518 research outputs found
A Correlation Between Galaxy Morphology and MgII Halo Absorption Strength
(Abridged) We compared the quantified morphological properties of 37
intermediate redshift MgII absorption selected galaxies to the properties of
the absorbing halo gas, observed in the spectra of background quasars. The
galaxy morphologies were measured using GIM2D modeling of Hubble Space
Telescope WFPC-2 images and the absorbing gas properties were obtained from
HIRES/Keck and UVES/VLT quasar spectra. We found a 3.1 sigma correlation
between galaxy morphological asymmetries normalized by the quasar-galaxy
projected separations, A/D, and the MgII rest-frame equivalent widths.
Saturation effects cause increased scatter in the relationship with increasing
W_r(2796). We defined a subsample for which the fraction of saturated pixels in
the absorption profiles is f_sat<0.5. The correlation strengthened to 3.3
sigma. We also find a paucity of small morphological asymmetries for galaxies
selected by MgII absorption as compared to those of the general population of
field galaxies, as measured in the Medium Deep Survey. The K-S probability that
the two samples are drawn from the same galaxy population is ruled out at a
99.8% confidence level. The A/D-W_r(2796) correlation suggests a connection
between the processes that perturb galaxies and the quantity of gas in their
halos, normalized by the impact parameter. Since the perturbations are minor,
it is clear that dramatic processes or events are not required for a galaxy to
have an extended halo; the galaxies appear "normal". We suggest that common,
more mild processes that populate halos with gas, such as satellite galaxy
merging, accretion of the local cosmic web, and longer-range galaxy-galaxy
interactions, consequently also induce the observed minor perturbations in the
galaxies.Comment: Accepted for publication in the Astrophysical Journa
Detection of an ultra-bright submillimeter galaxy in the Subaru/XMM-Newton Deep Field using AzTEC/ASTE
We report the detection of an extremely bright (37 mJy at 1100 m
and 91 mJy at 880 m) submillimeter galaxy (SMG),
AzTEC-ASTE-SXDF1100.001 (hereafter referred to as SXDF1100.001 or Orochi),
discovered in 1100 m observations of the Subaru/XMM-Newton Deep Field
using AzTEC on ASTE. Subsequent CARMA 1300 m and SMA 880 m
observations successfully pinpoint the location of Orochi and suggest that it
has two components, one extended (FWHM of 4) and one
compact (unresolved). Z-Spec on CSO has also been used to obtain a wide band
spectrum from 190 to 308 GHz, although no significant emission/absorption lines
are found. The derived upper limit to the line-to-continuum flux ratio is
0.1--0.3 (2 ) across the Z-Spec band.
Based on the analysis of the derived spectral energy distribution from
optical to radio wavelengths of possible counterparts near the SMA/CARMA peak
position, we suggest that Orochi is a lensed, optically dark SMG lying at behind a foreground, optically visible (but red) galaxy at . The deduced apparent (i.e., no correction for magnification) infrared
luminosity () and star formation rate (SFR) are
and 11000 yr, respectively, assuming that the
is dominated by star formation. These values suggest that Orochi
will consume its gas reservoir within a short time scale (
yr), which is indeed comparable to those in extreme starbursts like the centres
of local ULIRGs.Comment: 18 pages, 13 figure
Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.
Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection
Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.
Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery
The source counts of submillimetre galaxies detected at 1.1 mm
The source counts of galaxies discovered at sub-millimetre and millimetre
wavelengths provide important information on the evolution of infrared-bright
galaxies. We combine the data from six blank-field surveys carried out at 1.1
mm with AzTEC, totalling 1.6 square degrees in area with root-mean-square
depths ranging from 0.4 to 1.7 mJy, and derive the strongest constraints to
date on the 1.1 mm source counts at flux densities S(1100) = 1-12 mJy. Using
additional data from the AzTEC Cluster Environment Survey to extend the counts
to S(1100) ~ 20 mJy, we see tentative evidence for an enhancement relative to
the exponential drop in the counts at S(1100) ~ 13 mJy and a smooth connection
to the bright source counts at >20 mJy measured by the South Pole Telescope;
this excess may be due to strong lensing effects. We compare these counts to
predictions from several semi-analytical and phenomenological models and find
that for most the agreement is quite good at flux densities > 4 mJy; however,
we find significant discrepancies (>3sigma) between the models and the observed
1.1 mm counts at lower flux densities, and none of them are consistent with the
observed turnover in the Euclidean-normalised counts at S(1100) < 2 mJy. Our
new results therefore may require modifications to existing evolutionary models
for low luminosity galaxies. Alternatively, the discrepancy between the
measured counts at the faint end and predictions from phenomenological models
could arise from limited knowledge of the spectral energy distributions of
faint galaxies in the local Universe.Comment: 16 pages, 3 figures, 4 tables; accepted for publication in MNRA
Detection of an ultra-bright submillimeter galaxy in the Subaru/XMM-Newton Deep Field using AzTEC/ASTE
We report the detection of an extremely bright (37 mJy at 1100 m
and 91 mJy at 880 m) submillimeter galaxy (SMG),
AzTEC-ASTE-SXDF1100.001 (hereafter referred to as SXDF1100.001 or Orochi),
discovered in 1100 m observations of the Subaru/XMM-Newton Deep Field
using AzTEC on ASTE. Subsequent CARMA 1300 m and SMA 880 m
observations successfully pinpoint the location of Orochi and suggest that it
has two components, one extended (FWHM of 4) and one
compact (unresolved). Z-Spec on CSO has also been used to obtain a wide band
spectrum from 190 to 308 GHz, although no significant emission/absorption lines
are found. The derived upper limit to the line-to-continuum flux ratio is
0.1--0.3 (2 ) across the Z-Spec band.
