24 research outputs found
Consistency of the black hole mass determination in AGN from the reverberation and the X-ray excess variance method
Values of black hole masses are frequently determined with the help of the
reverberation method. This method requires a specific geometrical factor
related to the distribution of the orbits of the Broad Line Region clouds.
Onken et al. determined the value f^2= 1.37+/-0.45 from the black hole mass -
dispersion relation. In this paper we determine this factor using an
independent mass determination from the X-ray variance method for a number of
Seyfert 1 galaxies and comparing them with the reverberation results by
Peterson et al. We obtain mean value f^2 = 1.12 +/- 0.54, consistent with Onken
et al. Both values are larger than the value 0.75 corresponding to a spherical
geometry. It indicates that most probably all values of the black hole masses
obtained with the use of the Kaspi et al. formulae should be multiplied by a
factor of \sim 1.7. This also shows that the Broad Line Region is rather flat,
and hints for a dependence of the factor f^2 on a source inclination seem to be
present in the data.Comment: 7 pages, 4 figures, 1 table; accepted for publication in MNRA
Potencial do flavedo (epicarpo) de Citrus aurantifolia cv. Tahiti no controle do bolor verde e da antracnose em citros
Krijgsmacht en politietaken
This special issue is about the role of the armed forces in domestic law enforcement. Internal and external security are nowadays interwoven in a variety of ways and to an increasing extent. Consider, for example, international tensions that can lead to local polarization between population groups, also called glocalization. The threat of terrorism in the past twenty years also arises directly from armed conflicts abroad and bring new dilemmas, such as the return of extremist Syria fighters. A phenomenon such as cybercrime is also international in nature. In addition, local crime often has international aspects. Against this background, we see that military personnel have frequently been deployed in international peace operations over the past decades. As a result, the armed forces themselves have changed because soldiers have had to develop additional skills aimed at performing safety tasks in a civilian environment, in cooperation with civilians and civil organizations ('constabularisation'). Moreover, due to these changing tasks, the armed forces now have more technical tools at their disposal that are also useful in the investigation of common crimes. It is not uncommon nowadays that military personnel perform tasks that are strongly reminiscent of the work of investigative services: securing evidence for an (international) criminal case, intercepting drug parties or, for example, assisting a police investigation team in the Netherlands with a special search team. Defense aid to the police and judiciary is not only provided by the investigating officers of the Royal Netherlands Marechaussee, but also by military personnel from 'green' army units. This is done within the framework of so-called 'national operations'. This military assistance is not undisputed and sometimes produces friction between the armed forces and the police organization. Furthermore, we will see in this issue that the boundaries between the police and the armed forces have always been fluid in practice, in spite of official assumptions. It is obvious that the Royal Netherlands Marechaussee, a police organization with a military status, plays a special role in this. Until certainly the Second World War, the Marechaussee provided the basic police task in large parts of the Netherlands. This hybrid organization operates in the border area of __the armed forces and police forces. This also applies to the special units that are responsible in the Netherlands for combating terror and arresting dangerous suspects