Estimating Black Hole Spin from AGN SED Fitting: The Impact of General-Relativistic Ray Tracing

Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black holes have the highest spin, with implications on the hierarchical growth of supermassive black holes and their host galaxies over cosmic time. However, these accretion disc models did not include the effects of relativistic ray tracing. Here we show that gravitational redshift cancels out most of the increase in temperature and luminosity from the smaller radii characteristic of high spin. Disc models which include the self consistent general relativistic ray tracing do not fit the UV spectra of the most massive quasars ($\log M/M_{\odot} \geq 9.5$), most likely showing that the disc structure is very different to that assumed. We extend the relativistic ray tracing on more complex disc models, where the emission is not limited to (colour temperature corrected) black body radiation but can instead be emitted as warm and hot Comptonisation. We demonstrate this on the broadband (UV/X-ray) spectrum of Fairall 9, a local intensively monitored 'bare' AGN (no significant intrinsic cold or warm absorption). We show that including relativistic corrections does make a difference even to these more complex models, but caution that the inferred black hole spin depends on the assumed nature and geometry of the accretion flow. Additionally, we make our model code publicly available, and name it RELAGN.Comment: 10 Pages, 6 Figures, 4 Appendices. Accepted to MNRA

Professionally limited influence, politically limited legitimacy? About politization and expertification

Denne artikkelen har som mål å undersøke en mulig ekspertifisering av den norske politikkutformingen, samt en eventuell politisering av embetsverket. Dette gjøres gjennom et casestudie av prosessen som ledet fram til etableringen av Statens undersøkelseskommisjon for helse- og omsorgssektoren (UKOM). Undersøkelser viser at under særlige forutsetninger er politikkutformingen mer preget av politisering enn av ekspertifisering.publishedVersio

Answering Comparative Questions: Better than Ten-Blue-Links?

We present CAM (comparative argumentative machine), a novel open-domain IR system to argumentatively compare objects with respect to information extracted from the Common Crawl. In a user study, the participants obtained 15% more accurate answers using CAM compared to a "traditional" keyword-based search and were 20% faster in finding the answer to comparative questions.Comment: In Proceeding of 2019 Conference on Human Information Interaction and Retrieval (CHIIR '19), March 10--14, 2019, Glasgow, United Kingdo

Probing the face-on disc-corona system of the bare AGN Mrk 110 from UV to hard X-rays: a moderate changing-state AGN?

[Abridged] The X-ray broadband spectra of the bare AGN Mrk 110, obtained by simultaneous XMM-Newton and NuSTAR observations (Nov 2019 and April 2020), are characterised by the presence of a prominent and absorption-free smooth soft X-ray excess, moderately broad OVII and Fe Kalpha emission lines, and a lack of a strong Compton hump. While relativistic reflection as the sole emission is ruled out, a simplified combination of soft and hard Comptonisation from a warm and a hot coronae, plus mild relativistic disc reflection reproduces the data very well. We aim to confirm the physical origin of the soft X-ray excess of Mrk 110 and to determine its disc-corona system properties from its energetics using two new sophisticated models: reXcor and relagn, respectively. At both epochs, the inferred high-values of the warm-corona heating from the X-ray broadband spectral analysis using reXcor confirm that the soft X-ray excess originates mainly from a warm corona rather than relativistic reflection. The intrinsic best-fit SED determined at both epochs using relagn show a high X-ray contribution relative to the UV and are very well reproduced by a warm and hot coronae plus mild relativistic reflection. The outer radii of the hot and warm coronae are located at a few 10s and ~100 Rg, respectively. Moreover, combining the inferred low Eddington ratio (~ a few %) from this work, and previous multi-wavelength spectral and timing studies suggests that Mrk 110 could be classified as a moderate changing-state AGN. Our analysis confirms the existence of a warm corona as a significant contribution to the soft X-ray excess and UV emission in Mrk 110, adding to growing evidence that AGN accretion deviates from standard disc theory. This strengthens the importance of long-term multi-wavelength monitoring on both single targets and large AGN surveys to reveal the real nature of disc-corona system in AGN.Comment: 12 pages, 7 figures, accepted for publication in A&

The importance of exercise : Increased water velocity improves growth of Atlantic salmon in closed cages

There is increasing concern about Norwegian salmon farming and the possible environmental impacts from sea lice, escaped fish and release of toxic chemicals and organic emissions to the coastal waters. Closed containment systems (CCS) have the potential to eliminate the problems with sea lice and to reduce escapes and emissions. When closing the cages, water volumes and velocity are regulated and the identification of optimal current velocities for growth and fish welfare from sea transfer to harvest size becomes necessary. This study describes two trials with LOW (0.10–0.27 BL/s) and MODERATE (0.36–0.63 BL/s) water velocity on performance of post-smolt Atlantic salmon in CCS. In trial 1 (168 days, 10.9 °C, fish size: 884–3007 g and 41.5–59.0 cm), round weight increased with 219 g (p = .012) and condition factor with 0.11 (p = .016) in the MODERATE group compared with LOW group. The MODERATE group obtained specific growth rate (SGR) of 0.76 and thermal growth coefficient (TGC) of 2.75, compared to 0.72 and 2.56 in the LOW group. MODERATE water velocity was also associated with higher relative heart size (RHS) (p = .016), higher liver index (HSI) (p = .005), increased fillet yield (p ≤ .001) and lower levels of cathepsin activity in muscle tissue. In trial 2 (46 days, 7.1 °C, fish size: 327–482 g and 29.9–33.7 cm), round weight increased with 52 g (p = .019) and condition factor with 0.05 (p = .009) in the MODERATE group compared with LOW group. The MODERATE group obtained SGR of 0.77 and TGC of 2.68, compared to SGR of 0.60 and TGC of 2.02 in the LOW group. No significant difference was observed in white muscle cell hyperplasia, measured as the proportion of small (< 20 μm diameter) muscle fibres (p = .145). Both trials showed only minor differences in slaughter yield, fillet quality (protein, fat, water) and mortality. The present study shows that moderate water velocity (0.36–0.63 BL/s) is favourable for growth rates for Atlantic salmon during the entire on-growing period in CCS. Effects on a broader range of metabolic variables and welfare indicators were also documented.publishedVersionPaid Open Acces

