I segni del passato geologico. Viaggio tra i geositi della provincia di Treviso.

I geositi, e pi\uf9 in generale tutte le aree di interesse geologico, naturalistico e biologico, beneficiano oramai di ampie letterature di settore, nelle quali il concetto \ue8 ben rappresentato secondo canoni di forme e contenuti. La trattazione classica \ue8 quasi sempre quella di un \u201cinventario\u201d, il quale, a causa della variabilit\ue0 del quadro geografico, deve coprire ambiti territoriali che spaziano dalla descrizione della singola particolarit\ue0 sino a veri e propri cataloghi regionali. Questo schema di trattazione ha l\u2019innegabile vantaggio del rigore metodologico e della completezza delle informazioni. I contenuti sono solitamente resi con modalit\ue0 utili agli addetti ai lavori, ma che difficilmente potranno rivolgersi al grande pubblico senza un\u2019efficace premessa tecnico-divulgativa e una chiara contestualizzazione territoriale. I geositi provinciali hanno gi\ue0 avuto una prima mappatura in forma di catalogo e sono stati anche oggetto di una tesi di laurea in Scienze geologiche che ne ha approfondito talune caratteristiche. Da questa prima esperienza, preso atto della qualit\ue0 e dell\u2019abbondanza del materiale documentale disponibile, \ue8 maturata una nuova visione della materia. Si tratta di un approccio innovativo che ribalta il punto di vista passando dall\u2019illustrazione dei processi geologici che hanno concorso alla creazione di un geosito alla spiegazione degli stessi processi con l\u2019ausilio dei geositi. Sono stati individuati quattro filoni tematici principali: i rilievi montuosi, gli ambiti fluviali, le tracce glaciali e i fenomeni carsici. La trattazione di ciascun tema \ue8 preceduta da un\u2019introduzione di tipo descrittivo che ha il fine di illustrare i meccanismi all\u2019origine delle forme che oggi possiamo ammirare viaggiando attraverso la provincia di Treviso. Il libro ha la forma di un testo che \ue8 prima di tutto didattico, con lo scopo di valorizzare e far comprendere le tante bellezze del nostro territorio a prescindere dall\u2019etichetta di \u201cgeosito\u201d. Si tratta quindi di una sorta di guida attiva che stimola ognuno a stilare un proprio elenco di geositi, testimonianza di un paesaggio visto e vissuto con diverse sensibilit\ue0 e attenzioni. Secondo noi, il geosito deve rappresentare un luogo dove poter \u201cleggere\u201d la complessit\ue0 dei fenomeni che l\u2019hanno originato e comprendere la logica che ne fa un luogo in qualche modo particolare, distinto dagli altri e, quindi, fuori dal comune. Il libro si discosta perci\uf2 da una mera trattazione scientifica e mira piuttosto alla pi\uf9 ampia divulgazione; esso \ue8 il frutto di una raccolta e di una rielaborazione sia di nozioni acquisite nel corso di specifici studi, sia di informazioni che si trovano in svariate pubblicazioni, in rete e nelle biblioteche, con il fine di incuriosire il lettore e di avvicinarlo alla conoscenza consapevole del proprio territorio

Making the most othe relic density for dark matter searches at the LHC 14TeV Run

As the LHC continues to search for new weakly interacting particles, it is important to remember that the search is strongly motivated by the existence of dark matter. In view of a possible positive signal, it is essential to ask whether the newly discovered weakly interacting particle can be be assigned the label "dark matter". Within a given set of simplified models and modest working assumptions, we reinterpret the relic abundance bound as a relic abundance range, and compare the parameter space yielding the correct relic abundance with projections of the Run II exclusion regions. Assuming that dark matter is within the reach of the LHC, we also make the comparison with the potential 5\u3c3 discovery regions. Reversing the logic, relic density calculations can be used to optimize dark matter searches by motivating choices of parameters where the LHC can probe most deeply into the dark matter parameter space. In the event that DM is seen outside of the region giving the correct relic abundance, we will learn that either thermal relic DM is ruled out in that model, or the DM-quark coupling is suppressed relative to the DM coupling strength to other SM particles

Atmospheric turbulence profiling using the SLODAR technique with ARGOS at LBT

ARGOS is the Ground Layer Adaptive Optics system of the Large Binocular Telescope, it uses three Laser Guide Stars, generated by Rayleigh backscattered light of pulsed lasers. Three Shack-Hartmann WFS measure the wavefront distortion in the Ground Layer. The SLOpe Detection And Ranging (SLODAR) is a method used to measure the turbulence profiles. Cross correlation of wavefronts gradient from multiple stars is used to estimate the relative strengths of turbulent layers at different altitudes. We present here the results on sky of the SLODAR profile on ARGOS

Numerical control matrix rotation for the LINC-NIRVANA Multi-Conjugate Adaptive Optics system

