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Opis: This research examines the spatial patterns and economic significance of cultural heritage sites along Beijing’s metro lines, with an emphasis on how urban infrastructure influences heritage preservation. Using spatial analysis methods, including the nearest-neighbor index, geographic concentration index, and location entropy, the research identifies patterns in the distribution of cultural heritage sites - such as ancient architecture, industrial heritage, and tombs - particularly concentrated within Beijing’s second ring road. The study highlights the connectivity provided by key metro lines, including Lines 1, 2, 4, 5, 7, and 8, which link cultural sites in a point distribution pattern. On these premises, the research established a hierarchical framework to evaluate cultural heritage based on proximity to metro stations, with historical and artistic values being the most significant factors. The findings suggest that heritage sites within one kilometre of metro stations exert more significant influence on their surrounding areas and emphasize the importance of integrating metro infrastructure with cultural heritage preservation. This study contributes to understanding the spatial dynamics of cultural heritage in urban environments, offering a framework for assessing the impact of heritage within contemporary infrastructure systems. Practically, the study offers insights for urban planners, metro authorities, and cultural preservation bodies, proposing thematic routes along metro lines—such as Line 1 representing a fusion of Chinese and Western cultures and Line 5 emphasizing religious culture—to enhance cultural tourism. It also emphasizes the need for coordinated efforts between stakeholders to balance heritage conservation and urban development for sustainable growth.
Ključne besede: dissertations, linear cultural heritage, national cultural heritage, Beijing, spatial distribution, economic assessment
Objavljeno v RUNG: 31.03.2025; Ogledov: 349; Prenosov: 9
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Opis: A dedicated search for upward-going air showers at zenith angles exceeding 110° and energies E>0.1  EeV has been performed using the Fluorescence Detector of the Pierre Auger Observatory. The search is motivated by two “anomalous” radio pulses observed by the ANITA flights I and III that appear inconsistent with the standard model of particle physics. Using simulations of both regular cosmic-ray showers and upward-going events, a selection procedure has been defined to separate potential upward-going candidate events and the corresponding exposure has been calculated in the energy range [0.1–33] EeV. One event has been found in the search period between January 1, 2004, and December 31, 2018, consistent with an expected background of 0.27 ± 0.12 events from misreconstructed cosmic-ray showers. This translates to an upper bound on the integral flux of (7.2±0.2)×10[sup]−21  cm[sup]−2 sr[sup]−1 y[sup]−1 and (3.6±0.2)×10−20  cm[sup]−2 sr[sup]−1 y[sup]−1 for an E[sup]−1 and E[sup]−2 spectrum, respectively. An upward-going flux of showers normalized to the ANITA observations is shown to predict over 34 events for an E[sup]−3 spectrum and over 8.1 events for a conservative E[sup]−5 spectrum, in strong disagreement with the interpretation of the anomalous events as upward-going showers.
Ključne besede: ultra-high-energy cosmic rays, extensive air showers, upward-going air showers, Pierre Auger Observatory, Fluorescence Detector, anomalous ANITA events
Objavljeno v RUNG: 28.03.2025; Ogledov: 374; Prenosov: 5
Celotno besedilo (447,09 KB)
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Opis: The Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory is an array of 153 radio-antenna stations that measure the 30−80 MHz radio emission produced in extensive air showers in the energy range between 0.1 and 10 EeV. It has been taking data for over a decade. In this contribution, we present the recent results of AERA. We show the measurements of the depths of the shower maxima (Xmax) using the radio footprint and using interferometry, demonstrating compatibility and competitiveness with the established fluorescence detection method. We also show the measurement of the stability of the radio signal over close to a decade determined using the Galactic radio background as a calibration source, demonstrating that a radio detector can be used to lower systematic uncertainties on the energy scale of, for example, fluorescence and water-Cherenkov detectors.
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, radio emission
Objavljeno v RUNG: 28.03.2025; Ogledov: 362; Prenosov: 5
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Opis: The distribution of the arrival directions of cosmic rays observed by the Pierre Auger Observatory has a dipolar component that implies a flux dependence on declination. Previously, we showed that the spectrum built from events arriving with a zenith angle less than 60° is qualitatively consistent with the dipole. In this work, we go one step further and show that the Auger spectrum cannot reject the hypothesis of a declination-independent flux. By using events of up 80°, we extend the previous survey from +25° of declination to +45°, thus covering 85% of the sky.
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, UHECR arrival directions, large-scale dipolar anisotropy
Objavljeno v RUNG: 28.03.2025; Ogledov: 354; Prenosov: 6
Celotno besedilo (364,62 KB)
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Opis: The combination of fluorescence and surface detectors at the Pierre Auger Observatory offers unprecedented precision in testing models of hadronic interactions at center-of-mass energies around 70 TeV and beyond. However, for some time, discrepancies between model predictions and measured air-shower data have complicated efforts to accurately determine the mass composition of ultra-high-energy cosmic rays. A key inconsistency is the deficit of simulated signals compared to those measured with the surface detectors, typically interpreted as a deficit in the muon signal generated by the hadronic component of simulated showers. Recently, a new global method has been applied to the combined data from the surface and fluorescence detectors at the Pierre Auger Observatory. This method simultaneously determines the mass composition of cosmic rays and evaluates variations in the simulated depth of the shower maximum and hadronic signals on the ground. The findings reveal not only the alleviated muon problem but also show that all current models of hadronic interactions predict depths of the shower maximum that are too shallow, offering new insights into deficiencies in these models from a broader perspective.
Ključne besede: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, hadronic interactions
Objavljeno v RUNG: 28.03.2025; Ogledov: 339; Prenosov: 8
Celotno besedilo (782,91 KB)
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