70 research outputs found

    Modelling the Molecular Gas in NGC 6240

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    We present the first observations of H13^{13}CN(10)(1-0), H13^{13}CO+(10)^+(1-0) and SiO(21)(2-1) in NGC\,6240, obtained with the IRAM PdBI. Combining a Markov Chain Monte Carlo (MCMC) code with Large Velocity Gradient (LVG) modelling, and with additional data from the literature, we simultaneously fit three gas phases and six molecular species to constrain the physical condition of the molecular gas, including mass-luminosity conversion factors. We find 1010M\sim10^{10}M_\odot of dense molecular gas in cold, dense clouds (Tk10T_{\rm k}\sim10\,K, nH2106n_{{\rm H}_2}\sim10^6\,cm3^{-3}) with a volume filling factor <0.002<0.002, embedded in a shock heated molecular medium (Tk2000T_{\rm k}\sim2000\,K, nH2103.6n_{{\rm H}_2}\sim10^{3.6}\,cm3^{-3}), both surrounded by an extended diffuse phase (Tk200T_{\rm k}\sim200\,K, nH2102.5n_{{\rm H}_2}\sim10^{2.5}\,cm3^{-3}). We derive a global αCO=1.51.17.1\alpha_{\rm CO}=1.5^{7.1}_{1.1} with gas masses log10(M/[M])=10.110.010.8\log_{10}\left(M / [M_\odot]\right)=10.1_{10.0}^{10.8}, dominated by the dense gas. We also find αHCN=321389\alpha_{\rm HCN} = 32^{89}_{13}, which traces the cold, dense gas. The [12^{12}C]/[13^{13}C] ratio is only slightly elevated (986523098^{230}_{65}), contrary to the very high [CO]/[13^{13}CO] ratio (300-500) reported in the literature. However, we find very high [HCN]/[H13^{13}CN] and [HCO+^+]/[H13^{13}CO+^+] abundance ratios (300200500)(300^{500}_{200}) which we attribute to isotope fractionation in the cold, dense clouds.Comment: 27 pages, 17 figures, 9 tables. Accepted in Ap

    Chemically Distinct Nuclei and Outflowing Shocked Molecular Gas in Arp 220

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    We present the results of interferometric spectral line observations of Arp 220 at 3.5mm and 1.2mm from the Plateau de Bure Interferometer (PdBI), imaging the two nuclear disks in H13^{13}CN(10)(1 - 0) and (32)(3 - 2), H13^{13}CO+(10)^+(1 - 0) and (32)(3 - 2), and HN13^{13}C(32)(3 - 2) as well as SiO(21)(2 - 1) and (65)(6 - 5), HC15^{15}N(32)(3 - 2), and SO(6655)(6_6 - 5_5). The gas traced by SiO(65)(6 - 5) has a complex and extended kinematic signature including a prominent P Cygni profile, almost identical to previous observations of HCO+(32)^+(3 - 2). Spatial offsets 0.10.1'' north and south of the continuum centre in the emission and absorption of the SiO(65)(6 - 5) P Cygni profile in the western nucleus (WN) imply a bipolar outflow, delineating the northern and southern edges of its disk and suggesting a disk radius of 40\sim40 pc, consistent with that found by ALMA observations of Arp 220. We address the blending of SiO(65)(6 - 5) and H13^{13}CO+(32)^+(3 - 2) by considering two limiting cases with regards to the H13^{13}CO+^+ emission throughout our analysis. Large velocity gradient (LVG) modelling is used to constrain the physical conditions of the gas and to infer abundance ratios in the two nuclei. Our most conservative lower limit on the [H13^{13}CN]/[H13^{13}CO+^+] abundance ratio is 11 in the WN, cf. 0.10 in the eastern nucleus (EN). Comparing these ratios to the literature we argue on chemical grounds for an energetically significant AGN in the WN driving either X-ray or shock chemistry, and a dominant starburst in the EN.Comment: 28 pages, 17 figures, accepted to Ap

    Improving implementation of evidence based practice for people with psychosis through training the wider workforce: Results of the GOALS feasibility randomised controlled trial

