81 research outputs found
The Social Networks of Korean Female Adult Learners in a Middle School
This study investigates the social networks of Korean female adult learners in middle school through social network analysis and examines the development of these networks by interviewing the main actors involved
A small solitary non-parasitic hepatic cyst causing an intra-hepatic bile duct stricture: a case report
<p>Abstract</p> <p>Introduction</p> <p>We report an unusual presentation of a small hepatic cyst causing cholangitis.</p> <p>Case presentation</p> <p>A 70-year-old Asian man was hospitalized for aggravated chronic pain in the right upper portion of his abdomen. Fever developed after admission. Laboratory tests revealed elevated hepatobiliary enzymes, inflammatory markers and carbohydrate antigen 19-9 without hyperbilirubinemia. Ultrasound and computed tomography demonstrated dilatation of the left intra-hepatic bile ducts. Endoscopic retrograde cholangiopancreatography showed that the right intra-hepatic bile ducts were normally filled with contrast medium, but the left intra-hepatic bile ducts were not seen in the confluence. A left hepatectomy was performed because a hidden malignancy could not be excluded. The surgical findings showed no tumor around the bile duct but rather a 2 cm cyst in segment four of Couinaud's category of the liver around the hilum. The pathology report was a solitary non-parasitic hepatic cyst compressing the bile duct.</p> <p>Conclusion</p> <p>A very small solitary hepatic cyst might cause hepatic duct stricture if it is located near the hepatic hilum, and should be considered in the differential diagnosis of a hepatic duct stricture.</p
Strongly lensed [O III] emitters at Cosmic Noon with Roman: Characterizing extreme emission line galaxies on star cluster complex scales (100 pc)
Extreme emission line galaxies (EELGs) are considered the primary contributor
to cosmic reionization and are valuable laboratories to study the astrophysics
of massive stars. It is strongly expected that Roman's High Latitude Wide Area
Survey (HLWAS) will find many strongly gravitationally lensed [O III] emitters
at Cosmic Noon (1 < z < 2.8). Roman imaging and grism spectroscopy alone will
simultaneously confirm these strong lens systems and probe their interstellar
medium (ISM) and stellar properties on small scales ( 100 pc).
Moreover, these observations will synergize with ground-based and space-based
follow-up observations of the discovered lensed [O III] emitters in
multi-wavelength analyses of their properties (e.g., massive stars and possible
escape of ionizing radiation), spatially resolved on the scales of individual
star cluster complexes. Only Roman can uniquely sample a large number of lensed
[O III] emitters to study the small scale (~ 100 pc) ISM and stellar properties
of these extreme emission line galaxies, detailing the key physics of massive
stars and the ISM that govern cosmic reionization.Comment: Submitted in response to the call for Roman Telescope CCS white
paper
Spectrophotometric Redshifts In The Faint Infrared Grism Survey: Finding Overdensities Of Faint Galaxies
We improve the accuracy of photometric redshifts by including low-resolution
spectral data from the G102 grism on the Hubble Space Telescope, which assists
in redshift determination by further constraining the shape of the broadband
Spectral Energy Disribution (SED) and identifying spectral features. The
photometry used in the redshift fits includes near-IR photometry from
FIGS+CANDELS, as well as optical data from ground-based surveys and HST ACS,
and mid-IR data from Spitzer. We calculated the redshifts through the
comparison of measured photometry with template galaxy models, using the EAZY
photometric redshift code. For objects with F105W AB mag with a
redshift range of , we find a typical error of for the purely photometric redshifts; with the addition of FIGS spectra,
these become , an improvement of 50\%. Addition of
grism data also reduces the outlier rate from 8\% to 7\% across all fields.
With the more-accurate spectrophotometric redshifts (SPZs), we searched the
FIGS fields for galaxy overdensities. We identified 24 overdensities across the
4 fields. The strongest overdensity, matching a spectroscopically identified
cluster at , has 28 potential member galaxies, of which 8 have previous
spectroscopic confirmation, and features a corresponding X-ray signal. Another
corresponding to a cluster at has 22 members, 18 of which are
spectroscopically confirmed. Additionally, we find 4 overdensities that are
detected at an equal or higher significance in at least one metric to the two
confirmed clusters.Comment: 17 pages, 13 figures. To appear in Ap
Emission Line Metallicities From The Faint Infrared Grism Survey and VLT/MUSE
We derive direct measurement gas-phase metallicities of for 14 low-mass Emission Line Galaxies (ELGs) at
identified in the Faint Infrared Grism Survey (FIGS). We use deep slitless G102
grism spectroscopy of the Hubble Ultra Deep Field (HUDF), dispersing light from
all objects in the field at wavelengths between 0.85 and 1.15 microns. We run
an automatic search routine on these spectra to robustly identify 71 emission
line sources, using archival data from VLT/MUSE to measure additional lines and
confirm redshifts. We identify 14 objects with with measurable
O[III]4363 \AA\ emission lines in matching VLT/MUSE spectra. For these
galaxies, we derive direct electron-temperature gas-phase metallicities with a
range of . With matching stellar masses in the
range of , we construct a
mass-metallicity (MZ) relation and find that the relation is offset to lower
metallicities compared to metallicities derived from alternative methods
(e.g.,, O3N2, N2O2) and continuum selected samples. Using star
formation rates (SFR) derived from the emission line, we calculate
our galaxies' position on the Fundamental Metallicity Relation (FMR), where we
also find an offset toward lower metallicities. This demonstrates that this
emission-line-selected sample probes objects of low stellar masses but even
lower metallicities than many comparable surveys. We detect a trend suggesting
galaxies with higher Specific Star Formation (SSFR) are more likely to have
lower metallicity. This could be due to cold accretion of metal-poor gas that
drives star formation, or could be because outflows of metal-rich stellar winds
and SNe ejecta are more common in galaxies with higher SSFR.Comment: 14 pages, 11 figures, accepted in Ap
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