296 research outputs found
X-ray Temperature and Mass Measurements to the Virial Radius of Abell 1413 with Suzaku
We present X-ray observations of the northern outskirts of the relaxed galaxy
cluster A1413 with Suzaku, whose XIS instrument has the low intrinsic
background needed to make measurements of these low surface brightness regions.
We excise 15 point sources superimposed on the image above a flux of \fluxunit (2--10keV) using XMM-Newton and Suzaku images of the
cluster. We quantify all known systematic errors as part of our analysis, and
show our statistical errors encompasses them for the most part. Our results
extend previous measurements with Chandra and XMM-Newton, and show a
significant temperature drop to about 3keV at the virial radius, . Our
entropy profile in the outer region () joins smoothly onto that
of XMM-Newton, and shows a flatter slope compared with simple models, similar
to a few other clusters observed at the virial radius. The integrated mass of
the cluster at the virial radius is approximately
and varies by about 30% depending on the particular method used to measure it.Comment: 32pages, 9 figures, accepted for publication in PAS
Pengaruh Komposisi Daun Gamal (Gliricidia sepium Hbr.) dan Kotoran Sapi dengan Nutrisi Pisang terhadap Rasio C/N Kompos
It has been done a research on the effect of the composition of gliricidia sepium Hbr. And cow dung with banana nutrition on the composting process on the C/N ratio. This research was conducted with the aim of knowing the effect of the composition and the length of time required for fermentation. Composting was made with a variety of cow dung : gliricidia sepium Hbr. In a ratio of 1:9, 1:1, 3:2, 7:3, 9:1, and 2:3 in % by using 25% banana nutrition and 100% water from the total weight of the manure. On this research was found that the optimal time is on 14th day with characteristic of compost that was produced, equal with the the Indonesia National Standar (SNI Kompos 19-7030-2004). The conclusion is the compcsition of cow dung and Gliricidia sepium leaves did not significant affect to the C/N compost ratio
X-ray Spectroscopy of the Core of the Perseus Cluster with Suzaku: Elemental Abundances in the Intracluster Medium
The results from Suzaku observations of the central region of the Perseus
cluster are presented. Deep exposures with the X-ray Imaging Spectrometer
provide high quality X-ray spectra from the intracluster medium. X-ray lines
from helium-like Cr and Mn have been detected significantly for the first time
in clusters. In addition, elemental abundances of Ne, Mg, Si, S, Ar, Ca, Fe,
and Ni are accurately measured within 10' (or 220 kpc) from the cluster center.
The relative abundance ratios are found to be within a range of 0.8-1.5 times
the solar value. These abundance ratios are compared with previous
measurements, those in extremely metal-poor stars in the Galaxy, and
theoretical models.Comment: 10 pages, 3 figures, accepted for ApJ
X-ray and UV spectroscopy of Galactic diffuse hot gas along the LMC X--3 sight line
We present Suzaku spectra of X-ray emission in the fields just off the LMC
X-3 sight line. OVII, OVIII, and NeIX emission lines are clearly detected,
suggesting the presence of an optically thin thermal plasma with an average
temperature of 2.4E6. This temperature is significantly higher than that
inferred from existing X-ray absorption line data obtained with Chandra grating
observations of LMC X-3, strongly suggesting that the gas is not isothermal. We
then jointly analyze these data to characterize the spatial and temperature
distributions of the gas. Assuming a vertical exponential Galactic disk model,
we estimate the gas temperature and density at the Galactic plane and their
scale heights as 3.6(2.9, 4.7)E6 K and 1.4(0.3, 3.4)E-3 cm^{-3} and 1.4(0.2,
5.2) kpc and kpc, respectively. This characterization can
account for all the \ovi line absorption, as observed in a FUSE spectrum of LMC
X-3, but only predicts less than one tenth of the OVI line emission intensity
typically detected at high Galactic latitudes. The bulk of the OVI emission
most likely arises at interfaces between cool and hot gases.Comment: 10 pages, 7 figures, 3 tables, accepted for publication in ApJ, 200
On the lack of strong O-line excess in the Coma cluster outskirts from Suzaku
About half of the baryons in the local Universe are thought to reside in the
so-called warm-hot intergalactic medium (WHIM) at temperatures of 0.1-10
million K. Thermal soft excess emission in the spectrum of some cluster
outskirts that contains OVII and/or OVIII emission lines is regarded as
evidence of the WHIM, although the origin of the lines is controversial due to
strong Galactic and solar system foreground emission. We observed the Coma-11
