Using a sample of about 123,000 stars with accurate 3D velocity measurements from the LAMOST-TGAS data, we confirm the kinematic signature of the Galactic warp recently found by Schönrich & Dehnen. ...The data reveal a clear trend of increasing mean vertical velocity as a function of absolute vertical angular momentum Lz and azimuthal velocity Vφ for guiding center radius Rg between 6.0 and 10.5 kpc. The trend is consistent with a large-scale Galactic warp. Similar to Schönrich & Dehnen, we also find a wave-like pattern of versus Lz with an amplitude of ∼0.9 km s−1 on a scale of ∼2.0 kpc, which could arise from bending waves or a winding warp. Finally, we confirm a prominent, localized peak in near Lz ∼ 2150 kpc km s−1 (corresponding to Rg ∼ 9 kpc and Vφ ∼ 255 km s−1). The additional line-of-sight velocity information from LAMOST reveals that stars in this feature have a large, inward radial velocity of VR ∼ −13.33 0.59 km s−1 and a small radial velocity dispersion of R ∼ 25.27 0.89 km s−1, suggesting that a stellar stream gives rise to this feature.
We have investigated the distributions of stellar azimuthal and radial velocity components VΦ and VR in the vertical position-velocity plane Z-VZ across the Galactic disk of 6.34 R 12.34 kpc and ...using a Gaia and Gaia-LAMOST sample of stars. As found in previous works, the distributions exhibit significant spiral patterns. The VR distributions also show clear quadrupole patterns, which are the consequence of the well-known tilt of the velocity ellipsoid. The observed spiral and quadrupole patterns in the phase space plane vary strongly with radial and azimuthal positions. The phase spirals of VΦ become more and more relaxed as R increases. The spiral patterns of VΦ and VR and the quadrupole patterns of VR are strongest at −2° < Φ < 2° but negligible at 4° < Φ < 6° and −6° < Φ < −4°. Our results suggest an external origin of the phase spirals. In this scenario, the intruder, most likely the previously well-known Sagittarius dwarf galaxy, passed through the Galactic plane in the direction toward either Galactic center or anti-center. The azimuthal variations of the phase spirals also help us constrain the passage duration of the intruder. A detailed model is required to reproduce the observed radial and azimuthal variations of the phase spirals of VΦ and VR.
We investigate the three-dimensional asymmetrical kinematics and present time stamps of the Milky Way disk between Galactocentric distances of R = 12 and 15 kpc, using red clump stars selected from ...the LAMOST Galactic survey, also with proper motion measurements provided by the Gaia DR2. We discover velocity substructure above the Galactic plane corresponding to a density dip found recently ("South-middle opposite" density structure R ∼ 12-15 kpc, Z ∼ 1.5 kpc discovered in Wang et al.) in the radial and azimuthal velocity. For the vertical velocity, we detect clear vertical bulk motions or bending mode motions, which has no clear North-South asymmetry corresponding to the in-plane asymmetrical features. In the subsample of stars with different ages, we find that there is little temporal evolution of the in-plane asymmetry from 0 to 14 Gyr, which means the structure is possibly sensitive to the perturbations in almost cosmic time. We propose that the possible scenario of this asymmetric velocity structure is caused by the mechanisms generated in-plane, rather than vertical perturbations.
Accurate determinations of atmospheric parameters (effective temperature Teff, surface gravity log g, and metallicity Fe/H) and distances for large complete samples are of vital importance for ...various Galactic studies. We have developed a photometric method to select red giant stars and estimate their atmospheric parameters from the photometric colors provided by SkyMapper Southern Survey (SMSS) data release (DR) 1.1, using stars in common with the LAMOST Galactic spectroscopic surveys as a training set. Distances are estimated with two different approaches: one based on the Gaia DR2 parallaxes for nearby (d ≤ 4.5 kpc) bright stars and another based on the absolute magnitudes predicted by intrinsic color (g − i)0 and photometric metallicity Fe/H for distant (d > 4.5 kpc) faint stars. Various tests show that our method is capable of delivering atmospheric parameters with a precision of ∼80 K for Teff, ∼ 0.18 dex for Fe/H, and ∼0.35 dex for log g but with a significant systematic error at log g ∼ 2.3. For distances delivered from (g − i)0 and photometric Fe/H, our test with the member stars of globular clusters show a median uncertainty of 16% with a negligible zero-point offset. Using this method, the atmospheric parameters and distances of nearly one million red giant stars are derived from SMSS DR1.1. Proper motion measurements from Gaia DR2 are available for almost all of the red giant stars, and radial velocity measurements from several large spectroscopic surveys are available for 44% of these. This sample will be accessible at https://yanghuang0.wixsite.com/yangh/research.
