197 research outputs found
Construction of a [15]Annulenone-[15]annulenyl Ion Cycle
Previously, we have reported the synthesis of furanoid
[15]annulenones and their protonated species. With the benefits of
FT NMR spectroscopy, some of experiments have now been reinvestigated.
The annulenone may undergo dynamic conformational changes
to provide an interesting cycle, which can be driven by protonation-
deprotonation sequence
Construction of a [15]Annulenone-[15]annulenyl Ion Cycle
Previously, we have reported the synthesis of furanoid
[15]annulenones and their protonated species. With the benefits of
FT NMR spectroscopy, some of experiments have now been reinvestigated.
The annulenone may undergo dynamic conformational changes
to provide an interesting cycle, which can be driven by protonation-
deprotonation sequence
Septic Pulmonary Embolism Induced by Dental Infection
Dental infection can be an important source for septic pulmonary embolism (SPE), but only a few cases of SPE accompanying dental infection have been reported. The aim of this study was to characterize the clinical features of SPE induced by dental infection. Patients who fulfilled the diagnostic criteria described in the text were recruited in a retrospective fashion. All 9 patients were men, with a median age of 59 years (range:47 to 74 years). Eight patients had chest pain (88.9%), 5 had a preceding toothache (55.6%) and 3 had preceding gingival swelling (33.3%). Blood cultures obtained from 7 patients were negative. Periodontitis was found in all of the cases, periapical periodontitis in 5 cases, and gingival abscess in 3 cases. The median duration of hospitalization was 15 days, and symptoms were mild in some cases. In addition to antimicrobial therapy, tooth extraction was performed in 3 cases, tooth scaling in 6. SPE induced by dental infection has prominent clinical characteristics such as male preponderance, chest pain, preceding toothache, and mild clinical course
Characterization of sensitivity and responses of a 2-element prototype wavefront sensor for millimeter-wave adaptive optics attached to the Nobeyama 45 m telescope
We report the results of the performance characterization of a prototype
wavefront sensor for millimetric adaptive optics (MAO) installed on the
Nobeyama 45 m radio telescope. MAO is a key component to realize a future
large-aperture submillimeter telescope, such as Large Submillimeter Telescope
(LST) or Atacama Large Aperture Submillimeter Telescope (AtLAST). The
difficulty of MAO is, however, real-time sensing of wavefront deformation with
~10 um accuracy across the aperture. Our wavefront sensor operating at 20 GHz
measures the radio path length between a certain position of the primary mirror
surface to the focal point where a 20 GHz coherent receiver is placed. With the
2-element prototype, we sampled two positions on the primary mirror surface (at
radii of 5 m and 16 m) at a sampling rate of 10 Hz. Then an excess path length
(EPL) between the two positions was obtained by differentiating the two optical
paths. A power spectral density of the EPL shows three components: a
low-frequency drift (1/f^n), oscillations, and a white noise. A comparison of
EPL measurements under a variety of wind conditions suggests that the former
two are likely induced by the wind load on the telescope structure. The power
of the white noise corresponds to a 1sigma statistical error of 8 um in EPL
measurements. The 8 um r.m.s. is significant with respect to the mirror surface
accuracy required by the LST and AtLAST (~20-40 um r.m.s.), which demonstrates
that our technique is also useful for the future large-aperture submillimeter
telescopes.Comment: 10 pages, 9 figures. Published in SPIE Pro
Pair-density wave signature observed by x-ray scattering in La-based high- cuprates
Suggestive, but indirect evidence of the existence of pair-density wave (PDW)
order in several high- cuprates has been reported. As this
constitutes a new quantum phase of matter, it is important to {\it establish}
its existence at least somewhere in the phase diagram. However, a direct
correspondence between experiment and theory has remained elusive. Here, we
report the observation of a theoretically predicted PDW {\it bulk} signature in
two La-based cuprates, Sr-doped LaBaCuO and Fe-doped
LaSrCuO, through a comprehensive study that incorporates
zero-magnetic field x-ray scattering, neutron scattering, and transport
measurements. Specifically, we observe the emergence of so-called "1Q" order,
which is to say subharmonic order associated with the charge-density wave (CDW)
stripes, in a range of temperatures in which independent evidence suggests the
co-existence of PDW long-range order and fluctuating uniform superconducting
order. The subharmonic order is most pronounced around a half-integer
-vector, where the CDW diffraction peak is also strongest. This is
consistent with the theoretical proposal that the cancellation of the Josephson
coupling ("layer-decoupling"), is a signature of PDW order and that it is
