3,933 research outputs found
Spatially Resolved Observations of the Bipolar Optical Outflow from the Brown Dwarf 2MASSJ12073347-3932540
Studies of brown dwarf (BD) outflows provide information pertinent to
questions on BD formation, as well as allowing outflow mechanisms to be
investigated at the lowest masses. Here new observations of the bipolar outflow
from the 24 M BD, 2MASSJ12073347-3932540 are presented. The outflow was
originally identified through the spectro-astrometric analysis of the
[OI]6300 emission line. Follow-up observations consisting of spectra
and [SII], R-band and I-band images were obtained. The new spectra confirm the
original results and are used to constrain the outflow PA at
65. The [OI]6300 emission line region is spatially resolved
and the outflow is detected in the [SII] images. The detection is firstly in
the form of an elongation of the point spread function along the direction of
the outflow PA. Four faint knot-like features (labelled {\it A-D}) are also
observed to the south-west of 2MASSJ12073347-3932540 along the same PA
suggested by the spectra and the elongation in the PSF. Interestingly, {\it D},
the feature furthest from the source is bow-shaped with the apex pointing away
from 2MASSJ12073347-3932540. A color-color analysis allows us to conclude that
at least feature {\it D} is part of the outflow under investigation while {\it
A} is likely a star or galaxy. Follow-up observations are needed to confirm the
origin of {\it B} and {\it C}. This is a first for a BD, as BD optical outflows
have to date only been detected using spectro-astrometry. This result also
demonstrates for the first time that BD outflows can be collimated and
episodic.Comment: Accepted by ApJ, ref ApJ89096R
Deep H-band Galaxy Counts and Half-light Radii from HST/NICMOS Parallel Observations
We present deep galaxy counts and half-light radii from F160W
() images obtained with NICMOS on HST. Nearly 9 arcmin
have been imaged with camera 3, with depths ranging from H = 24.3 to
25.5 in a 0.6 diameter aperture. The slope of the counts fainter than H~ is 0.31, and the integrated surface density to H is galaxies per square degree. The half-light radii of the galaxies declines
steeply with apparent magnitude. At H~ we are limited by both the
delivered FWHM and the detection threshold of the images.Comment: 8 pages. Accepted for publication in ApJ Letter
Land Collateral and Labor Market Dynamics in France
The value of land in the balance sheet of French firms correlates positively with their hiring and investment flows. To explore the relationship between these variables, we develop a macroeconomic model with firms that are subject to both credit and labor market frictions. The value of collateral is driven by the forward-looking dynamics of the land price, which reacts endogenously to fundamental and non-fundamental (sunspot) shocks. We calibrate the model to French data and find that land price shocks give rise to significant amplification and hump-shaped responses of investment, vacancies and unemployment that are in line with the data. We show that both the endogenous movements in the firm’s discount factor and the sluggish response of the land price are key elements that drive the results
Cross-checking to reduce adverse events resulting from medical errors in the emergency department: study protocol of the CHARMED cluster randomized study
International audienceBackgroundMedical errors and preventable adverse events are a major cause of concern, especially in the emergency department (ED) where its prevalence has been reported to be roughly of 5–10 % of visits. Due to a short length of stay, emergency patients are often managed by a sole physician – in contrast with other specialties where they can benefit from multiples handover, ward rounds and staff meetings. As some studies report that the rate and severity of errors may decrease when there is more than one physician involved in the management in different settings, we sought to assess the impact of regular systematic cross-checkings between physicians in the ED.DesignThe CHARMED (Cross-checking to reduce adverse events resulting from medical errors in the emergency department) study is a multicenter cluster randomized study that aim to evaluate the reduction of the rate of severe medical errors with implementation of systematic cross checkings between emergency physician, compared to a control period with usual care. This study will evaluate the effect of this intervention on the rate of severe medical errors (i.e. preventable adverse events or near miss) using a previously described two-level chart abstraction. We made the hypothesis that implementing frequent and systematic cross checking will reduce the rate of severe medical errors from 10 to 6 % - 1584 patients will be included, 140 for each period in each center.DiscussionThe CHARMED study will be the largest study that analyse unselected ED charts for medical errors. This could provide evidence that frequent systematic cross-checking will reduce the incidence of severe medical errors
Clustering of Very Red Galaxies in the Las Campanas IR Survey
We report results from the first 1000 square arc-minutes of the Las Campanas
IR survey. We have imaged 1 square degree of high latitude sky in six distinct
fields to a 5-sigma H-band depth of 20.5 (Vega). Optical imaging in the
V,R,I,and z' bands allow us to select color subsets and
photometric-redshift-defined shells. We show that the angular clustering of
faint red galaxies (18 3) is an order of magnitude stronger
than that of the complete H-selected field sample. We employ three approaches
to estimate in order to invert w(theta) to derive r_0. We find that our
n(z) is well described by a Gaussian with = 1.2, sigma(z) = 0.15. From this
we derive a value for r_0 of 7 (+2,-1) co-moving H^{-1} Mpc at = 1.2. This
is a factor of ~ 2 larger than the clustering length for Lyman break galaxies
and is similar to the expectation for early type galaxies at this epoch.Comment: 5 pages, 2 figures, 1 table. To appear in proceedings of the
ESO/ECF/STScI workshop "Deep Fields" held in Garching, Germany, 9-12 October
200
Deep H-Band Galaxy Counts and Half-Light Radii from Hubble Space Telescope/NICMOS Parallel Observations
We present deep galaxy counts and half-light radii from F160W (λ_c=1.6 μm) images obtained with the Near-Infrared Camera and Multiobject Spectrograph on the Hubble Space Telescope. Nearly 9 arcmin^2 have been imaged with camera 3, with 3 σ depths ranging from H=24.3 to 25.5 in a 0."6 diameter aperture. The slope of the counts fainter than H = 20 is 0.31, and the integrated surface density to H ≤ 24.75 is 4×10^5 galaxies deg^(-2). The half-light radii of the galaxies decline steeply with apparent magnitude. At H = 24, we are limited by both the delivered FWHM and the detection threshold of the images
Modular Invariance of Finite Size Corrections and a Vortex Critical Phase
We analyze a continuous spin Gaussian model on a toroidal triangular lattice
with periods and where the spins carry a representation of the
fundamental group of the torus labeled by phases and . We find the
{\it exact finite size and lattice corrections}, to the partition function ,
for arbitrary mass and phases . Summing over phases gives
the corresponding result for the Ising model. The limits and
do not commute. With the model exhibits a {\it vortex
critical phase} when at least one of the is non-zero. In the continuum or
scaling limit, for arbitrary , the finite size corrections to are
{\it modular invariant} and for the critical phase are given by elliptic theta
functions. In the cylinder limit the ``cylinder charge''
is a non-monotonic function of that ranges from
for to zero for .Comment: 12 pages of Plain TeX with two postscript figure insertions called
torusfg1.ps and torusfg2.ps which can be obtained upon request from
[email protected]
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