Deliverable D32 Core indicators for the interconnection between short and long-distance transport networks ; projet 7FP CLOSER (Connecting LOng and Short-distance networks for Efficient Transport); September 2011

The CLOSER project has been set to analyse the interfaces and interconnections between long distance transport networks and local/regional transport networks of all modes. The project is funded within the Seventh Framework Programme of the European Commission, under the topic TPT-2008.0.0.13 “New mobility/organisational schemes: interconnection between short and long-distance transport networks”. The goal of WP3 of CLOSER is to establish a set of core indicators that reflect the most crucial issues connected to interfaces between short and long-distance transport networks, both for passenger and freight transport. This includes the creation of a structured representation of these interfaces, determination of core indicators, and the assessment of usability of the core indicators. CLOSER WP3 has produced two deliverables, of which the current document is the second. The first deliverable “Interconnections between short and long-distance transport networks: Structure of interface and existing indicators” (Andersen et al., 2010) contained a review of existing indicators related to interfaces between long and short-distance freight and passenger transport.The aim of this document is to structure the interconnections between short and longdistancetransport networks. This in particular includes:- Establishment of selection criteria to choose core indicators- Selection and validation of core indicators and new indicators- Set of typologies of interfacesThe document also presents the results of the WP3 workshop arranged in Lille on May 24, 2011

Resident's preferences for urban brownfield revitalization: Insights from two Czech cities.

Residents’ preferences are one of the factors in deciding how brownfields should be revitalized. We compare the views of residents in a city with many brownfields (Karviná) with those in a city with only few brownfields (České Budějovice). We assessed the preferences of residents for four global regeneration alternatives (refurbishment, demolition, open space, (re)development) in three different areas of a city (city centre, inner city, city outskirts). A one percent population sample of two post-socialistic cities in the Czech Republic, was used for the comparison. Positive preferences towards brownfield regeneration were confirmed. We found spatial differences in preferences between refurbishment and demolition of brownfields in each city area: demolition was preferred for inner city brownfields whereas refurbishment was preferred in the city centre and outskirts. Differences were also identified between the two cities: residents of the brownfield rich city preferred demolition, whereas residents of the city with few brownfields preferred refurbishment. Creating new public open space, for residents′ recreation, was given a lower importance within the city centre and a higher significance in outskirts. With the support of a combined ANOVA model, significant differences in residents’ preferences were found for distinct types of regeneration with regards to the cities’ character, the location of brownfields within the city and residents′ proximity

The Brownfield Ground Risk Calculator: a new spatial decision support tool for estimating ground risk and remediation costs for site located in Greater Manchester, UK

The Greater Manchester Brownfield Ground Risk Calculator (BGR_calc) is a Geographical Information System (GIS) spatial decision support tool designed to provide an early indication of potentially abnormal ground conditions and the indicative costs of mitigating them. This is important because abnormal ground conditions can affect the viability of the constructing of new homes on post-industrial brownfield sites. Multi-criteria decision analysis methods were used process and utilise over 30 input dataets. BGR_calc comprises four primary outputs, each represents a different set of ground risk or cost mitigation characteristics that occur within the Greater Manchester area, presented alongside their associated input data. Each output comprises risk scores (scored between 0 to 1) or risk mitigation cost estimates (£) presented as 50 m grid cells and site based summaries for over 2000 individual sites. BGR_calc makes the assumption that all brownfield land evaluated will be used to develop two storey residential housing at a density of 30 houses per hectare. Ground risk scores reflect the nominal risk that soil and groundwater contamination and soil and rock hazards might pose to human health, controlled waters and the structural integrity of new homes. The scores are derived from data on sources of contamination or ground conditions resulting from previous land-uses and/or natural processes, the presence of exposure pathways and sensitive receptors (residents, water resources and homes). For there to be a risk, the source, pathway and receptor components must be linked. Risk mitigation cost estimates represent the amount that might need to be paid to develop a brownfield site over and above ‘normal’ development costs. No allowance is made in BGR_calc for the financial benefits of pre-existing infrastructure, proximity to services and employment that brownfield land usually have but these ought to be considered within the overall economic evaluation of individual sites

Constraints on black-hole charges with the 2017 EHT observations of M87*

Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is already sufficient to rule out that M87* is a highly charged dilaton black hole. Similarly, when considering black holes with two physical and independent charges, we are able to exclude considerable regions of the space of parameters for the doubly-charged dilaton and the Sen black holes

