Variability of Active Galactic Nuclei from the Optical to X-ray Regions

Some progress in understanding AGN variability is reviewed. Reprocessing of X-ray radiation to produce significant amounts of longer-wavelength continua seems to be ruled out. In some objects where there has been correlated X-ray and optical variability, the amplitude of the optical variability has exceeded the amplitude of X-ray variability. We suggest that accelerated particles striking material could be linking X-ray and optical variability (as in activity in the solar chromosphere). Beaming effects could be significant in all types of AGN. The diversity in optical/X-ray relationships at different times in the same object, and between different objects, might be explained by changes in geometry and directions of motion relative to our line of sight. Linear shot-noise models of the variability are ruled out; instead there must be large-scale organization of variability. Variability occurs on light-crossing timescales rather than viscous timescales and this probably rules out the standard Shakura-Sunyaev accretion disk. Radio-loud and radio-quiet AGNs have similar continuum shapes and similar variability properties. This suggests similar continuum origins and variability mechanisms. Despite their extreme X-ray variability, narrow-line Seyfert 1s (NLS1s) do not show extreme optical variability.Comment: Invited talk given at Euro Asian Astronomical Society meeting in Moscow, June 2002. 20 pages, 4 figures. References update

The effectiveness of cognitive analytic therapy for borderline personality disorder : utilizing a withdrawal experimental design to improve sensitivity to abandonment

Objectives A primary methodological weakness of the single‐case experimental design (SCED) outcome studies conducted of the treatment of personality disorder with cognitive analytic therapy (CAT) is that they have failed to employ a withdrawal phase or cross‐over design and so are deemed quasi‐experimental. This study sought to implement a withdrawal design, in order to improve the internal validity of the study to make it a true SCED, and also in order to enable the patient to explore abandonment dynamics. Design The study employed an A1/B1/A2/B2 with extended follow‐up SCED with a female patient treated with CAT meeting diagnostic criteria for borderline personality disorder (BPD). Following the 6‐week baseline period ‘A1’, treatment occurred in two phases (21 sessions ‘B1’ and 24 sessions ‘B2’) sandwiching a 12‐week treatment withdrawal phase (‘A2’) and a 24‐week structured follow‐up phase. Seven idiographic daily measures were collected that created a N = 698 day timeline. Nomothetic outcome measures were collected at baseline and at the end of each phase of the study, and the Session Impact Scale was completed after each treatment session. Results There was a significant increase in the task focus of treatment sessions. Ideographically, CAT was an effective treatment for improving the participant’s self‐to‐self relationship, as their self‐hate reduced and their sense‐of‐self increased. There was a broad pattern of deterioration during the second treatment phase (B2) and follow‐up phase across the ideographic measures, and CAT was ineffective for BPD ideographic emotional or self‐to‐other measures. Reliable change occurred on the primary BPD nomothetic outcome measure from baseline to end of first treatment phase. Conclusions The study suggests that the CAT intervention was partially successful and that it is possible to integrate good research practice with clinical innovation. The methodological strengths and limitations of the design and the clinical implications of the results are discussed. Practitioner points Cognitive analytic therapy was partially effective in the treatment of BPD in a case that had been unresponsive to other psychological interventions. Therapists need to complete lengthy and structured follow‐up to capture any emerging relapse. Therapists need to discuss the patient’s thoughts and feelings about termination regularly in a relationally informed manner

Setting UBVRI Photometric Zero-Points Using Sloan Digital Sky Survey ugriz Magnitudes

