86,235 research outputs found
The basic parameters of gamma-ray-loud blazars
We determined the basic parameters, such as the central black hole mass
(), the boosting factor (or Doppler factor) (), the propagation
angle () and the distance along the axis to the site of -ray
production () for 23 -ray-loud blazars using their available
variability timescales. In this method, the absorption effect depends on the
-ray energy, emission size and property of the accretion disk. Using
the intrinsic -ray luminosity as a fraction of the Eddington
luminosity, and the optical depth equal to
unity, we can determine the upper limit of the central black hole masses. We
found that the black hole masses range between and
when = 0.1 and 1.0 are adopted. Since this method
is based on gamma-ray emissions and the short time-scale of the sources, it can
also be used for central black hole mass determination of high redshift
gamma-ray sources. In the case of the upper limit of black hole mass there is
no clear difference between BLs and FSRQs, which suggests that the central
black hole masses do not play an important role in the evolutionary sequence of
blazars.Comment: 8 pages, 3 figures, 1 table, Accepted by A&
Recommended from our members
Surrogate Brands - The pull to adopt an âOtherâ nation; via sports merchandise
A growing number of consumers are choosing to wear sporting merchandise, from an âotherâ nation â whom they have no geographic or ethnic affiliation with. In addition, nation sports branding appears to have scaled pandemic heights; by reaching fever pitch, when actively carrying its message across boarders. Consumer preferences are being driven past simple behavioural characteristics; towards more transient psychographic and emotional constructs. In short, nation branded sporting uniform is no longer viewed as demanding restrictive monogamous loyalty. Ownership of a uniform largely suggests exclusivity and encouraged competition. However, manufactures, national teams, athletes and sponsors are entering symbiotic brand relationships - where they are actively seeking publics, open to multiple adopted nationalities. This phenomenon draws consumers towards embracing temporal national identities, which are converted into an over-arching cross-border identity; ultimately gifting sports brands more significance. The following paper explores consumersâ entry into relationships with another nation, in preference to their own - in manner that has been likened to a form of surrogacy; by the authors. The aim is to stimulate further thinking in a field; which transcends national and cultural boundaries - in the interests of developing new insight, and to provide a platform for marketers to develop more effective communication
Environmental modelling of the Chief Information Officer
Since the introduction of the term in the 1980âs, the role of the Chief Information Officer (CIO) has been widely researched. Various perceptions and dimensions of the role have been explored and debated. However, the explosion in data proliferation (and the inevitable resulting information fuelled change) further complicates organisational expectations of the CIOs role. If organisations are to competitively exploit the digital trend, then those charged with recruiting and developing CIOs now need to be more effective in determining (and shaping) CIO traits and attributes, within the context of their own organisational circumstances and in line with stakeholder expectations. CIOs also need to determine their own suitability and progression within their chosen organisation if they are to remain motivated and effective. Before modelling the role of the future CIO, it is necessary to synthesise our current knowledge (and the lessons learnt) about the CIO. This paper, therefore, aims to identify and summate the spectrum of key researched âthemesâ pertaining to the role of the CIO. Summating previous research, themes are modelled around four key CIO âdimensionsâ, namely (1) Impacting factors, (2) Controlling factors (3) Responses and (4) CIO âattributesâ. Having modelled the CIOs current environment, and recognising the evolving IT enabled information landscape, the authors call for further research to inform the recruitment and development of the future CIO in terms of personal attributes and the measurable impact such attributes will have on their respective organisation
- âŠ