216 research outputs found
Efficient Algorithms for Finding Maximum and Maximal Cliques: Effective Tools for Bioinformatics
Characteristics of Kiso Ultra-Violet Excess Galaxies
We examined the general characteristics of the Kiso Ultra-violet Excess
Galaxies (KUGs). We present for the first time the quantitative expressions for
the criteria of the KUGs; the boundary color separating the KUGs from the
non-KUGs is (B-V)_{T} = 0.74 and the KUG degrees of UV strength are found to
correlate with the mean (B-V)_{T} colors. We investigate the nature of the
KUGs, a sample of blue galaxy population, and show that (1) about a half of the
KUGs are spiral galaxies with Sb to Scd, (2) the KUGs are biased to late-type
galaxies and include early-type galaxies with young star populations, and (3)
the KUGs are preferably found among less luminous galaxies with log L(B) < 10.
The KUGs also contain the post-starburst galaxies, many of which are found
among the blue galaxy population at intermediate redshifts. The analysis of the
far-infrared data shows that a typical present-to-past star formation rate for
a KUG is 0.4.Comment: Revised version of astro-ph/9706088, accepted manuscript for AJ;
uuencoded gzip'ed tar'ed file containing 25 files; a manuscript (aasms4), 7
tables (aj_pt4), 17 PS figures; To be appeared in The Astronomical Journal,
Vol. 114, No. 5 (1997 November issue
Calibration of AGN Reverberation Distance Measurements
In Yoshii et al. (2014), we described a new method for measuring
extragalactic distances based on dust reverberation in active galactic nuclei
(AGNs), and we validated our new method with Cepheid variable stars. In this
paper, we validate our new method with Type Ia supernovae (SNe Ia) which
occurred in two of the AGN host galaxies during our AGN monitoring program: SN
2004bd in NGC 3786 and SN 2008ec in NGC 7469. Their multicolor light curves
were observed and analyzed using two widely accepted methods for measuring SN
distances, and the distance moduli derived are for SN
2004bd and for SN 2008ec. These results are used to obtain
independently the distance measurement calibration factor, . The value
obtained from the SN Ia discussed in this paper is
which matches, within the range of 1 uncertainty, , previously calculated ab initio in Yoshii et al. (2014). Having
validated our new method for measuring extragalactic distances, we use our new
method to calibrate reverberation distances derived from variations of H
emission in the AGN broad line region (BLR), extending the Hubble diagram to
where distinguishing between cosmologies is becoming possible.Comment: Astrophysical Journal Letters accepte
Variation of Inner Radius of Dust Torus in NGC4151
The long-term optical and near infrared monitoring observations for a type 1
act ive galactic nucleus NGC 4151 were carried out for six years from 2001 to
2006 b y using the MAGNUM telescope, and delayed response of flux variations in
the band to those in the band was clearly
detected. Based on cross correlation analysis, we precisely measured a lag time
for eight separate periods, and we found that is not
constant changing be tween 30 and 70 days during the monitoring period. Since
is the ligh t travel time from the central energy source out to the
surrounding dust torus, this is the first convincing evidence that the inner
radius of dust torus did ch ange in an individual AGN. In order to relate such
a change of with a change of AGN luminosity , we presented a
method of taking an average of th e observed -band fluxes that corresponds
to the measured value of , and we found that the time-changing track
of NGC 4151 in the versus diagram during the monitoring period
deviates from the relation of expected from dust
reverberation. This result, combined with t he elapsed time from period to
period for which was measured, indicat es that the timescale of dust
formation is about one year, which should be taken into account as a new
constraint in future studies of dust evolution in AGNs.Comment: 5 pages, 3 figures, To appear in the ApJ Lette
The Infrared Cloud Monitor for the MAGNUM Robotic Telescope at Haleakala
We present the most successful infrared cloud monitor for a robotic
telescope. This system was originally developed for the MAGNUM 2-m telescope,
which has been achieving unmanned and automated monitoring observation of
active galactic nuclei at Haleakala on the Hawaiian island of Maui since 2001.
