2,107 research outputs found
X-ray view of four high-luminosity Swift/BAT AGN: Unveiling obscuration and reflection with Suzaku
The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray
BAT fluxes in excess of 10^-11 erg cm^-2 s^-1 and an average redshift of 0.03.
Among them, four of the most luminous BAT AGN (44.73 < Log L(BAT) < 45.31) were
selected as targets of Suzaku follow-up observations: J2246.0+3941 (3C 452),
J0407.4+0339 (3C 105), J0318.7+6828, and J0918.5+0425. The column density,
scattered/reflected emission, the properties of the Fe K line, and a possible
variability are fully analyzed. For the latter, the spectral properties from
Chandra, XMM-Newton and Swift/XRT public observations were compared with the
present Suzaku analysis. Of our sample, 3C 452 is the only certain
Compton-thick AGN candidate because of i) the high absorption and strong
Compton reflection; ii) the lack of variability; iii) the "buried" nature, i.e.
the low scattering fraction (<0.5%) and the extremely low relative [OIII]
luminosity. In contrast 3C 105 is not reflection-dominated, despite the
comparable column density, X-ray luminosity and radio morphology, but shows a
strong long-term variability in flux and scattering fraction, consistent with
the soft emission being scattered from a distant region (e.g., the narrow
emission line region). The sample presents high (>100) X-to-[OIII] luminosity
ratios, confirming the [OIII] luminosity to be affected by residual extinction
in presence of mild absorption, especially for "buried" AGN such as 3C 452.
Three of our targets are powerful FRII radio galaxies, making them the most
luminous and absorbed AGN of the BAT Seyfert survey despite the inversely
proportional N_H - L_X relation.Comment: A&A paper in press, 17 page
Optical and X-ray Properties of the Swift BAT-detected AGN
The Swift Gamma-Ray Burst satellite has detected a largely unbiased towards
absorption sample of local () AGN, based solely on their
14--195 keV flux. In the first 9 months of the survey, 153 AGN sources were
detected. The X-ray properties in the 0.3--10 keV band have been compiled and
presented based on analyses with XMM-Newton, Chandra, Suzaku, and the Swift XRT
(Winter et al. 2009). Additionally, we have compiled a sub-sample of sources
with medium resolution optical ground-based spectra from the SDSS or our own
observations at KPNO. In this sample of 60 sources, we have classified the
sources using standard emission line diagnostic plots, obtained masses for the
broad line sources through measurement of the broad H emission line, and
measured the [OIII] 5007\AA luminosity of this sample. Based on continuum fits
to the intrinsic absorption features, we have obtained clues about the stellar
populations of the host galaxies. We now present the highlights of our X-ray
and optical studies of this unique sample of local AGNs, including a comparison
of the 2--10 keV and 14--195 keV X-ray luminosities with the [OIII] 5007\AA
luminosity and the implications of our results towards measurements of
bolometric luminosities.Comment: 4 pages, 2 figures, to appear in proceedings for 'X-ray Astronomy
2009', Bologna 09/2009, AIP Conference Series, Eds. A. Comastri, M. Cappi, L.
Angelin
First case of HIV seroconversion with integrase resistance mutations on long-acting cabotegravir for prevention in routine care
BACKGROUND: Long-acting cabotegravir (CAB-LA) is highly effective for HIV prevention, but delayed HIV diagnoses and integrase strand transfer inhibitor (INSTI) resistance were observed in trials. We report the first case in routine clinical care of HIV infection on CAB-LA with INSTI resistance.
METHODS: The SeroPrEP study enrolls individuals in the United States who acquire HIV on pre-exposure prophylaxis modalities to assess diagnostics, antiretroviral (ARV) drug levels, resistance, and treatment outcomes. Resistance mutations in full-length HIV-1 integrase were identified by single-genome sequencing (SGS). Cabotegravir concentrations in plasma and hair segments were measured by liquid chromatography-tandem mass spectrometry.
