240 research outputs found
New views on price-making markets and the capitalist impulse: beyond Polanyi
Anthropologists have persistently diminished the importance of the market and marketplace exchange in premodern, preindustrial times. This strident anti-market mentality, derived largely from the writings of Karl Polanyi, underpins an ideological and politicized argument that neither sets useful guideposts to advance anthropological research, nor does it yield the necessary insights or empirically valid foundations to comprehend the deep historical origins of modern economies or polities. In fact, by envisioning the past that is categorically caged from the modern, the school of thought crystalized through Polanyi's perspectives circumvents the role of diachronic processes that are at the heart of a truly historical social science. Although it is not our principal aim to relitigate the vast literature pertaining to the rise and fall of Polanyian thought, our approach expands on prior arguments about his project both by highlighting critical perspectives on capitalism that long predated Polanyian thought and by identifying a veritable bounty of new evidence and theory concerning premodern and contemporary marketplace economies that enable us to transcend these now-entrenched claims. The scheme we present that distinguishes between open and competitive marketplaces, on the one hand, and the capitalist impulse, on the other, we believe, adds depth and breadth to the analysis of price-making markets and their divergent social and economic outcomes across time and space
The Tully-Fisher Relation and Its Residuals for a Broadly Selected Sample of Galaxies
We measure the relation between galaxy luminosity and disk circular velocity
(the Tully-Fisher [TF] relation), in the g, r, i, and z-bands, for a broadly
selected sample of galaxies from the Sloan Digital Sky Survey, with the goal of
providing well defined observational constraints for theoretical models of
galaxy formation. The input sample of 234 galaxies has a roughly flat
distribution of absolute magnitudes in the range -18.5 > Mr > -22, and our only
morphological selection is an axis-ratio cut b/a < 0.6 to allow accurate
inclination corrections. Long-slit spectroscopy yields usable H-alpha rotation
curves for 162 galaxies. Observational errors, including distance errors due to
peculiar velocities, are small compared to the intrinsic scatter of the TF
relation. The slope of the forward TF relation steepens from -5.5 +/- 0.2
mag/log(km/s) in the g-band to -6.6 +/- 0.2 mag/log(km/s) in the z-band. The
intrinsic scatter is approximately 0.4 mag in all bands. The scatter is not
dominated by rare outliers or by any particular class of galaxies, though it
drops slightly, to 0.36 mag, if we restrict the sample to nearly bulgeless
systems. Correlations of TF residuals with other galaxy properties are weak:
bluer galaxies are significantly brighter than average in the g-band but only
marginally brighter in the i-band; more concentrated galaxies are slightly
fainter than average; and the TF residual is virtually independent of
half-light radius, contrary to the trend expected for gravitationally dominant
disks. The observed residual correlations do not account for most of the
intrinsic scatter, implying that this scatter is instead driven largely by
variations in the ratio of dark to luminous matter within the disk galaxy
population.Comment: 23 figures, accepted by AJ, includes cosmological corrections to the
dat
Detection of a CMB decrement towards a cluster of mJy radiosources
We present the results of radio, optical and near-infrared observations of
the field of TOC J0233.3+3021, a cluster of milliJansky radiosources from the
TexOx Cluster survey. In an observation of this field with the Ryle Telescope
(RT) at 15 GHz, we measure a decrement in the cosmic microwave background (CMB)
of Jy on the RT's 0.65 k baseline. Using
optical and infrared imaging with the McDonald 2.7-m Smith Reflector, Calar
Alto 3.5-m telescope and UKIRT, we identify the host galaxies of five of the
radiosources and measure magnitudes of , , .
The CMB decrement is consistent with the Sunyaev-Zel'dovich (SZ) effect of a
massive cluster of galaxies, which if modelled as a spherical King profile of
core radius has a central temperature decrement
of K. The magnitudes and colours of the galaxies are consistent with
those of old ellipticals at . We therefore conclude that TOC
J0233.3+3021 is a massive, high redshift cluster. These observations add to the
growing evidence for a significant population of massive clusters at high
redshift, and demonstrate the effectiveness of combining searches for AGN
`signposts' to clusters with the redshift-independence of the SZ effect.Comment: Six pages; accepted for publication in MNRAS. Version with
full-resolution UV plot available from
http://www.mrao.cam.ac.uk/~garret/MB185.p
SDSS Pre-Burst Observations of Recent Gamma-Ray Burst Fields
In this paper, we present Sloan Digital Sky Survey (SDSS) photometry and
spectroscopy in the fields of 24 gamma-ray bursts (GRBs) observed by Swift,
including bursts localized by Swift, HETE-2, and INTEGRAL, after December 2004.
