886 research outputs found
Near- to mid-infrared spectroscopy of the heavily obscured AGN LEDA 1712304 with AKARI/IRC
Context. Although heavily obscured active galactic nuclei (AGNs) have been
found by many observational studies, the properties of the surrounding dust are
poorly understood. Using AKARI/IRC spectroscopy, we discover a new sample of a
heavily obscured AGN in LEDA 1712304 which shows a deep spectral absorption
feature due to silicate dust. Aims. We study the infrared (IR) spectral
properties of circumnuclear silicate dust in LEDA 1712304. Methods. We perform
IR spectral fitting, considering silicate dust properties such as composition,
porosity, size and crystallinity. Spectral energy distribution (SED) fitting is
also performed to the flux densities in the UV to sub-millimeter range to
investigate the global spectral properties. Results. The best-fit model
indicates 0.1 m-sized porous amorphous olivine (; ) with crystalline pyroxene. The optical
depth is , while the total IR luminosity and stellar
mass are estimated to be and
, respectively. In such low
and ranges, there are few galaxies which show that
large . Conclusions. The silicate dust in the AGN torus of
LEDA 1712304 has properties notably similar to those in other AGNs as a whole,
but slightly different in the wing shape of the absorption profile. The
porosity of the silicate dust suggests dust coagulation or processing in the
circumnuclear environments, while the crystallinity suggests that the silicate
dust is relatively fresh.Comment: 9 pages, 6 figures, accepted for publication in A&
Genes, Neurons, and Circuits Underlying the Reproductive Behavior in Drosophila (Advanced Studies on Sustainable Animal Production: Interrelationships among Human, Animal and Environment, 8th International Symposium of Integrated Field Science)
Oral Sessio
AKARI Detections of Hot Dust in Luminous Infrared Galaxies
We present a new sample of active galactic nuclei (AGNs) identified using the
catalog of the AKARI Mid-infrared(MIR) All-Sky Survey. Our MIR search has an
advantage in detecting AGNs that are obscured at optical wavelengths due to
extinction. We first selected AKARI 9micron excess sources with
F(9micron)/F(K_S)>2 where K_S magnitudes were taken from the Two Micron All Sky
Survey. We then obtained follow-up near-infrared spectroscopy with the
AKARI/IRC, to confirm that the excess is caused by hot dust. We also obtained
optical spectroscopy with the Kast Double Spectrograph on the Shane 3-m
telescope at Lick Observatory. On the basis of on these observations, we
detected hot dust with a characteristic temperature of ~500K in two luminous
infrared galaxies. The hot dust is suspected to be associated with AGNs that
exhibit their nonstellar activity not in the optical, but in the near- and
mid-infrared bands, i.e., they harbor buried AGNs. The host galaxy stellar
masses of 4-6 x 10^9 M_sun are small compared with the hosts in
optically-selected AGN populations. These objects were missed by previous
surveys, demonstrating the power of the AKARI MIR All-Sky Survey to widen AGN
searches to include more heavily obscured objects. The existence of multiple
dusty star clusters with massive stars cannot be completely ruled out with our
current data.Comment: 15 pages, 4 figures, to be published in Astronomy & Astrophysic
A study of the selective hydroconversion of biocarboxylic acids to bioalcohols over novel indium-nickel/zeolite catalysts using octanoic acid as model reactant
Octanoic acid (OA) was hydrotreated in a flow-through reactor at 21 bar total pressure and 240-340 °C over supported metal catalysts prepared from Ni-zeolites (A, X, P) by indium modification. The Ni-zeolites were activated first in H2 flow at 21 bar and 450 °C. While a fraction of the nickel got fully reduced, the zeolite structure became partially destructed. However, some nickel cations remained unreduced, therefore a large fraction of the crystalline zeolite structure was retained. The indium modification of the reduced Ni-zeolites generated bimetallic NiIn/Ni,H-zeolite catalysts having higher stability, hydroconversion activity, octanol selectivity, and lower hydrodecarbonylation activity than the parent partially destructed Ni-zeolite and the Adkins-type catalysts, commercially applied for the conversion of fatty acids to alcohols. © 2013 Akadémiai Kiadó, Budapest, Hungary
Electromagnetic field in matter. Surface enhanced Raman scattering
The polarization and magnetization degrees of freedom are included in the general treatment of the electromagnetic field in matter, and their governing equations are given. Particular cases of solutions are discussed for polarizable, non-magnetic matter, including quasi-static fields, surface plasmons, propagation, zero-point fluctuations of the eigenmodes, especially for a semi-infinite homogeneous body (half-space). The van der Waals London-Casimir force acting between a neutral nano-particle and a half-space is computed and the response of this electromagnetically coupled system to an external field is given, with relevance for the surface enhanced Raman scattering
Freely decaying weak turbulence for sea surface gravity waves
We study numerically the generation of power laws in the framework of weak
turbulence theory for surface gravity waves in deep water. Starting from a
random wave field, we let the system evolve numerically according to the
nonlinear Euler equations for gravity waves in infinitely deep water. In
agreement with the theory of Zakharov and Filonenko, we find the formation of a
power spectrum characterized by a power law of the form of .Comment: 4 pages, 3 figure
Komposisi Kimia dan Kualitas Fisik Daging Ayam Broiler Dimarinasi dengan Pasta Lengkuas pada Lama Penyimpanan Berbeda
The aim of this study is to know the chemical composition and physical qualities breast meat broiler which is marinated in 20% galangal juice. The method used completely randomized design with stroge period, Treatments O hour (To), 3 hours (T1), 6 hours (T2), and 8 hours (T3) and four replications. Each treatment used breast meat broiler (BMB) 100 grams. Variables included chemical composition (moisture and crude protein %) and physical quality (cooking loss). The data analysis used analysis of Variance (ANOVA) and Tukey’s test The results that stroge period 9 hours (T3) has significant effect of cooking loss percentage but does not have significant effect of moisture content and crude protein content. The conclusion that storage period longer can increase cooking loss percentage and cannot change Chemical composition breast meat broiler marinated with galangal juice
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