143 research outputs found
Spectroscopy along Multiple, Lensed Sightlines through Outflowing Winds in the Quasar SDSS J1029+2623
We study the origin of absorption features on the blue side of the C IV broad
emission line of the large-separation lensed quasar SDSS J1029+2623 at z_em ~
2.197. The quasar images, produced by a foreground cluster of galaxies, have a
maximum separation angle of ~ 22".5. The large angular separation suggests that
the sight-lines to the quasar central source can go through different regions
of outflowing winds from the accretion disk of the quasar, providing a unique
opportunity to study the structure of outflows from the accretion disk, a key
ingredient for the evolution of quasars as well as for galaxy formation and
evolution. Based on medium- and high-resolution spectroscopy of the two
brightest images conducted at the Subaru telescope, we find that each image has
different intrinsic levels of absorptions, which can be attributed either to
variability of absorption features over the time delay between the lensed
images, ~ 774 days, or to the fine structure of quasar outflows probed by the
multiple sight-lines toward the quasar. While both these scenarios are
consistent with the current data, we argue that they can be distinguished with
additional spectroscopic monitoring observations.Comment: 17 pages, including 7 figures; accepted for publication in the
Astronomical Journa
Suzaku wide-band X-ray Spectroscopy of the Seyfert 2 AGN in NGC 4945
Suzaku observed a nearby Seyfert 2 galaxy NGC4945, which hosts one of the
brightest active galactic nuclei above 20 keV. Combining data from the X-ray
CCD camera (XIS) and the Hard X-ray Detector (HXD), the AGN intrinsic nuclear
emission and its reprocessed signals were observed simultaneously. The
intrinsic emission is highly obscured with an absorbing column of cm, and was detectable only above keV. The
spectrum below 10 keV is dominated by reflection continuum and emission lines
from neutral/ionized material. Along with a neutral iron K line, a
neutral iron K and a neutral nickel K line were detected for the
first time from this source. The neutral lines and the cold reflection
continuum are consistent with both originating in the same location. The
Compton down-scattered shoulder in the neutral Fe-K line is
in flux of the narrow core, which confirms that the line originates from
reflection rather than transmission. The weakness of the Compton shoulder also
indicates that the reflector is probably seen nearly edge-on. Flux of the
intrinsic emission varied by a factor of within ks, which
requires the obscuring material to be geometrically thin. Broadband spectral
modeling showed that the solid angle of the neutral reflector is less than a
few . All this evidence regarding the reprocessed
signals suggests that a disk-like absorber/reflector is viewed from a near
edge-on angle.Comment: 11 pages, 11 figure
Development of the analog ASIC for multi-channel readout X-ray CCD camera
We report on the performance of an analog application-specific integrated
circuit (ASIC) developed aiming for the front-end electronics of the X-ray
CCDcamera system onboard the next X-ray astronomical satellite, ASTRO-H. It has
four identical channels that simultaneously process the CCD signals.
Distinctive capability of analog-to-digital conversion enables us to construct
a CCD camera body that outputs only digital signals. As the result of the
front-end electronics test, it works properly with low input noise of =<30 uV
at the pixel rate below 100 kHz. The power consumption is sufficiently low of
about 150 mW/chip. The input signal range of 720 mV covers the effective energy
range of the typical X-ray photon counting CCD (up to 20 keV). The integrated
non-linearity is 0.2% that is similar as those of the conventional CCDs in
orbit. We also performed a radiation tolerance test against the total ionizing
dose (TID) effect and the single event effect. The irradiation test using 60Co
and proton beam showed that the ASIC has the sufficient tolerance against TID
up to 200 krad, which absolutely exceeds the expected amount of dose during the
period of operating in a low-inclination low-earth orbit. The irradiation of Fe
ions with the fluence of 5.2x10^8 Ion/cm2 resulted in no single event latchup
(SEL), although there were some possible single event upsets. The threshold
against SEL is higher than 1.68 MeV cm^2/mg, which is sufficiently high enough
that the SEL event should not be one of major causes of instrument downtime in
orbit.Comment: 16 pages, 6 figure
Wide-band spectroscopy of the Compton thick Seyfert 2 galaxy Mrk 3 with Suzaku
We obtained a wide-band spectrum of the Compton-thick Seyfert 2 galaxy Mrk 3
with Suzaku. The observed spectrum was clearly resolved into weak, soft
power-law emission, a heavily absorbed power-law component, cold reflection,
and many emission lines. The heavily absorbed component, absorbed by gas with a
column density of 1.1x10^24 cm^-2, has an intrinsic 2--10 keV luminosity of
~1.6x10^43 erg s^-1, and is considered to be direct emission from the Mrk 3
nucleus. The reflection component was interpreted as reflection of the direct
light off cold, thick material; the reflection fraction was 1.36+/-0.20.
