78 research outputs found

    Molecular Clouds in the Galactic Plane from ll = [59.75∘^\circ, 74.75∘^\circ] and bb = [βˆ’-5.25∘^\circ, +5.25∘^\circ]

    Full text link
    In this paper we present the distribution of molecular gas in the Milky Way Galactic plane from ll = [59.75, 74.75]∘^{\circ} and bb = [βˆ’{-}5.25, +5.25]∘^{\circ}, using the MWISP 12^{12}CO/13^{13}CO/C18O\rm {C}^{18}{O} emission line data. The molecular gas in this region can be mainly attributed to the Local spur, Local arm, Perseus arm, and Outer arm. Statistics of the physical properties of the molecular gas in each arm, such as excitation temperature, optical depth, and column density, are presented. Using the DBSCAN algorithm, we identified 15 extremely distant molecular clouds with kinematic distances of 14.72βˆ’-17.77 kpc and masses of 363βˆ’-520 MβŠ™_{\odot}, which we find could be part of the Outer Scutum-Centaurus (OSC) arm identified by \cite{2011ApJ...734L..24D} and \cite{2015ApJ...798L..27S}. It is also possible that, 12 of these 15 extremely distant molecular clouds constitute an independent structure between the Outer and the OSC arms or a spur. There exist two Gaussian components in the vertical distribution of the molecular gas in the Perseus spiral arm. These two Gaussian components correspond to two giant filaments parallel to the Galactic plane. We find an upward warping of the molecular gas in the Outer spiral arm with a displacement of around 270 pc with respect to the Galactic mid-plane.Comment: 33 pages, 19 figure

    The molecular clouds in a section of the third Galactic quadrant: observational properties and chemical abundance ratio between CO and its isotopologues

    Full text link
    We compare the observational properties between 12^{12}CO, 13^{13}CO, and C18^{18}O and summarize the observational parameters based on 7069 clouds sample from the Milky Way Imaging Scroll Painting (MWISP) CO survey in a section of the third Galactic quadrant. We find that the 13^{13}CO angular area (A13COA_{\rm ^{13}CO}) generally increases with that of 12^{12}CO (A12COA_{\rm ^{12}CO}), and the ratio of A13COA_{\rm ^{13}CO} to A12COA_{\rm ^{12}CO} is 0.38 by linear fitting. We find that the 12^{12}CO and 13^{13}CO flux are tightly correlated as F13COΒ =Β 0.17Β F12COF_{\rm ^{13}CO}~=~0.17~ F_{\rm ^{12}CO} with both fluxes calculated within the 13^{13}CO-bright region. This indicates that the abundance X13COX_{\rm ^{13}CO} is a constant to be 6.5βˆ’0.5+0.1^{+0.1}_{-0.5} Γ—10βˆ’7\times 10^{-7} for all samples under assumption of local thermodynamic equilibrium (LTE). Additionally, we observed that the X-factor is approximately constant in large sample molecular clouds. Similarly, we find FC18OΒ =Β 0.11Β F13COF_{\rm C^{18}O}~=~0.11~F_{\rm ^{13}CO} with both fluxes calculated within C18^{18}O-bright region, which indicates that the abundance ratios X13CO/XC18O{X_{\rm ^{13}CO}/X_{\rm C^{18}O}} stays the same value 9.7βˆ’0.8+0.6^{+0.6}_{-0.8} across the molecular clouds under LTE assumption. The linear relationships of F12COF_{\rm ^{12}CO} vs. F13COF_{\rm ^{13}CO} and F13COF_{\rm ^{13}CO} vs. FC18OF_{\rm C^{18}O} hold not only for the 13^{13}CO-bright region or C18^{18}O-bright region, but also for the entire molecular cloud scale with lower flux ratio. The abundance ratio X13CO/XC18O{X_{\rm ^{13}CO}/X_{\rm C^{18}O}} inside clouds shows a strong correlation with column density and temperature. This indicates that the X13CO/XC18O{X_{\rm ^{13}CO}/X_{\rm C^{18}O}} is dominated by a combination of chemical fractionation, selectively dissociation, and self-shielding effect inside clouds.Comment: 11 pages, 16 figures, 1 table, accepted by A

    A Systematic Study of Associations between Supernova Remnants and Molecular Clouds

