The star formation histories of galaxies in different stages of pre-processing in the Fornax A group

We study the recent star formation histories of ten galaxies in the Fornax A galaxy group, on the outskirts of the Fornax cluster. The group galaxies are gas-rich, and their neutral atomic hydrogen (HI) was studied in detail with observations from the MeerKAT telescope. This allowed them to be classified into different stages of pre-processing (early, ongoing, advanced). We use long-slit spectra obtained with the South African Large Telescope (SALT) to analyse stellar population indicators to constrain quenching timescales and to compare these to the HI gas content of the galaxies. The H$\alpha$ equivalent width, EW(H$\alpha$), suggest that the pre-processing stage is closely related to the recent (< 10 Myr) specific Star Formation Rate (sSFR). The early-stage galaxy (NGC 1326B) is not yet quenched in its outer parts, while the ongoing-stage galaxies mostly have a distributed population of very young stars, though less so in their outer parts. The galaxies in the advanced stage of pre-processing show very low recent sSFR in the outer parts. Our results suggest that NGC 1326B, FCC 35 and FCC 46 underwent significantly different histories from secular evolution during the last Gyr. The fact that most galaxies are on the secular evolution sequence implies that pre-processing has a negligible effect on these galaxies compared to secular evolution. We find EW(H$\alpha$) to be a useful tool for classifying the stage of pre-processing in group galaxies. The recent sSFR and HI morphology show that galaxies in the Fornax A vicinity are pre-processing from the outside in.Comment: 17 pages, accepted for publication in MNRA

The impact of the Lesotho Child Grant Programme in the lives of children and adults with disabilities: Disaggregated analysis of a community randomized controlled trial

Globally, people with disabilities are disproportionally affected by poverty. Social protection policies, including cash transfers, are key strategies to address poverty “in all its forms”, but it is currently unclear how such programmes affect people with disabilities. This study examines differences in the impact of the Lesotho Child Grant Programme (CGP) on food security, health, education and livelihoods between people with and without disabilities using data from a community randomized control trial. Overall, this study finds the CGP had significant and differential impacts for people with disabilities across multiple health indicators (e.g. increased health expenditures, self-rated health, likelihood of seeking healthcare). The CGP also had an impact on food security, decreasing the number of months households with and without members with disabilities faced extreme food shortages. There was also a modest but significant and differential impact of the CGP on the engagement of people with disabilities in paid work. The CGP only had an impact on school enrolment for children without disabilities, however the difference in impact was non-significant and likely due to underpowered sample sizes. Overall, people with disabilities receiving the CGP still experienced high levels of absolute deprivation, and were generally still worse off compared to people without disabilities, indicating a need for adapted or complementary social protection and other poverty alleviation programmes

Precipitation intensity-duration-frequency curves and their uncertainties for Ghaap plateau

Engineering infrastructures such as stormwater drains and bridges are commonly designed using the concept of Intensity-Duration-Frequency (IDF) curves, which assume that the occurrence of precipitation patterns and distributions are spatially similar within the drainage area and remain unchanged throughout the lifespan of the infrastructures (stationary). Based on the premise that climate change will alter the spatial and temporal variability of precipitation patterns, inaccuracy in the estimation of IDF curves may occur. As such, prior to developing IDF curves, it is crucial to analyse trends of annual precipitation maxima. The objective of this study was to estimate the precipitation intensities and their uncertainties (lower and upper limits) for durations of 0.125, 0.25, 0.5, 1, 2, 4, and 6 h and return periods of 2, 10, 25, 50 and 100 years in the Ghaap plateau, Northern Cape Province, South Africa using the Generalized Extreme Value (GEV) distribution. The annual precipitation maxima were extracted from long-term (1918–2014) precipitation data for four meteorological stations (Postmasburg, Douglas, Kuruman and Groblershoop) sourced from the South African Weather Services (SAWS). On average, the estimated extreme precipitation intensities for the plateau ranged from 4.2 mm/h for 6 h storm duration to 55.8 mm/h for 0.125 h at 2 years return period. At 100 year return period, the intensity ranged from 13.3 mm/h for 6 h duration to 175.5 mm/h for the duration of 0.125 h. The lower limit of uncertainty ranged from 11.7% at 2 years return period to 26% at 100 year return period, and from 12.8% to 58.4% for the upper limit for the respective return periods. This methodology can be integrated into policy formulation for the design of stormwater and flood management infrastructures in the Ghaap plateau, where mining is the main economic activity