The cold material is inferred to be located > 1 pc from the central black hole
of Mrk 3 due to the low ionization parameter of iron (xi < 1 erg cm s^-1) and
the narrow iron line width (s < 22 eV). A Compton shoulder to the iron line was
detected, but the intensity of the shoulder component was less than that
expected from spherically distributed Compton-thick material. The weak, soft
power-law emission is considered to be scattered light by ionized gas. The
existence of many highly-ionized lines from O, Ne, Mg, Si, S, and Fe in the
observed spectrum indicates that the ionized gas has a broad ionized structure,
with xi=10--1000. The scattering fraction with respect to the direct light was
estimated to be 0.9+/-0.2%, which indicates that the column density of the
scattering region is about 3.6x10^22 cm^-2. This high-quality spectrum obtained
by Suzaku can be considered a template for studies of Seyfert 2 galaxies.Comment: 24 pages, 8 figures, accepted in PASJ for publicatio
The Impact of Reduced Skeletal Muscle Mass on Patients with Knee Osteoarthritis
Although several studies have suggested a possible association between sarcopenia and knee osteoarthritis (OA) in the elderly, there remains no definitive evidence. Recently, however, the serum creatinine/cystatin C ratio (sarcopenia index: SI) was reported to correlate with skeletal muscle mass. The present retrospective study therefore investigated the impact of reduced skeletal muscle mass on advanced knee OA using SI. In 55 individuals scheduled for knee osteotomy or knee arthroplasty, correlations between SI and patient-reported outcomes such as the Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Oxford Knee Score (OKS) were explored. Significant associations were found between SI and the KSS functional activity score (β=0.37; p=0.022), KOOS subscale for activities of daily living (β=0.42; p=0.0096), and OKS (β=0.42; p=0.0095). This study underscores the role of reduced muscle mass in functional outcomes and introduces SI as a valuable marker for assessing muscle loss in knee OA patients
Thermal Equation of State of Fe3C to 327 GPa and Carbon in the Core
The density and sound velocity structure of the Earth’s interior is modeled on seismological observations and is known as the preliminary reference Earth model (PREM). The density of the core is lower than that of pure Fe, which suggests that the Earth’s core contains light elements. Carbon is one plausible light element that may exist in the core. We determined the equation of state (EOS) of Fe3C based on in situ high-pressure and high-temperature X-ray diffraction experiments using a diamond anvil cell. We obtained the P–V data of Fe3C up to 327 GPa at 300 K and 70–180 GPa up to around 2300 K. The EOS of nonmagnetic (NM) Fe3C was expressed by two models using two different pressure scales and the third-order Birch–Murnaghan EOS at 300 K with the Mie–Grüneisen–Debye EOS under high-temperature conditions. The EOS can be expressed with parameters of V0 = 148.8(±1.0) Å3, K0 = 311.1(±17.1) GPa, K0′ = 3.40(±0.1), γ0 = 1.06(±0.42), and q = 1.92(±1.73), with a fixed value of θ0 = 314 K using the KBr pressure scale (Model 1), and V0 = 147.3(±1.0) Å3, K0 = 323.0(±16.6) GPa, K0′ = 3.43(±0.09), γ0 = 1.37(±0.33), and q = 0.98(±1.01), with a fixed value of θ0 = 314 K using the MgO pressure scale (Model 2). The density of Fe3C under inner core conditions (assuming P = 329 GPa and T = 5000 K) calculated from the EOS is compatible with the PREM inner core
Implementation of endoscopic submucosal dissection in Europe: survey after ten ESD expert training workshops 2009 – 2018
Background and aims
Transfer of ESD technique for early gastrointestinal cancer from Japan requires expert-supervised experimental training before unsupervised implementation of clinical ESD.
Aims
To evaluate unsupervised implementation of ESD-intention-to-treat (-ITT).
Methods
ESD Workshops (in-vivo porcine model) lasted 3.3 days including one day theory for 177 participants from 135 Western referral centers. A questionnaire was sent to the senior participant of all 135 centers.
Design
Cross-sectional questionnaire survey.
Main outcome measurements
Performance, organ distribution, severe adverse events of ESD-ITT.
Results
Feedback was received from 113 centers (84%), i.e. 73 (54%) ESD centers and 40 centers (30%) with zero ESD; 10 (7%) had published ESD; no feedback from 12 (9%) centers with unknown status. Altogether, 83 centers (61.5%) perform ESD: 21 (16%) had >150 ESD (professional category), 33 (24%) had 31-150 ESD (competent category), and 29 (21.5%) had ≤ 30 ESD (initial learning category). Most implemented ESD centers (91%, 72 of 79) were analyzed: Centers on initial learning (420 ESD) compared to centers with >30 ESD (5676 ESD) performed en-bloc ESD in 64% vs. 84%, hybrid-ESD in 26% vs.11% and piecemeal-EMR in 10% vs. 5.2%. Majority of ESD (66-68%) were in colorectum, overall with low risk (30-day mortality 0.03%, surgical repair 3.5% vs. 1.7%) and satisfactory outcome (oncosurgery 7.4% vs. 5.2%, local recurrence 1.5% vs. 0.3%).
Conclusions
Beyond guideline recommendations, unsupervised implementation of ESD was successful in colorectum with step-up approach. Now, Western ESD centers have to aim for professional (i.e. >80%) curative ESD
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