Far infrared luminosity function of local galaxies in the AKARI Deep Field South

We present the first far-infrared luminosity function in the AKARI Deep Field South, a premier deep field of the AKARI Space Telescope, using spectroscopic redshifts obtained with AAOmega. To date, we have found spectroscopic redshifts for 389 galaxies in this field and have measured the local (z<0.25) 90 μm luminosity function using about one-third of these redshifts. The results are in reasonable agreement with recent theoretical predictions

AKARI Deep Field South: spectroscopic observations of infrared sources

We present a summary of our spectroscopic redshift catalogue of 404 sources in the AKARI Deep Field South (ADF-S). We have used the AAOmega spectrograph to target mid-infrared and far-infrared sources selected primarily from AKARI observations in this field for which we were able to obtain optical counterparts. Our sources with identified redshifts include 316 with Hα detections at z ≤ 0.345 and 15 sources at z > 1 with MgII or Lα emission lines. About 13% of our z ≤ 0.345 sources are dominated by active galactic nuclei (AGN) emission, although many show emission from both star formation and AGNs. The median Balmer decrement is 5.9. Ultra-luminous infrared galaxies (ULIRGs) were found only in the higher-redshift sources. Optical and near infrared data will be available shortly, enabling calibration of the line luminosities and spectral energy distribution (SED) fitting for these sources

A deep ATCA 20cm radio survey of the AKARI Deep Field South near the South Ecliptic Pole

The results of a deep 20 cm radio survey at 20 cm are reported of the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array telescope, ATCA. The survey has 1 sigma detection limits ranging from 18.7--50 microJy per beam over an area of ~1.1 sq degrees, and ~2.5 sq degrees to lower sensitivity. The observations, data reduction and source count analysis are presented, along with a description of the overall scientific objectives, and a catalogue containing 530 radio sources detected with a resolution of 6.2" x 4.9". The derived differential source counts show a pronounced excess of sources fainter than ~1 mJy, consistent with an emerging population of star forming galaxies. Cross-correlating the radio with AKARI sources and archival data we find 95 cross matches, with most galaxies having optical R-magnitudes in the range 18-24 mag, and 52 components lying within 1" of a radio position in at least one further catalogue (either IR or optical). We have reported redshifts for a sub-sample of our catalogue finding that they vary between galaxies in the local universe to those having redshifts of up to 0.825. Associating the radio sources with the Spitzer catalogue at 24 microns, we find 173 matches within one Spitzer pixel, of which a small sample of the identifications are clearly radio loud compared to the bulk of the galaxies. The radio luminosity plot and a colour-colour analysis suggest that the majority of the radio sources are in fact luminous star forming galaxies, rather than radio-loud AGN. There are additionally five cross matches between ASTE or BLAST submillimetre galaxies and radio sources from this survey, two of which are also detected at 90 microns, and 41 cross-matches with submillimetre sources detected in the Herschel HerMES survey Public Data release.Comment: MNRAS accepted and in press 9 July 2012: 28 pages, 15 Figures, 17 Table

Infrared luminosity functions of AKARI Sloan Digital Sky Survey galaxies

By cross-correlating the AKARI all-sky survey in six infrared (IR) bands (9, 18, 65, 90, 140 and 160 μm) with the Sloan Digital Sky Survey (SDSS) galaxies, we identified 2357 IR galaxies with a spectroscopic redshift. This is not just one of the largest samples of local IR galaxies, but AKARI provides crucial far-IR (FIR) bands for accurately measuring the galaxy spectral energy distribution (SED) across the peak of the dust emission at > 100 μ m. By fitting modern IR SED models to the AKARI photometry, we measured the total infrared luminosity (L_(IR)) of individual galaxies. Using this L_(IR), we constructed the luminosity functions (LF) of IR galaxies at a median redshift of z= 0.031. The LF agrees well with that at z= 0.0082 (the Revised Bright Galaxy Sample), showing smooth and continuous evolution towards higher redshift LFs measured in the AKARI North Ecliptic Pole (NEP) deep field. By integrating the IR LF weighted by L_(IR), we measured the local cosmic IR luminosity density of Ω_(IR_= (3.8^(+5.8)_(−1.2)) × 10^8 L_⊙ Mpc^(−3). We separate galaxies into active galactic nuclei (AGN), star-forming galaxies (SFG) and composite by using the [N ii]/Hα versus [O iii]/Hβ line ratios. The fraction of AGN shows a continuous increase with increasing L_(IR) from 25 to 90 per cent at 9 10^(11) L_⊙, coinciding with the break of both the SFG and AGN IR LFs. At L_(IR)≤ 10^(11) L_⊙, SFG dominates IR LFs. Only 1.1 ± 0.1 per cent of Ω_(IR) is produced by luminous infrared galaxies (L_(IR) > 10^(11) L_⊙), and only 0.03 ± 0.01 per cent by ultraluminous infrared galaxies (L_(IR) > 10^(12) L_⊙) in the local Universe. Compared with high-redshift results from the AKARI NEP deep survey, we observed a strong evolution of Ω^(SFG)IR^∝ (1 +z)^(4.1±0.4) and Ω^(AGN)IR^∝ (1+z)^(4.1±0.5). Our results show that all of our measured quantities (IR LFs, L^*, Ω^(AGN)IR, Ω^(SFG)IR) show smooth and steady increase from lower redshift (the Revised Bright Galaxy Sample) to higher redshift (the AKARI NEP deep survey)

