is more difficult to compute realistic rates for them. However, we show that at least one isolated neutron star has likely produced detectable events during the past several decades. This work is particularly relevant to the upcoming data releases by the Gaia mission and also to data that will be collected by JWST. Monitoring predicted microlensing events will not only help to determine the masses of compact objects, but will also potentially discover dim companions to these stellar remnants, including orbiting exoplanets., 16 pages, 10 figures, 8 tables