87 research outputs found

    On the Cohomological Derivation of Yang-Mills Theory in the Antifield Formalism

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    We present a brief review of the cohomological solutions of self-coupling interactions of the fields in the free Yang-Mills theory. All consistent interactions among the fields have been obtained using the antifield formalism through several order BRST deformations of the master equation. It is found that the coupling deformations halt exclusively at the second order, whereas higher order deformations are obstructed due to non-local interactions. The results demonstrate the BRST cohomological derivation of the interacting Yang-Mills theory.Comment: 19 pages, few typos corrected, final versio

    Spatially resolved kinematic observations of the planetary nebulae Hen 3-1333 and Hen 2-113

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    We have performed integral field spectroscopy of the planetary nebulae Hen 3-1333 (PNG332.9-09.9) and Hen 2-113 (PNG321.0+03.9), which are unusual in exhibiting dual-dust chemistry and multipolar lobes but also ionized by late-type [WC 10] central stars. The spatially resolved velocity distributions of the Hα\alpha emission line were used to determine their primary orientations. The integrated Hα\alpha emission profiles indicate that Hen 3-1333 and Hen 2-113 expand with velocities of ~ 32 and 23 km/s, respectively. The Hubble Space Telescope observations suggest that these planetary nebulae have two pairs of tenuous lobes extending upwardly from their bright compact cores. From three-dimensional geometric models, the primary lobes of Hen 3-1333 and Hen 2-113 were found to have inclination angles of about -30∘^{\circ} and 40∘^{\circ} relative to the line of sight, and position angles of -15∘^{\circ} and 65∘^{\circ} measured east of north in the equatorial coordinate system, respectively.Comment: 4 pages, 3 figures, accepted for publication in MNRAS Letter

    Morpho-kinematic properties of Wolf-Rayet planetary nebulae

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    The majority of planetary nebulae (PNe) show axisymmetric morphologies, whose causes are not well understood. In this work, we present spatially resolved kinematic observations of 14 Galactic PNe surrounding Wolf-Rayet ([WR]) and weak emission-line stars (welswels) based on the HΞ±\alpha and [N II] emission taken with the Wide Field Spectrograph on the Australian National University 2.3-m telescope. Velocity-resolved channel maps and position--velocity diagrams, together with archival Hubble Space Telescope (HSTHST) and ground-based images, are employed to construct three-dimensional morpho-kinematic models of 12 objects using the program SHAPE. Our results indicate that these 12 PNe mostly have elliptical morphologies with either open or closed outer ends. The kinematic maps show the on-sky orientations of the interior shells in NGC6578 and NGC6629, as well as the compact (≀6\leq 6 arcsec) PNe Pe1-1, M3-15, M1-25, Hen2-142, and NGC6567, in agreement with the elliptically symmetric morphologies seen in high-resolution HSTHST images. Point-symmetric knots in Hb4 exhibit deceleration with distance from the central star, which could be due to shock collisions with the ambient medium. The velocity dispersion maps of Pe1-1 also disclose the shock interaction between its collimated outflows and the interstellar medium. Collimated bipolar outflows are also visible in the position--velocity diagrams of M3-30, M1-32, and M3-15, which are reconstructed by tenuous prolate ellipsoids extending upward from dense equatorial regions in the kinematic models. The formation of aspherical morphologies and collimated outflows in these PNe could be related to the stellar evolution of hydrogen-deficient [WR] and welswels nuclei, which require further investigation.Comment: 68 pages (17+51 in Supplementary), 5 figures (inc. 4 fig.sets, 1 interactive fig), 5 tables, published by ApJS, interactive 3D models available on https://astroneb.github.io/WR_PN_Kinematic_Models/figure5/ and https://skfb.ly/opFZv archived on https://doi.org/10.5281/zenodo.539397

