234 research outputs found
MgII Absorption Lines in z=2.974 Damped Lyman-alpha System toward Gravitationally Lensed QSO APM 08279+5255: Detection of Small-scale Structure in MgII Absorbing Clouds
1.02-1.16 micron spectra (R ~ 7,000) of the gravitationally lensed QSO APM
08279+5255 at z_em=3.911 were obtained during the commissioning run of IRCS,
the 1-5 micron near-infrared camera and spectrograph for the Subaru 8.2 m
Telescope. Strong MgII doublet at 2976,2800 angstrom and FeII (2600 angstrom),
FeII (2587 angstrom) absorption lines at z_abs=2.974 were clearly detected in
the rest-frame UV spectra, confirming the presence of a damped Lyman-alpha
system at the redshift as suggested by Petitjean et al. Also MgI (2853
angstrom) absorption line is probably detected. An analysis of the absorption
lines including velocity decomposition was performed. This is a first detailed
study of MgII absorption system at high redshift (z > 2.5) where the MgII
doublet shifts into the near-infrared in the observer's frame.
The spectra of the lensed QSO pair A and B with 0.38 arcsec separation were
resolved in some exposure frames under excellent seeing condition. We extracted
the MgII doublet spectra of A and B separately. Although three velocity
components (v ~ -28, +5, +45 km/s) are known to exist in this MgII system
(Petitjean et al.), the v ~ +45 km/s absorption line was not detected toward
source B, showing that the +45 km/s MgII cloud lies only in the line of sight
to the source A. Our results suggests that the size of the MgII absorbing
clouds is as small as 200 pc, which corresponds to the separation of A and B at
the redshift of the absorber. This is the first direct detection of the
small-scale structure of MgII clouds at high-redshift, confirming the estimated
cloud sizes from photoionization model by Churchill and Charlton.Comment: ApJ in press (Vol.569, 20 April 2002 issue
Kinematic modeling and error sensitivity analysis for on-machine five-axis laser scanning measurement under machine geometric errors and workpiece setup errors
On-machine scanning measurement of workpiece geometry has a strong advantage in its efficiency, compared to conventional discrete measurement using a touch-trigger probe. When a workpiece is rotated and tilted, position and orientation errors of the workpiece with respect to the machine’s rotary axes can be a significant contributor to the measurement error. Rotary axis geometric errors also influence the measurement error. To establish the traceability of on-machine measurement with workpiece rotation, this paper kinematically formulates their contribution to measured profiles. As a practical application example, this paper presents the measurement error assessment for an axis-symmetric part. Based on the present kinematic model, this paper compares error contributors to the cases (1) where an axis-symmetric part is placed concentric to the rotary axis, and (2) where it is placed away from the rotary axis
Deep Near-Infrared Observations and Identifications of Chandra Sources in the Orion Molecular Cloud 2 and 3
We conducted deep NIR imaging observations of the Orion molecular cloud 2 and
3 using QUIRC on the 88-inch telescope of the University of Hawaii. Our
purposes are 1) to generate a comprehensive NIR source catalog of these star
forming clouds, and 2) to identify the NIR counterpart of the Chandra X-ray
sources that have no counterpart in the 2MASS catalog. Our J-, H-, and K-band
observations are about 2 mag deeper than those of 2MASS, and well match the
current Chandra observation. We detected 1448 NIR sources, for which we derived
the position, the J-, H-, and K-band magnitude, and the 2MASS counterpart.