RESULTS: A 23-year-old gender-nonbinary person, male at birth, restarted CAB-LA 6 months after discontinuation due to losing insurance. Prior to restart, HIV-1 RNA was not detected, but 20 days elapsed before CAB-LA injection. After the second CAB-LA injection, HIV antigen/antibody returned reactive (HIV-1 RNA 451 copies/mL). SGS of plasma HIV-1 RNA identified INSTI mutation Q148R in 2/24 sequences 2 days postdiagnosis; commercial genotype failed amplification. Cabotegravir hair concentration was 0.190 ng/mg 2 weeks prediagnosis; plasma cabotegravir was high (3.37 μg/mL; ∼20× PA-IC
CONCLUSIONS: In this first case of HIV infection on CAB-LA with INSTI resistance in routine care, cabotegravir resistance was detected only with a sensitive research assay. Accelerated pathways to minimize time between HIV testing and CAB-LA initiation are needed to optimize acute HIV detection and mitigate resistance risk. Sustained product access regardless of insurance is imperative to reduce HIV infections on CAB-LA
Design and Development of the Clementine Spacecraft Sensor Bench
The Clementine spacecraft was developed to demonstrate the performance of BMDO\u27s lightweight sensor suite. The suite consisted of five different sensors (Star Trackers, UV/Vis, HiRes, NIR, LWIR) and a UDAR (Laser Impulse Detection And Ranging) system. The worst-case sensor operating requirements for the Clementine mission were: interface temperature with -20 to 2° C, alignment to +/- 100µRad, and jitter kept below 40 Rad in 40msec. The average hear dissipation of the suite was over 100 Watts while operating for two of the five hour lunar orbit. To accomplish the mission the sensor suite was integrated onto a single-substrate sensor bench within the spacecraft. The bench met the stringent thermal, alignment, and jitter requirements of the sensors, and concurrently isolated the sensors from outside spacecraft contamination, as well as thermal and structural flexure. Also taken into account were the mission design drivers of hot thermal environment in lunar orbit, limited volume in the spacecraft, minimal weight, limited budget, and a six month schedule from concept to delivery of a flight bench. The design and development of the sensor bench will be discussed. Three different types of heat pipes were used to transport the heat of the sensors to radiators located on the side of the spacecraft. A beryllium metal block was used as a thermal capacitor during peak heat loads. Thermal straps connected sensors to heat pipes to keep thermal gradients as little as 3° C per inch across the interface. The bench was fastened in a quasi-kinematic fashion to eliminate the transfer of spacecraft structural loads and thermal flexing, and yet was rigid enough to keep alignment through launch. The bench substrate itself was made out of aluminum honeycomb. The alignment mechanism consisted of a nut-on-nut method to attain and keep the 100µRad requirement. Volume and alignment constraints dictated sensor location on the bench. Development of the bench involved rigorous testing to insure requirements were met. These tests involved development alignment checks, vibration testing at the sensor bench level, system level qual vibes and TDVT, system level jitter testing, as well as the flight system vibe, TV AC and functional. Lessons learned will be discussed
Detection of Explosives Using Heated Micro-Cantilever Sensors
The objective of this study is to demonstrate the ability to detect the presence of energetic materials by analyzing the bending response of an electrically heated micro-cantilever thermal bi-morph array. Heating the cantilevers that are made of materials with different coefficients of thermal expansion affects the bending and is measured using an optical device in real time. The detection scheme is based on the threshold value of current that results in a deviation (from the control value) of the actuation of the micro-cantilver. This threshold current is found to provide a unique signature to identify an equilibrium concentration of iso-propyl alcohol, acetone or gasoline vapors at room temperature. The threshold current is proportional with the vapor pressure of the volatile species and the ignition temperature. This shows sensors can be used for specific detection of different energetic material. The sensor array can be used to detect and identify volatile combustibles species in real time. Further, the sensor array can be multiplexed (i.e., detect multiple explosives simultaneously) and also allows redundancy checks so that false positive or false negative results can be eliminated. The sensor permits detection without coming in contact with the contaminated surface or source of the combustible material because it detects the vapors effused by the explosive materials. Thus it can be used at a nominal distance away from the source
Visual rehabilitation in combined surgical procedures: bridging two eye poles for better vision
Augenzentrum Nymphenburger Höfe and Augenklinik Herzog Carl Theodor, München, GermanyDepartment of Ophthalmology, University of Heidelberg, Heidelberg, GermanyDepartment of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of KoreaCleveland Clinic Foundation, Cole Eye Institute, Cleveland, OH, USADepartment of Ophthalmology, Universidade Federal de São Paulo, São Paulo, SP, BrazilDepartment of Ophthalmology, Tan Tock Seng Hospital, SingaporeDepartment of Ophthalmology, Universidade Federal de São Paulo, São Paulo, SP, BrazilWeb of Scienc
[O III] and X-ray Properties of a Complete Sample of Hard X-ray Selected AGNs in the Local Universe
We study the correlation between the [O III] and X-ray
luminosities of local Active Galactic Nuclei (AGNs), using a complete, hard
X-ray ( keV) selected sample in the Swift/BAT 9-month catalog. From our
optical spectroscopic observations at the South African Astronomical
Observatory and the literature, a catalog of [O III] line flux
for all 103 AGNs at Galactic latitudes of is complied.
Significant correlations with intrinsic X-ray luminosity () are
found both for observed () and extinction-corrected () luminosities, separately for X-ray unabsorbed and absorbed
AGNs. We obtain the regression form of and from the whole sample. The absorbed AGNs with low
(0.5\%) scattering fractions in soft X-rays show on average smaller and ratios than the
other absorbed AGNs, while those in edge-on host galaxies do not. These results
suggest that a significant fraction of this population are buried in tori with
small opening angles. By using these vs.
correlations, the X-ray luminosity function of local AGNs (including Compton
thick AGNs) in a standard population synthesis model gives much better
agreement with the [O III] luminosity function derived from the
Sloan Digital Sky Survey than previously reported. This confirms that hard
X-ray observations are a very powerful tool to find AGNs with high
completeness.Comment: 14 pages including 11 figures and 3 tables, accepted for publication
in ApJ. In this manuscript, the observed 14-195 keV luminosities in Table 1
have been corrected to be exactly the same as in the original Swift/BAT
9-month catalog. Accordingly, Figures 2(a) and 3(a) and a part of Tables 2
and 3 have been updated. The changes from the previous version are small and
do not affect the tex
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