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    BACKGROUND AND OBJECTIVES: There is a pressing need to improve access to evidence-based practice for people with psychosis. The primary aim of this study was to assess clinical feasibility of a manualised, evidence-based CBT intervention (GOALS) targeting a personalised recovery goal, delivered by the frontline workforce, following brief training. Secondly, we aimed to conduct preliminary statistical analyses of key outcomes and costs. METHODS:\ud The GOALS study is a feasibility randomised controlled trial (ISRCTN 73188383). 75 participants with current psychosis were recruited and randomly allocated to receive either treatment as usual alone or with GOALS therapy. RESULTS: Brief training enabled frontline staff to deliver the therapy according to protocol and 74% of therapy participants partially or fully achieved their goals. There were significant improvements with a moderate effect size of 0.56 on goal attainment. However, preliminary statistical analyses found no significant differences between groups on our primary outcome of activity levels or other secondary outcomes Health economic analysis found that point estimates of costs, controlling for baseline costs, implied savings (even including intervention costs), but the difference was not statistically significant. LIMITATIONS: The study was designed as a feasibility RCT, and therefore the results of secondary estimates of efficacy effects should be treated with caution. CONCLUSIONS: This approach holds promise in supporting people with psychosis to reach personal recovery goals, cost effectively

    High Dense Gas Fraction in Intensely Star-forming Dusty Galaxies

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    We present ALMA and VLA detections of the dense molecular gas tracers HCN, HCO+^+ and HNC in two lensed, high-redshift starbursts selected from the {\it Herschel}-ATLAS survey: {\it H}-ATLAS\,J090740.0-004200 (SDP.9, z1.6z \sim 1.6) and {\it H}-ATLAS\,J091043.1-000321 (SDP.11, z1.8z \sim 1.8). ALMA observed the J=32J = 3-2 transitions in both sources, while the VLA observed the J=10J = 1-0 transitions in SDP.9. We have detected all observed HCN and HCO+^+ lines in SDP.9 and SDP.11, and also HNC(3--2) in SDP.9. The amplification factors for both galaxies have been determined from sub-arcsec resolution CO and dust emission observations carried out with NOEMA and the SMA. The HNC(1--0)/HCN(1--0) line ratio in SDP.9 suggests the presence of photon-dominated regions, as it happens to most local (U)LIRGs. The CO, HCN and HCO+^+ SLEDs of SDP.9 are compatible to those found for many local, infrared (IR) bright galaxies, indicating that the molecular gas in local and high-redshift dusty starbursts can have similar excitation conditions. We obtain that the correlation between total IR (LIRL_{\rm IR}) and dense line (LdenseL_{\rm dense}) luminosity in SDP.9 and SDP.11 and local star-forming galaxies can be represented by a single relation. The scatter of the LIRLdenseL_{\rm IR} - L_{\rm dense} correlation, together with the lack of sensitive dense molecular gas tracer observations for a homogeneous sample of high-redshift galaxies, prevents us from distinguishing differential trends with redshift. Our results suggest that the intense star formation found in some high-redshift dusty, luminous starbursts is associated with more massive dense molecular gas reservoirs and higher dense molecular gas fractions.Comment: Submitted to ApJ. Comments most welcom

    Might Depression, Psychosocial Adversity, and Limited Social Assets Explain Vulnerability to and Resistance against Violent Radicalisation?

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    BACKGROUND: This study tests whether depression, psychosocial adversity, and limited social assets offer protection or suggest vulnerability to the process of radicalisation. METHODS: A population sample of 608 men and women of Pakistani or Bangladeshi origin, of Muslim heritage, and aged 18-45 were recruited by quota sampling. Radicalisation was measured by 16 questions asking about sympathies for violent protest and terrorism. Cluster analysis of the 16 items generated three groups: most sympathetic (or most vulnerable), most condemning (most resistant), and a large intermediary group that acted as a reference group. Associations were calculated with depression (PHQ9), anxiety (GAD7), poor health, and psychosocial adversity (adverse life events, perceived discrimination, unemployment). We also investigated protective factors such as the number social contacts, social capital (trust, satisfaction, feeling safe), political engagement and religiosity. RESULTS: Those showing the most sympathy for violent protest and terrorism were more likely to report depression (PHQ9 score of 5 or more; RR = 5.43, 1.35 to 21.84) and to report religion to be important (less often said religion was fairly rather than very important; RR = 0.08, 0.01 to 0.48). Resistance to radicalisation measured by condemnation of violent protest and terrorism was associated with larger number of social contacts (per contact: RR = 1.52, 1.26 to 1.83), less social capital (RR = 0.63, 0.50 to 0.80), unavailability for work due to housekeeping or disability (RR = 8.81, 1.06 to 37.46), and not being born in the UK (RR = 0.22, 0.08 to 0.65). CONCLUSIONS: Vulnerability to radicalisation is characterised by depression but resistance to radicalisation shows a different profile of health and psychosocial variables. The paradoxical role of social capital warrants further investigation

