ABSTRACT
We present results from high signal-to-noise optical spectropolarimetric observations of the Seyfert 1 galaxies NGC 3783 and Mrk 509 in the 3500–7000 Å range. We find complex structure in ...the polarized emission for both objects. In particular, Position Angle (PA) changes across the Balmer lines show a distinctive ‘M’-shaped profile that had not been observed in this detail before, but could represent a common trait in Seyfert 1 galaxies. In fact, while this shape is observed in all Balmer lines in NGC 3783, Mrk 509 transitions into a ‘M’-shaped PA profile for higher transitions lines. We have modelled the observed profiles using the STOKES radiative transfer code and assuming that the scattering region is co-spatial with the BLR and outflowing. The results give compelling new evidence for the presence of nuclear winds in these two Seyfert 1 galaxies.
Achievements of NEDO durability projects on SOFC mode are summarized with a focus on the physicochemical mechanisms characterized by diffusion properties of cell components and chemical reactions of ...cell components with gaseous impurities. Ni sintering and depletion including impurity (P, B, S) effects have been examined in terms of the surface/interface energies of Ni/oxide cermet anodes. The conductivity degradation due to the transformation of the cubic YSZ electrolyte was found to be characterized in terms of two time constants for the reductive and the oxidative regions to be determined by the Y‐diffusivity and its enhancement on NiO internal reduction in YSZ, while observed gaps in conductivity degradation behavior between stacks and button cells were ascribed to differences in those physicochemical properties involved, namely cation diffusion and kinetics associated with NiO internal reduction. The cathode performance degradation due to sulfur poisoning exhibits a variety of dependences on the microstructure (dense or porous) of doped‐ceria interlayers, the thickness of YSZ electrolyte and the humidity in the anode atmosphere, suggesting effects of protons in the cathode vicinity and the SrO activity changes during fabrication the LSCF/GDC/YSZ multilayers. Some defect chemical considerations were made on how such defects are affected by fabrication processes.
To determine the clinical profile of axial psoriatic arthritis (PsA) in a worldwide setting. Secondly, to identify factors associated with the development of axial involvement in patients with PsA.
...Data from 3684 patients with axial spondyloarthritis (axSpA) or PsA from the ASAS-perSpA study were analysed. The ASAS-perSpA is a cross-sectional study that recruited consecutive patients with SpA (as diagnosed by their rheumatologist) from 68 centers worldwide and collected patient and disease data. First, 2651 axSpA patients and 367 PsA patients with any history of axial involvement (axPsA) were compared using logistic regression to later identify predictive factors for rheumatologist diagnosis of axPsA. Secondly, 367 axPsA patients were compared with 666 PsA patients lacking axial involvement (peripheral PsA pPsA) and the characteristics associated with axial manifestations were explored by logistic regression analysis.
Patients with axPsA were older and less frequently males or HLA*B27 positive in comparison with axSpA patients. Additionally, while patients with axPsA had more peripheral manifestations and psoriasis, other extra-musculoskeletal manifestations (IBD and uveitis) were more frequent in those with axSpA. In the multivariable analysis, older age at diagnosis (OR = 1.04), peripheral arthritis (OR = 7.32) and dactylitis (OR = 2.82) were significantly associated with the diagnosis of axPsA. However, uveitis (OR = 0.22), IBD (OR = 0.12), HLA*B27 carriership (OR = 0.26) or sacroiliitis on imaging (OR = 0.5) were inversely associated with axPsA diagnosis as compared to axSpA. Axial involvement in patients with PsA was significantly associated with male gender (OR = 1.68), elevated CRP (OR = 2.87) and the absence of psoriasis (OR = 0.33).
In this worldwide setting axPsA was defined by rheumatologists as a unique phenotype, with disease features lying between axSpA and pure pPsA.
A diversity of dusty AGN tori Burtscher, L; Meisenheimer, K; Tristram, K R W ...
Astronomy and astrophysics (Berlin),
10/2013, Letnik:
558
Journal Article
Recenzirano
Odprti dostop
The AGN-heated dust distribution is increasingly recognized not only as the absorber required in unifying models, but as a tracer for the reservoir that feeds the nuclear super-massive black hole. ...Yet, even its most basic structural properties are unknown for all but a few archetypical objects. In order to understand how the properties of AGN tori are related to feeding and obscuration, we need to resolve the matter distribution on parsec scales. Since most AGNs are unresolved in the mid-IR, even with the largest telescopes, we utilize the MID-infrared interferometric Instrument (MIDI) at the Very Large Telescope Interferometer (VLTI) that is sensitive to structures as small as a few milli-arcseconds. Variations in the relative contribution of extended dust in the narrow line region or heated by star formation vs. compact AGN-heated dust and non-thermal emission also have to be taken into account.
To improve the electrochemical performance of anode‐supported solid oxide fuel cells (SOFCs), microextrusion printing and wet infiltration techniques are employed for structural modification on the ...meso‐ (10–100 µm) and nanoscale order, respectively. In the mesoscale structural modification, anode ridge structures are fabricated by extruding an anode slurry on the surface of a flat anode disk to extend the electrode–electrolyte interfacial area. In the nanoscale structural modification, gadolinium‐doped ceria (GDC) nanoparticles are introduced into a porous lanthanum strontium cobalt ferrite (LSCF) cathode. To investigate the effects of mesoscale and nanoscale structural modifications, four different types of anode‐supported SOFC including a conventional cell are prepared, and their performance is evaluated at several operating temperatures. It is found that both the mesoscale and nanoscale structural modifications reduce not only the polarization resistance but also the ohmic resistance in the cells, resulting in the improvement in cell performance. Moreover, it is clarified that the improvement in cell performance becomes greater with decreasing operating temperature. Specifically, the maximum power density in the cell where both mesoscale and nanoscale structural modifications are applied is increased by 66% at 600 °C and 34% at 700 °C, compared with that in the conventional cell.
