16 research outputs found
CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303
We present the results of CO(=1-0) and CO(=1-0)
simultaneous mappings toward the nearby barred spiral galaxy NGC 4303 as a part
of the CO Multi-line Imaging of Nearby Galaxies (COMING) project. Barred spiral
galaxies often show lower star-formation efficiency (SFE) in their bar region
compared to the spiral arms. In this paper, we examine the relation between the
SFEs and the volume densities of molecular gas in the eight
different regions within the galactic disk with CO data combined with archival
far-ultraviolet and 24 m data. We confirmed that SFE in the bar region is
lower by 39% than that in the spiral arms. Moreover, velocity-alignment
stacking analysis was performed for the spectra in the individual regions. The
integrated intensity ratios of CO to CO () range from
10 to 17 as the results of stacking. Fixing a kinetic temperature of molecular
gas, was derived from via non-local thermodynamic
equilibrium (non-LTE) analysis. The density in the bar is lower
by 31-37% than that in the arms and there is a rather tight positive
correlation between SFEs and , with a correlation coefficient of
. Furthermore, we found a dependence of on the velocity
dispersion of inter-molecular clouds (). Specifically,
increases as increases when km s. On the other hand, decreases as increases when km s. These relations
indicate that the variations of SFE could be caused by the volume densities of
molecular gas, and the volume densities could be governed by the dynamical
influence such as cloud-cloud collisions, shear and enhanced inner-cloud
turbulence.Comment: 15 pages, 8 figures, accepted for publication in PAS
KMT-2021-BLG-1150Lb: Microlensing planet detected through a densely covered planetary-caustic signal
Recently, there have been reports of various types of degeneracies in the
interpretation of planetary signals induced by planetary caustics. In this
work, we check whether such degeneracies persist in the case of well-covered
signals by analyzing the lensing event KMT-2021-BLG-1150, for which the light
curve exhibits a densely and continuously covered short-term anomaly. In order
to identify degenerate solutions, we thoroughly investigate the parameter space
by conducting dense grid searches for the lensing parameters. We then check the
severity of the degeneracy among the identified solutions. We identify a pair
of planetary solutions resulting from the well-known inner-outer degeneracy,
and find that interpreting the anomaly is not subject to any degeneracy other
than the inner-outer degeneracy. The measured parameters of the planet
separation (normalized to the Einstein radius) and mass ratio between the lens
components are for the inner
solution and for the outer
solution. According to a Bayesian estimation, the lens is a planetary system
consisting of a planet with a mass
and its host with a mass lying toward
the Galactic center at a distance ~kpc. By
conducting analyses using mock data sets prepared to mimic those obtained with
data gaps and under various observational cadences, it is found that gaps in
data can result in various degenerate solutions, while the observational
cadence does not pose a serious degeneracy problem as long as the anomaly
feature can be delineated.Comment: 9 pages, 8 figure
KMT-2022-BLG-0440Lb: A New Microlensing Planet with the Central-Resonant Caustic Degeneracy Broken
We present the observations and analysis of a high-magnification microlensing
planetary event, KMT-2022-BLG-0440, for which the weak and short-lived
planetary signal was covered by both the KMTNet survey and follow-up
observations. The binary-lens models with a central caustic provide the best
fits, with a planet/host mass ratio, -- at
. The binary-lens models with a resonant caustic and a brown-dwarf
mass ratio are both excluded by . The binary-source model
can fit the anomaly well but is rejected by the ``color argument'' on the
second source. From Bayesian analyses, it is estimated that the host star is
likely a K or M dwarf located in the Galactic disk, the planet probably has a
Neptune-mass, and the projected planet-host separation is
or au, subject to the close/wide degeneracy. This is the
third planet from a high-magnification planetary signal (). Together with another such planet, KMT-2021-BLG-0171Lb, the
ongoing follow-up program for the KMTNet high-magnification events has
demonstrated its ability in detecting high-magnification planetary signals for
planets, which are challenging for the current microlensing
surveys.Comment: MNRAS accepte
OGLE-2019-BLG-0825: Constraints on the Source System and Effect on Binary-lens Parameters arising from a Five Day Xallarap Effect in a Candidate Planetary Microlensing Event
We present an analysis of microlensing event OGLE-2019-BLG-0825. This event
was identified as a planetary candidate by preliminary modeling. We find that
significant residuals from the best-fit static binary-lens model exist and a
xallarap effect can fit the residuals very well and significantly improves
values. On the other hand, by including the xallarap effect in our
models, we find that binary-lens parameters like mass-ratio, , and
separation, , cannot be constrained well. However, we also find that the
parameters for the source system like the orbital period and semi major axis
are consistent between all the models we analyzed. We therefore constrain the
properties of the source system better than the properties of the lens system.