    Defeating Milošević: The role of networked organizations and the internet in Serbia in the 1990s

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    People in conflict areas are increasingly using new technologies to organize resistance networks and mount opposition to established organizations and régimes. While resistance movements are using these technologies in innovative ways (e.g., Twitter in Iran), no one really knows how effective or efficient they are. There is little research at the intersection of the relevant disciplines: social networks, social movements, and technology diffusion. Much of the writing on resistance movements in the Internet era focuses on the paradigm-shifting role of the Internet (e.g., the Zapatistas in Mexico or the WTO Seattle demonstrations), but further analysis shows that the formation of social and organizational networks is what really changes the calculus. So the focus of future studies on the impact of technologies should be on their intermediate role as facilitators of network development, rather than their direct influence on the outcomes. But how does one measure the impact of new technologies on the development of social networks and resistance movements? Drawing on data obtained from interviews with more than fifty principals in the Serbian resistance and an accompanying survey, I examine the “base case” of the Internet era: the development and eventual success of the Serbian resistance to Slobodan Milošević during the breakup of Yugoslavia in the 1990s. First, I use social network analysis to depict and then to analyze the formation of informal networks, then communities of interest and resistance organizations, and finally, a united political resistance network, demonstrating how the resistance became more efficient as a result of technological innovation and penetration. Then I then examine the impact of new ICTs on both organizational and individual effectiveness. To examine organizational effectiveness, I trace several important technology-enabled processes that enabled the opposition to take advantage of technological efficiencies to become much more effective. To assess effectiveness at the individual level, I present and discuss responses of survey participants to open-ended questions about their perceptions of the impact of technology on personal security and the war’s outcome. This combined analysis results in a new and improved method for using SNA to measure the effectiveness and efficiency of small organizations linked by weak-tie, short-path computer and email connections and their ability to defeat much-larger adversaries. Researchers seeking new approaches to looking at technology-enabled resistance networks and assessing or measuring their efficiency and effectiveness can use this kind of analysis

    The Role of the CMB in Redshift Related Departures from the Gao-Solomon Relation

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    A strong correlation between the far-IR and HCN(1−0) line luminosities, known as the Gao–Solomon relation, has been observed to hold over more than 10 orders of magnitude in the local universe. Departures from this relation at redshifts 1.5 have been interpreted as evidence for increased dense gas star formation efficiency in luminous galaxies during the period of peak of star formation in the history of the universe. We examine whether the offsets from the relation can be explained by the hotter Cosmic Microwave Background (CMB) at high redshift, which, due to a loss of contrast against the hotter background, reduces the observable molecular-line flux far more significantly than the far-IR continuum bands. Simple line-of-sight modeling argues for highly significant departures from the Gao–Solomon relation at high redshift for kinetic temperatures ∼15 K, while more complex toy-galaxy models based on NGC 1068 suggest a much weaker effect with the galaxy integrated HCN line flux falling by only 10% at z = 3, within the intrinsic scatter of the relation. We conclude that, while the CMB is unlikely to explain the deviations reported in the literature, it may introduce a second-order effect on the relation by raising the low-luminosity end of the Gao–Solomon relation in cooler galaxies. A similar examination of the COIR relation finds tantalizing signs of the CMB having a measurable effect on the integrated CO emission in highredshift galaxies, but these signs cannot be confirmed with the current data
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