Using a thermal imager and two aspherical mirrors, it at once sees almost the
whole sky at a wavelength of . Its outdoor part is
weather-proof and is totally maintenance-free. The images obtained every one or
two minutes are analysed immediately into several ranks of weather condition,
from which our automated observing system not only decides to open or close the
dome, but also selects what types of observations should be done. The whole-sky
data accumulated over four years show that 5060 % of all nights are
photometric, and about 75 % are observable with respect to cloud condition at
Haleakala. Many copies of this system are now used all over the world such as
Mauna Kea in Hawaii, Atacama in Chile, and Okayama and Kiso in Japan.Comment: 18 pages, 15 figures, 7 tables, accepted for publication in PAS
The Optical/Near-Infrared Light Curves of SN 2002ap for the First 1.5 Years after Discovery
Late-time BVRIJHK photometry of the peculiar Type Ic SN 2002ap, taken between
2002 June 12 and 2003 August 29 with the MAGNUM telescope, is presented. The
light curve decline rate is derived in each band and the color evolution is
studied through comparison with nebular spectra and with SN 1998bw. Using the
photometry, the OIR bolometric light curve is built, extending from before
light maximum to day 580 after explosion. The light curve has a late-time shape
strikingly similar to that of the hypernova SN 1998bw. The decline rate changes
from 0.018 mag/day between day 130 and 230 to 0.014 mag/day between day 270 and
580. To reproduce the late-time light curve, a dense core must be added to the
1-D hypernova model that best fits the early-time observations, bringing the
ejecta mass from 2.5 Msun to 3 Msun without much change in the kinetic energy,
which is 4 times 10^51 ergs. This is similar to the case of other hypernovae
and suggests asymmetry. A large H-band bump developed in the spectral energy
distribution after about day 300, probably caused by strong [Si I] 1.646 micron
and 1.608 micron emissions. The near-infrared flux contribution increased
simultaneously from 50% at day 580. The near-infrared light curves
were compared with those of other Type Ib/c supernovae, among which SN 1983I
seems similar to SN 2002ap both in the near-infrared and in the optical.Comment: 24pages, 9 figures, ApJ in press (10 June 2006, v644 1 issue).
Acknowledgements update
Surgery for Congenital Duodenal Atresia
Congenital duodenal atresia consists of extrinsic duodenal obstruction of annular pancreas and intrinsic obstruction of intestinal atresia. The aim of this study is to clarify clinical patterns of congenital duodenal atresia on the basis of surgical experiece and discuss major problems with respect to surgical treatment
Effect of Keishibukuryogan, a Japanese Traditional Kampo Prescription, on Improvement of Microcirculation and Oketsu and Induction of Endothelial Nitric Oxide: A Live Imaging Study
Oketsu is a characteristic condition that plays an important role in Kampo, Japanese traditional medicine, and includes multiple aspects of hemodynamic disorders. This study aims to clarify the microcirculation of Oketsu and the pharmacological effect of Keishibukuryogan, an anti-Oketsu Kampo prescription, using live imaging techniques. Oral administration of Keishibukuryogan induced significant vasodilation of murine subcutaneous arterioles compared to the preadministration level. This vasodilatation peaked 60 min after administration and persisted for 90 min. The blood velocity in the subcutaneous capillary was also increased by Keishibukuryogan in generally the same manner. In rat mesenteric arterioles, Keishibukuryogan administration improved microhemodynamic parameters, including the resolution of erythrocyte congestion and the cell-free layer, which are representative of Oketsu pathology. Live imaging revealed an increase of diaminofluorescein-2 diacetate fluorescence, a nitric oxide (NO) specific reagent, in the arterial endothelium following Keishibukuryogan administration. This fluorescence was most remarkable at vascular bifurcations but was present throughout the mesenteric arterioles. This study demonstrates the successful imaging of Oketsu pathology with respect to microcirculation and the anti-Oketsu effects of Keishibukuryogan, namely, vasodilation of arterioles, increased blood velocity, and resolution of erythrocyte congestion. The anti-Oketsu effect of Keishibukuryogan is related to endothelial NO production
First Detection of Near-Infrared Intraday Variations in the Seyfert 1 Nucleus NGC4395
We carried out a one-night optical V and near-infrared JHK monitoring
observation of the least luminous Seyfert 1 galaxy, NGC4395, on 2004 May 1, and
detected for the first time the intraday flux variations in the J and H bands,
while such variation was not clearly seen for the K band. The detected J and H
variations are synchronized with the flux variation in the V band, which
indicates that the intraday-variable component of near-infrared continuum
emission of the NGC4395 nucleus is an extension of power-law continuum emission
to the near-infrared and originates in an outer region of the central accretion
disk. On the other hand, from our regular program of long-term optical BVI and
near-infrared JHK monitoring observation of NGC4395 from 2004 February 12 until
2005 January 22, we found large flux variations in all the bands on time scales
of days to months. The optical BVI variations are almost synchronized with each
other, but not completely with the near-infrared JHK variations. The color
temperature of the near-infrared variable component is estimated to be
T=1320-1710 K, in agreement with thermal emission from hot dust tori in active
galactic nuclei (AGNs). We therefore conclude that the near-infrared variation
consists of two components having different time scales, so that a small K-flux
variation on a time scale of a few hours would possibly be veiled by large
variation of thermal dust emission on a time scale of days.Comment: 4 pages including figures, accepted for publication in ApJ
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