Estimating Black Hole Masses in Quasars Using Broad Optical and UV Emission Lines

We review past work using broad emission lines as virial estimators of black hole masses in quasars. Basically one requires estimates of the emitting region radius and virial velocity dispersion to obtain black hole masses. The three major ways to estimate the broad-line emitting region (BLR) radius involve: (1) direct reverberation mapping, (2) derivation of BLR radius for larger samples using the radius-luminosity correlation derived from reverberation measures, and (3) estimates of BLR radius using the definition of the ionization parameter solved for BLR radius (photoionization method). At low redshift (z < 0.7) FWHM H-beta serves as the most widely used estimator of virial velocity dispersion. FWHM H-beta can provide estimates for tens of thousands of quasars out to z ~ 3.8 (IR spectroscopy beyond z ~ 1). A new photoionization method also shows promise for providing many reasonable estimates of BLR radius via high S/N IR spectroscopy of the UV region 1300 -- 2000 A. FWHM MgII 2800 can serve as a surrogate for FWHM H-beta in the range 0.4 < z < 6.5 while CIV 1549 is affected by broadening due to non-virial motions and best avoided (i.e. there is no clear conversion factor between FWHM H-beta and FWHM CIV 1549). Most quasars yield black hole mass estimates in the range 7 < log M< 9.7. There is no strong evidence for values above 10.0 and there may be evidence for a turnover in the maximum black hole mass near z ~ 5.Comment: Accepted for publication in New Astronomy Reviews. The work was presented as an invited talk at special workshop "Spectral lines and super-massive black holes" held on June 10, 2011 as a part of activity in the frame of COST action 0905 "Black holes in an violent universe" and as a part of the 8th Serbian Conference on Spectral Line Shapes in Astrophysic

Pediatrics of disasters in the structure of professional training of pediatricians of the city children’s polyclinic to work in emergencies and terrorist acts: View from Russia

Introduction: Modern pediatrics of disasters is built on 5 basic principles: integrity, structure, causality, dynamism, and hierarchy.Material and methods: Methodological approaches were used: systemic, complex, integration, functional, dynamic, process, normative, quantitative, administrative, and situational, and methods: historical, analytical, and comparison. Techniques were used: grouping, absolute and relative values, detailing, and generalization.Results: The algorithms of actions of the doctor of the children&rsquo;s clinic in the event of a fire, the receipt of a call about the laying of explosives and the threat of explosion were considered, the scope of the provision of first qualified aid to the pediatric nursing team was clarified. The issues of the organization of the first qualified and specialized medical care, taking into account the anatomical and physiological characteristics of children and adolescents, as well as medical tactics for small-medium, and large disasters in rural areas and cities are discussed.Conclusion: Pediatrics of disasters is an independent section of organizational and medical work in emergencies and terrorist acts, providing specialized medical care for at least 25% of victims, who are children and adolescents. The training of doctors of a specialized children&rsquo;s polyclinic is regulated by regulatory documents of the Russian Federation and the Republic of Komi, Orders of the Ministry of Health of the region, a municipal formation, and a medical institution in the field of civil defense and emergency situations. In case of minor emergencies and disasters within the city boundaries with the occurrence of a single or a small number of group losses, medical support repeats that in road traffic accidents, with the exception of the organization and conduct of medical triage. In rural areas, it is required to attract additional medical and nursing teams (emergency medical aid teams), created on the basis of medical institutions of the victim and neighboring areas. At the same time, a forced maneuver by the forces and means of territorial health care is necessary for the medical evacuation of a significant part of the affected children to specialized institutions (departments) located in cities. The provision of psychological and psychiatric assistance to children and adolescents in emergencies is carried out on the basis of its basic modules (departments and offices of psychological and psychiatric assistance, and advisory mobile team of psychological and psychiatric assistance, anonymous psychological and psychiatric assistance by telephone)

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. XVI. A 13 year study of spectral variability in NGC 5548

We present the final installment of an intensive 13 year study of variations of the optical continuum and broad Hbeta emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 Hbeta measurements. The Hbeta variations follow the continuum variations closely, with a typical time delay of about 20 days. However, a year-by-year analysis shows that the magnitude of emission-line time delay is correlated with the mean continuum flux. We argue that the data are consistent with the simple model prediction between the size of the broad-line region and the ionizing luminosity, rproportional toL(ion)(1/2). Moreover, the apparently linear nature of the correlation between the Hbeta response time and the nonstellar optical continuum F-opt arises as a consequence of the changing shape of the continuum as it varies, specifically F(opt)proportional toF(UV)(0.56).

Influenza interaction with cocirculating pathogens and its impact on surveillance, pathogenesis, and epidemic profile: A key role for mathematical modelling

International audienceEvidence is mounting that influenza virus interacts with other pathogens colonising or infecting the human respiratory tract. Taking into account interactions with other pathogens may be critical to determining the real influenza burden and the full impact of public health policies targeting influenza. This is particularly true for mathematical modelling studies, which have become critical in public health decision-making. Yet models usually focus on influenza virus acquisition and infection alone, thereby making broad oversimplifications of pathogen ecology. Herein, we report evidence of influenza virus interactions with bacteria and viruses and systematically review the modelling studies that have incorporated interactions. Despite the many studies examining possible associations between influenza and Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Neisseria meningitidis, respiratory syncytial virus (RSV), human rhinoviruses, human parainfluenza viruses, etc., very few mathematical models have integrated other pathogens alongside influenza. The notable exception is the pneumococcus-influenza interaction, for which several recent modelling studies demonstrate the power of dynamic modelling as an approach to test biological hypotheses on interaction mechanisms and estimate the strength of those interactions. We explore how different interference mechanisms may lead to unexpected incidence trends and possible misinterpretation, and we illustrate the impact of interactions on public health surveillance using simple transmission models. We demonstrate that the development of multipathogen models is essential to assessing the true public health burden of influenza and that it is needed to help improve planning and evaluation of control measures. Finally, we identify the public health, surveillance, modelling, and biological challenges and propose avenues of research for the coming years