IDCS J1426.5+3508: Cosmological implications of a massive, strong lensing cluster at Z = 1.75

The galaxy cluster IDCS J1426.5+3508 at z = 1.75 is the most massive galaxy cluster yet discovered at z > 1.4 and the first cluster at this epoch for which the Sunyaev-Zel'Dovich effect has been observed. In this paper we report on the discovery with HST imaging of a giant arc associated with this cluster. The curvature of the arc suggests that the lensing mass is nearly coincident with the brightest cluster galaxy, and the color is consistent with the arc being a star-forming galaxy. We compare the constraint on M200 based upon strong lensing with Sunyaev-Zel'Dovich results, finding that the two are consistent if the redshift of the arc is z > 3. Finally, we explore the cosmological implications of this system, considering the likelihood of the existence of a strongly lensing galaxy cluster at this epoch in an LCDM universe. While the existence of the cluster itself can potentially be accomodated if one considers the entire volume covered at this redshift by all current high-redshift cluster surveys, the existence of this strongly lensed galaxy greatly exacerbates the long-standing giant arc problem. For standard LCDM structure formation and observed background field galaxy counts this lens system should not exist. Specifically, there should be no giant arcs in the entire sky as bright in F814W as the observed arc for clusters at z \geq 1.75, and only \sim 0.3 as bright in F160W as the observed arc. If we relax the redshift constraint to consider all clusters at z \geq 1.5, the expected number of giant arcs rises to \sim15 in F160W, but the number of giant arcs of this brightness in F814W remains zero. These arc statistic results are independent of the mass of IDCS J1426.5+3508. We consider possible explanations for this discrepancy.Comment: 7 pages, 4 figures, Accepted to The Astrophysical Journa

Le nuove tecnologie immersive degli ambienti museali-monumentali. Applicazione alla Certosa di Calci

Questa tesi si pone l’obiettivo di donare un nuovo volto al Museo Nazionale della Certosa Monumentale di Pisa, tramite l’utilizzo di nuove tecnologie come realtà virtuali o aumentate, video-mapping ed altre applicazioni innovative che renderebbero il viaggio all’interno degli ambienti del monastero più immersivo e coinvolgente. Partendo da uno studio a larga scala dello stato dell’arte in Italia e passando attraverso la storia dell’edificio della Certosa, è stato possibile ideare un nuovo percorso di visita nel quale sono state introdotte alcune applicazioni. Tali applicazioni hanno il compito di legarsi maggiormente con il visitatore, fornendo a quest’ultimo informazioni dettagliate e indirizzate ad un pubblico ampio e diversificato. This thesis aims to give a new face to the National Museum of the Monumental Charterhouse in Pisa, through the use of new technologies such as virtual or augmented reality, video-mapping and other innovative applications that would make the journey inside the environments of the monastery most immersive and engaging. Starting from a large-scale study of the state of the art in Italy and going through the history of the Charterhouse building, it was possible to devise a new visit path in which some applications were introduced. These applications have the task of linking more with the visitor, providing the latter with detailed information and addressed to a wide and diverse audience

Immersive Technologies for the Museum of the Charterhouse of Calci

The Charterhouse of Pisa in Calci, one of the most important monasteries in Tuscany, now houses two important museums: the Natural History Museum of the University of Pisa and the National Museum of the Monumental Charterhouse of Calci. While the Natural History Museum has recently enriched its collection by offering structured and differentiated visits based on user type, the offerings of the Museum of the Monumental Charterhouse are not sufficiently adequate to meet the great historical value of the complex. This contribution therefore presents the first results of a project aimed at enhancing visits to the National Museum of the Charterhouse using immersive technologies. The project envisages the definition of a new visit path, modifying the current path and integrating it with immersive experiences of video mapping, VR/AR, sound immersion, informative totems, audio–visual supports, and multisensory activities