279 research outputs found
Dividend drop ratios and tax theory:An intraday analysis under different tax and price quoting regimes
Intraday REIT Liquidity
Real Estate Investment Trusts (REITs) may be classified as a real estate investment or more generally as an equity investment. While REITs are more liquid than direct real estate investments, the liquidity relationship between REITs and common stocks is less clear-cut. This study measures and analyzes the liquidity differences between REITs and other common stocks. The intraday variations documented in this study have implications for: 1) the appropriate timing of trades to minimize transaction costs and, 2) the substitutability of investments if illiquidity is priced. Our results reveal intraday patterns indicating lower liquidity for REITs than for common stocks when the liquidity measure is friction-based. In contrast, activity measures exhibit higher liquidity levels for REITs than for common stocks but this difference is only statistically significant at the beginning of the trading day. Finally, from an economic perspective we find that the ability to trade without influencing prices is 15-25% greater for non-REITS compared to REITs, and the price of immediacy is 7% higher for REITs.
The Observational and Theoretical Tidal Radii of Globular Clusters in M87
Globular clusters have linear sizes (tidal radii) which theory tells us are
determined by their masses and by the gravitational potential of their host
galaxy. To explore the relationship between observed and expected radii, we
utilize the globular cluster population of the Virgo giant M87. Unusually deep,
high signal-to-noise images of M87 are used to measure the effective and
limiting radii of approximately 2000 globular clusters. To compare with these
observations, we simulate a globular cluster population that has the same
characteristics as the observed M87 cluster population. Placing these simulated
clusters in the well-studied tidal field of M87, the orbit of each cluster is
solved and the theoretical tidal radius of each cluster is determined. We
compare the predicted relationship between cluster size and projected
galactocentric distance to observations. We find that for an isotropic
distribution of cluster velocities, theoretical tidal radii are approximately
equal to observed limiting radii for Rgc < 10 kpc. However, the isotropic
simulation predicts a steep increase in cluster size at larger radii, which is
not observed in large galaxies beyond the Milky Way. To minimize the
discrepancy between theory and observations, we explore the effects of orbital
anisotropy on cluster sizes, and suggest a possible orbital anisotropy profile
for M87 which yields a better match between theory and observations. Finally,
we suggest future studies which will establish a stronger link between
theoretical tidal radii and observed radii.Comment: 8 pages, 8 figures, Accepted for publication in Ap
Exploring the progenitors of brightest cluster galaxies at z ⌠2
We present a new method for tracing the evolution of brightest cluster galaxies (BCGs) from z ⌠2 to z ⌠0. We conclude on the basis of semi-analytical models that the best method to select BCG progenitors at z ⌠2 is a hybrid environmental density and stellar mass ranking approach. Ultimately, we are able to retrieve 45 per cent of BCG progenitors. We apply this method on the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Ultra Deep Survey data to construct a progenitor sample at high redshift. We furthermore populate the comparisons in local Universe by using Sloan Digital Sky Survey data with statistically likely contamination to ensure a fair comparison between high and low redshifts. Using these samples we demonstrate that the BCG sizes have grown by a factor of âŒ3.2 since z ⌠2, and BCG progenitors are mainly late-type galaxies, exhibiting less concentrated profiles than their early type local counterparts. We find that BCG progenitors have more disturbed morphologies. In contrast, local BCGs have much smoother profiles. Moreover, we find that the stellar masses of BCGs have grown by a factor of âŒ2.5 since z ⌠2, and the star formation rate of BCG progenitors has a median value of 13.5 MÊ yrâŸÂč, much higher than their quiescent local descendants. We demonstrate that over z = 1â2 star formation and merging contribute equally to BCG mass growth. However, merging plays a dominant role in BCG assembly at z âČ 1. We also find that BCG progenitors at high z are not significantly different from other galaxies of similar mass at the same epoch. This suggests that the processes which differentiate BCGs from normal massive elliptical galaxies must occur at z âČ 2
Physical and mechanical properties of Ayous wood (Triplochiton scleroxylon) from Cameroon
The present study deals with Ayous wood from the East Cameroon forest reserve in the locality of Abong-Mbang. The water absorption rate of Ayous wood and the absorption kinetics were evaluated. Ayous wood reached its absorption saturation around 28 days. The primary diffusion coefficient was found to be 1.51 x 10-11 m2/s with a standard deviation of 0.23x10-11 m2/s while the saturation absorption rate is 144% with a standard deviation of 16.3%. About the modeling of kinetic absorption, many models were tested, and (Sikame, 2014) was the best model for our experiments. In order to determine the mechanical properties, four point bending and compression test were done through the three orthotropic directions. Â It is found that the modulus of elasticity value is 8792.75 MPa with a standard deviation of 527 MPa and the fracture stress (Ïl) value is 53.6 MPa with a standard deviation of 8 MPa. Longitudinal, radial and tangential compressive stress are 31.51 MPa, 29.15 MPa and 31.4 MPa respectively, with standard deviations of 4.34MPa, 4.52 MPa and 4.23 MPa