We discuss the use of Sloan Digital Sky Survey (SDSS) ugriz point-spread function (PSF) photometry for setting the zero points of UBVRI CCD images. From a comparison with the Landolt (1992) standards and our own photometry we find that there is a fairly abrupt change in B, V, R, & I zero points around g, r, i ~ 14.5, and in the U zero point at u ~ 16. These changes correspond to where there is significant interpolation due to saturation in the SDSS PSF fluxes. There also seems to be another, much smaller systematic effect for stars with g, r > 19.5. The latter effect is consistent with a small Malmquist bias. Because of the difficulties with PSF fluxes of brighter stars, we recommend that comparisons of ugriz and UBVRI photometry should only be made for unsaturated stars with g, r and i in the range 14.5 - 19.5, and u in the range 16 - 19.5. We give a prescription for setting the UBVRI zero points for CCD images, and general equations for transforming from ugriz to UBVRI.Comment: 13 pages. 6 figures. Accepted for publication in the Astronomical Journa

NGC 5548: THE AGN ENERGY BUDGET PROBLEM AND THE GEOMETRY OF THE BROAD-LINE REGION AND TORUS

We consider in detail the spectral energy distribution (SED) and multi-wavelength variability of NGC 5548. Comparison with the SEDs of other AGNs implies that the internal reddening of NGC 5548 is E(B-V) = 0.17 mag. The extinction curve is consistent with the mean curve of other AGNs found by Gaskell & Benker, but inconsistent with an SMC-type reddening curve. Because most IR emission originates exterior to the broad-line region (BLR), the SED seen by the inner BLR is different from that seen by the outer BLR and from the earth. The most likely BLR covering factor is ~ 40% and it is not possible to get an overall BLR covering factor of less than 20%. This requires that the BLR is not spherically symmetric and that we are viewing through a hole. Line-continuum variability transfer functions are consistent with this geometry. The covering factor and geometry imply that near the equatorial plane the BLR covering approaches 100%. The spectrum seen by the outer regions of the BLR and by the torus is thus modified by the absorption in the inner BLR. This shielding solves the problem of observed BLR ionization stratification being much greater than implied by photoionization models. The BLR obscuration also removes the problem of the torus covering factor being greater than the BLR covering factor, and gives consistency with the observed fraction of obscured AGNs. The flux reduction at the torus also reduces the problem of AGN dust-reverberation lags giving sizes smaller than the dust-sublimation radii

Reverberation Mapping Results from MDM Observatory

We present results from a multi-month reverberation mapping campaign undertaken primarily at MDM Observatory with supporting observations from around the world. We measure broad line region (BLR) radii and black hole masses for six objects. A velocity-resolved analysis of the H_beta response shows the presence of diverse kinematic signatures in the BLR.Comment: To appear in the Proceedings of the IAU Symposium No. 267: Co-Evolution of Central Black Holes and Galaxies, Rio de Janeiro, 200

Have GM crops and food a future in Europe?

Intensive mono-functional agriculture, typical across many European Member States, is designed to increase the efficiency and productivity of the agricultural sector. This is accompanied by frequent spraying of crops with chemicals for protection against pests and diseases. While the health and environmental impacts of pesticides and their residues are debated among scientific experts, in the minds of European citizens they constitute the most significant food risk. The Eurobarometer public opinion survey on Food-Related Risks commissioned by the European Food Safety Authority (EFSA) in 2010 looked at risk perceptions in two ways. First, an open-ended question which invited respondents to say ‘what comes to mind when they think about possible problems and risks associated with food and eating’, and second a closed question asked respondents to rate the extent to which they worry about 17 food-related risks, including pesticides in fruit and vegetables (EFSA, 2010). The most frequent response to the open question was ‘chemicals and pesticides’, mentioned spontaneously by 17% of Europeans – 7% mentioned genetically modified organisms (GMOs). In the closed question 74% of Europeans say they are fairly or very worried about pesticides in fruit and vegetables – the highest percentage of worry across 17 food risks. Sixty-seven per cent say they are fairly or very worried about GMOs. The 2010 survey replicated a number of questions from EFSA’s first Risk Issues Eurobarometer in 2005 (EFSA, 2005). The findings on worry about pesticides in fruit and vegetables show an increase of 4% over the period – 12 countries show a 4% or more increase in worry, including Austria, Belgium, Denmark, France, Germany, Hungary, The Netherlands and Sweden. Overall, it appears that pesticides in fruit and vegetables are not only the top concern among Europeans, but also an increasing concern

