Is there room for highly magnetized pulsar wind nebulae among those non-detected at TeV?

We make a time-dependent characterization of pulsar wind nebulae (PWNe) surrounding some of the highest spin-down pulsars that have not yet been detected at TeV. Our aim is assessing their possible level of magnetization. We analyze the nebulae driven by J2022+3842 in G76.9+1.0, J0540-6919 in N158A (the Crab twin), J1400--6325 in G310.6--1.6, and J1124--5916 in G292.0+0.18, none of which have been found at TeV energies. For comparison we refer to published models of G54.1+0.3, the Crab nebula, and develop a model for N157B in the Large Magellanic Cloud (LMC). We conclude that further observations of N158A could lead to its detection at VHE. According to our model, a FIR energy density of 5 eV cm$^{-3}$ could already lead to a detection in H.E.S.S. (assuming no other IC target field) within 50 hours of exposure and just the CMB inverse Compton contribution would produce VHE photons at the CTA sensitivity. We also propose models for G76.9+1.0, G310.6--1.6 and G292.0+1.8 which suggest their TeV detection in a moderate exposure for the latter two with the current generation of Cherenkov telescopes. We analyze the possibility that these PWNe are highly magnetized, where the low number of particles explains the residual detection in X-rays and their lack of detection at TeV energies.Comment: Accepted for publication in MNRA

The effects of magnetic field, age, and intrinsic luminosity on Crab-like pulsar wind nebulae

We investigate the time-dependent behavior of Crab-like pulsar wind nebulae (PWNe) generating a set of models using 4 different initial spin-down luminosities ($L_0 =\{1,0.1,0.01,0.001\} \times L_{0, {\rm Crab}}$), 8 values of magnetic fraction ($\eta =$ 0.001, 0.01, 0.03, 0.1, 0.5, 0.9, 0.99, and 0.999, i.e., from fully particle dominated to fully magnetically dominated nebulae), and 3 distinctive ages: 940, 3000, and 9000 years. We find that the self-synchrotron Compton (SSC) contribution is irrelevant for $L_{SD}$=0.1, 1, and 10% of the Crab power, disregarding the age and the magnetic fraction. SSC only becomes relevant for highly energetic ($\sim 70$ of the Crab), particle dominated nebulae at low ages (of less than a few kyr), located in a FIR background with relatively low energy density. Since no pulsar other than Crab is known to have these features, these results clarify why the Crab Nebula, and only it, is SSC dominated. No young PWN would be detectable at TeV energies if the pulsar's spin-down power is 0.1% Crab or lower. For 1% of the Crab spin-down, only particle dominated nebulae can be detected by H.E.S.S.-like telescopes when young enough (with details depending on the precise injection and environmental parameters). Above 10% of the Crab's power, all PWNe are detectable by H.E.S.S.-like telescopes if they are particle dominated, no matter the age. The impact of the magnetic fraction on the final SED is varied and important, generating order of magnitude variations in the luminosity output for systems that are otherwise the same (equal $P$, $\dot P$, injection, and environment).Comment: Accepted for publication in MNRA

A GIS-based approach to monitor and assess historical forest landscape evolution

In order to assess landscape dynamics, as well as the effectiveness of relevant management strategies, it is necessary to develop monitoring systems based on qualitative and quantitative tools for its conservation, valorisation and restoration. This approach is particularly important for historical rural landscapes having a recognized ecological and cultural value. To do this, it is first necessary to apply a chronological methodology since, by definition, landscapes result from an interaction of natural and anthropogenic factors over time. Thanks to the constant evolution of Geographic Information Systems and of different geodata available, the monitoring of historical landscapes is increasingly effective and inclusive. Using as a case study an historical forest landscape recognized at Italian level for its high value (Lucanian Apennines’s beech forest - Basilicata Region), a diachronic analysis was applied to evaluate its multi-temporal evolution. Starting from historical cartographies up to Sentinel-2 satellite imagery, a GIS-based approach was implemented to evaluate the spatial variations of forest cover in this landscape. The techniques applied have allowed to reconstruct the original structure of the beech forests, useful for a possible restoration in some areas, but also to monitor the processes in place by using vegetation indices derived from remote sensing

Integrating remote-sensed and historical geodata to assess interactions between rural buildings and agroforestry land

The rural built heritage constitutes a unique example, due to architectural and technical issues, which plays a central role in the formation of rural landscape. In this research, interactions between rural buildings and the surrounding land have been examined. Two case studies exemplifying some of typical dynamics of some internal mountain areas of Mediterranean region have been considered. These areas are located in Basilicata Region (Southern Italy) and suffer from land and rural buildings heritage abandonment, as well as from the concurrent disappearance of agroforestry systems with high ecological value. A multi-chronological geo-database incorporating different land cover datasets over a period of 62 years (1955–1988–2008–2017) has been implemented into a GIS to assess relationships between some rural buildings and the surrounding land have been then assessed. This has been achieved by integrating different types of remote-sensed geodata: historical aerial photos, digital orthophotos and satellite images. The analyses carried out have shown that the intensity of land abandonment can also be related to the type of rural building and prevalent agricultural activity. Moreover, thanks to this methodology, it has been possible to produce several spatial information useful to support public decisionmakers at different level

Valorization of an old sheep trail as a new opportunity for sustainable public recreation: a case study in southern Italy.

