216 research outputs found
From Austerity to Expansion? Consolidation, Budget Surpluses, and the Decline of Fiscal Capacity
In the wake of the financial crisis, most developed countries have entered a period of prolonged budgetary austerity. While the success of austerity programs is still unclear, it is also an open question what success would mean for activist government in the long run. This paper rejects the progressive belief that successful fiscal consolidation will lead to a strengthening of fiscal capacity, arguing that consolidations transform the political context in which fiscal policy is made. By analyzing the evolution of public expenditure in six countries with sustained budget surpluses, it shows that while surpluses were mostly achieved through expenditure cuts, they were predominantly used for cutting taxes. While fiscal crises abated, their collateral damage to public expenditure remained. This result is further elaborated by a case study of the Swedish budget surplus. The paper concludes that consolidations can create a specific type of fiscal regime and thus have long-term consequences for the fiscal capacity of the state.Angesichts der Schuldenprobleme in vielen entwickelten Ländern befinden sich die meisten von ihnen in einer Phase lang anhaltender Austerität. Und während noch völlig unklar ist, ob die Sparprogramme Erfolg haben, werden sie immer wieder mit dem Versprechen verbunden, erfolgreiche Konsolidierungen würden zu einer Wiedergewinnung staatlicher Handlungsfähigkeit führen. Diese Studie verwirft diese „progressive Konsolidierungsthese“ auf Basis einer theoretischen und empirischen Analyse. Ihr Argument lautet, dass Haushaltskonsolidierungen den Kontext, in dem Fiskalpolitik gemacht wird, dauerhaft verändern. Zwar erhöhen sie fiskalische Spielräume, zugleich aber schränken sie politische Spielräume ein. Anhand von sechs Ländern mit dauerhaften Haushaltsüberschüssen wird gezeigt, dass diese Überschüsse durch Ausgabenkürzungen erzielt, aber für Steuersenkungen verwendet wurden. Die Kollateralschäden der Konsolidierung blieben über Jahre in den Budgets sichtbar. Dieses Ergebnis wird von einer Fallstudie zu den schwedischen Haushaltsüberschüssen bestätigt. Das Fazit der Untersuchung ist, dass Konsolidierungen zu einem Wechsel des fiskalischen Regimes führen können, wodurch die staatliche Handlungsfähigkeit langfristig beschränkt wird. Überschüsse sind insofern nicht Ausdruck wachsender Gestaltungsfreiheit, sondern schrumpfender Ambitionen des Staates.1 Introduction 2 The argument 3 Research design and case selection 4 Comparative results 5 The Swedish case up close 6 Conclusion Appendix 1 Appendix 2 Appendix 3 Reference
Reconstruction of nuclear quadrupole interaction in (In,Ga)As/GaAs quantum dots observed by transmission electron microscopy
A microscopic study of the individual annealed (In,Ga)As/GaAs quantum dots is
done by means of high-resolution transmission electron microscopy. The
Cauchy-Green strain-tensor component distribution and the chemical composition
of the (In,Ga)As alloy are extracted from the microscopy images. The image
processing allows for the reconstruction of the strain-induced electric-field
gradients at the individual atomic columns extracting thereby the magnitude and
asymmetry parameter of the nuclear quadrupole interaction. Nuclear magnetic
resonance absorption spectra are analyzed for parallel and transverse mutual
orientations of the electric-field gradient and a static magnetic field.Comment: 8 pages, 6 figure
The XMM Cluster Survey: The Stellar Mass Assembly of Fossil Galaxies
This paper presents both the result of a search for fossil systems (FSs)
within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results
of a study of the stellar mass assembly and stellar populations of their fossil
galaxies. In total, 17 groups and clusters are identified at z < 0.25 with
large magnitude gaps between the first and fourth brightest galaxies. All the
information necessary to classify these systems as fossils is provided. For
both groups and clusters, the total and fractional luminosity of the brightest
galaxy is positively correlated with the magnitude gap. The brightest galaxies
in FSs (called fossil galaxies) have stellar populations and star formation
histories which are similar to normal brightest cluster galaxies (BCGs).
