The energy spectrum of cosmic rays beyond the turn-down around 10^17 eV as measured with the surface detector of the Pierre Auger Observatory

We present a measurement of the cosmic-ray spectrum above 100 PeV using the part of the surface detector of the Pierre Auger Observatory that has a spacing of 750 m. An inflection of the spectrum is observed, confirming the presence of the so-called second-knee feature. The spectrum is then combined with that of the 1500 m array to produce a single measurement of the flux, linking this spectral feature with the three additional breaks at the highest energies. The combined spectrum, with an energy scale set calorimetrically via fluorescence telescopes and using a single detector type, results in the most statistically and systematically precise measurement of spectral breaks yet obtained. These measurements are critical for furthering our understanding of the highest energy cosmic rays

Ethnic out-group faces are biased in the prejudiced mind

Contains fulltext : 73137.pdf (publisher's version ) (Closed access)Prejudice biases cognition, affect, and behavior toward ethnic out-groups. We propose that prejudice also biases the way people conceptualize the facial appearance of out-group members. Popular belief holds that people's personality traits are reflected in their facial features. We hypothesized that prejudiced people also have more negatively stereotyped mental representations of faces of people in the out-group. To test this hypothesis, we conducted two studies involving the category of Moroccans, a highly stigmatized immigrant group in The Netherlands. The results of the first study suggested that highly prejudiced people have biased mental representations of Moroccan faces. We ran a second study using more trials in the image construction phase, but with an otherwise identical design, to enhance the quality of individual participants' classification images. This allowed us to replicate the findings of the first study on an individual rather than subgroup level.3 p

The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory

FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operation of a robotic telescope for such a purpose and their implementation within the FRAM system