We present new near-infrared VLTI/GRAVITY interferometric spectra that spatially resolve the broad Br
γ
emission line in the nucleus of the active galaxy IRAS 09149−6206. We use these data to measure ...the size of the broad line region (BLR) and estimate the mass of the central black hole. Using an improved phase calibration method that reduces the differential phase uncertainty to 0.05° per baseline across the spectrum, we detect a differential phase signal that reaches a maximum of ∼0.5° between the line and continuum. This represents an offset of ∼120
μ
as (0.14 pc) between the BLR and the centroid of the hot dust distribution traced by the 2.3
μ
m continuum. The offset is well within the dust sublimation region, which matches the measured ∼0.6 mas (0.7 pc) diameter of the continuum. A clear velocity gradient, almost perpendicular to the offset, is traced by the reconstructed photocentres of the spectral channels of the Br
γ
line. We infer the radius of the BLR to be ∼65
μ
as (0.075 pc), which is consistent with the radius–luminosity relation of nearby active galactic nuclei derived based on the time lag of the H
β
line from reverberation mapping campaigns. Our dynamical modelling indicates the black hole mass is ∼1 × 10
8
M
⊙
, which is a little below, but consistent with, the standard
M
BH
–
σ
*
relation.
Mapping the radial structure of AGN tori Kishimoto, M.; Hönig, S. F.; Antonucci, R. ...
Astronomy and astrophysics (Berlin),
12/2011, Letnik:
536
Journal Article
Recenzirano
Odprti dostop
We present mid-IR interferometric observations of six type 1 AGNs at multiple baseline lengths ranging from 27 m to 130 m, reaching high angular resolutions up to λ/B ~ 0.02 arcsec. For two of the ...targets, we have simultaneous near-IR interferometric measurements as well, taken within a week. We find that all the objects are partially resolved at long baselines in these IR wavelengths. The multiple-baseline data directly probe the radial distribution of the material on sub-pc scales. We show that for our sample, which is small but spans over ~2.5 orders of magnitudes in the UV/optical luminosity L of the central engine, the radial distribution clearly and systematically changes with luminosity. The brightness distribution at a given mid-IR wavelength seems to be rather well described by a power law, which makes a simple Gaussian or ring size estimation quite inadequate. In this case, a half-light radius R1/2 can be used as a representative size. We show that the higher luminosity objects become more compact in normalized half-light radii R1/2/Rin in the mid-IR, where Rin is the dust sublimation radius empirically given by the L1/2 fit of the near-IR reverberation radii. This means that, contrary to previous studies, the physical mid-IR emission size (e.g. in pc) is not proportional to L1/2, but increases with L much more slowly. With our current datasets, we find that R1/2 ∝ L0.21 ± 0.05 at 8.5 μm, and R1/2 nearly constant at 13 μm. The derived size information also seems to correlate with the properties of the total flux spectrum, in particular the smaller R1/2/Rin objects having bluer mid-IR spectral shape. We use a power-law temperature/density gradient model as a reference, and infer that the radial surface density distribution of the heated dust grains at a radius r changes from a steep ~r-1 structure in high luminosity objects to a shallower ~r0 structure in those of lower luminosity. The inward dust temperature distribution does not seem to smoothly reach the sublimation temperature – on the innermost scale of ~Rin, a relatively low temperature core seems to co-exist with a slightly distinct brightness concentration emitting roughly at the sublimation temperature.
We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with the GRAVITY instrument on the European Southern Observatory Very Large Telescope Interferometer. The ...extensive baseline coverage from 5 to 60
M
λ
allowed us to reconstruct a continuum image of the nucleus with an unrivaled 0.2 pc resolution in the
K
-band. We find a thin ring-like structure of emission with a radius
r
= 0.24 ± 0.03 pc, inclination
i
= 70 ± 5°, position angle PA = −50 ± 4°, and
h
/
r
< 0.14, which we associate with the dust sublimation region. The observed morphology is inconsistent with the expected signatures of a geometrically and optically thick torus. Instead, the infrared emission shows a striking resemblance to the 22 GHz maser disc, which suggests they share a common region of origin. The near-infrared spectral energy distribution indicates a bolometric luminosity of (0.4–4.7) × 10
45
erg s
−1
, behind a large
A
K
≈ 5.5 (
A
V
≈ 90) screen of extinction that also appears to contribute significantly to obscuring the broad line region.
We use VLTI/GRAVITY near-infrared interferometry measurements of eight bright type 1 AGN to study the size and structure of hot dust that is heated by the central engine. We partially resolve each ...source, and report Gaussian full width at half-maximum sizes in the range 0.3−0.8 mas. In all but one object, we find no evidence for significant elongation or asymmetry (closure phases ≲1°). The narrow range of measured angular sizes is expected given the similar optical flux of our targets, and implies an increasing effective physical radius with bolometric luminosity, as found from previous reverberation and interferometry measurements. The measured sizes for Seyfert galaxies are systematically larger than for the two quasars in our sample when measured relative to the previously reported
R
∼
L
1/2
relationship, which is explained by emission at the sublimation radius. This could be evidence of an evolving near-infrared emission region structure as a function of central luminosity.
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