LINC-NIRVANA will realize the interferometric imaging focal station of the Large Binocular Telescope. A double Layer Oriented multi-conjugate adaptive optics system assists the two arms of the interferometer, supplying high order wave-front correction. In order to counterbalance the field rotation, mechanical derotation for the two ground wave-front sensors, and optical derotators for the mid-high layers sensors fix the positions of the focal planes with respect to the pyramids aboard the wave-front sensors. The derotation introduces pupil images rotation on the wavefront sensors: the projection of the deformable mirrors on the sensor consequently change. The proper adjustment of the control matrix will be applied in real-time through numerical computation of the new matrix. In this paper we investigate the temporal and computational aspects related to the pupils rotation, explicitly computing the wave-front errors that may be generated.Comment: 6 pages, 2 figures, presented at SPIE Symposium "Astronomical Telescopes and Instrumentation'' conference "Adaptive Optics Systems II'',Sunday 27 June 2010, San Diego, California, US

Evaporation and scattering of momentum- and velocity-dependent dark matter in the Sun

Dark matter with momentum- or velocity-dependent interactions with nuclei has shown significant promise for explaining the so-called Solar Abundance Problem, a longstanding discrepancy between solar spectroscopy and helioseismology. The best-fit models are all rather light, typically with masses in the range of 3–5 GeV. This is exactly the mass range where dark matter evaporation from the Sun can be important, but to date no detailed calculation of the evaporation of such models has been performed. Here we carry out this calculation, for the first time including arbitrary velocity- and momentum-dependent interactions, thermal effects, and a completely general treatment valid from the optically thin limit all the way through to the optically thick regime. We find that depending on the dark matter mass, interaction strength and type, the mass below which evaporation is relevant can vary from 1 to 4 GeV. This has the effect of weakening some of the better-fitting solutions to the Solar Abundance Problem, but also improving a number of others. As a by-product, we also provide an improved derivation of the capture rate that takes into account thermal and optical depth effects, allowing the standard result to be smoothly matched to the well-known saturation limit

On the Validity of the Effective Field Theory for Dark Matter Searches at the LHC Part III: Analysis for the t-channel

We extend our recent analysis of the limitations of the effective field theory approach to studying dark matter at the LHC, by investigating the case in which Dirac dark matter couples to standard model quarks via t-channel exchange of a heavy scalar mediator. We provide analytical results for the validity of the effective field theory description, for both 1as = 8 TeV and 14 TeV. We make use of a MonteCarlo event generator to assess the validity of our analytical conclusions. We also point out the general trend that in the regions where the effective field theory is valid, the dark matter relic abundance is typically large

MAORY AO performances

The Multi-conjugate Adaptive Optics RelaY (MAORY) should provide 30% SR in K band (50% goal) on half of the sky at the South Galactic Pole. Assessing its performance and the sensitivity to parameter variations during the design phase is a fundamental step for the engineering of such a complex system. This step, centered on numerical simulations, is the connection between the performance requirements and the Adaptive Optics system configuration. In this work we present MAORY configuration and performance and we justify theAdaptive Optics system design choices.Comment: 9 pages, 7 figures, 1 table. SPIE conference Astronomical Telescopes and Instrumentation, 14 - 18 December 2020, digital foru

Performance and First Science Observations with ARGOS

Coming online for scientific operations, the ARGOS facility is boosting the imaging and spectroscopic capabilities at the LBT. With six Rayleigh laser guide stars and the corresponding wavefront sensing, ARGOS corrects the ground layer distortions for both LBT 8.4 m telescopes with its adaptive secondary mirrors. Under most conditions this setup delivers a PSF size reduction by a factor ~2-3. With the two LUCI infrared imaging and MOS spectroscopy instruments receiving the corrected images, observations in the near infrared can be performed at high spatial and spectral resolution. We will briefly discuss the final ARGOS technical setup and the adaptive optics performances. With first scientific observations been conducted, we will show that imaging cases with GLAO are nicely boosting several science programs from cluster CMD, Milky Way embedded star formation and Cepheids, BHs in nearby galaxies to extragalactic deep fields. In the unique combination of ARGOS with the multi-object NIR spectroscopy available in LUCI, first scientific observations have been performed on local and high-z objects. Those high spatial and spectral resolution observations nicely demonstrate the capabilities now at hand with ARGOS at the LBT. Inhere we describe briefly the system and show examples of science observations from nearby clusters to high redshift gravitationally lensed objects

Rolling shutter-induced aberrations in laser guide star wavefront sensing

Laser guide star (LGS) Shack-Hartmann (SH) wavefront sensors for next-generation Extremely Large Telescopes (ELTs) require low-noise, large format ( 1/41 Mpx), fast detectors to match the need for a large number of subapertures and a good sampling of the very elongated spots. One path envisaged to fulfill this need has been the adoption of complementary metal metal-oxide semiconductor detectors with a rolling shutter read-out scheme that allows low read-out noise and fast readout time at the cost of image distortion due to the detector rows exposed in different moments. Here, we analyze the impact of the rolling shutter read-out scheme when used for LGS SH wavefront sensing; in particular, we focus on the impact on the adaptive optics (AO) correction of the distortion-induced aberrations created by the rolling exposure in the case of fast varying aberrations, like the ones coming from the LGS tilt jitter due to the up-link propagation of laser beams. We show that the LGS jitter-induced aberration for an ELT can be as large as 100-nm root-mean-square, a significant term in the wavefront error budget of a typical AO system on an ELT, and we discuss possible mitigation strategies