1,050 research outputs found
Spectral Statistics and Luminosity Function of a Hard X-ray Complete Sample of Brightest AGNs
We investigated the statistics of the X-ray spectral properties of a complete
flux-limited sample of bright AGNs from HEAO-1 all-sky catalogs to provide the
bright end constraint of the evolution of AGN hard X-ray luminosity function
(HXLF) and the AGN population synthesis model of the X-ray background. Spectral
studies have been made using ASCA and XMM-Newton observation data for almost
all AGNs in this sample.Comment: PTPTex v0.88, 2 pages with 4 figures, Proceedings of the
"Stellar-Mass, Intermediate -Masss, and Supermassive Black Holes" in Kyoto,
Japa
Chandra survey in the AKARI North Ecliptic Pole Deep Field. I. X-ray data, point-like source catalog, sensitivity maps, and number counts
We present data products from the 300 ks Chandra survey in the AKARI North
Ecliptic Pole (NEP) deep field. This field has a unique set of 9-band infrared
photometry covering 2-24 micron from the AKARI Infrared Camera, including
mid-infrared (MIR) bands not covered by Spitzer. The survey is one of the
deepest ever achieved at ~15 micron, and is by far the widest among those with
similar depths in the MIR. This makes this field unique for the MIR-selection
of AGN at z~1. We design a source detection procedure, which performs joint
Maximum Likelihood PSF fits on all of our 15 mosaicked Chandra pointings
covering an area of 0.34 square degree. The procedure has been highly optimized
and tested by simulations. We provide a point source catalog with photometry
and Bayesian-based 90 per cent confidence upper limits in the 0.5-7, 0.5-2,
2-7, 2-4, and 4-7 keV bands. The catalog contains 457 X-ray sources and the
spurious fraction is estimated to be ~1.7 per cent. Sensitivity and 90 per cent
confidence upper flux limits maps in all bands are provided as well. We search
for optical MIR counterparts in the central 0.25 square degree, where deep
Subaru Suprime-Cam multiband images exist. Among the 377 X-ray sources detected
there, ~80 per cent have optical counterparts and ~60 per cent also have AKARI
mid-IR counterparts. We cross-match our X-ray sources with MIR-selected AGN
from Hanami et al. (2012). Around 30 per cent of all AGN that have MID-IR SEDs
purely explainable by AGN activity are strong Compton-thick AGN candidates.Comment: 23 pages, 20 figures; catalogs, sensitivity maps, and upper limit
flux maps are available from the VizieR Servic
Multiple Components of the Luminous Compact X-ray Source at the Edge of Holmberg II observed by ASCA and ROSAT
We report the results of the analysis of ASCA/ROSAT observations of the
compact luminous X-ray source found at the edge of the nearby star-forming
dwarf galaxy Holmberg II (UGC 4305).Our ASCA spectrum revealed that the X-ray
emission extends to the hard band and can be best described by a power-law with
a photon spectral index of 1.9. The ASCA spectrum does not fit with a
multi-color disk blackbody. The joint ASCA-ROSAT spectrum suggests two
components to the spectrum: the hard power-law component and a warm thermal
plasma kT~0.3[keV]. An additional absorption over that of our galaxy is
required. The wobble correction of the ROSAT HRI image has clearly unveiled the
existence of an extended component which amounts to 27+/-5% of the total X-ray
emission.
These observations indicate that there are more than one component in the
X-ray emission. The properties of the point-like component is indicative of an
accretion onto an intermediate mass blackhole, unless a beaming is taking
place. We argue that the extended component does not come from electron
scattering and/or reflection by scattered optically-thick clouds of the central
radiation. Possible explanations of this X-ray source include multiple
supernova remnants feeding an intermediate-mass blackhole. (abridged)Comment: 12 pages, 6 figures accepted to Astronomical Journa
Arthroscopic management of temporomandibular closed lock
The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included
<人文學報>否定表現の一考察
この小論は大別して二部にわけられる。一部は日本語における否定表現の性格に關する本質的な考察であり,二部はそれによつて解釋される具體的な現象の例示である。思ふに,日本語における否定は言語表現として定立しようとするところの或概念乃至は判斷の排除の意圖を話手があらはすといふことを本質とする。否定判斷は肯定判斷に對立する一つの判斷樣式といふよりは,むしろ積極的排除の意圖の表現として考へられる。從つて逆に否定によつて何らかの概念や判斷が明示されることはないといふことがわかるのである。これによつて,情意表現における否定の問題や,所謂二重否定の問題,又は否定的應答の問題などに對して,原理的な一つの解釋が可能なのではないかと思はれる。排除の意圖といふことがこれであり,或いは民族感情的なものの考へ方にもとづくかもしれない。いづれにせよこれは,日本語の表現論における體系的な位置づけを俟つべき一小論である
The Evolution in the Faint-End Slope of the Quasar Luminosity Function
(Abridged) Based on numerical simulations of galaxy mergers that incorporate
black hole (BH) growth, we predict the faint end slope of the quasar luminosity
function (QLF) and its evolution with redshift. Our simulations have yielded a
new model for quasar lifetimes where the lifetime depends on both the
instantaneous and peak quasar luminosities. This motivates a new interpretation
of the QLF in which the bright end consists of quasars radiating at nearly
their peak luminosities, but the faint end is mostly made up of quasars in less
luminous phases of evolution. The faint-end QLF slope is then determined by the
faint-end slope of the quasar lifetime for quasars with peak luminosities near
the observed break. We determine this slope from the quasar lifetime as a
function of peak luminosity, based on a large set of simulations spanning a
wide variety of host galaxy, merger, BH, and ISM gas properties. Brighter peak
luminosity (higher BH mass) systems undergo more violent evolution, and expel
and heat gas more rapidly in the final stages of quasar evolution, resulting in
a flatter faint-end slope (as these objects fall below the observed break in
the QLF more rapidly). Therefore, as the QLF break luminosity moves to higher
luminosities with increasing redshift, implying a larger typical quasar peak
luminosity, the faint-end QLF slope flattens. From the quasar lifetime as a
function of peak luminosity and this interpretation of the QLF, we predict the
faint-end QLF slope and its evolution with redshift in good agreement with
observations. Although BHs grow anti-hierarchically (with lower-mass BHs formed
primarily at lower redshifts), the observed change in slope and differential or
luminosity dependent density evolution in the QLF is completely determined by
the luminosity-dependent quasar lifetime and physics of quasar feedback.Comment: 13 pages, 4 figures, submitted to ApJ (Replacement with minor
revisions and changed sign convention
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