Effectiveness of the unified protocol for treating co-morbid health anxiety and depression : an empirical case study

Aims: The unified protocol (UP) is indicated when patients present with co-morbidity, but no studies have previously investigated the effectiveness of the UP with co-morbid health anxiety and depression. Method: An A/B single case design evaluated outcomes for a 27-year-old male presenting with health anxiety and co-morbid depression. Following a 21-day assessment-baseline period containing three sessions, the manualised UP was delivered across a 42-day period containing seven intervention sessions. Four idiographic measures (occurrence and duration of health checking, sleep duration and food intake satisfaction) were collected daily throughout, and two nomothetic measures were collected at four time points. Results: All sessions were attended. Number of health checking episodes reduced from four per day to two per day. A 59 minute per day reduction in time spent health checking occurred, and sleep increased by 100 minutes per night. There was little apparent change in terms of food intake satisfaction. There was a reliable and clinically significant reduction in depression. Discussion: Further testing of the effectiveness of the UP with co-morbid health anxiety and depression in true single case experimental designs is now indicated

Chemical Abundances in AGN Environment: X-Ray/UV Campaign on the MRK 279 Outflow

We present the first reliable determination of chemical abundances in an AGN outflow. The abundances are extracted from the deep and simultaneous FUSE and HST/STIS observations of Mrk 279. This data set is exceptional for its high signal-to-noise, unblended doublet troughs and little Galactic absorption contamination. These attributes allow us to solve for the velocity-dependent covering fraction, and therefore obtain reliable column densities for many ionic species. For the first time we have enough such column densities to simultaneously determine the ionization equilibrium and abundances in the flow. Our analysis uses the full spectral information embedded in these high-resolution data. Slicing a given trough into many independent outflow elements yields the extra constraints needed for a physically meaningful abundances determination. We find that relative to solar the abundances in the Mrk 279 outflow are (linear scaling): carbon 2.2+/-0.7, nitrogen 3.5+/-1.1 and oxygen 1.6+/-0.8. Our UV-based photoionization and abundances results are in good agreement with the independent analysis of the simultaneous Mrk 279 X-ray spectra. This is the best agreement between the UV and X-ray analyses of the same outflow to date.Comment: 28 pages, 7 figures, accepted on 29 Nov 2006 for publication in the ApJ (submission date: 27 Jul 2006

The End of the Lines for OX 169: No Binary Broad-Line Region

We show that unusual Balmer emission line profiles of the quasar OX 169, frequently described as either self-absorbed or double peaked, are actually neither. The effect is an illusion resulting from two coincidences. First, the forbidden lines are quite strong and broad. Consequently, the [N II]6583 line and the associated narrow-line component of H-alpha present the appearance of twin H-alpha peaks. Second, the redshift of 0.2110 brings H-beta into coincidence with Na I D at zero redshift, and ISM absorption in Na I D divides the H-beta emission line. In spectra obtained over the past decade, we see no substantial change in the character of the line profiles, and no indication of intrinsic double-peaked structure. The H-gamma, Mg II, and Ly-alpha emission lines are single peaked, and all of the emission-line redshifts are consistent once they are correctly attributed to their permitted and forbidden-line identifications. A systematic shift of up to 700 km/s between broad and narrow lines is seen, but such differences are common, and could be due to gravitational and transverse redshift in a low-inclination disk. Stockton & Farnham (1991) had called attention to an apparent tidal tail in the host galaxy of OX 169, and speculated that a recent merger had supplied the nucleus with a coalescing pair of black holes which was now revealing its existence in the form of two physically distinct broad-line regions. Although there is no longer any evidence for two broad emission-line regions in OX 169, binary black holes should form frequently in galaxy mergers, and it is still worthwhile to monitor the radial velocities of emission lines which could supply evidence of their existence in certain objects.Comment: 19 pages, 5 figures, accepted for publication in Ap.