Galactic Kinematics Towards the South Galactic Pole. First Results from the Yale-San Juan Southern Proper-Motion Program
The predictions from a Galactic Structure and Kinematic model code are
compared to the color counts and absolute proper-motions derived from the
Southern Proper-Motion survey covering more than 700 toward the South
Galactic Pole in the range . The theoretical assumptions
and associated computational procedures, the geometry for the kinematic model,
and the adopted parameters are presented in detail and compared to other
Galactic Kinematic models of its kind. The data to which the model is compared
consists of more than 30,000 randomly selected stars, and it is best fit by
models with a solar peculiar motion of +5 km s in the V-component
(pointing in the direction of Galactic rotation), a large LSR speed of 270 km
s, and a (disk) velocity ellipsoid that always points towards the
Galactic center. The absolute proper-motions in the U-component indicate a
solar peculiar motion of km s, with no need for a local
expansion or contraction term. The fainter absolute motions show an indication
that the thick-disk must exhibit a rather steep velocity gradient of about -36
km s kpc with respect to the LSR. We are not able to set
constraints on the overall rotation for the halo, nor on the thick-disk or halo
velocity dispersions. Some substructure in the U & V proper-motions could be
present in the brighter bins , and it might be indicative
of (disk) moving groups.Comment: 24 double-column pages, 12 tables, AAS Latex macros v4.0, 19 B&W
figures, 1 color figure. Accepted for publication on The Astronomical Journa
Thinking Wetly: Causeways and Communities in East Anglian Hagiography
Water defined the landscapes of medieval East Anglia. Hitherto scholarly attention has focussed on the physical geography of the region, with landscape archaeology and excavations revealing sites of international importance and speaking to the potency and ubiquity of water as a ritual element. Surprisingly, however, very little attention has been paid to the symbolic importance of water in medieval East Anglian literature, and this article addresses this scholarly lacuna. Water features prominently in the literature from the region, particularly in the lives and legends of the numerous saints venerated at its many cult centres. This article begins by outlining some of the key ways in which water signifies in these contexts, before discussing a case study from the Liber Eliensis which, at first reading, seems to confound the received notion of waterâs symbolic resonances but which, on closer consideration, reveals an additional, previously unidentified aspect of this most fluid of metaphors
GREAT3 results I: systematic errors in shear estimation and the impact of real galaxy morphology
We present first results from the third GRavitational lEnsing Accuracy
Testing (GREAT3) challenge, the third in a sequence of challenges for testing
methods of inferring weak gravitational lensing shear distortions from
simulated galaxy images. GREAT3 was divided into experiments to test three
specific questions, and included simulated space- and ground-based data with
constant or cosmologically-varying shear fields. The simplest (control)
experiment included parametric galaxies with a realistic distribution of
signal-to-noise, size, and ellipticity, and a complex point spread function
(PSF). The other experiments tested the additional impact of realistic galaxy
morphology, multiple exposure imaging, and the uncertainty about a
spatially-varying PSF; the last two questions will be explored in Paper II. The
24 participating teams competed to estimate lensing shears to within systematic
error tolerances for upcoming Stage-IV dark energy surveys, making 1525
submissions overall. GREAT3 saw considerable variety and innovation in the
types of methods applied. Several teams now meet or exceed the targets in many
of the tests conducted (to within the statistical errors). We conclude that the
presence of realistic galaxy morphology in simulations changes shear
calibration biases by per cent for a wide range of methods. Other
effects such as truncation biases due to finite galaxy postage stamps, and the
impact of galaxy type as measured by the S\'{e}rsic index, are quantified for
the first time. Our results generalize previous studies regarding sensitivities
to galaxy size and signal-to-noise, and to PSF properties such as seeing and
defocus. Almost all methods' results support the simple model in which additive
shear biases depend linearly on PSF ellipticity.Comment: 32 pages + 15 pages of technical appendices; 28 figures; submitted to
MNRAS; latest version has minor updates in presentation of 4 figures, no
changes in content or conclusion
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Synergism of anisotropic and computational NMR methods reveals the likely configuration of phormidolide A.
Characterization of the complex molecular scaffold of the marine polyketide natural product phormidolide A represents a challenge that has persisted for nearly two decades. In light of discordant results arising from recent synthetic and biosynthetic reports, a rigorous study of the configuration of phormidolide A was necessary. This report outlines a synergistic effort employing computational and anisotropic NMR investigation, that provided orthogonal confirmation of the reassigned side chain, as well as supporting a further correction of the C7 stereocenter
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