153 research outputs found
Resolving discs and mergers in z ∼ 2 heavily reddened quasars and their companion galaxies with ALMA
No full textWe present sub-arcsecond resolution Atacama Large Millimeter Array imaging of the CO(3–2) emission in two z ∼ 2.5 heavily reddened quasars (HRQs) – ULASJ1234+0907 and ULASJ2315+0143 – and their companion galaxies. Dynamical modelling of the resolved velocity fields enables us to constrain the molecular gas morphologies and host galaxy masses. Combining the new data with extensive multiwavelength observations, we are able to study the relative kinematics of different molecular emission lines, the molecular gas fractions, and the locations of the quasars on the MBH–Mgal relation. Despite having similar black hole properties, the two HRQs display markedly different host galaxy properties and local environments. J1234 has a very massive host – Mdyn ∼ 5 × 1011 M⊙ and two companion galaxies that are similarly massive located within 200 kpc of the quasar. The molecular gas fraction is low (∼6 per cent). The significant ongoing star formation in the host galaxy is entirely obscured at rest-frame ultraviolet (UV) and optical wavelengths. J2315 is resolved into a close-separation major merger (Δr = 15 kpc; Δv = 170 km s−1) with a ∼1:2 mass ratio. The total dynamical mass is estimated to be ≲1011 M⊙ and the molecular gas fraction is high (>45 per cent). A new HSC image of the galaxy shows unobscured UV-luminous star-forming regions co-incident with the extended reservoir of cold molecular gas in the merger. We use the outputs from the Illustris simulations to track the growth of such massive black holes from z ∼ 6 to the present day. While J1234 is consistent with the simulated z ∼ 2 relation, J2315 has a black hole that is overmassive relative to its host galaxy
The interstellar medium properties of heavily reddened quasarsand companions at z∼ 2.5 with ALMA and JVLA
No full textWe study the interstellar medium (ISM) properties of three heavily reddened quasars at z∼ 2.5 and three millimetre-bright companion galaxies near these quasars. New Karl G. Jansky Very Large Array (JVLA) and Atacama Large Millimeter Array (ALMA) observations constrain the CO(1-0), CO(7-6), and [CI]3P2-3P1 line emission and the far-infrared to radio continuum. The gas excitation and physical properties of the ISM are constrained by comparing our observations to photodissociation region models. The ISM in our high-redshift quasars is composed of very high-density, high-temperature gas that is already highly enriched in elements like carbon. One of our quasar hosts is shown to be a close-separation
Helical Inerter Test Data from 2016
No full textData from the testing of a novel type of fluid inerter system where the inertance can be varied. This inertance is achieved by having a fluid filled cylinder that induces flow in a helical pipe system. The parameters of the helical pipe system can be adjusted to give different amounts of inertial force depending on the requirements. See Reference below for full details.Parameters for the tests are given in the file name: Xmm_Yhz_Z.txtWhere X is amplitude in mmY is sine wave frequency in HzZ is the test case: For test case 2, the radius of the helix was 120mm and for test case 3 the radius of the helix was 80mm. See reference below for full details of the parameters.Further details of the tests cab be found in the following paper:@CONFERENCE{SmithWaggEACS, author = {Smith, N.D.J. and Wagg, D. J.}, title = {A fluid inerter with variable inertance properties}, booktitle = {Proceedings of the 6th European Conference on Structural Control}, year = {2016}, pages = {1--8}, note = {https://doi.org/10.15131/shef.data.4206096.v1}}</p
Prospects for future synergies between SKA and AtLAST
No full textThe Square Kilometre Array will be the next major global radio astronomy observatory. Being built in two phases, the first phase will consist of a low frequency array in Australia and a mid to high frequency array of dishes in the Karoo of South Africa. The design of SKA1 is nearly complete with the expectation that construction should begin within the next two years. A significant fraction of the observing time on both SKA1-MID and SKA1-LOW will likely be devoted to large survey programmes covering a broad range of science objectives. Given the timeline for these SKA1 programmes to be completed, it is anticipated that they could naturally complement future high frequency surveys using AtLAST. I will highlight a few areas where such synergies should exist
A Deep Search For Co J = 2–1 Emission From A Lyα Blob At Z ∼ 6.595
No full textWe have used the Green Bank Telescope to carry out a deep search for redshifted CO J = 2−1 line emission from an extended (>17 kpc) Lyα blob (LAB), "Himiko," at z ~ 6.595. Our non-detection of CO J = 2−1 emission places the strong 3σ upper limit of L'CO < 1.8 × 1010 × (ΔV/250)1/2 K km s-1 pc2 on the CO line luminosity. This is comparable to the best current limits on the CO line luminosity in LABs at z ~ 3 and lower-luminosity Lyα emitters at z gsim 6.5. High-z LABs appear to have lower CO line luminosities than the host galaxies of luminous quasars and submillimeter galaxies at similar redshifts, despite their high stellar mass. Although the CO-to-H2 conversion factor is uncertain for galaxies in the early universe, we assume XCO = 0.8 M⊙ (K km s-1 pc2)-1 to obtain the limit M(H2) <1.4 × 1010 M⊙ on Himiko's molecular gas mass; this is a factor of gsim 2.5 lower than the stellar mass in the z ~ 6.595 LAB
The D'Oliveira Affair: cricket, 'race' and politics