Photometric data from the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC) and the Sloan Digital Sky Survey (SDSS) are used to derive the global structure parameters ...of the smooth components of the Milky Way. The data, which cover nearly 11 000 deg2 sky area and the full range of Galactic latitude, allow us to construct a globally representative Galactic model. The number density distribution of Galactic halo stars is fitted with an oblate spheroid that decays by power law. The best fitting yields an axis ratio and a power-law index K = 0.65 and p = 2.79, respectively. The r-band differential star counts of three dwarf samples are then fitted with a Galactic model. The best-fitting model yielded by a Markov Chain Monte Carlo analysis has thin and thick disc scale heights and lengths of H1 = 322 pc and L1 = 2343 pc, H2 = 794 pc and L2 = 3638 pc, a local thick-to-thin disc density ratio of f2 = 11 per cent, and a local density ratio of the oblate halo to the thin disc of fh = 0.16 per cent. The measured star count distribution, which is in good agreement with the above model for most of the sky area, shows a number of statistically significant large-scale overdensities, including some of the previously known substructures, such as the Virgo overdensity and the so-called 'north near structure', and a new feature between 150 degree <l<240 degree and -1 degree <b<-5 degree , at an estimated distance between 1.0 and 1.5 kpc. The Galactic North-South asymmetry in the anticentre is even stronger than previously thought.
Summary
Allergic asthma is associated with excessive T helper type 2 (Th2) cells activation and airway hyperreactivity (AHR), implicated in the context of significant morbidity and mortality. Soluble ...ST2, a member of the interleukin (IL)‐1 receptor family, has been shown to play a critical role in modulation of inflammatory disorders, yet the function of soluble ST2 in allergic inflammation remains unclear. In this study, we examined the possibility of regulating ovalbumin (OVA)‐challenged airway inflammation by recombinant adenovirus‐mediated sST2‐Fc (Ad‐sST2‐Fc) gene transfer. Single intranasal administration of Ad‐sST2‐Fc before allergen challenge in OVA‐immunized mice profoundly reduced serum immunoglobulin (Ig)E secretion, eosinophil infiltration and concentrations of IL‐4, IL‐5 and IL‐13 in bronchoalveolar lavage fluid compared with administration of a control Ad vector. Histopathological examination of the lungs revealed that sST2‐Fc over‐expression markedly suppressed allergen‐induced peribronchial inflammation and disruption of the alveolar architecture. Moreover, the beneficial effect of sST2‐Fc in allergic lung inflammation is related to blocking the IL–33/ST2L signalling. Taken together, these results suggested that administration of Ad‐sST2‐Fc gene transfer may have therapeutic potential for the immunomodulatory treatment of OVA‐mediated allergic pulmonary diseases.
ABSTRACT In this paper, multiwavelength data are compiled for a sample of 1425 Fermi blazars to calculate their spectral energy distributions (SEDs). A parabolic function, is used for SED fitting. ...Synchrotron peak frequency ( ), spectral curvature (P1), peak flux ( ), and integrated flux ( ) are successfully obtained for 1392 blazars (461 flat-spectrum radio quasars FSRQs, 620 BL Lacs BLs, and 311 blazars of uncertain type BCUs; 999 sources have known redshifts). Monochromatic luminosity at radio 1.4 GHz, optical R band, X-ray at 1 keV and γ-ray at 1 GeV, peak luminosity, integrated luminosity, and effective spectral indices of radio to optical ( ) and optical to X-ray ( ) are calculated. The "Bayesian classification" is employed to log in the rest frame for 999 blazars with available redshift, and the results show that three components are enough to fit the log distribution; there is no ultra-high peaked subclass. Based on the three components, the subclasses of blazars using the acronyms of Abdo et al. are classified, and some mutual correlations are also studied. Conclusions are finally drawn as follows: (1) SEDs are successfully obtained for 1392 blazars. The fitted peak frequencies are compared with common sources from available samples. (2) Blazars are classified as low synchrotron peak sources if log , intermediate synchrotron peak sources if , and high synchrotron peak sources if . (3) Gamma-ray emissions are strongly correlated with radio emissions. Gamma-ray luminosity is also correlated with synchrotron peak luminosity and integrated luminosity. (4) There is an anticorrelation between peak frequency and peak luminosity within the whole blazar sample. However, there is a marginally positive correlation for high synchrotron peak BL Lacs (HBLs), and no correlations for FSRQs or low synchrotron peak BL Lacs (LBLs). (5) There are anticorrelations between the monochromatic luminosities (γ-ray and radio bands) and the peak frequency within the whole sample and BL Lacs. (6) The optical to X-ray ( ) and radio to optical ( ) spectral indices are strongly anticorrelated with peak frequency (log ) within the whole sample, but the correlations for subclasses of FSRQs, LBLs, and HBLs are different.
Summary
Dexmedetomidine might reduce delirium after cardiac surgery. We allocated 326 participants to an infusion of dexmedetomidine at a rate of 0.6 μg kg−1 for 10 min and then at 0.4 μg.kg−1.h−1 ...until the end of surgery; 326 control participants received comparable volumes of saline. We detected delirium in 98/652 (15%) participants during the first seven postoperative days: 47/326 after dexmedetomidine vs. 51/326 after placebo, p = 0.62, adjusted relative risk (95%CI) 0.86 (0.56–1.33), p = 0.51. Postoperative renal impairment (Kidney Disease Improving Global Outcomes stages 1, 2 and 3) was detected in 46, 9 and 2 participants after dexmedetomidine and 25, 7 and 4 control participants, p = 0.040. Intra‐operative dexmedetomidine infusion did not reduce the incidence of delirium after cardiac valve surgery but might impair renal function.
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