First M87 Event Horizon Telescope Results. VII. Polarization of the Ring

In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in the immediate vicinity of the black hole. Here we present the corresponding linear-polarimetric EHT images of the center of M87. We find that only a part of the ring is significantly polarized. The resolved fractional linear polarization has a maximum located in the southwest part of the ring, where it rises to the level of similar to 15%. The polarization position angles are arranged in a nearly azimuthal pattern. We perform quantitative measurements of relevant polarimetric properties of the compact emission and find evidence for the temporal evolution of the polarized source structure over one week of EHT observations. The details of the polarimetric data reduction and calibration methodology are provided. We carry out the data analysis using multiple independent imaging and modeling techniques, each of which is validated against a suite of synthetic data sets. The gross polarimetric structure and its apparent evolution with time are insensitive to the method used to reconstruct the image. These polarimetric images carry information about the structure of the magnetic fields responsible for the synchrotron emission. Their physical interpretation is discussed in an accompanying publication

The Event Horizon Telescope Image of the Quasar NRAO 530

We report on the observations of the quasar NRAO 530 with the Event Horizon Telescope (EHT) on 2017 April 5−7, when NRAO 530 was used as a calibrator for the EHT observations of Sagittarius A*. At z = 0.902, this is the most distant object imaged by the EHT so far. We reconstruct the first images of the source at 230 GHz, at an unprecedented angular resolution of ∼20 μas, both in total intensity and in linear polarization (LP). We do not detect source variability, allowing us to represent the whole data set with static images. The images reveal a bright feature located on the southern end of the jet, which we associate with the core. The feature is linearly polarized, with a fractional polarization of ∼5%-8%, and it has a substructure consisting of two components. Their observed brightness temperature suggests that the energy density of the jet is dominated by the magnetic field. The jet extends over 60 μas along a position angle ∼ −28°. It includes two features with orthogonal directions of polarization (electric vector position angle), parallel and perpendicular to the jet axis, consistent with a helical structure of the magnetic field in the jet. The outermost feature has a particularly high degree of LP, suggestive of a nearly uniform magnetic field. Future EHT observations will probe the variability of the jet structure on microarcsecond scales, while simultaneous multiwavelength monitoring will provide insight into the high-energy emission origin

Constraints on black-hole charges with the 2017 EHT observations of M87*

Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87* shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is already sufficient to rule out that M87* is a highly charged dilaton black hole. Similarly, when considering black holes with two physical and independent charges, we are able to exclude considerable regions of the space of parameters for the doubly-charged dilaton and the Sen black holes

The Polarized Image of a Synchrotron-emitting Ring of Gas Orbiting a Black Hole

Synchrotron radiation from hot gas near a black hole results in a polarized image. The image polarization is determined by effects including the orientation of the magnetic field in the emitting region, relativistic motion of the gas, strong gravitational lensing by the black hole, and parallel transport in the curved spacetime. We explore these effects using a simple model of an axisymmetric, equatorial accretion disk around a Schwarzschild black hole. By using an approximate expression for the null geodesics derived by Beloborodov and conservation of the Walker–Penrose constant, we provide analytic estimates for the image polarization. We test this model using currently favored general relativistic magnetohydrodynamic simulations of M87*, using ring parameters given by the simulations. For a subset of these with modest Faraday effects, we show that the ring model broadly reproduces the polarimetric image morphology. Our model also predicts the polarization evolution for compact flaring regions, such as those observed from Sgr A* with GRAVITY. With suitably chosen parameters, our simple model can reproduce the EVPA pattern and relative polarized intensity in Event Horizon Telescope images of M87*. Under the physically motivated assumption that the magnetic field trails the fluid velocity, this comparison is consistent with the clockwise rotation inferred from total intensity images

First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon

Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotron radiation probes the structure of magnetic fields and the plasma properties near the black hole. Here we compare the resolved polarization structure observed by the EHT, along with simultaneous unresolved observations with the Atacama Large Millimeter/submillimeter Array, to expectations from theoretical models. The low fractional linear polarization in the resolved image suggests that the polarization is scrambled on scales smaller than the EHT beam, which we attribute to Faraday rotation internal to the emission region. We estimate the average density n_{e} ~ 10^{4–7} cm^{−3}, magnetic field strength B ~ 1–30 G, and electron temperature T_{e} ~ (1–12) × 10^{10} K of the radiating plasma in a simple one-zone emission model. We show that the net azimuthal linear polarization pattern may result from organized, poloidal magnetic fields in the emission region. In a quantitative comparison with a large library of simulated polarimetric images from general relativistic magnetohydrodynamic (GRMHD) simulations, we identify a subset of physical models that can explain critical features of the polarimetric EHT observations while producing a relativistic jet of sufficient power. The consistent GRMHD models are all of magnetically arrested accretion disks, where near-horizon magnetic fields are dynamically important. We use the models to infer a mass accretion rate onto the black hole in M87 of (3–20) × 10^{−4} M⊙ yr^{−1}