Within the valorization process of rural landscape for public recreation, an increasing interest is currently registered on ancient sheep-tracks. Indeed, these paths constitute the historical infrastructure of the transhumance system, that covered all over Europe thousands of kilometers, forming the routes of shepherds, merchants, warriors and pilgrims. In Italy, these tracks - known as “tratturi“ - are landscape-bound, while the practice of transhumance has recently been included in the intangible UNESCO World Heritage. In addition to their cultural and scenic value, today some old sheep-tracks are being rediscovered as new rural hiking trails. However, they present some technical drawbacks, that make them barely usable by tourists for walking in the nature. Taking as a case study an old sheep-track connecting the two cities of Matera and Montescaglioso (Basilicata Region - Southern Italy), a GIS approach was applied, to evaluate the possibilities to use this path as an hiking trail, highlighting the difficulties to be solved for its valorization. The final results showed how, thanks to a GIS tool, it is possible to compare different types of data, from historical to modern ones, so relating the route with all elements of tourist interest, evaluating its potential for excursion purposes as well

Reducing the visual impact of plasticulture on rural landscapes by a sustainable management of agricultural plastics.

The use of plastics in agriculture represents one of the main factors having a major impact on the environmental sustainability of the agricultural sector. The effectiveness, economy and versatility of using different plastic polymers has made these products widespread in highly profitable agricultural activities (orchards and horticulture). However, their incorrect management can determine serious environmental impacts, mainly connected to large quantities of post-consume plastic waste. Another problem is linked to the visual impact that these large clusters can have on the surrounding rural landscape. Indeed, the aesthetic quality of these territories may be reduced, with negative impacts on the surrounding areas - often characterized by a fragile environment and a marked tourist vocation - whose perception is difficult to quantify and evaluate. In this paper, a GIS-based methodology has been implemented, to perform a visual impact assessment, by applying it to the case study of the agri-food district of “Metapontino” (Basilicata Region - Southern Italy). GIS tools, besides allowing complex spatial analysis, revealed as a planning instrument that can be used by public authority also to activate suitable strategies for mitigating the visual impact of plastics on rural landscape, so as to contribute to reducing the plastic footprint of agriculture

Investigating the Time Evolution of a Rural Landscape: How Historical Maps May Provide Environmental Information When Processed Using a GIS.

A rural landscape is the result of the interaction among natural elements and human activities which takes place in time and space. It represents a non-renewable resource that can provide incomparable information on the general state of the environment. The rapid transformations that are taking place in the last century push towards the implementation of monitoring actions able to take into account the various components of the land use, including their concurrent time evolution as well. We performed an analysis of temporal transformations of a rural landscape using an open-source GIS approach that allowed for mainstreaming of the main features of this rural landscape, i.e. land use patterns, naturalness dynamics, landscape diversity and visual quality. These four parameters have been selected since they represent those which most affect the processes at the base of the environmental planning and management of a rural landscape. The survey has been carried out over a period of 138 years, using historical maps, interpretation of aerial photos and implementing digital cartography, that have been retrieved with reference to a study area located in the Basilicata Region (southern Italy), which is considered a territory with an high rural – i.e., both natural and agricultural - landscape value. This methodology has allowed for the examination of the landscape from different points of view, experimenting the performance of a multi-temporal and inter-disciplinary analysis. The main results show – since the landscape has been completely transformed by man in terms of land use – that the areas covered in the past by forest have been transformed into agricultural areas, as opposed to some areas where re-naturalisation processes have taken place. Starting from this first analysis, the implemented methodology, based on a multidisciplinary approach, has enabled to identify the transformations which have greatly influenced the time evolution of the study area. The resulted assessment of land use patterns, landscape diversity, naturalness dynamics and visual quality of this study area, thus enables suitable strategies for the restoration of the local rural ecosystems

Assessing the impact of built heritage on the rural landscape through the integration in a GIS of cartographic information and remote-sensed data.

Rural landscapes are the result of the interaction occurred over time between human activities and natural environment. Humanity has built constructions conceived to host farmers and biological productions, that have contributed to increase the level of agricultural productivity, meeting the food demand. This built heritage constitutes now a unique example - due to architectural and technical issues different from other building sectors - which plays indeed a central role in the formation of the rural landscape, as well as on relevant ecosystem services. In this paper, the interactions between historical rural buildings and the surrounding landscape have been examined. A specific geo-database incorporating different datasets from topographical maps, aerial photos and satellite images has been implemented into a GIS. This approach has enabled to assess land dynamics around rural buildings, in terms of land cover and landscape indexes. A case study in an internal mountain area of Southern Italy has been considered. Thanks to a large-scale detailed spatial analysis, the relationships between some rural buildings and the surrounding landscape have been then assessed. This methodology allowed to implement a spatial system finalized to support solutions useful to public decision-makers, as well as to evaluate activities of protection and/or valorisation of the agro-forestry landscapes