MALT-45: A 7mm survey of the southern Galaxy - II. ATCA follow-up observations of 44GHz class I methanol masers

We detail interferometric observations of 44 GHz class I methanol masers detected by MALT-45 (a 7 mm unbiased auto-correlated spectral-line Galactic-plane survey) using the Australia Telescope Compact Array. We detect 238 maser spots across 77 maser sites. Using high-resolution positions, we compare the class I CH3OH masers to other star formation maser species, including CS (1–0), SiO v = 0 and the H53 α radio-recombination line. Comparison between the cross- and auto-correlated data has allowed us to also identify quasi-thermal emission in the 44 GHz class I methanol maser line. We find that the majority of class I methanol masers have small spatial and velocity ranges (<0.5 pc and <5 km s−1), and closely trace the systemic velocities of associated clouds. Using 870 μm dust continuum emission from the ATLASGAL survey, we determine clump masses associated with class I masers, and find that they are generally associated with clumps between 1000 and 3000 M⊙. For each class I methanol maser site, we use the presence of OH masers and radio recombination lines to identify relatively evolved regions of high-mass star formation; we find that maser sites without these associations have lower luminosities and preferentially appear towards dark infrared regions

Inverse Multview I: Multi-Calibrator inverse phase referencing for Microarcsecond VLBI Astrometry

Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving $\pm10~\mu$as parallax accuracies at frequencies well above 10~GHz. At lower frequencies, uncompensated interferometer delays associated with the ionosphere play the dominant role in limiting the astrometric accuracy. Multiview is a novel VLBI calibration method, which uses observations of multiple quasars to accurately model and remove time-variable, directional-dependent changes to the interferometer delay. Here we extend the Multiview technique by phase referencing data to the target source ("inverse Multiview") and test its performance. Multiple observations with a four-antenna VLBI array operating at 8.3~GHz show single-epoch astrometric accuracies near $20~\mu$as for target-reference quasar separations up to about 7 degrees. This represents an improvement in astrometric accuracy by up to an order of magnitude compared to standard phase referencing.Comment: 11 pages, 5 figure

TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry. III. First-epoch S band images

With the emergence of very high energy astronomy (VHE; E>100 GeV), new open questions were presented to astronomers studying the multi-wavelength emission from blazars. Answers to these open questions, such as the Doppler crisis, and finding the location of the high-energy activity have eluded us thus far. Recently, quasi-simultaneous multi-wavelength monitoring programs have shown considerable success in investigating blazar activity. After the launch of the Fermi Gamma-ray Space Telescope in 2008, such quasi-simultaneous observations across the electromagnetic spectrum became possible. In addition, with very long baseline interferometry (VLBI) observations we can resolve the central parsec region of active galactic nuclei (AGN) and compare morphological changes to the gamma-ray activity to study high-energy emitting blazars. To achieve our goals, we need sensitive, long-term VLBI monitoring of a complete sample of VHE detected AGN. We performed VLBI observations of TeV-detected AGN and high likelihood neutrino associations as of December of 2021 with the Long Baseline Array (LBA) and other southern hemisphere radio telescopes at 2.3 GHz. In this paper we present first light TANAMI S-band images, focusing on the TeV-detected sub-sample of the full TANAMI sample. Apart from these very high energy-detected sources, we also show images of the two flux density calibrators and two additional sources included in the observations. We study the redshift, 0.1-100 GeV photon flux and S-band core brightness temperature distributions of the TeV-detected objects, and find that flat spectrum radio quasars and low synchrotron peaked sources on average show higher brightness temperatures than high-synchrotron-peaked BL Lacs. Sources with bright GeV gamma-ray emission also show higher brightness temperature values than gamma-low sources

Swift J1727.8–1613 Has the Largest Resolved Continuous Jet Ever Seen in an X-Ray Binary

Multiwavelength polarimetry and radio observations of Swift J1727.8–1613 at the beginning of its recent 2023 outburst suggested the presence of a bright compact jet aligned in the north–south direction, which could not be confirmed without high-angular-resolution images. Using the Very Long Baseline Array and the Long Baseline Array, we imaged Swift J1727.8–1613 during the hard/hard-intermediate state, revealing a bright core and a large, two-sided, asymmetrical, resolved jet. The jet extends in the north–south direction, at a position angle of −0.60° ± 0.07° east of north. At 8.4 GHz, the entire resolved jet structure is ∼110(d/2.7kpc)/sini au long, with the southern approaching jet extending ∼80(d/2.7kpc)/sini au from the core, where d is the distance to the source and i is the inclination of the jet axis to the line of sight. These images reveal the most resolved continuous X-ray binary jet, and possibly the most physically extended continuous X-ray binary jet ever observed. Based on the brightness ratio of the approaching and receding jets, we put a lower limit on the intrinsic jet speed of β ≥ 0.27 and an upper limit on the jet inclination of i ≤ 74°. In our first observation we also detected a rapidly fading discrete jet knot 66.89 ± 0.04 mas south of the core, with a proper motion of 0.66 ± 0.05 mas hr−1, which we interpret as the result of a downstream internal shock or a jet–interstellar medium interaction, as opposed to a transient relativistic jet launched at the beginning of the outburst

Locating mathematics within post-16 vocational education in England

The political importance of mathematics in post-16 education is clear. Far less clear is how mathematics does and should relate to vocational education. Successive mathematics curricula (e.g. core skills, key skills) have been developed in England with vocational learners in mind. Meanwhile, general mathematics qualifications remain largely disconnected from vocational learning. Following a brief historical survey of mathematics within vocational education, the paper presents findings from a nested case study of student groups in three large Further Education colleges in England. The primary unit of analysis herein is student groups learning Functional Mathematics in two vocational areas: construction and hairdressing. We show how approaches to organising teaching, developing connected curricula and classroom pedagogy tend to isolate or integrate mathematics from/with the vocational experience. Integrated approaches are shown to impact positively on student engagement and attitudes to learning mathematics. The paper concludes by discussing the potential impact of academic qualifications displacing vocationally relevant mathematics

Civilising the natives? Liberal studies in further education revisited

This paper uses Basil Bernstein’s work on pedagogic discourses to examine a largely neglected facet of the history of vocational education – the liberal studies movement in English further education (FE) colleges. Initially, the paper discusses some of the competing conceptions of education, work and society which underpinned the rise and fall of the liberal studies movement – if indeed it can be described as such. It then draws on data from interviews with former liberal and general studies (LS/GS) lecturers to focus on the ways in which different variants of liberal studies were, over time, implicated in inculcating certain forms of knowledge in vocational learners. Whilst it is acknowledged that LS/GS always represented contested territory and that it was highly variable both in terms of content and quality, the paper argues that, at least and under certain circumstances, liberal studies provided young working-class people with the opportunity to locate their experiences of vocational learning within a critical framework which is largely absent from FE today. This, it is argued, can be conceptualised as an engagement with what Bernstein described as ‘powerful knowledge’

Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Open data from the third observing run of LIGO, Virgo, KAGRA and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in April of 2019 and lasting six months, O3b starting in November of 2019 and lasting five months, and O3GK starting in April of 2020 and lasting 2 weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main dataset, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.Comment: 27 pages, 3 figure

Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass $M>70$ $M_\odot$) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities $0 < e \leq 0.3$ at $0.33$ Gpc$^{-3}$ yr$^{-1}$ at 90\% confidence level.Comment: 24 pages, 5 figure

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe