111,689 research outputs found
An 80 pc Long Massive Molecular Filament in the Galactic Mid-Plane
The ubiquity of filaments in star forming regions on a range of scales is
clear, yet their role in the star formation process remains in question. We
suggest that there are distinct classes of filaments which are responsible for
their observed diversity in star-forming regions. An example of a massive
molecular filament in the Galactic mid-plane formed at the intersection of
UV-driven bubbles which displays a coherent velocity structure (< 4 km/s) over
80 pc is presented. We classify such sources as Massive Molecular Filaments
(MMFs; M > 10^4 Msun, length > 10 pc, velocity gradient < 5 km/s) and suggest
that MMFs are just one of the many different classes of filaments discussed in
the literature today. Many MMFs are aligned with the Galactic Plane and may be
akin to the dark dust lanes seen in Grand Design Spirals.Comment: To appear in proceedings of the 'Labyrinth of Star Formation' meeting
(18-22 June 2012, Chania, Greece), published by Springe
Fingers of God
Very long wavelength universal gravitational waves cannot now produce in
clusters of galaxies velocity dispersions greater than that which these systems
would possess if they were expanding with the Universe, if the Universe is not
younger than yr and Hubble's constant is not less than 50 km/sec/
Mpc. A diagram shows that actual velocity dispersions are significantly greater
than this limit.Comment: Published long before the advent of large-scale redshift surveys, as
"A Critique of Rees's Theory of Primordial Gravitational Radiation", this
paper includes the first presentation of what has come to be known as the
fingers-of-god effect. The effect is mentioned several hundred times in
arXive papers, rarely with a wrong attribution, usually with none at al
The interpretive approach to religious education : challenging Thompson's interpretation
In a recent book chapter, Matthew Thompson makes some criticisms of my work, including the interpretive approach to religious education and the research and activity of Warwick Religions and Education Research Unit. Against the background of a discussion of religious education in the public sphere, my response challenges Thompson’s account, commenting on his own position in relation to dialogical approaches to religious education. The article rehearses my long held view that the ideal form of religious education in fully state funded schools of a liberal democracy should be ‘secular’ but not ‘secularist’; there should be no implication of an axiomatic secular humanist interpretation of religions
Deceleration without dark matter
In homogeneous isotropic cosmological models the angular size theta of a
standard measuring rod changes with redshift z in a manner that depends upon
the parameters of the model. It has been argued that as a population
ultracompact (milliarcsecond) radio sources measured by very long-baseline
interferometry (VLBI) do not evolve with cosmic epoch, and thus comprise a set
of standard objects, at least in a statistical sense. Here we examine the
angular-size/redshift relation for 256 ultracompact sources with z in the range
0.5 to 3.8 for cosmological models with two degrees of freedom (Omega_0 and
Lambda_0). The canonical inflationary cold dark matter model(Omega_0=1,
Lambda_0=0) appears to be ruled out by the observed relationship, whereas
low-density models with a cosmological constant of either sign are favoured.Comment: Although published (MNRAS 285, 806, 1997, submitted 1996 May 3), this
paper has not previously appeared on the arXive. Despite its title, a
prominent conclusion is that if the Universe is spatially flat, then the best
cosmological parameters are Omega_m=0.2, Omega_Lambda=0.8, with probable
range 0.1<Omega_m<0.3. It is the first in a series, the second being JCAP
0411(2004)007, astro-ph/0309390; the third is a recent preprint,
astro-ph/060506
A legislative bargaining approach to earmarked public expenditures
This paper develops a model of legislative spending in which revenues can be spent through earmarks or a general fund. Legislative choice is modeled as a Baron and Ferejohn style legislative bargaining game. The novel approach is to model the bargaining process as a two-stage game reflecting the reality that earmarked expenditures precede general fund appropriations. This drives the result that all revenue is spent by way of earmarking leaving no revenue in the general fund.Earmarking, legislative bargaining, public goods.
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