Using this catalog, we identified the NIR counterpart for about 42% of the
2MASS-unIDed Chandra sources. The nature of these Chandra sources are discussed
using their NIR colors and spatial distributions, and a dozen protostar and
brown dwarf candidates are identified.Comment: 39 pages, 9 postscript figures, accepted for publication in A
Heat and moisture balance simulation of a building with vapor-open envelope system for subtropical regions
Global warming and the resource depletion induced discussions on sustainable developments within the construction sector. Also the rapid urbanization in subtropical regions is becoming one of the most important global issues. Appropriate measures must be taken in such developments to avoid further damage to the environment. In this study, the heat and moisture balance simulation of building with a sustainable building envelope system for subtropical climate was proposed. In the moisture balance simulation the moisture buffering by the interior materials was taken into account. The prediction of moisture buffer value (MBV) of the interior finishing materials was attempted and validated by measurements. Subsequently, the whole building calculation was carried out and the contribution of the moisture buffering to the indoor comfort and energy consumption was investigated. The MBVs of the mineral-based materials were predicted with high accuracy. However, that of wood-based composite was much higher than the experimental value. In order to create a more accurate model, nonlinear moisture conductance should be accounted when modeling wood-based materials. The heating and cooling demand of a test house was 9.4 kWh/m2 and 14.5 kWh/m2, respectively. It was concluded that the utilization of the building envelope system has a high potential to provide sustainable houses in subtropical regions. In order to enhance both energy efficiency and indoor comfort of buildings in subtropical regions, there still is a strong need to develop a holistic method to find the optimum building design considering not only moisture buffering but also all the relevant factors. The presented model will be validated by in-situ measurements in the near futur
Comprehensive Analysis of Bacterial Flora in Postoperative Maxillary Cyst Fluid by 16S rRNA Gene and Culture Methods
Intracystic fluid was aseptically collected from 11 patients with postoperative maxillary cyst (POMC), and DNA was extracted from the POMC fluid. Bacterial species were identified by sequencing after cloning of approximately 580 bp of the 16S rRNA gene. Identification of pathogenic bacteria was also performed by culture methods. The phylogenetic identity was determined by sequencing 517–596 bp in each of the 1139 16S rRNA gene clones. A total of 1114 clones were classified while the remaining 25 clones were unclassified. A total of 103 bacterial species belonging to 42 genera were identified in POMC fluid samples by 16S rRNA gene analysis. Species of Prevotella (91%), Neisseria (73%), Fusobacterium (73%), Porphyromonas (73%), and Propionibacterium (73%) were found to be highly prevalent in all patients. Streptococcus mitis (64%), Fusobacterium nucleatum (55%), Propionibacterium acnes (55%), Staphylococcus capitis (55%), and Streptococcus salivarius (55%) were detected in more than 6 of the 11 patients. The results obtained by the culture method were different from those obtained by 16S rRNA gene analysis, but both approaches may be necessary for the identification of pathogens, especially of bacteria that are difficult to detect by culture methods, and the development of rational treatments for patients with POMC
Imaging and Spatially Resolved Spectroscopy of AFGL 2688 in the Thermal Infrared Region
We present ground-based high-resolution (~0".3) imaging of AFGL 2688 at L'
(3.8 um) and M'(4.7um). A wealth of structure in the central region is revealed
due to less extinction in the thermal infrared. A clear border in the southern
lobe at L' corresponds to the edge of the heavily obscured region in visible,
indicating there is a dense material surrounding the central region. The images
also show a narrow dark lane oriented to 140 deg east of north with the normal
at 50 deg. The normal position angle is inconsistent with the optical polar
axis (PA = 15 deg), but is aligned to the high-velocity CO components found in
the radio wavelength observations. The central star remains invisible at L' and
M'. Several clumpy regions in the north lobe dominate in L' and M' luminosity.
In particular a pointlike source (peak A) at 0".5 northeast of the center of
the nebula exhibits the highest surface brightness with a very red spectral
energy distribution (SED). Based on the almost identical SED as adjacent
regions, we suggest that the pointlike source is not self-luminous, as was
proposed, but is a dense dusty blob reflecting thermal emission from the
central star.
We also present spatially resolved slit spectroscopy of the bright dusty
blobs. An emission feature at 3.4 um as well as at 3.3 um is detected
everywhere within our field of view. There is no spatial variation in the
infrared emission feature (IEF) throughout the observed area (0".2-1".5, or
240-1800 AU from the central source). The constant flux ratio of the emission
feature relative to the continuum is consistent with the view that the blobs
are mostly reflecting the light from the central star in the 3 um region.Comment: 20 pages, 12 figures, LaTeX, accepted for publication in Ap
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