The star formation histories of galaxies in different stages of pre-processing in the Fornax A group

We study the recent star formation histories of 10 galaxies in the Fornax A galaxy group, on the outskirts of the Fornax cluster. The group galaxies are gas-rich, and their neutral atomic hydrogen (H i) was studied in detail with observations from the MeerKAT telescope. This allowed them to be classified into different stages of pre-processing (early, ongoing, advanced). We use long-slit spectra obtained with the South African Large Telescope (SALT) to analyse stellar population indicators to constrain quenching time-scales and to compare these to the H i gas content of the galaxies. The H α equivalent width, EW(H α), suggest that the pre-processing stage is closely related to the recent (&lt;10 Myr) specific Star Formation Rate (sSFR). The early-stage galaxy (NGC 1326B) is not yet quenched in its outer parts, while the ongoing-stage galaxies mostly have a distributed population of very young stars, though less so in their outer parts. The galaxies in the advanced stage of pre-processing show very low recent sSFR in the outer parts. Our results suggest that NGC 1326B, FCC 35, and FCC 46 underwent significantly different histories from secular evolution during the last Gyr. The fact that most galaxies are on the secular evolution sequence implies that pre-processing has a negligible effect on these galaxies compared to secular evolution. We find EW(H α) to be a useful tool for classifying the stage of pre-processing in group galaxies. The recent sSFR and H i morphology show that galaxies in the Fornax A vicinity are pre-processing from the outside in.</p

The star formation histories of galaxies in different stages of pre-processing in the Fornax A group

We study the recent star formation histories of 10 galaxies in the Fornax A galaxy group, on the outskirts of the Fornax cluster. The group galaxies are gas-rich, and their neutral atomic hydrogen (H i) was studied in detail with observations from the MeerKAT telescope. This allowed them to be classified into different stages of pre-processing (early, ongoing, advanced). We use long-slit spectra obtained with the South African Large Telescope (SALT) to analyse stellar population indicators to constrain quenching time-scales and to compare these to the H i gas content of the galaxies. The H α equivalent width, EW(H α), suggest that the pre-processing stage is closely related to the recent (&lt;10 Myr) specific Star Formation Rate (sSFR). The early-stage galaxy (NGC 1326B) is not yet quenched in its outer parts, while the ongoing-stage galaxies mostly have a distributed population of very young stars, though less so in their outer parts. The galaxies in the advanced stage of pre-processing show very low recent sSFR in the outer parts. Our results suggest that NGC 1326B, FCC 35, and FCC 46 underwent significantly different histories from secular evolution during the last Gyr. The fact that most galaxies are on the secular evolution sequence implies that pre-processing has a negligible effect on these galaxies compared to secular evolution. We find EW(H α) to be a useful tool for classifying the stage of pre-processing in group galaxies. The recent sSFR and H i morphology show that galaxies in the Fornax A vicinity are pre-processing from the outside in.</p

Three waves of media repression in Zimbabwe

This article seeks to highlight how the media – especially radio – have always been used in Zimbabwe to consolidate the power of the government. This invariably led to oppositional media emerging from outside the country, giving the populace access to alternative discourses from those churned out by state media. The response to the alternative media run by blacks led the Southern Rhodesian and Rhodesian regimes to come up with repressive legislation that criminalised these media. After independence the state media embarked on consolidating the status quo and eliminating some sectors of the community from coverage – a repeat of the past. Legislation inherited from Rhodesia continued to be used in independent Zimbabwe, where the criminalisation of alternative voices and limitations in access to alternative media are predominant. Such a scenario reveals that there have been three waves of media repression in Zimbabwe, from Southern Rhodesia to Rhodesia and then to independent Zimbabwe, to deny the media their independence