After this bulk release, we plan to provide individual releases of similar data
shortly after the localization of future bursts falling in the SDSS survey
area. These data provide a solid basis for the astrometric and photometric
calibration of follow-up afterglow searches and monitoring. Furthermore, the
images provided with this release will allow observers to find transient
objects up to a magnitude fainter than possible with Digitized Sky Survey image
comparisons.Comment: Submitted in PASP. Data for GRB fields included in this release can
be found at http://mizar.as.arizona.edu/grb/public. Updated with corrected
object counts. Replaced with revised versio
The Swift BAT Perspective on Non-thermal Emission in HIFLUGCS Galaxy Clusters
The search for diffuse non-thermal, inverse Compton (IC) emission from galaxy
clusters at hard X-ray energies has been underway for many years, with most
detections being either of low significance or controversial. In this work, we
investigate 14-195 keV spectra from the Swift Burst Alert Telescope (BAT)
all-sky survey for evidence of non-thermal excess emission above the
exponentially decreasing tail of thermal emission in the flux-limited HIFLUGCS
sample. To account for the thermal contribution at BAT energies, XMM-Newton
EPIC spectra are extracted from coincident spatial regions so that both thermal
and non-thermal spectral components can be determined simultaneously. We find
marginally significant IC components in six clusters, though after closer
inspection and consideration of systematic errors we are unable to claim a
clear detection in any of them. The spectra of all clusters are also summed to
enhance a cumulative non-thermal signal not quite detectable in individual
clusters. After constructing a model based on single-temperature fits to the
XMM-Newton data alone, we see no significant excess emission above that
predicted by the thermal model determined at soft energies. This result also
holds for the summed spectra of various subgroups, except for the subsample of
clusters with diffuse radio emission. For clusters hosting a diffuse radio
halo, a relic, or a mini-halo, non-thermal emission is initially detected at
the \sim5-sigma confidence level - driven by clusters with mini-halos - but
modeling and systematic uncertainties ultimately degrade this significance. In
individual clusters, the non-thermal pressure of relativistic electrons is
limited to \sim10% of the thermal electron pressure, with stricter limits for
the more massive clusters, indicating that these electrons are likely not
dynamically important in the central regions of clusters.Comment: 25 pages, 15 figures; some figure and table numbering differs from
published ApJ version: please see that for superior formattin
Identifying High Metallicity M Giants at Intragroup Distances with SDSS
Tidal stripping and three-body interactions with the central supermassive
black hole may eject stars from the Milky Way. These stars would comprise a set
of `intragroup' stars that trace the past history of interactions in our
galactic neighborhood. Using the Sloan Digital Sky Survey DR7, we identify
candidate solar metallicity red giant intragroup stars using color cuts that
are designed to exclude nearby M and L dwarfs. We present 677 intragroup
candidates that are selected between 300 kpc and 2 Mpc, and are either the
reddest intragroup candidates (M7-M10) or are L dwarfs at larger distances than
previously detected.Comment: 8 pages, 6 figures, 1 table (for full version, see
http://astro.phy.vanderbilt.edu/~palladl2), Accepted for publication in A
A population of luminous accreting black holes with hidden mergers
Major galaxy mergers are thought to play an important part in fuelling the
growth of supermassive black holes. However, observational support for this
hypothesis is mixed, with some studies showing a correlation between merging
galaxies and luminous quasars and others showing no such association. Recent
observations have shown that a black hole is likely to become heavily obscured
behind merger-driven gas and dust, even in the early stages of the merger, when
the galaxies are well separated (5 to 40 kiloparsecs). Merger simulations
further suggest that such obscuration and black-hole accretion peaks in the
final merger stage, when the two galactic nuclei are closely separated (less
than 3 kiloparsecs). Resolving this final stage requires a combination of
high-spatial-resolution infrared imaging and high-sensitivity hard-X-ray
observations to detect highly obscured sources. However, large numbers of
obscured luminous accreting supermassive black holes have been recently
detected nearby (distances below 250 megaparsecs) in X-ray observations. Here
we report high-resolution infrared observations of hard-X-ray-selected black
holes and the discovery of obscured nuclear mergers, the parent populations of
supermassive-black-hole mergers. We find that obscured luminous black holes
(bolometric luminosity higher than 2x10^44 ergs per second) show a significant
(P<0.001) excess of late-stage nuclear mergers (17.6 per cent) compared to a
sample of inactive galaxies with matching stellar masses and star formation
rates (1.1 per cent), in agreement with theoretical predictions. Using
hydrodynamic simulations, we confirm that the excess of nuclear mergers is
indeed strongest for gas-rich major-merger hosts of obscured luminous black
holes in this final stage.Comment: To appear in the 8 November 2018 issue of Nature. This is the
authors' version of the wor
Evolution in the Disks and Bulges of Group Galaxies since z=0.4
We present quantitative morphology measurements of a sample of optically
selected group galaxies at 0.3 < z < 0.55 using the Hubble Space Telescope
(HST) Advanced Camera for Surveys (ACS) and the GIM2D surface
brightness--fitting software package. The group sample is derived from the
Canadian Network for Observational Cosmology Field Redshift survey (CNOC2) and
follow-up Magellan spectroscopy. We compare these measurements to a similarly
selected group sample from the Millennium Galaxy Catalogue (MGC) at 0.05 < z <
0.12. We find that, at both epochs, the group and field fractional bulge
luminosity (B/T) distributions differ significantly, with the dominant
difference being a deficit of disk--dominated (B/T < 0.2) galaxies in the group
samples. At fixed luminosity, z=0.4 groups have ~ 5.5 +/- 2 % fewer
disk--dominated galaxies than the field, while by z=0.1 this difference has
increased to ~ 19 +/- 6 %. Despite the morphological evolution we see no
evidence that the group environment is actively perturbing or otherwise
affecting the entire existing disk population. At both redshifts, the disks of
group galaxies have similar scaling relations and show similar median
asymmetries as the disks of field galaxies. We do find evidence that the
fraction of highly asymmetric, bulge--dominated galaxies is 6 +/- 3 % higher in
groups than in the field, suggesting there may be enhanced merging in group
environments. We replicate our group samples at z=0.4 and z=0 using the
semi-analytic galaxy catalogues of Bower et al (2006). This model accurately
reproduces the B/T distributions of the group and field at z=0.1. However, the
model does not reproduce our finding that the deficit of disks in groups has
increased significantly since z=0.4.Comment: Accepted for publication in MNRAS. 20 pages, 17 figure
Enzootic Rabies Elimination from Dogs and Reemergence in Wild Terrestrial Carnivores, United States
Independent enzootics in wild terrestrial carnivores resulted from spillover events from long-term enzootics associated with dogs
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