However, at fixed group/cluster mass, the stellar masses of the fossil galaxies
are larger compared to normal BCGs, a fact that holds true over a wide range of
group/cluster masses. Moreover, the fossil galaxies are found to contain a
significant fraction of the total optical luminosity of the group/cluster
within 0.5R200, as much as 85%, compared to the non-fossils, which can have as
little as 10%. Our results suggest that FSs formed early and in the highest
density regions of the universe and that fossil galaxies represent the end
products of galaxy mergers in groups and clusters. The online FS catalog can be
found at http://www.astro.ljmu.ac.uk/~xcs/Harrison2012/XCSFSCat.html.Comment: 30 pages, 50 figures. ApJ published version, online FS catalog added:
http://www.astro.ljmu.ac.uk/~xcs/Harrison2012/XCSFSCat.htm
The XMM Cluster Survey: Evidence for energy injection at high redshift from evolution of the X-ray luminosity-temperature relation
We measure the evolution of the X-ray luminosity-temperature (L_X-T) relation
since z~1.5 using a sample of 211 serendipitously detected galaxy clusters with
spectroscopic redshifts drawn from the XMM Cluster Survey first data release
(XCS-DR1). This is the first study spanning this redshift range using a single,
large, homogeneous cluster sample. Using an orthogonal regression technique, we
find no evidence for evolution in the slope or intrinsic scatter of the
relation since z~1.5, finding both to be consistent with previous measurements
at z~0.1. However, the normalisation is seen to evolve negatively with respect
to the self-similar expectation: we find E(z)^{-1} L_X = 10^{44.67 +/- 0.09}
(T/5)^{3.04 +/- 0.16} (1+z)^{-1.5 +/- 0.5}, which is within 2 sigma of the zero
evolution case. We see milder, but still negative, evolution with respect to
self-similar when using a bisector regression technique. We compare our results
to numerical simulations, where we fit simulated cluster samples using the same
methods used on the XCS data. Our data favour models in which the majority of
the excess entropy required to explain the slope of the L_X-T relation is
injected at high redshift. Simulations in which AGN feedback is implemented
using prescriptions from current semi-analytic galaxy formation models predict
positive evolution of the normalisation, and differ from our data at more than
5 sigma. This suggests that more efficient feedback at high redshift may be
needed in these models.Comment: Accepted for publication in MNRAS; 12 pages, 6 figures; added
references to match published versio
Redshift-space correlation functions in large galaxy cluster surveys
Large ongoing and upcoming galaxy cluster surveys in the optical, X-ray and
millimetric wavelengths will provide rich samples of galaxy clusters at
unprecedented depths. One key observable for constraining cosmological models
is the correlation function of these objects, measured through their
spectroscopic redshift. We study the redshift-space correlation functions of
clusters of galaxies, averaged over finite redshift intervals, and their
covariance matrices. Expanding as usual the angular anisotropy of the
redshift-space correlation on Legendre polynomials, we consider the
redshift-space distortions of the monopole as well as the next two multipoles,
and 4. Taking into account the Kaiser effect, we developed an
analytical formalism to obtain explicit expressions of all contributions to
these mean correlations and covariance matrices. We include shot-noise and
sample-variance effects as well as Gaussian and non-Gaussian contributions. We
obtain a reasonable agreement with numerical simulations for the mean
correlations and covariance matrices on large scales (Mpc).
Redshift-space distortions amplify the monopole correlation by about ,
depending on the halo mass, but the signal-to-noise ratio remains of the same
order as for the real-space correlation. This distortion will be significant
for surveys such as DES, Erosita, and Euclid, which should also measure the
quadrupole . The third multipole, , may only be marginally
detected by Euclid.Comment: 20 page
Support for Redistribution in Western Europe: Assessing the role of religion
Previous sociological studies have paid little attention to religion as a central determinant of individual preferences for redistribution. In this article we argue that religious individuals, living in increasingly secular societies, differ in political preferences from their secular counterparts. Based on the theory of religious cleavages, we expect that religious individuals will oppose income redistribution by the state. Furthermore, in contexts where the polarization between religious and secular individuals is large, preferences for redistribution will be lower. In the empirical analysis we test our predictions in a multilevel framework, using data from the European Social Survey 2002–2006 for 16 Western European countries. After controlling for a wide range of individual socio-economic factors and for welfare-state policies, religion plays and important explanatory role. We find that both Catholics and Protestants strongly oppose income redistribution by the state. The cleavage between religious and secular individuals is far more important than the difference between denominations. Using a refined measure of religious polarization, we also find that in more polarized context the overall level of support for redistribution is lower
The XMM Cluster Survey: Active Galactic Nuclei and Starburst Galaxies in XMMXCS J2215.9-1738 at z=1.46
We use Chandra X-ray and Spitzer infrared observations to explore the AGN and
starburst populations of XMMXCS J2215.9-1738 at z=1.46, one of the most distant
spectroscopically confirmed galaxy clusters known. The high resolution X-ray
imaging reveals that the cluster emission is contaminated by point sources that
were not resolved in XMM observations of the system, and have the effect of
hardening the spectrum, leading to the previously reported temperature for this
system being overestimated. From a joint spectroscopic analysis of the Chandra
and XMM data, the cluster is found to have temperature T=4.1_-0.9^+0.6 keV and
luminosity L_X=(2.92_-0.35^+0.24)x10^44 erg/s extrapolated to a radius of 2
Mpc. As a result of this revised analysis, the cluster is found to lie on the