No full textA dissection of the so-called The D'Oliveira Affair, focusing in particular on hitherto neglected (save by the author) but crucial aspects of the 1968 episode that did most to spur and promote the sporting boycott that helped, ultimately, to bring about the end of apartheid in South Africa - 1) Tom Cartwright's conscience-based decision not to accept an invitation to tour Southy Africa in the winter of 1968, which in turn allowed Basil D'Oliveira to be chosen, which in turn caused the tour to be cancelled. 2) The decision to drop D'Oliveira from the England team for the Lord's Test, which spoke all too eloquently, I argue, for the desire of Whitehall to maintain a cordial relationship with Pretoria. This chapter is the definitive version of the author's research into this subject (to date), drawing on first-hand interviews with key figures
The D'Oliveira Affair: cricket, 'race' and politics
No full textA dissection of the so-called The D'Oliveira Affair, focusing in particular on hitherto neglected (save by the author) but crucial aspects of the 1968 episode that did most to spur and promote the sporting boycott that helped, ultimately, to bring about the end of apartheid in South Africa - 1) Tom Cartwright's conscience-based decision not to accept an invitation to tour Southy Africa in the winter of 1968, which in turn allowed Basil D'Oliveira to be chosen, which in turn caused the tour to be cancelled. 2) The decision to drop D'Oliveira from the England team for the Lord's Test, which spoke all too eloquently, I argue, for the desire of Whitehall to maintain a cordial relationship with Pretoria. This chapter is the definitive version of the author's research into this subject (to date), drawing on first-hand interviews with key figures
Producing (in(visible)) girls : the politics of production in young adult fiction with adolescent lesbian characters
No full textWhile there has been an increase in the publication of homosexuality-themed young adult (YA) literature, novels that feature adolescent lesbian characters account for fewer than one-quarter of all published titles. The politics of production in YA literature with adolescent lesbian characters is a complex and multifaceted network of power relations. Originating with the author, or the hub, a production network linking author, editor/publishing house, reviewer and vendor/purchaser nodes, maintains gatekeeping functions that determine which lesbian images are constructed for consumption. While the author creates the lesbian characters in her book and decides the lesbian experiences therein conceived, these choices--whether or not conscious--have been impacted by both her personal ideologies and her perceptions of dominant values and norms, including those inherent within the network itself, which govern and inform notions of acceptability. Based upon interviews with seven authors regarding their novels, publication dates spanning from 1978 to 2003, a socioeconomic network model is deployed to understand how the politics of production makes the adolescent lesbian an invisible/visible girl in YA literature
Understanding children’s constructions of meanings about other children: implications for inclusiveeducation
No full textThis paper explores the factors that influence the way children construct meanings about other children, and especially those who seem to experience marginalisation, within school contexts. The research involved an ethnographic study in a primary school in Cyprus over a period of 5 months. Qualitative methods were used, particularly participant observations and interviews with children. Interpretation of the data suggests that children's perceptions about other children, and especially those who come to experience marginalisation, are influenced by the following factors: other children and the interactions between them; adults’ way of behaving in the school; the existing structures within the school; and the cultures of the school and the wider educational context. Even though the most powerful factor was viewed to be the adults’ influence, it was rather the interweaving between different factors that seemed to lead to the creation of particular meanings for other children. In the end, it is argued that children's voices should be seen as an essential element within the process of developing inclusive practices.<br/
The Molecular Gas Content Of z > 6.5 Lyman-α Emitters
No full textWe present results from a sensitive search for CO J = 1–0 line emission in two z > 6.5 Lyman-α emitters (LAEs) with the Green Bank Telescope. CO J = 1–0 emission was not detected from either object. For HCM 6A, at z ~ 6.56, the lensing magnification factor of ~4.5 implies that the CO nondetection yields stringent constraints on the CO J = 1–0 line luminosity and molecular gas mass of the LAE, L'CO < 6.1 × 109 × (ΔV/300)1/2 K km s−1 pc2 and M_{\rm H_2} < 4.9 \times 10^{9} \times (\Delta V/300)^{1/2} \times (X_{\rm CO}/0.8) \: M_\odot. These are the strongest limits obtained so far for a z gsim 6 galaxy. For IOK-1, the constraints are somewhat less sensitive, L'CO < 2.3 × 1010 × (ΔV/300)1/2 K km s−1 pc2 and M_{\rm H_2} < 1.9 \times 10^{10} \times (\Delta V/300)^{1/2} \times (X_{\rm CO}/0.8) \: M_\odot. The nondetection of CO J = 1–0 emission in HCM 6A, whose high estimated star formation rate, dust extinction, and lensing magnification make it one of the best high-z LAEs for such a search, implies that typical z gsim 6 LAEs are likely to have significantly lower CO J = 1–0 line luminosities than massive submillimeter galaxies and hyperluminous infrared quasars at similar redshifts, due to either a significantly lower molecular gas content or a higher CO-to-H2 conversion factor
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