29 research outputs found
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
Comptonization in Super-Eddington Accretion Flow and Growth Timescale of Supermassive Black Holes
Super-Eddington accretion onto black holes (BHs) may occur at ultraluminous
compact X-ray sources in nearby galaxies, Galactic microquasars and narrow-line
Seyfert 1 galaxies (NLS1s). Effects of electron scattering (opacity and
Comptonization) and the relativistic correction (gravitational redshift and
transverse Doppler effect) on the emergent spectra from super-Eddington
accretion flows onto non-rotating BHs are examined for 10^{1.5} and 10^{6.5}
M_sun BH masses (M_BH). With mdot [= Mdot / (L_Edd / c^2), where Mdot is the
accretion rate] > 100, the spectral hardening factor via electron scattering is
\lesssim 2.3 - 6.5. Due to the mdot-sensitive hardening factor, the color
temperature of the innermost radiation is not proportional to L^{0.25},
differing from the simplest standard accretion disk. The model is applied to
optical--soft X-ray emission from NLS1s. We pick up one NLS1, namely PG
1448+273 with an inferred M_BH of 10^{6.4} M_sun, among the highest mdot
candidates. The broadband spectral distribution is successfully reproduced by
the model with an extremely high mdot (= 1000) and the viscosity parameter
alpha of 0.01. This implies that this object, as well as some other highest
mdot systems, is really young: the inferred age, M_BH / Mdot, is about 10^6
years. We also briefly discuss the distribution of mdot for transient and
highly variable NLS1s, finding that those are located at 3 \lesssim mdot
\lesssim 300. Such a moderately high accretion rate is indicative of thermal
instability. Furthermore, mdot for a possible type-2 counterpart of NLS1s, NGC
1068, is found to be similar to mdot for NLS1s.Comment: 16 pages (including 14 color figures), LaTeX emulateapj5.sty, The
Astrophysical Journal in press, corrected some typos and added reference
JASMINE: Near-infrared astrometry and time-series photometry science
The Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is Galactic archaeology with a Galactic Center survey, which aims to reveal the Milky Way’s central core structure and formation history from Gaia-level (∼25 as) astrometry in the near-infrared (NIR) Hw band (1.0–1.6 m). The other is an exoplanet survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic Center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information on the stars in the Galactic Center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic Center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars, and microlensing studies, including discovery of (intermediate-mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions
Studies on the Reduction of Bilirubin by Fecal Flora Part 1 A Study on the Bile Pigment Fraction in the Bile with the Positive Ehrlich's aldehyde reaction
The mesobiliviolin reaction and the intermediate products of bilirubin were observed on the B-bile, with the positive Ehrlich's aldehyde reaction, odtained from 20 cases of cholecystopathy, and the results were as follows. 1. After mesobiliviolin reaction on 19 cases the chloroform extract was separated into each pigment by column chromatography, and the absorption curves of each pigment and their changes on the addition of a saturated alcoholic solution of zine acetate were observed. 2. The question whether or not stercoblinogen occupies the position superior to mesobilinogen can be explained by the intensity of bile duct infection, especially the infection by B. coli, or by the intensity of the inflammation findings of bile duct. 3. From the 4 cases treated with antibiotics stercobilinogen could not be detected but only mesobilinogen, suggesting that antibiotics reduce the chemical activity of bacteria. 4. In 4 cases bilirubin and mesobilirubin could be detected and also a pigment that apears to be dihydromesobilirubin. From these results it bas been clarified that the in vivo reduction of bilirubin to urobilinogen is not conducted by liver enzymes but by bacterial enzymes. 5. On 2 cases the detection of d-urobilin was attempted by means of polarimeter and dioxan-HCl boiling method, but the existence of this pigment could not be observed
Studies on the Reduction of Bilirubin by Fecal Flora Part 2 A Study on the Bile Pigment Reduction Capacity of B. Coli Communis
The reduction of biliverdin was attempted by dissolving biliverdin in various media with the cultivation of either E. coli communis and the filtered bacterium solution. And the results were as follows. 1. In the non-proteinous media or in the pepton aqueous solution as the medium provided in the presence of 0.1% glucose biliverdin is reduced to bilirubin. However, in this instance the reduction takes place only at the central methin group but not at the vinyl group of side chain. 2. Even in the presence of pentose or hexose besides glucose similar result can be obtained, though the reduction power is less. In this instance sugar alone can not produce bilirubin. 3. Even under the condition unfavorable to the growth of bacterium, in the presence of glucose a small quantity of bilirubin is produced. 4. When various amino-acid sulfur compounds, l-ascorbic acid or egg-white exudate solution are added to the medium along with glucose, such addition only affected the velocity of the reduction and gave the same result. 5. In the presence of these substances added to various media a pigment possessing the characteristics of direct birect bilirubin has been isolated simultaneously. 6. Under the aerobic condition no effect other than the slowing-down of the reduction velocity can be recognized. 7. The factor that plays a role in the reduction of biliverdin is also excreted outside the body of E. coli communis during the culture. Furthermore, this factor is heatresistant and its reduction capacity shows itself only in the presence of glucose
Education Effect on Healthcare Professionals in Study Sessions Using the Confirmation Test
Household Transmission of Streptococcus pneumoniae among Siblings with Acute Otitis Media
Nasopharyngeal transmission of Streptococcus pneumoniae was evaluated among 23 siblings with acute otitis media (AOM). Restriction fragment length polymorphism revealed that the nasopharyngeal strains were identical between siblings in 12 of 13 clusters of AOM experienced in 11 families. This study demonstrated person-to-person transmission of S. pneumoniae, especially drug-resistant strains, among siblings with AOM