Covariant Evolution of Gravitoelectromagnetism
The long-range gravitational terms associated with tidal forces, frame-dragging effects, and gravitational waves are described by the Weyl conformal tensor, the traceless part of the Riemann curvature that is not locally affected by the matter field. The Ricci and Bianchi identities provide a set of dynamical and kinematic equations governing the matter coupling and evolution of the electric and magnetic parts of the Weyl tensor, so-called gravitoelectric and gravitomagnetic fields. A detailed analysis of the Weyl gravitoelectromagnetic fields can be conducted using a number of algebraic and differential identities prescribed by the 1+3 covariant formalism. In this review, we consider the dynamical constraints and propagation equations of the gravitoelectric/-magnetic fields and covariantly debate their analytic properties. We discuss the special conditions under which gravitational waves can propagate, the inconsistency of a Newtonian-like model without gravitomagnetism, the nonlinear generalization to multi-fluid models with different matter species, as well as observational effects caused by the Weyl fields via the kinematic quantities. The 1+3 tetrad and 1+1+2 semi-covariant methods, which can equally be used for gravitoelectromagnetism, are briefly explained, along with their correspondence with the covariant formulations.
"Morpho-kinematic Properties of Wolf–Rayet Planetary Nebulae"
https://t.co/Ptqh1bH6vE via @AAS_Publishing published by The Astrophysical Journal Supplement Series @MichiganAstro
#umich #astronomy https://t.co/AMluhsJQMC https://t.co/gXkuMigwFs"Physical conditions and chemical abundances of the variable planetary nebula IC 4997"
https://t.co/VWv3hM9Viu published in Monthly Notices of the Royal Astronomical Society (MNRAS)
https://t.co/rSBn3L4ECP @michiganastro @Eureka_Sci
#umich #astronomy @RAS_Journals
https://t.co/E3RUN8qwMJ
Physical conditions and chemical abundances of the variable planetary nebula IC 4997
ABSTRACT. The planetary nebula (PN) IC 4997 is one of a few rapidly evolving objects with variable brightness and nebular emission around a hydrogen-deficient s
Morphologies of Wolf–Rayet Planetary Nebulae Based on IFU Observations
https://t.co/2PTXrFLgn2 #mdpigalaxies via @Galaxies_MDPI
https://t.co/R77RqdhqEA
Morphologies of Wolf–Rayet Planetary Nebulae Based on IFU Observations
Integral field unit (IFU) spectroscopy of planetary nebulae (PNe) provides a plethora of information about their morphologies and ionization structures. An IFU survey of a sample of PNe around hydrogen-deficient stars has been conducted with the Wide Field Spectrograph (WiFeS) on the ANU 2.3-m telescope. In this paper, we present the Hα kinematic observations of the PN M 2-42 with a weak emission-line star (wels), and the compact PNe Hen 3-1333 and Hen 2-113 around Wolf–Rayet ([WR]) stars from this WiFeS survey. We see that the ring and point-symmetric knots previously identified in the velocity [N ii] channels of M 2-42 are also surrounded by a thin exterior ionized Hα halo, whose polar expansion is apparently faster than the low-ionization knots. The velocity-resolved Hα channel maps of Hen 3-1333 and Hen 2-113 also suggest that the faint multipolar lobes may get to a projected outflow velocity of ∼100 ± 20 km s−1 far from the central stars. Our recent kinematic studies of the WiFeS/IFU survey of other PNe around [WR] and wels mostly hint at elliptical morphologies, while collimated outflows are present in many of them. As the WiFeS does not have adequate resolution for compact (≤6 arcsec) PNe, future high-resolution spatially-resolved observations are necessary to unveil full details of their morpho-kinematic structures.
My recent paper "Physical and Chemical Properties of Wolf–Rayet Planetary Nebulae"
https://t.co/TJiw5YS0ju published in The Astrophysical Journal Supplement Series (ApJS) via @AAS_Publishing
https://t.co/D6OKaV1p6c @MichiganAstro
#umich #astronomy https://t.co/3vSQ8wimkY"3D spatio-kinematic modeling of Abell 48, a planetary nebula around a Wolf-Rayet [WN] star"
https://t.co/5994PPGfTa accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS) @OUPAcademic
https://t.co/TEkEutBEZu @MichiganAstro
#umich #astronomy https://t.co/thVeroencm
3D spatio-kinematic modelling of Abell 48, a planetary nebula around a Wolf–Rayet [WN] star
ABSTRACT. The planetary nebula (PN) Abell 48 (PN G029.0+00.4) is around a rare Wolf–Rayet [WN5] star whose stellar history is as yet unknown. Using the integral
My Poster "Silicon K-edge Dust Properties of Neutron Star Low-mass X-ray Binaries"
https://t.co/SKlVs2yh7w #IAUsymposium #IAUS363 #IAU Symposium 363:
#Neutron Star
#Astrophysics at the Crossroads
https://t.co/rUkX9ImbmV
Silicon K-edge Dust Properties of Neutron Star Low-mass X-ray Binaries
Poster presented at IAU Symposium 363: Neutron Star Astrophysics at the Crossroads: Magnetars and the Multimessenger Revolution (Remote Symposium), 29 Nov - 3 Dec 2021
My recent hydrodynamic work "Catastrophic Cooling in Superwinds. II. Exploring the Parameter Space" published in The Astrophysical Journal
https://t.co/aQEWT6BczG via @AAS_Publishing
https://t.co/2FSfb6x3gC @MichiganAstro
#umich #astronomy https://t.co/sDOsZQSWR4