7,987 research outputs found
Deconstructing the concept of 'Creative Industries'
âCreative industriesâ and âcultural industriesâ are terms that tend to be used interchangeably by UK policymakers. However their meanings and uses are in fact very different. In this paper we will be exploring the differences between the two and arguing that, despite how influential it has become, the creative industries definition adopted by the British government is ill conceived in relation to culture.
First, it confuses or conflates culture and creativity, two quite different concepts. This is partly because of terminological confusion about the word culture, which we will look at later in more detail. Second, we argue that the UK creative industries definition is wedded to notions of the knowledge economy, within which culture is valued primarily for its economic contribution. The result is a creative industries definition that fails to take account of the importance and distinctiveness of culture â in policy terms the creative arts have been subsumed within a concept which, as we shall show, has no cultural content at all
Sub-mm clues to elliptical galaxy formation
There is growing evidence that, at the S(850) < 1 mJy level, the sub-mm
galaxy population (and hence a potentially significant fraction of the sub-mm
background) is associated with the star-forming Lyman-break population already
detected at optical wavelengths. However, the implied star-formation rates in
such objects (typically 3-30 solar masses per year) fall one or two orders of
magnitude short of the level of star-forming activity required to produce the
most massive elliptical galaxies on a timescale ~ 1 Gyr. If a significant
fraction of massive ellipticals did form the bulk of their stars in short-lived
massive starbursts at high redshift, then they should presumably be found among
the brighter, S(850) ~ 10 mJy sub-mm sources which are undoubtedly not part of
the Lyman-break population. A first powerful clue that this is indeed the case
comes from our major SCUBA survey of radio galaxies, which indicates that
massive dust-enshrouded star-formation in at least this subset of massive
ellipticals is largely confined to z > 2.5, with a mean redshift z = 3.5. While
radio selection raises concerns about bias, I argue that our current knowledge
of the brightest (S(850) ~ 10 mJy) sub-mm sources detected in unbiased SCUBA
imaging surveys indicates that they are also largely confined to this same
high-z regime. Consequently, while the most recent number counts imply such
extreme sources can contribute only 5-10% of the sub-mm background, their
comoving number density (in the redshift band 3 < z < 5) is 1-2 x 10^{-5} per
cubic megaparsec, sufficient to account for the formation of all ellipticals of
comparable mass to radio galaxies (~4L-star) in the present-day universe.Comment: 8 pages, 5 figures, UMass/INAOE conference proceedings on `Deep
millimeter surveys', eds. J. Lowenthal and D. Hughes, World Scientifi
Structures Produced by the Collision of Extragalactic Jets with Dense Clouds
We have investigated how several parameters can affect the results of a
collision between an extragalactic jet and a dense, intergalactic cloud,
through a series of hydrodynamic simulations. Such collisions are often
suggested to explain the distorted structures of some radio jets. However,
theoretical studies of this mechanism are in conflict over whether it can
actually reproduce the observations.
The parameters are the Mach number, and the relative densities of the jet and
the cloud to the ambient medium. Using a simple prescription we have produced
synthetic radio images for comparison with observations. These show that a
variety of structures may be produced from simple jet-cloud collisions. We
illustrate this with a few examples, and examine the details in one case. In
most cases we do not see a clear, sustained deflection. Lighter jets are
completely disrupted. The most powerful jets produce a hotspot at the impact
which outshines any jet emission and erode the cloud too quickly to develop a
deflected arm. It appears that moderate Mach numbers and density contrasts are
needed to produce bends in the radio structure. This explains the apparent
conflict between theoretical studies, as conclusions were based on different
values of these parameters. Shocks are produced in the ambient medium that
might plausibly reproduce the observed alignment of the extended emission line
regions with the radio axis.Comment: 21 pages, 11 figures. Submitted to MNRAS. Also available in html
version at http://www.doc.mmu.ac.uk/STAFF/S.Higgins/jcmnpaper/jc_mn.htm
Cosmology with redshift surveys of radio sources
We use the K-z relation for radio galaxies to illustrate why it has proved
difficult to obtain definitive cosmological results from studies based entirely
on catalogues of the brightest radio sources, e.g. 3C. To improve on this
situation we have been undertaking redshift surveys of complete samples drawn
from the fainter 6C and 7C radio catalogues. We describe these surveys, and
illustrate the new studies they are allowing. We also discuss our `filtered' 6C
redshift surveys: these have led to the discovery of a radio galaxy at z=4.4,
and are sensitive to similar objects at higher redshift provided the space
density of these objects is not declining too rapidly with z. There is
currently no direct evidence for a sharp decline in the space density of radio
galaxies for z > 4, a result only barely consistent with the observed decline
of flat-spectrum radio quasars.Comment: 8 pages Latex, To appear in the "Cosmology with the New Radio
Surveys" Conference - Tenerife 13-15 January 199
Time and M-theory
We review our recent proposal for a background independent formulation of a
holographic theory of quantum gravity. The present review incorporates the
necessary background material on geometry of canonical quantum theory,
holography and spacetime thermodynamics, Matrix theory, as well as our specific
proposal for a dynamical theory of geometric quantum mechanics, as applied to
Matrix theory. At the heart of this review is a new analysis of the conceptual
problem of time and the closely related and phenomenologically relevant problem
of vacuum energy in quantum gravity. We also present a discussion of some
observational implications of this new viewpoint on the problem of vacuum
energy.Comment: 86 pages, 5 figures, LaTeX, typos fixed, references added, and Sec.
6.2 revised; invited review for Int. J. Mod. Phys.
The Sun, stellar-population models, and the age estimation of high-redshift galaxies
Given sufficiently deep optical spectroscopy, the age estimation of
high-redshif t () galaxies has been claimed to be a relatively robust
process (e.g. Dunlop et al. 1996) due to the fact that, for ages Gyr, the
near-ultraviolet light of a stellar population is expected to be dominated by
`well-understood' main-sequence (MS) stars. Recently, however, the reliability
of this process has been called into question by Yi et al (2000), who claim to
have developed models in which the spectrum produced by the main sequence
reddens much more rapidly than in the models of Jimenez et al (2000a), leading
to much younger age estimates for the reddest known high-redshift ellipticals.
In support of their revised age estimates, Yi et al cite the fact that their
models can reproduce the spectrum of the Sun at an age of 5 Gyr, whereas the
solar spectrum is not reproduced by the Jimenez et al models until
Gyr. Here we confirm this discrepancy, but point out that this is in fact a
{\it strength} of the Jimenez et al models and indicative of some flaw in the
models of Yi et al (which, in effect, imply that the Sun will turn into a red
giant any minute now). We have also explored the models of Worthey (1994)
(which are known to differ greatly from those of Jimenez et al in the treatment
of post-MS evolution) and find that the main-sequence component of Worthey's
models also cannot reproduce the solar spectrum until an age of 9-10 Gyr. We
conclude that either the models of Yi et al are not as main-sequence dominated
at 4-5 Gyr as claimed, or that the stellar evolutionary timescale in these
models is in error by a factor possibly as high as two. (abridged)Comment: Submitted to MNRAS, final versio
- âŠ