Based on the analysis of the derived spectral energy distribution from
optical to radio wavelengths of possible counterparts near the SMA/CARMA peak
position, we suggest that Orochi is a lensed, optically dark SMG lying at behind a foreground, optically visible (but red) galaxy at . The deduced apparent (i.e., no correction for magnification) infrared
luminosity () and star formation rate (SFR) are
and 11000 yr, respectively, assuming that the
is dominated by star formation. These values suggest that Orochi
will consume its gas reservoir within a short time scale (
yr), which is indeed comparable to those in extreme starbursts like the centres
of local ULIRGs.Comment: 18 pages, 13 figure
Assessment of subpatent Plasmodium infection in northwestern Ethiopia.
BACKGROUND: Ethiopia has set a goal for malaria elimination by 2030. Low parasite density infections may go undetected by conventional diagnostic methods (microscopy and rapid diagnostic tests) and their contribution to malaria transmission varies by transmission settings. This study quantified the burden of subpatent infections from samples collected from three regions of northwest Ethiopia. METHODS: Sub-samples of dried blood spots from the Ethiopian Malaria Indicator Survey 2015 (EMIS-2015) were tested and compared using microscopy, rapid diagnostic tests (RDTs), and nested polymerase chain reaction (nPCR) to determine the prevalence of subpatent infection. Paired seroprevalence results previously reported along with gender, age, and elevation of residence were explored as risk factors for Plasmodium infection. RESULTS: Of the 2608 samples collected, the highest positive rate for Plasmodium infection was found with nPCR 3.3% (95% CI 2.7-4.1) compared with RDT 2.8% (95% CI 2.2-3.5) and microscopy 1.2% (95% CI 0.8-1.7). Of the nPCR positive cases, Plasmodium falciparum accounted for 3.1% (95% CI 2.5-3.8), Plasmodium vivax 0.4% (95% CI 0.2-0.7), mixed P. falciparum and P. vivax 0.1% (95% CI 0.0-0.4), and mixed P. falciparum and Plasmodium malariae 0.1% (95% CI 0.0-0.3). nPCR detected an additional 30 samples that had not been detected by conventional methods. The majority of the nPCR positive cases (61% (53/87)) were from the Benishangul-Gumuz Region. Malaria seropositivity had significant association with nPCR positivity [adjusted OR 10.0 (95% CI 3.2-29.4), P < 0.001]. CONCLUSION: Using nPCR the detection rate of malaria parasites increased by nearly threefold over rates based on microscopy in samples collected during a national cross-sectional survey in 2015 in Ethiopia. Such subpatent infections might contribute to malaria transmission. In addition to strengthening routine surveillance systems, malaria programmes may need to consider low-density, subpatent infections in order to accelerate malaria elimination efforts
Search for Production via Trilepton Final States in collisions at TeV
We have searched for associated production of the lightest chargino,
, and next-to-lightest neutralino, , of the
Minimal Supersymmetric Standard Model in collisions at
\mbox{ = 1.8 TeV} using the \D0 detector at the Fermilab Tevatron
collider. Data corresponding to an integrated luminosity of 12.5 \ipb
were examined for events containing three isolated leptons. No evidence for
pair production was found. Limits on
BrBr are
presented.Comment: 17 pages (13 + 1 page table + 3 pages figures). 3 PostScript figures
will follow in a UUEncoded, gzip'd, tar file. Text in LaTex format. Submitted
to Physical Review Letters. Replace comments - Had to resumbmit version with
EPSF directive
Second Generation Leptoquark Search in p\bar{p} Collisions at = 1.8 TeV
We report on a search for second generation leptoquarks with the D\O\
detector at the Fermilab Tevatron collider at = 1.8 TeV.
This search is based on 12.7 pb of data. Second generation leptoquarks
are assumed to be produced in pairs and to decay into a muon and quark with
branching ratio or to neutrino and quark with branching ratio
. We obtain cross section times branching ratio limits as a function
of leptoquark mass and set a lower limit on the leptoquark mass of 111
GeV/c for and 89 GeV/c for at the 95%\
confidence level.Comment: 18 pages, FERMILAB-PUB-95/185-
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