In the UK a significant proportion of Multi-Owned Properties (MoPs) – characterised by buildings segmented into individually owned flats – must undergo retrofitting to achieve net zero emissions. ...Despite this requirement, advancement has been minimal, with existing government policy failing to consider a pivotal role of social dynamics among residents in the retrofit decision-making process. This research adopts an innovative perspective grounded in relational sociology, leveraging Viviana A. Zelizer's concept of ‘relational work’ and integrating two of the three types of social relations identified by Hargreaves and Middlemiss' (intimacy and institutions) to dissect the retrofit challenges faced by owners of historic MoPs in South Glasgow, UK. The study reveals that the necessity for heightened relational work among property owners acts as a barrier to retrofit initiative. Nevertheless, it identifies potential pathway to invigorate the retrofit sector by enhancing neighbourly connections and recognising the influential, yet underexplored, role of property managers in facilitating retrofit activities within MoPs. This inquiry not only underscores the significance of social relations in environmental retrofit projects but also suggests a re-evaluation of policy frameworks to accommodate the social intricacies inherent in MoPs, thereby fostering a more conducive environment for achieving net-zero targets.
•Progress is minimal for retrofit in Multi-owned properties (MoPs).•Current policies ignore social dynamics in retrofit decision-making.•Relational sociology holds promise for the retrofit challenge in historic MoPs.•Better connecting key retrofit actors drives retrofit progress in MoPs.
We analyze the Sun as a source for the indirect detection of dark matter through a search for gamma rays from the solar disk. Capture of dark matter by elastic interactions with the solar nuclei ...followed by annihilation to long-lived mediators can produce a detectable gamma-ray flux. We search 3 years of data from the High Altitude Water Cherenkov (HAWC) observatory and find no statistically significant detection of TeV gamma-ray emission from the Sun. Using this, we constrain the spin-dependent elastic scattering cross section of dark matter with protons for dark matter masses above 1 TeV, assuming a sufficiently long-lived mediator. The results complement constraints obtained from Fermi-LAT observations of the Sun and together cover WIMP masses between 4 and 106 GeV . In the optimal scenario, the cross-section constraints for mediator decays to gamma rays can be as strong as ∼ 10−45 cm2 , which is more than 4 orders of magnitude stronger than current direct-detection experiments for a 1 TeV dark matter mass. The cross-section constraints at higher masses are even better, nearly 7 orders of magnitude better than the current direct-detection constraints for a 100 TeV dark matter mass. This demonstration of sensitivity encourages detailed development of theoretical models in light of these powerful new constraints.
We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground-based ...air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken over 234 days between June 2016 and February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of −2.49±0.01 prior to a break at (45.7±0.1) TeV, followed by an index of −2.71±0.01. The spectrum also represents a single measurement that spans the energy range between direct detection and ground-based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow’s dependence on energy.
Although complementarity achieved by combining multiple renewable energy sources (RES) is an important method to increase shares of RES, it is often overlooked in policy prescriptions supporting an ...energy transition. Complementarity can be implemented by multiple actors, however there has been little attention to which actors are involved, and their roles. A systematic review was conducted to provide an overview of the state of academic literature on the topic of combinations of multiple RES and the involvement of multiple associated actors. The sample included 78 articles using a range of methodologies to analyze varying combinations of wind, solar, bioenergy, hydro, geothermal, and ocean energy, alongside combinations of traditional, new, and supporting energy actors. Studies included contextualized (location specific) agent-based, techno-economic, economic, business model, and qualitative analyses, and decontextualized reviews, agent-based, and optimization models. Multi-actor complementarity is being addressed by diverse disciplines in diverse contexts globally, across a range of geographic scales. The majority of studies focus on solar-wind, although more diverse RES combinations were found in contextualized studies. New actors usually participate alongside traditional system actors. More attention to supporting actors is required. Findings highlight the need for further research beyond the technical benefits of combining multiple RES, to explore the roles of various actors. This can be accomplished by incorporating more context in studies, for example, using the substantial existing body of data and research, and by including a greater range of RES combinations, and incorporating more perspectives of associated actors.
•Systematic review to understand actor involvement in complementarity of renewables.•The sample represents diverse disciplines with various methodologies.•The topic is being studied both in and out of geographical context, at varying scales.•Wind and solar were most common, but more diverse combinations are found in context.•Traditional and new actors found across studies; supporting actors require attention.
Local dwarf spheroidal galaxies (dSphs) are nearby dark-matter dominated systems, making them excellent targets for searching for gamma rays from particle dark matter interactions. If dark matter ...annihilates or decays directly into two gamma rays (or a gamma ray and a neutral particle), a monochromatic spectral line is created. At TeV energies, no other process is predicted to produce spectral lines, making this a very clean indirect dark matter search channel. With the development of event-by-event energy reconstruction, we can now search for spectral lines with the High Altitude Water Cherenkov (HAWC) Observatory. HAWC is a wide field of view survey instrument located in central Mexico that observes gamma rays from ∼ 200 GeV to ∼ 200 TeV . In this work we present results from a recent search for spectral lines from local, dark matter dominated, dwarf galaxies using 1038 days of HAWC data. We also present updated limits on several continuum channels that were reported in a previous publication. Our gamma-ray spectral line limits are the most constraining obtained so far from 20 TeV to 100 TeV.