commensurately locked to the density wave stripes that are known to alternate
orientation between adjacent layers. Even if the PDW is not the "mother of all
state", it is at least a close relative -- possibly a second cousin
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection
of the [O III] 88 m line and rest-frame 90 m dust continuum emission
in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier
Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a
spectroscopic redshift of , making this object one of
the furthest galaxies ever identified spectroscopically. The observed 850
m flux density of Jy corresponds to a de-lensed total
infrared (IR) luminosity of if assuming a dust temperature of K and an
emissivity index of , yielding a large dust mass of . The ultraviolet-to-far IR spectral energy distribution modeling
where the [O III] emissivity model is incorporated suggests the presence of a
young ( Myr), star-forming (SFR yr), moderately metal-polluted ()
stellar component with a mass of . An
analytic dust mass evolution model with a single episode of star-formation does
not reproduce the metallicity and dust mass in Myr,
suggesting a pre-existing evolved stellar component with and Gyr as the origin of the
dust mass.Comment: Accepted by ApJ. 18 pages, 10 figures, 5 table
Submillimeter ALMA Observations of the Dense Gas in the Low-Luminosity Type-1 Active Nucleus of NGC 1097
We present the first 100 pc scale view of the dense molecular gas in the
central ~ 1.3 kpc region of the type-1 Seyfert NGC 1097 traced by HCN (J=4-3)
and HCO+ (J=4-3) lines afforded with ALMA band 7. This galaxy shows significant
HCN enhancement with respect to HCO+ and CO in the low-J transitions, which
seems to be a common characteristic in AGN environments. Using the ALMA data,
we study the characteristics of the dense gas around this AGN and search for
the mechanism of HCN enhancement. We find a high HCN (J=4-3) to HCO+ (J=4-3)
line ratio in the nucleus. The upper limit of the brightness temperature ratio
of HCN (v2=1^{1f}, J=4-3) to HCN (J=4-3) is 0.08, which indicates that IR
pumping does not significantly affect the pure rotational population in this
nucleus. We also find a higher HCN (J=4-3) to CS (J=7-6) line ratio in NGC 1097
than in starburst galaxies, which is more than 12.7 on the brightness
temperature scale. Combined from similar observations from other galaxies, we
tentatively suggest that this ratio appears to be higher in AGN-host galaxies
than in pure starburst ones similar to the widely used HCN to HCO+ ratio. LTE
and non-LTE modeling of the observed HCN and HCO+ lines using J=4-3 and 1-0
data from ALMA, and J=3-2 data from SMA, reveals a high HCN to HCO+ abundance
ratio (5 < [HCN]/[HCO+] < 20: non-LTE analysis) in the nucleus, and that the
high-J lines (J=4-3 and 3-2) are emitted from dense (10^{4.5} < n_H2 [/cc] <
10^6), hot (70 < Tkin [K] < 550) regions. Finally we propose that the high
temperature chemistry is more plausible to explain the observed enhanced HCN
emission in NGC 1097 than the pure gas phase PDR/XDR chemistry.Comment: 28 pages, 17 figures, 10 tables. Accepted to PAS
Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) VIII. A less biased view of the early co-evolution of black holes and host galaxies
We present ALMA [CII] line and far-infrared (FIR) continuum observations of
three low-luminosity quasars () discovered by our
Subaru Hyper Suprime-Cam (HSC) survey. The [CII] line was detected in all three
targets with luminosities of , about one order
of magnitude smaller than optically luminous ()
quasars. The FIR continuum luminosities range from
(3 limit) to , indicating a wide range
in star formation rates in these galaxies. Most of the HSC quasars studied thus
far show [CII]/FIR luminosity ratios similar to local star-forming galaxies.
Using the [CII]-based dynamical mass () as a surrogate for bulge
stellar mass (), we find that a significant fraction of
low-luminosity quasars are located on or even below the local relation, particularly at the massive end of the galaxy mass
distribution. In contrast, previous studies of optically luminous quasars have
found that black holes are overmassive relative to the local relation. Given
the low luminosities of our targets, we are exploring the nature of the early
co-evolution of supermassive black holes and their hosts in a less biased way.
Almost all of the quasars presented in this work are growing their black hole
mass at much higher pace at than the parallel growth model, in which
supermassive black holes and their hosts grow simultaneously to match the local
relation at all redshifts. As the low-luminosity
quasars appear to realize the local co-evolutionary relation even at , they should have experienced vigorous starbursts prior to the currently
observed quasar phase to catch up with the relation.Comment: 19 pages, 11 figures, 4 tables. Accepted for publication in
Publications of the Astronomical Society of Japan (PASJ
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