Mid-infrared dust in two nearby radio galaxies, NGC 1316 (Fornax A) and NGC 612 (PKS 0131-36)

Context. Most radio galaxies are hosted by giant gas-poor ellipticals, but some contain significant amounts of dust, which is likely to be of external origin

The LOFAR LBA Sky Survey II. First data release

The Low Frequency Array (LOFAR) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 MHz) with high resolution (<15") and high sensitivity (<1 mJy/beam). To exploit these capabilities, the LOFAR Surveys Key Science Project is using the LOFAR Low Band Antenna (LBA) to carry out a sensitive wide-area survey at 41-66 MHz named the LOFAR LBA Sky Survey (LoLSS). LoLSS is covering the whole northern sky above declination 24 deg with a resolution of 15" and a sensitivity of 1-2 mJy/beam (1 sigma) depending on declination, field properties, and observing conditions. Here we present the first data release. An automated pipeline was used to reduce the 95 fields included in this data release. The data reduction procedures developed for this project have general application and are currently being used to process LOFAR LBA interferometric observations. Compared to the preliminary release, direction-dependent errors have been corrected for during the calibration process. This results in a typical sensitivity of 1.55 mJy/beam at the target resolution of 15". The first data release of the LOFAR LBA Sky Survey covers 650 sqdeg in the HETDEX spring field. The resultant data products released to the community include mosaic images (I and V Stokes) of the region, and a catalogue of 42463 detected sources and related Gaussian components used to describe sources' morphologies. Separate catalogues for 6 in-band frequencies are also released. The first data release of LoLSS shows that, despite the influences of the ionosphere, LOFAR can conduct large-scale surveys in the frequency window 42-66 MHz with unprecedentedly high sensitivity and resolution. The data can be used to derive unique information on the low-frequency spectral properties of many thousands of sources with a wide range of applications in extragalactic and galactic astronomy.Comment: 20 pages, 22 figures, images and catalogues available at https://www.lofar-surveys.org/lolss.htm

Co-movements of REIT indices with structural changes before and during the subprime mortgage crisis: evidence from Euro-Med markets

This paper examines the long-run relationships between the REIT indices of the UK, Turkey and Israel in the Euro-Med zone with that of MSCI US REIT Index by using weekly data over the period 2003Q3 through 2009Q3, which includes the latest US subprime mortgage crisis and its effects on global stock markets. Although our EG test results do not indicate a long-run relationship, after taking account of the structural changes by applying the GH test, we find a long-run interaction between the REIT indices of UK and Israel with that of the US. However, our results indicate the lack of co-movement between REIT index of Turkey with the US. In addition, our dynamic OLS test results indicate a perfect relationship between the UK and the US indices. Our findings show that international investors who make long-term investments can only gain from diversifying into the real estate market of Turkey among the involved markets in the Euro-Med zone

Urban expansion and differential accessibility by car and public transport in the Greater Kumasi City-region, Ghana—a geospatial modelling approach

There is a growing recognition of the worsening problems of accessibility in Africa\u27s major urban centres and city-regions. Yet, research assessing differential accessibility in these contexts is limited, partly because of the lack of population and land-use data at granular spatial resolutions. In this paper, we contribute to addressing the existing challenges by presenting a geospatial modelling approach that combines historical urban physical development data extracted from Landsat satellite images, travel time data from Openrouteservice and Google Maps API services, and relevant transport infrastructure data. We apply the approach to analyse place-based (100 m2) accessibility in the Greater Kumasi city-region of Ghana. The analysis reveals a strong co-evolutionary relationship between physical development and geographical accessibility, with an estimated 83% of the emergent physical development located within half-a-kilometre distance of a primary road. First-and-last-mile accessibility in terms of walking time to public transport stations and public transport service routes are quantified. We reveal huge first-and-last-mile accessibility deficits, with an estimated 14% and 33% of the city-region\u27s built-up area having a 5-minute and 10-minute walking time reachability to a public transport station, as a critical node of accessibility. Differential accessibility by car and public transport is analysed, focusing on the city-region\u27s most important functional centre (i.e. CBD). The results show that the CBD is within 15 min and nearly 30 min reach by car and public transport respectively, for only 1% of the city-region\u27s built-up area. This implies that overall accessibility is poor regardless of mode choice, due to congestion. The findings underscore the need for integrative urban development and accessibility planning in the city-region for equitable transport and mobility outcomes