Steady gamma-ray emission up to at least 200 GeV has been detected from the solar disk in the Fermi-LAT data, with the brightest, hardest emission occurring during solar minimum. The likely cause is ...hadronic cosmic rays undergoing collisions in the Sun’s atmosphere after being redirected from ingoing to outgoing in magnetic fields, though the exact mechanism is not understood. An important new test of the gamma-ray production mechanism will follow from observations at higher energies. Only the High Altitude Water Cherenkov (HAWC) Observatory has the required sensitivity to effectively probe the Sun in the TeV range. Using 3 years of HAWC data from November 2014 to December 2017, just prior to the solar minimum, we search for 1–100 TeV gamma rays from the solar disk. No evidence of a signal is observed, and we set strong upper limits on the flux at a few 10−12 TeV − 1 cm − 2 s − 1 at 1 TeV. Our limit, which is the most constraining result on TeV gamma rays from the Sun, is ∼ 10 % of the theoretical maximum flux (based on a model where all incoming cosmic rays produce outgoing photons), which in turn is comparable to the Fermi-LAT data near 100 GeV. The prospects for a first TeV detection of the Sun by HAWC are especially high during the solar minimum, which began in early 2018.
Context.
Ground-based γ-ray astronomy is still a rather young field of research, with strong historical connections to particle physics. This is why most observations are conducted by experiments ...with proprietary data and analysis software, as is usual in the particle physics field. However, in recent years, this paradigm has been slowly shifting toward the development and use of open-source data formats and tools, driven by upcoming observatories such as the Cherenkov Telescope Array (CTA). In this context, a community-driven, shared data format (the
gamma-astro-data-format
, or GADF) and analysis tools such as
Gammapy
and
ctools
have been developed. So far, these efforts have been led by the Imaging Atmospheric Cherenkov Telescope community, leaving out other types of ground-based
γ
-ray instruments.
Aims.
We aim to show that the data from ground particle arrays, such as the High-Altitude Water Cherenkov (HAWC) observatory, are also compatible with the GADF and can thus be fully analyzed using the related tools, in this case,
Gammapy.
Methods.
We reproduced several published HAWC results using
Gammapy
and data products compliant with GADF standard. We also illustrate the capabilities of the shared format and tools by producing a joint fit of the Crab spectrum including data from six different
γ
-ray experiments.
Results.
We find excellent agreement with the reference results, a powerful confirmation of both the published results and the tools involved.
Conclusions.
The data from particle detector arrays such as the HAWC observatory can be adapted to the GADF and thus analyzed with
Gammapy.
A common data format and shared analysis tools allow multi-instrument joint analysis and effective data sharing. To emphasize this, a sample of Crab nebula event lists is made public with this paper. Because of the complementary nature of pointing and wide-field instruments, this synergy will be distinctly beneficial for the joint scientific exploitation of future observatories such as the Southern Wide-field Gamma-ray Observatory and CTA.
Gamma/hadron separation with the HAWC observatory Alfaro, R.; Alvarez, C.; Álvarez, J.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2022, Letnik:
1039
Journal Article
Recenzirano
Odprti dostop
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory observes atmospheric showers produced by incident gamma rays and cosmic rays with energy from 300 GeV to more than 100 TeV. A crucial ...phase in analyzing gamma-ray sources using ground-based gamma-ray detectors like HAWC is to identify the showers produced by gamma rays or hadrons. The HAWC observatory records roughly 25,000 events per second, with hadrons representing the vast majority (>99.9%) of these events. The standard gamma/hadron separation technique in HAWC uses a simple rectangular cut involving only two parameters. This work describes the implementation of more sophisticated gamma/hadron separation techniques, via machine learning methods (boosted decision trees and neural networks), and summarizes the resulting improvements in gamma/hadron separation obtained in HAWC.
An indirect measurement of the antiproton flux in cosmic rays is possible as the particles undergo deflection by the geomagnetic field. This effect can be measured by studying the deficit in the ...flux, or shadow, created by the Moon as it absorbs cosmic rays that are headed toward the Earth. The shadow is displaced from the actual position of the Moon due to geomagnetic deflection, which is a function of the energy and charge of the cosmic rays. The displacement provides a natural tool for momentum/charge discrimination that can be used to study the composition of cosmic rays. Using 33 months of data comprising more than 80 billion cosmic rays measured by the High Altitude Water Cherenkov observatory, we have analyzed the Moon shadow to search for TeV antiprotons in cosmic rays. Here, we present our first upper limits on the p¯/p fraction, which in the absence of any direct measurements provide the tightest available constraints of ~1 % on the antiproton fraction for energies between 1 and 10 TeV.
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