sigma_v-T relation, but the cluster remains less luminous than would be
expected from self-similar evolution of the local L_X-T relation. Two of the
newly discovered X-ray AGN are cluster members, while a third object, which is
also a prominent 24 micron source, is found to have properties consistent with
it being a high redshift, highly obscured object in the background. We find a
total of eight >5 sigma 24 micron sources associated with cluster members (four
spectroscopically confirmed, and four selected using photometric redshifts),
and one additional 24 micron source with two possible optical/near-IR
counterparts that may be associated with the cluster. Examining the IRAC colors
of these sources, we find one object is likely to be an AGN. Assuming that the
other 24 micron sources are powered by star formation, their infrared
luminosities imply star formation rates ~100 M_sun/yr. We find that three of
these sources are located at projected distances of <250 kpc from the cluster
center, suggesting that a large amount of star formation may be taking place in
the cluster core, in contrast to clusters at low redshift.Comment: Accepted for publication in ApJ, 16 pages, 10 figure
The XMM Cluster Survey: X-ray analysis methodology
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters
using all publicly available data in the XMM-Newton Science Archive. Its main
aims are to measure cosmological parameters and trace the evolution of X-ray
scaling relations. In this paper we describe the data processing methodology
applied to the 5,776 XMM observations used to construct the current XCS source
catalogue. A total of 3,675 > 4-sigma cluster candidates with > 50
background-subtracted X-ray counts are extracted from a total non-overlapping
area suitable for cluster searching of 410 deg^2. Of these, 993 candidates are
detected with > 300 background-subtracted X-ray photon counts, and we
demonstrate that robust temperature measurements can be obtained down to this
count limit. We describe in detail the automated pipelines used to perform the
spectral and surface brightness fitting for these candidates, as well as to
estimate redshifts from the X-ray data alone. A total of 587 (122) X-ray
temperatures to a typical accuracy of < 40 (< 10) per cent have been measured
to date. We also present the methodology adopted for determining the selection
function of the survey, and show that the extended source detection algorithm
is robust to a range of cluster morphologies by inserting mock clusters derived
from hydrodynamical simulations into real XMM images. These tests show that the
simple isothermal beta-profiles is sufficient to capture the essential details
of the cluster population detected in the archival XMM observations. The
redshift follow-up of the XCS cluster sample is presented in a companion paper,
together with a first data release of 503 optically-confirmed clusters.Comment: MNRAS accepted, 45 pages, 38 figures. Our companion paper describing
our optical analysis methodology and presenting a first set of confirmed
clusters has now been submitted to MNRA
The XMM Cluster Survey: Predicted overlap with the Planck Cluster Catalogue
We present a list of 15 clusters of galaxies, serendipitously detected by the
XMM Cluster Survey (XCS), that have a high probability of detection by the
Planck satellite. Three of them already appear in the Planck Early
Sunyaev-Zel'dovich (ESZ) catalogue. The estimation of the Planck detection
probability assumes the flat Lambda cold dark matter (LambdaCDM) cosmology most
compatible with 7-year Wilkinson Microwave Anisotropy Probe (WMAP7) data. It
takes into account the XCS selection function and Planck sensitivity, as well
as the covariance of the cluster X-ray luminosity, temperature, and integrated
comptonization parameter, as a function of cluster mass and redshift,
determined by the Millennium Gas Simulations. We also characterize the
properties of the galaxy clusters in the final data release of the XCS that we
expect Planck will have detected by the end of its extended mission. Finally,
we briefly discuss possible joint applications of the XCS and Planck data.Comment: Closely matches the version accepted for publication by MNRAS, 7
pages, 3 figures. The XCS-DR1 catalogue, together with optical and X-ray
(colour-composite and greyscale) images for each cluster, is publicly
available from http://xcs-home.org/datarelease
The XMM Cluster Survey: The interplay between the brightest cluster galaxy and the intra-cluster medium via AGN feedback
Using a sample of 123 X-ray clusters and groups drawn from the XMM-Cluster
Survey first data release, we investigate the interplay between the brightest
cluster galaxy (BCG), its black hole, and the intra-cluster/group medium (ICM).
It appears that for groups and clusters with a BCG likely to host significant
AGN feedback, gas cooling dominates in those with Tx > 2 keV while AGN feedback
dominates below. This may be understood through the sub-unity exponent found in
the scaling relation we derive between the BCG mass and cluster mass over the
halo mass range 10^13 < M500 < 10^15Msol and the lack of correlation between
radio luminosity and cluster mass, such that BCG AGN in groups can have
relatively more energetic influence on the ICM. The Lx - Tx relation for
systems with the most massive BCGs, or those with BCGs co-located with the peak
of the ICM emission, is steeper than that for those with the least massive and
most offset, which instead follows self-similarity. This is evidence that a
combination of central gas cooling and powerful, well fuelled AGN causes the
departure of the ICM from pure gravitational heating, with the steepened
relation crossing self-similarity at Tx = 2 keV. Importantly, regardless of
their black hole mass, BCGs are more likely to host radio-loud AGN if they are
in a massive cluster (Tx > 2 keV) and again co-located with an effective fuel
supply of dense, cooling gas. This demonstrates that the most massive black
holes appear to know more about their host cluster than they do about their
host galaxy. The results lead us to propose a physically motivated, empirical
definition of 'cluster' and 'group', delineated at 2 keV.Comment: Accepted for publication in MNRAS - replaced to match corrected proo
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