Line width distributions as evidence for axisymmetry in the broad line regions of active galaxies

The nuclei of a wide class of active galaxies emit broad emission lines with widths at half maximum (FWHM) in the range $10^{3}-10^{4}$ km s$^{-1}$. This spread of widths is not solely a consequence of the range of the luminosities of these sources since a plot of width versus luminosity shows a large scatter. We propose that the broad line emission region (BLR) is axially symmetric and that this scatter in line width arises from an additional dependence on the angle of the line of sight to the axis of the emission region. Such a relation is natural in unified models of active nuclei which link a variety of observed properties to viewing angle. Adopting a simple form for the line width as a function of luminosity and angle, and convolving this with the observed luminosity function, allows us to predict a line width distribution consistent with the available data. Furthermore, we use the relation between the equivalent width of a line and the luminosity in the continuum (the `Baldwin Effect') to predict an observed correlation between line width and equivalent width. The scatter on this correlation is again provided by angular dependence. The results have applications as diagnostics of models of the broad line emission region and in cosmology.Comment: 8 pages including 4 figures. Accepted for publication in MNRAS Letter

The luminosity dependence of opening angle in unified models of active galaxies

In unified models of active galaxies the direct line of sight to the nucleus is unobscured only within a certain cone of directions. An opening angle for this cone is usually estimated by methods such as the overall ratio of Seyfert 1s to Seyfert2s, the latter assumed to be obscured versions of the former. Here we shall show, as has often been suspected, that the opening angle of the cone depends on the luminosity of the central source, with higher luminosities corresponding to larger opening angles. This conclusion depends only on the assumption that the width of the broad emission lines at a given luminosity is a measure of inclination angle, an assumption that is supported by observation in radio-loud systems. On the other hand we show that the scatter in X-ray spectral index is not primarily an effect of viewing angle, in contrast to what might be expected if the scatter on the spectral index versus luminosity relation were a consequence of absorption in the obscuring material. The observed correlation between linewidth and spectral index appears to be a further consequence of the dependence of opening angle on luminosity.Comment: 8 pages, 7 figures, uses mn.sty. Accepted for publication in MNRA

Determining the cosmological parameters from the linewidths of active galaxies

We have previously shown that the linewidth distribution in AGN can be accounted for by an axisymmetric broad emission line region. In this paper we show that the linewidth distribution changes with redshift and that these changes are dependent on H_0 and q_0. We show that relatively small samples of AGN at high redshift with measured linewidth at half maximum can be used to distinguish between values of H_0 and q_0. Furthermore larger low redshift samples can be used to distinguish between luminosity functions and hence different models of quasar evolution.Comment: Accepted for publication in MNRAS. 8 pages LaTeX, uses mn.st

Moving Detectors in Cavities

We consider two-level detectors, coupled to a quantum scalar field, moving inside cavities. We highlight some pathological resonant effects due to abrupt boundaries, and decide to describe the cavity by switching smoothly the interaction by a time-dependent gate-like function. Considering uniformly accelerated trajectories, we show that some specific choices of non-adiabatic switching have led to hazardous interpretations about the enhancement of the Unruh effect in cavities. More specifically, we show that the emission/absorption ratio takes arbitrary high values according to the emitted quanta properties and to the transients undergone at the entrance and the exit of the cavity, {\it independently of the acceleration}. An explicit example is provided where we show that inertial and uniformly accelerated world-lines can even lead to the same ``pseudo-temperature''.Comment: 13 pages, 6 figures, version accepted in Phys.Rev.

Einstein-Podolsky-Rosen correlations between two uniformly accelerated oscillators

We consider the quantum correlations, i.e. the entanglement, between two systems uniformly accelerated with identical acceleration a in opposite Rindler quadrants which have reached thermal equilibrium with the Unruh heat bath. To this end we study an exactly soluble model consisting of two oscillators coupled to a massless scalar field in 1+1 dimensions. We find that for some values of the parameters the oscillators get entangled shortly after the moment of closest approach. Because of boost invariance there are an infinite set of pairs of positions where the oscillators are entangled. The maximal entanglement between the oscillators is found to be approximately 1.4 entanglement bits.Comment: 11 page

Predictors of incident herpes simplex virus type 2 infections in young women at risk for unintended pregnancy in San Francisco.

BackgroundYoung women receiving family planning services are at risk for both unintended pregnancy and herpes simplex virus type 2 (HSV-2) infection.MethodsWe performed a secondary analysis using data from a previously published randomized controlled trial evaluating access to emergency contraception on reproductive health outcomes. Women aged 15 to 24 years were recruited from two Planned Parenthood clinics and two community health clinics in San Francisco. Demographic information and sexual history were obtained by interview. HSV-2 seropositivity was determined by fingerstick blood test. New pregnancies were measured by self-report, urine testing and medical chart review. Subjects were evaluated for incident HSV-2 infection and pregnancy at a 6-month follow-up appointment. Women who were pregnant or intending to become pregnant at enrolment were excluded.ResultsAt enrolment 2,104 women were screened for HSV-2 and 170 (8.1%) were seropositive. Eighty-seven percent of initially seronegative women completed the study (n = 1,672) and 73 (4.4%) became HSV-2 seropositive. HSV-2 seroincidence was 7.8 cases per 100 person-years. One hundred and seventeen women (7%) became pregnant and 7 (6%) of these had a seroincident HSV-2 infection during the study. After adjustment for confounders, predictors of incident HSV-2 infection were African American race and having multiple partners in the last six months. Condom use at last sexual encounter was protective.ConclusionHSV-2 seroincidence and the unintended pregnancy rate in young women were high. Providers who counsel women on contraceptive services and sexually transmitted infection prevention could play an expanded role in counselling women about HSV-2 prevention given the potential sequelae in pregnancy. The potential benefit of targeted screening and future vaccination against HSV-2 needs to be assessed in this population

Correction to: The hidden therapist: evidence for a central role of music in psychedelic therapy.

The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal

Modelling and comparison of in-field critical current density anisotropy in high temperature superconducting (HTS) coated conductors

The development of high-temperature superconducting (HTS) wires is now at a stage where long lengths of high quality are commercially available, and of these, (Re)BCO coated conductors show the most promise for practical applications. One of the most crucial aspects of coil and device modeling is providing accurate data for the anisotropy of the critical current density Jc(B, θ) of the superconductor. In this paper, the in-field critical current density characteristics Jc(B, θ) of two commercial HTS coated conductor samples are experimentally measured, and based on these data, an engineering formula is introduced to represent this electromagnetic behavior as the input data for numerical modeling. However, due to the complex nature of this behavior and the large number of variables involved, the computational speed of the model can be extremely slow. Therefore, a two-variable direct interpolation method is introduced, which completely avoids any complex data fitting for Jc(B, θ) and expresses the anisotropic behavior in the model directly and accurately with a significant improvement in computational speed. The two techniques are validated and compared using numerical models based on the H-formulation by calculating the self-field and in-field dc critical currents and the ac loss for a single coated conductor