The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc

We use the SOUX sample of ∼700 active galactic nucleus (AGN) to form average optical-ultraviolet (UV)-X-rays spectral energy distributions (SEDs) on a two-dimensional (2D) grid of MBH and L2500. We compare these with the predictions of a new AGN SED model, QSOSED, which includes prescriptions for both hot and warm Comptonization regions as well as an outer standard disc. This predicts the overall SED fairly well for 7.5 < log(MBH/M⊙) < 9.0 over a wide range in L/LEdd, but at higher masses the outer disc spectra in the model are far too cool to match the data. We create optical-UV composites from the entire Sloan Digital Sky Survey sample and use these to show that the mismatch is due to there being no significant change in spectral shape of the optical-UV continuum across several decades of MBH at constant luminosity. We show for the first time that this cannot be matched by standard disc models with high black hole spin. These apparently fit, but are not self-consistent as they do not include the General Relativistic effects for the emission to reach the observer. At high spin, increased gravitational redshift compensates for almost all of the higher temperature emission from the smaller inner disc radii. The data do not match the predictions made by any current accretion flow model. Either the disc is completely covered by a warm Comptonization layer whose properties change systematically with L/LEdd, or the accretion flow structure is fundamentally different to that of the standard disc models

Effects of Bergen 4-Day Treatment on Resting-State Graph Features in Obsessive-Compulsive Disorder

Background Exposure and response prevention is an effective treatment for obsessive-compulsive disorder (OCD), but it is unclear how symptom reduction is related to changes in the brain. We aimed to determine the effects of a 4-day concentrated exposure and response prevention program (Bergen 4-day treatment) on the static and dynamic functional connectome in patients with OCD. Methods Thirty-four patients with OCD (25 unmedicated) underwent resting-state functional magnetic resonance imaging the day before the Bergen 4-day treatment, and 28 (21 unmedicated) were rescanned after 1 week. Twenty-eight healthy control subjects were also scanned for baseline comparisons and 19 of them were rescanned after 1 week. Static and dynamic graph measures were quantified to determine network topology at the global, subnetwork, and regional levels (including efficiency, clustering, between-subnetwork connectivity, and node flexibility in module allegiance). The Yale-Brown Obsessive Compulsive Scale was used to measure symptom severity. Results Twenty-four patients (86%) responded to treatment. We found significant group × time effects in frontoparietal-limbic connectivity (ηp2 = .19, p = .03) and flexibility of the right subgenual anterior cingulate cortex (ηp2 = .18, p = .03), where, in both cases, unmedicated patients showed significant decreases while healthy control subjects showed no significant changes. Healthy control subjects showed increases in global and subnetwork efficiency and clustering coefficient, particularly in the somatomotor subnetwork. Conclusions Concentrated exposure and response prevention in unmedicated patients with OCD leads to decreased connectivity between the frontoparietal and limbic subnetworks and less flexibility of the connectivity of the subgenual anterior cingulate cortex, suggesting a more independent and stable network topology. This may represent less limbic interference on cognitive control subnetworks after treatment.acceptedVersio

CHANGING NURSING CARE TIME AS AN EFFECT OF CHANGED CHARACTERISTICS OF THE DIALYSIS POPULATION

Background: The population of dialysis patients is ageing. Dialysis nurses are confronted with geriatric patients with multiple comorbidities. Nurses are confronted with an increasing burden of care. Objectives: The present study focused on the question of whether, over time, the increasing age and comorbidities of the haemodialysis population increased nursing care time. Furthermore, we studied potential changes in the predictors of the required nursing time. Design: Observational study. Participants: A total of 980 dialysis patients from 12 dialysis centres were included. Measurements: Nurses filled out the classification tool for each patient and completed a form for reporting patient characteristics for groups of relevant haemodialysis patients at baseline and after 1 and four years. Changes in patient and dialysis characteristics were analysed, as well as the estimated nursing care time needed. Results: An increase in the nursing time needed for dialysis was largely due to decreased mobility, closing of the vascular access and a greater need for psychosocial attention and was most strongly present in incident dialysis patients. The time needed for dialysis decreased as patient participation increased and vascular access changed from catheters to fistulae. Over the four-year period, the average overall needed nursing care time per haemodialysis session did not change. Conclusions: Our study shows that the average nursing time needed per patient did not change in the four-year observation period. However, more time is required for incident patients; thus, if a centre has high patient turnover, more nursing care time is needed