    Full text link
    We universally search for evidence of kinematic and spatial correlation of supernova remnant (SNR) and molecular cloud (MC) associations for nearly all SNRs in the coverage of the MWISP CO survey, i.e. 149 SNRs, 170 SNR candidates, and 18 pure pulsar wind nebulae (PWNe) in 1 deg < l < 230 deg and -5.5 deg < b < 5.5 deg. Based on high-quality and unbiased 12CO/13CO/C18O (J = 1--0) survey data, we apply automatic algorithms to identify broad lines and spatial correlations for molecular gas in each SNR region. The 91% of SNR-MC associations detected previously are identified in this paper by CO line emission. Overall, there could be as high as 80% of SNRs associated with MCs. The proportion of SNRs associated with MCs is high within the Galactic longitude less than ~50 deg. Kinematic distances of all SNRs that are associated with MCs are estimated based on systemic velocities of associated MCs. The radius of SNRs associated with MCs follows a lognormal distribution, which peaks at ~8.1 pc. The progenitor initial mass of these SNRs follows a power-law distribution with an index of ~-2.3 that is consistent with the Salpeter index of -2.35. We find that SNR-MC associations are mainly distributed in a thin disk along the Galactic plane, while a small amount distributed in a thick disk. With the height of these SNRs from the Galactic plane below ~45 pc, the distribution of the average radius relative to the height of them is roughly flat, and the average radius increases with the height when above ~45 pc.Comment: 77 pages, 20 figures, 4 tables (with machine-readable versions), accepted for publication in ApJ

    Frisson Waves: Exploring Automatic Detection, Triggering and Sharing of Aesthetic Chills in Music Performances

    Get PDF
    Frisson is the feeling and experience of physical reactions such as shivers, tingling skin, and goosebumps. Using entrainment through facilitating interpersonal transmissions of embodied sensations, we present "Frisson Waves" with the aim to enhance live music performance experiences. "Frisson Waves" is an exploratory real-time system to detect, trigger and share frisson in a wave-like pattern over audience members during music performances. The system consists of a physiological sensing wristband for detecting frisson and a thermo-haptic neckband for inducing frisson. In a controlled environment, we evaluate detection (n=19) and triggering of frisson (n=15). Based on our findings, we conducted an in-the-wild music concert with 48 audience members using our system to share frisson. This paper summarizes a framework for accessing, triggering and sharing frisson. We report our research insights, lessons learned, and limitations of "Frisson Waves". Yan He, George Chernyshov, Jiawen Han, Dingding Zheng, Ragnar Thomsen, Danny Hynds, Muyu Liu, Yuehui Yang, Yulan Ju, Yun Suen Pai, Kouta Minamizawa, Kai Kunze, and Jamie A War

    Eightfold Fermionic Excitation in a Charge Density Wave Compound

    Full text link
    Unconventional quasiparticle excitations in condensed matter systems have become one of the most important research frontiers. Beyond two- and fourfold degenerate Weyl and Dirac fermions, three-, six- and eightfold symmetry protected degeneracies have been predicted however remain challenging to realize in solid state materials. Here, charge density wave compound TaTe4 is proposed to hold eightfold fermionic excitation and Dirac point in energy bands. High quality TaTe4 single crystals are prepared, where the charge density wave is revealed by directly imaging the atomic structure and a pseudogap of about 45 meV on the surface. Shubnikov de-Haas oscillations of TaTe4 are consistent with band structure calculation. Scanning tunneling microscopy reveals atomic step edge states on the surface of TaTe4. This work uncovers that charge density wave is able to induce new topological phases and sheds new light on the novel excitations in condensed matter materials.Comment: Accepted by PRB: https://journals.aps.org/prb/accepted/7907cK4eW0b1ee0b93fd67c1b42942bbb08eafc3

    Isolation and functional characterization of a Medicago sativa L. gene, MsLEA3-1

    Get PDF
    A full-length cDNA of 1,728Β nt, called MsLEA3-1, was cloned from alfalfa by rapid amplification of cDNA ends from an expressed sequence tag homologous to soybean pGmPM10 (accession No. AAA91965.1). MsLEA3-1, encodes a deduced protein of 436 amino acids, a calculated molecular weight of 47.0Β kDa, a theoretical isoelectric point of 5.18, and closest homology with late embryogenesis abundant proteins in soybean. Sequence homology suggested a signal peptide in the N terminus, and subcellular localization with GFP revealed that MsLEA3-1 was localized preferentially to the nucleolus. The transcript titre of MsLEA3-1 was strongly enriched in leaves compared with roots and stems of mature alfalfa plants. Gene expression of MsLEA3-1 was strongly induced when seedlings were treated with NaCl and ABA. Expression of the MsLEA3-1 transgenic was detected in transgenic tobacco. Malondialdehyde content and, electrical conductivity content were reduced and electrical conductivity and proline content were increased in transgenic tobacco compared with non-transgenic tobacco under salt stress. The results showed that accumulation of the MsLEA3-1 protein in the vegetative tissues of transgenic plants enhanced their tolerance to salt stress. These results demonstrate a role for the MsLEA3-1 protein in stress protection and suggest the potential of the MsLEA3-1 gene for genetic engineering of salt tolerance
    • …
    corecore