The source system comprises a G-type main-sequence star orbited by a brown
dwarf with a period of days. This analysis is the first to demonstrate
that the xallarap effect does affect binary-lens parameters in planetary
events. It would not be common for the presence or absence of the xallarap
effect to affect lens parameters in events with long orbital periods of the
source system or events with transits to caustics, but in other cases, such as
this event, the xallarap effect can affect binary-lens parameters.Comment: 19 pages, 7 figures, 6 tables. Accepted by A
An Artificial Metallolyase with Pliable 2-His-1-Carboxylate Facial Triad for Stereoselective Michael Addition
We repurposed the metal-binding site of a cupin superfamily protein into the 2-his-1-carboxylate facial triad, which is one of the common motifs in natural non-heme enzymes, to construct artificial metalloenzymes that can catalyze new-to-nature reactions. Cu2+-H52A/H58E variant catalyzed the stereoselective Michael addition reaction and was found to bear a flexible metal-binding site in the high-resolution crystal structure. Furthermore, the H52A/H58E/F104W mutant accommodated a water molecule, which was supported by Glu58 and Trp104 residues via hydrogen bonding, presumably leading to high stereoselectivity. Thus, the 2-his-1-carboxylate facial triad was confirmed to be a versatile and promising metal-binding motif for abiological and canonical biological reactions
DataSheet_1_Circulating plasmablasts and follicular helper T-cell subsets are associated with antibody-positive autoimmune epilepsy.docx
Autoimmune epilepsy (AE) is an inflammatory disease of the central nervous system with symptoms that have seizures that are refractory to antiepileptic drugs. Since the diagnosis of AE tends to rely on a limited number of anti-neuronal antibody tests, a more comprehensive analysis of the immune background could achieve better diagnostic accuracy. This study aimed to compare the characteristics of anti-neuronal antibody-positive autoimmune epilepsy (AE/Ab(+)) and antibody-negative suspected autoimmune epilepsy (AE/Ab(-)) groups. A total of 23 patients who met the diagnostic criteria for autoimmune encephalitis with seizures and 11 healthy controls (HC) were enrolled. All patients were comprehensively analyzed for anti-neuronal antibodies; 13 patients were identified in the AE/Ab(+) group and 10 in the AE/Ab(-) group. Differences in clinical characteristics, including laboratory and imaging findings, were evaluated between the groups. In addition, the immunophenotype of peripheral blood mononuclear cells (PBMCs) and CSF mononuclear cells, particularly B cells and circulating Tfh (cTfh) subsets, and multiplex assays of serum and CSF were analyzed using flow cytometry. Patients with AE/Ab(+) did not show any differences in clinical parameters compared to patients with AE/Ab(-). However, the frequency of plasmablasts within PBMCs and CSF in patients with AE/Ab(+) was higher than that in patients with AE/Ab(-) and HC, and the frequency of cTfh17 cells and inducible T-cell co-stimulator (ICOS) expressing cTfh17 cells within cTfh subsets was higher than that in patients with AE/Ab(-). Furthermore, the frequency of ICOShighcTfh17 cells was positively correlated with that of the unswitched memory B cells. We also found that IL-12, IL-23, IL-6, IL-17A, and IFN-γ levels were elevated in the serum and IL-17A and IL-6 levels were elevated in the CSF of patients with AE/Ab(+). Our findings indicate that patients with AE/Ab(+) showed increased differentiation of B cells and cTfh subsets associated with antibody production. The elevated frequency of plasmablasts and ICOS expressing cTfh17 shift in PBMCs may be indicative of the presence of antibodies in patients with AE.</p