field, where the most prominent thermal soft excess has ever been reported,
with Suzaku XIS in order to make clear the origin of the excess. We did not
confirm OVII or OVIII excess emission. The OVII and OVIII intensity in Coma-11
is more than 5 sigma below that reported before and we obtained 2 sigma upper
limits of 2.8 and 2.9 photons cm^-2 s^-1 sr^-1 for OVII and OVIII,
respectively. The intensities are consistent with those in another field
(Coma-7) that we measured, and with other measurements in the Coma outskirts
(Coma-7 and X Com fields with XMM-Newton). We did not confirm the spatial
variation within Coma outskirts. The strong oxygen emission lines previously
reported are likely due to solar wind charge exchange.Comment: 5 pages, 3 figures. Accepted for publication in Ap
Suzaku X-ray Imaging of the Extended Lobe in the Giant Radio Galaxy NGC6251 Associated with the Fermi-LAT Source 2FGLJ1629.4+8236
We report the results of a Suzaku X-ray imaging study of NGC6251, a nearby
giant radio galaxy with intermediate FR I/II radio properties. Our pointing
direction was centered on the gamma -ray emission peak recently discovered with
Fermi-LAT around the position of the north-west radio lobe 15 arcmin offset
from the nucleus. After subtracting two "off-source" pointings adjacent to the
radio lobe, and removing possible contaminants in the XIS field of view, we
found significant residual X-ray emission most likely diffuse in nature. The
spectrum of the excess X-ray emission is well fit by a power law with photon
index \Gamma = 1.90 +- 0.15 and a 0.5 - 8 keV flux of 4 x 10^{-13} erg cm^{-2}
s^{-1}. We interpret this diffuse X-ray emission component as being due to
inverse-Compton up-scattering of the cosmic microwave background photons by
ultrarelativistic electrons within the lobe, with only a minor contribution
from the beamed emission of the large-scale jet. Utilizing archival radio data
for the source, we demonstrate by means of broad-band spectral modeling that
the -ray flux of the Fermi-LAT source 2FGL J1629.4+8236 may well be accounted
for by the high-energy tail of the inverse-Compton continuum of the lobe. Thus,
this claimed association of gamma-rays from the north-west lobe of NGC6251,
together with the recent Fermi-LAT imaging of the extended lobes of Centaurus
A, indicates that particles may be efficiently (re-)accelerated up to
ultrarelativistic energies within extended radio lobes of nearby radio galaxies
in general.Comment: 19 pages, 4 figures, accepted for publication in the Ap
Suzaku measurement of Abell 2204's intracluster gas temperature profile out to 1800 kpc
Context: Measurements of intracluster gas temperatures out to large radii are
important for the use of clusters for precision cosmology and for studies of
cluster physics. Previous attempts to measure robust temperatures at cluster
virial radii failed. Aims: The goal of this work is to measure the temperature
profile of the very relaxed galaxy cluster Abell 2204 out to large radii,
possibly reaching the virial radius. Methods: Taking advantage of its low
particle background due to its low-Earth orbit, Suzaku data are used to measure
the outer temperature profile of Abell 2204. These data are combined with
Chandra and XMM-Newton data of the same cluster in order to make the connection
to the inner regions, unresolved by Suzaku, and to determine the smearing due
to Suzaku's PSF. Results: The temperature profile of Abell 2204 is determined
from 10 kpc to 1800 kpc, close to an estimate of r200 (the approximation to the
virial radius). The temperature rises steeply from below 4 keV in the very
center up to more than 8 keV in the intermediate range and then decreases again
to about 4 keV at the largest radii. Varying the measured particle background
normalization artificially by +-10 percent does not change the results
significantly. Predictions for outer temperature profiles based on hydrodynamic
simulations show good agreement. In particular, we find the observed
temperature profile to be slightly steeper but consistent with a drop of a
factor of 0.6 from 0.3 r200 to r200, as predicted by simulations. Conclusions:
Temperature measurements up to the virial radius seem feasible with Suzaku,
when a careful analysis of the different background components and the effects
of the PSF is performed. The result obtained here indicates that numerical
simulations capture the intracluster gas physics well in cluster outskirts.Comment: 7 pages; Astronomy and Astrophysics, accepted; additional systematic
effects have been quantified, results unchanged; also available at
http://www.reiprich.ne
Accuracy of magnetic resonance imaging in detecting lumbo-sacral nerve root compromise: A systematic literature review