Infrared luminosity functions based on 18 mid-infrared bands: revealing cosmic star formation history with AKARI and Hyper Suprime-Cam*

Much of star formation is obscured by dust. For a complete understanding of the cosmic star formation history (CSFH), infrared (IR) census is indispensable. AKARI carried out deep mid-infrared observations using its continuous nine-band filters in the North Ecliptic Pole (NEP) field (5.4 deg2). This took a significant amount of the satellite’s lifetime, ∼10% of the entire pointed observations. By combining archival Spitzer (five bands) and WISE (four bands) mid-IR photometry, we have, in total, 18-band mid-IR photometry, which is the most comprehensive photometric coverage in the mid-IR for thousands of galaxies. However, we only had shallow optical imaging (∼25.9 AB magnitude) in a small area, 1.0 deg2. As a result, thousands of AKARI’s infrared sources remained undetected in the optical. Using the new Hyper Suprime-Cam on the Subaru telescope, we obtained deep enough optical images of the entire AKARI NEP field in five broad bands (g ∼ 27.5 mag). These provided photometric redshift, and thereby IR luminosity, for the previously undetected faint AKARI IR sources. Combined with the accurate mid-IR luminosity measurement, we constructed mid-IR luminosity functions (LFs), and thereby performed a census of dust-obscured CSFH in the entire AKARI NEP field. We have measured restframe 8 μm and 12 μm LFs, and estimated total infrared LFs at 0.35 z z ∼ 2

Challenges of investigating a large food-borne norovirus outbreak across all branches of a restaurant group in the United Kingdom, October 2016

During October and November 2016, over 1,000 customers and staff reported gastroenteritis after eating at all 23 branches of a restaurant group in the United Kingdom. The outbreak coincided with a new menu launch and norovirus was identified as the causative agent. We conducted four retrospective cohort studies; one among all restaurant staff and three in customers at four branches. We investigated the dishes consumed, reviewed recipes, interviewed chefs and inspected restaurants to identify common ingredients and preparation methods for implicated dishes. Investigations were complicated by three public health agencies concurrently conducting multiple analytical studies, the complex menu with many shared constituent ingredients and the high media attention. The likely source was a contaminated batch of a nationally distributed ingredient, but analytical studies were unable to implicate a single ingredient. The most likely vehicle was a new chipotle chilli product imported from outside the European Union, that was used uncooked in the implicated dishes. This outbreak exemplifies the possibility of rapid spread of infectious agents within a restaurant supply chain, following introduction of a contaminated ingredient. It underlines the importance of appropriate risk assessments and control measures being in place, particularly for new ingredients and ready-to-eat foods

Habit and the Politics of Social Change: A comparison of nudge theory and pragmatist philosophy

Rethinking the political workings of habit and habituation, this paper suggests, is vital to understanding the logics and possibilities of social change today. Any endeavour to explore habit’s affirmative potential, however, must confront its legacies as a colonialist, imperialist and capitalist technology. As a means to explore what it is that differentiates contemporary neoliberal modes of governing through habit from more critical approaches, this article compares contemporary ‘nudge’ theory and policy, as espoused by the behavioural economist Richard Thaler and the legal scholar Cass Sunstein, with the pragmatist philosophies of habit offered by John Dewey, William James and Shannon Sullivan. While nudge advocates focus on how policymakers and corporate leaders can intervene in the ‘choice architectures’ that surround us to outsmart or bypass problematic human tendencies, I argue, pragmatist philosophers appreciate the necessity of collective efforts to develop new and flexible forms of habituation in order to engender more enduring and democratic forms of social transformation

Reading ‘Fundamental British Values’ Through Children’s Gothic: Imperialism, History, Pedagogy

This paper reads the U.K. Government’s “fundamental British values” project alongside two children’s Gothic novels, Coram Boy (2000) by Jamila Gavin and City of Ghosts (2009) by Bali Rai. In 2011 the U.K. Government outlined what it described as “fundamental British values” (FBV), making it a requirement for U.K. schools to promote these values. Many critics have shown that the root of FBV lies in Islamophobia and imperialist nostalgia and suggested that the promotion of “British” values in school will exclude minority groups already under siege from racist elements in contemporary Britain. Other critics argue that the promotion of FBV reduces opportunities to explore issues of belonging, belief, and nationhood in the classroom. This article argues that the Gothic fictions of Jamila Gavin and Bali Rai offer a space in which to critically examine British history (and so, its values) in a way that is acutely relevant to these education contexts. Coram Boy and City of Ghosts use the Gothic to interrogate aspects of British history elided by the FBV project. That is, they point to Britain’s imperial and colonial history and offer a rejoinder to the Government’s insistence that “British Values” equate to democracy, respect for the rule of law and mutual respect and tolerance of those from different faiths and religions. Furthermore, Gavin’s and Rai’s use of the Gothic creates a space in which the ambiguities and contradictions inherent in FBV can be explored. However, their “gothicized” histories of Britain do not render the idea of shared values invalid. The diversity and interconnectedness of the characters offer an alternative version of identity to the patronising and arrogant FBV project, which is aimed at promoting a national identity based on sameness and assimilation. Rai and Gavin look to Britain’s past through the lens of the Gothic not only to refute nationalism and racism, but also to offer a productive alternative that gestures towards a more cosmopolitan vision of identity