    Fast, low-ionization emission regions of the planetary nebula M2-42

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    Spatially resolved observations of the planetary nebula M2-42 (PN G008.2-04.8) obtained with the Wide Field Spectrograph on the Australian National University 2.3 m telescope have revealed the remarkable features of bipolar collimated jets emerging from its main structure. Velocity-resolved channel maps derived from the [N II] Ξ»\lambda6584 emission line disentangle different morphological components of the nebula. This information is used to develop a three-dimensional morpho-kinematic model, which consists of an equatorial dense torus and a pair of asymmetric bipolar outflows. The expansion velocity of about 20 km sβˆ’1^{-1} is measured from the spectrum integrated over the main shell. However, the deprojected velocities of the jets are found to be in the range of 80-160 km sβˆ’1^{-1} with respect to the nebular center. It is found that the mean density of the collimated outflows, 595 Β±\pm 125 cmβˆ’3^{-3}, is five times lower than that of the main shell, 3150 cmβˆ’3^{-3}, whereas their singly ionized nitrogen and sulfur abundances are about three times higher than those determined from the dense shell. The results indicate that the features of the collimated jets are typical of fast, low-ionization emission regions.Comment: 6 pages, 4 figures, 4 tables, accepted for publication in The Astronomical Journa

    Observations and three-dimensional ionization structure of the planetary nebula SuWt 2

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    The planetary nebula SuWt 2 (PN G311.0+02.4), is an unusual object with a prominent, inclined central emission ellipse and faint bipolar extensions. It has two A-type stars in a proven binary system at the centre. However, the radiation from these two central stars is too soft to ionize the surrounding material leading to a so far fruitless search for the responsible ionizing source. Such a source is clearly required and has already been inferred to exist via an observed temporal variation of the centre-of-mass velocity of the A-type stars. Moreover, the ejected nebula is nitrogen-rich which raises question about the mass-loss process from a likely intermediate-mass progenitor. We use optical integral-field spectroscopy to study the emission lines of the inner nebula ring. This has enabled us to perform an empirical analysis of the optical collisionally excited lines, together with a fully three-dimensional photoionization modelling. Our empirical results are used to constrain the photoionization models, which determine the evolutionary stage of the responsible ionizing source and its likely progenitor. The time-scale for the evolutionary track of a hydrogen-rich model atmosphere is inconsistent with the dynamical age obtained for the ring. This suggests that the central star has undergone a very late thermal pulse. We conclude that the ionizing star could be hydrogen-deficient and compatible with what is known as a PG 1159-type star. The evolutionary tracks for the very late thermal pulse models imply a central star mass of ~ 0.64MβŠ™{}_{\odot}, which originated from a ~ 3MβŠ™{}_{\odot} progenitor. The evolutionary time-scales suggest that the central star left the asymptotic giant branch about 25,000 years ago, which is consistent with the nebula's age.Comment: 18 pages, 11 figures, 10 tables, proof corrections applie

    Large-amplitude electron-acoustic solitons in a dusty plasma with kappa-distributed electrons

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    The Sagdeev pseudopotential method is used to investigate the occurrence and the dynamics of fully nonlinear electrostatic solitary structures in a plasma containing suprathermal hot electrons, in the presence of massive charged dust particles in the background. The soliton existence domain is delineated, and its parametric dependence on different physical parameters is clarified.Comment: 3 pages, 1 figure, presented as a poster at the 6th International Conference on the Physics of Dusty Plasmas (ICPDP6), Garmisch-Partenkirchen, Germany, 201

    Orientation of Galactic Bulge Planetary Nebulae toward the Galactic Center

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    We have used the Wide Field Spectrograph on the Australian National University 2.3-m telescope to perform the integral field spectroscopy for a sample of the Galactic planetary nebulae. The spatially resolved velocity distributions of the HΞ±\alpha emission line were used to determine the kinematic features and nebular orientations. Our findings show that some bulge planetary nebulae toward the Galactic center have a particular orientation.Comment: 2 pages, 1 figure, presented as a poster at the IAU Symposium 312 "Star Clusters and Black Holes in Galaxies across Cosmic Time", Beijing, China, 201
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