40 research outputs found
The origin of early Acheulean expansion in Europe 700Â ka ago: new findings at Notarchirico (Italy)
Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670Â ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route
The origin of early Acheulean expansion in Europe 700Â ka ago: new findings at Notarchirico (Italy)
Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670 ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route
Gli scavi dell’Università degli Studi di Napoli “L’Orientale” nell’abitato greco-romano di Cuma (2007-2013)
Sintesi degli scavi nell'abitato greco-romano di Cuma, anni 2007-201
Design, construction, and test of the Gas Pixel Detectors for the IXPE mission
Due to be launched in late 2021, the Imaging X-Ray Polarimetry Explorer
(IXPE) is a NASA Small Explorer mission designed to perform polarization
measurements in the 2-8 keV band, complemented with imaging, spectroscopy and
timing capabilities. At the heart of the focal plane is a set of three
polarization-sensitive Gas Pixel Detectors (GPD), each based on a custom ASIC
acting as a charge-collecting anode. In this paper we shall review the design,
manufacturing, and test of the IXPE focal-plane detectors, with particular
emphasis on the connection between the science drivers, the performance metrics
and the operational aspects. We shall present a thorough characterization of
the GPDs in terms of effective noise, trigger efficiency, dead time, uniformity
of response, and spectral and polarimetric performance. In addition, we shall
discuss in detail a number of instrumental effects that are relevant for
high-level science analysis -- particularly as far as the response to
unpolarized radiation and the stability in time are concerned.Comment: To be published in Astroparticle Physic
XIPE: the x-ray imaging polarimetry explorer
XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry window in high energy Astrophysics after more than 4 decades thanks to a detector that efficiently exploits the photoelectric effect and to X-ray optics with large effective area. XIPE uniqueness is time-spectrally-spatially- resolved X-ray polarimetry as a breakthrough in high energy astrophysics and fundamental physics. Indeed the payload consists of three Gas Pixel Detectors at the focus of three X-ray optics with a total effective area larger than one XMM mirror but with a low weight. The payload is compatible with the fairing of the Vega launcher. XIPE is designed as an observatory for X-ray astronomers with 75 % of the time dedicated to a Guest Observer competitive program and it is organized as a consortium across Europe with main contributions from Italy, Germany, Spain, United Kingdom, Poland, Sweden