Background: MRI is considered to be the diagnostic tool of choice in diagnosing nerve root compromise among patients presenting with clinical suspicion of lumbo-sacral radiculopathy. There exists controversy among researchers and clinicians regarding the diagnostic utility and accuracy of MRI in detecting nerve root compromise and radiculopathy. This review evaluated 4 primary diagnostic accuracy studies that specifically assessed the accuracy of MRI in detecting nerve root compromise, as established in the current literature. Methods: Eight electronic data bases were searched for relevant articles from inception until January 2014. All primary diagnostic studies which investigated the accuracy of MRI in diagnosing nerve root compromise among patients with low back and referred leg symptoms were screened for inclusion. Qualifying studies were retrieved and independently assessed for methodological quality using the 'Quality Assessment of Diagnostic tests Accuracy Studies' criteria. Results: Four studies qualified for inclusion in this review. The sensitivity of MRI in detecting lumbar nerve root compromise was very low at 0.25 (95 % CI) while the specificity was relatively high at 0.92 (95 % CI). Conclusions: There is lack of sufficient high quality scientific evidence in support or against the use of MRI in diagnosing nerve root compression and radiculopathy. Therefore, clinicians should always correlate the findings of MRI with the patients' medical history and clinical presentation in clinical decision making.IS
Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
We have developed a framework for the Monte-Carlo simulation of the X-Ray
Telescopes (XRT) and the X-ray Imaging Spectrometers (XIS) onboard Suzaku,
mainly for the scientific analysis of spatially and spectroscopically complex
celestial sources. A photon-by-photon instrumental simulator is built on the
ANL platform, which has been successfully used in ASCA data analysis. The
simulator has a modular structure, in which the XRT simulation is based on a
ray-tracing library, while the XIS simulation utilizes a spectral
"Redistribution Matrix File" (RMF), generated separately by other tools.
Instrumental characteristics and calibration results, e.g., XRT geometry,
reflectivity, mutual alignments, thermal shield transmission, build-up of the
contamination on the XIS optical blocking filters (OBF), are incorporated as
completely as possible. Most of this information is available in the form of
the FITS (Flexible Image Transport System) files in the standard calibration
database (CALDB). This simulator can also be utilized to generate an "Ancillary
Response File" (ARF), which describes the XRT response and the amount of OBF
contamination. The ARF is dependent on the spatial distribution of the
celestial target and the photon accumulation region on the detector, as well as
observing conditions such as the observation date and satellite attitude. We
describe principles of the simulator and the ARF generator, and demonstrate
their performance in comparison with in-flight data.Comment: 19 pages with 8 figures, accepted for publication in PASJ Vol 58,
Suzaku special issu
The simple and rapid detection of specific PCR products from bacterial genomes using Zn finger proteins
A novel method of rapid and specific detection of polymerase chain reaction (PCR) products from bacterial genomes using Zn finger proteins was developed. Zn finger proteins are DNA-binding proteins that can sequence specifically recognize PCR products. Since Zn finger proteins can directly detect PCR products without undergoing dehybridization, unlike probe DNA, and can double check the specific PCR amplification and sequence specificity of the PCR products, this novel method would be quick and highly accurate. In this study, we tried to detect Legionella pneumophila using Sp1. It was found that a 49 bp L. pneumophila-specific region containing the Sp1 recognition site is located on the flhA gene of the L. pneumophila genome. We succeeded in specifically detecting PCR products amplified from L. pneumophila in the presence of other bacterial genomes by ELISA, and demonstrated that Sp1 enables the discrimination of L. pneumophila-specific PCR products from others. By fluorescence depolarization measurement, these specific PCR products could be detected within 1 min. These results indicate that the rapid and simple detection of PCR products specific to L. pneumophila using a Zn finger protein was achieved. This methodology can be applied to the detection of other bacteria using various Zn finger proteins that have already been reported
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