Results 71 to 80 of about 559,591 (386)
The dynamics of spiral arms in pure stellar disks
, 2011 It has been believed that spirals in pure stellar disks, especially the ones spontaneously formed, decay in several galactic rotations due to the increase of stellar velocity dispersions.
Baba +22 more
core +1 more source
Star formation and ISM morphology in tidally induced spiral structures [PDF]
, 2017 Tidal encounters are believed to be one of the key drivers of galactic spiral structure in the Universe. Such spirals are expected to produce different morphological and kinematic features compared to density wave and dynamic spiral arms. In this work we
Benincasa, Samantha M. +4 more
core +2 more sources
Magnetic spiral arms in galaxy haloes [PDF]
Monthly Notices of the Royal Astronomical Society, 2017 We seek the conditions for a {\it steady} mean field galactic dynamo. The parameter set is reduced to those appearing in the $ ^2$ and $ / $ dynamo, namely velocity amplitudes, and the ratio of sub-scale helicity to diffusivity. The parameters can be allowed to vary on conical spirals.
openaire +2 more sources
Blobs, spiral arms, and a possible planet around HD 169142 [PDF]
Astronomy & Astrophysics, 2019 Context. Young planets are expected to cause cavities, spirals, and kinematic perturbations in protostellar disks that may be used to infer their presence.
R. Gratton +27 more
semanticscholar +1 more source
Stellar spiral arms in smooth-armed galaxies
The Astrophysical Journal, 1986 Deep multicolor surface photometry has been obtained for three extreme examples of smooth-armed spirals, galaxies with a global spiral pattern but with little or no interstellar gas, dust, or recent star formation: NGC 7743, NGC 495 and NGC 718. The results suggest that smooth-armed spirals may be transient bar-driven density waves (with a lifetime of ...
R. C., Jr. Kennicutt, B. K. Edgar
openaire +1 more source
Stiffness estimation of planar spiral spring based on Gaussian process regression
Scientific Reports, 2022 Planar spiral spring is important for the dimensional miniaturisation of motor-based elastic actuators. However, when the stiffness calculation of the spring arm is based on simple beam bending theory, the results possess substantial errors compared with
Jingjing Liu +6 more
doaj +1 more source
Zoom-in cosmological hydrodynamical simulation of a star-forming barred, spiral galaxy at redshift z=2 [PDF]
, 2019 Accepted for publication in MNRASWe present gas and stellar kinematics of a high-resolution zoom-in cosmological chemodynamical simulation, which fortuitously captures the formation and evolution of a star-forming barred spiral galaxy, from redshift $z ...
Kobayashi, Chiaki +2 more
core +5 more sources
The Galactic Branches as a Possible Evidence for Transient Spiral Arms
, 2015 With the use of a background Milky-Way-like potential model, we performed stellar orbital and magnetohydrodynamic (MHD) simulations. As a first experiment, we studied the gaseous response to a bisymmetric spiral arm potential: the widely employed cosine ...
Gómez, Gilberto C. +2 more
core +1 more source
Dependence of the Spiral Arms Pitch Angle on Wavelength as a Test of the Density Wave Theory [PDF]
Astrophysical Journal, 2018 Large-scale galactic shocks, predicted by density wave theory, trigger star formation (SF-arms) downstream from the potential of the oldest stars (P-arms), resulting in a color jump from red to blue across spiral arms in the direction of rotation, while ...
Sijie Yu, L. Ho
semanticscholar +1 more source
Phosphatidylinositol 4‐kinase as a target of pathogens—friend or foe?
FEBS Letters, EarlyView.This graphical summary illustrates the roles of phosphatidylinositol 4‐kinases (PI4Ks). PI4Ks regulate key cellular processes and can be hijacked by pathogens, such as viruses, bacteria and parasites, to support their intracellular replication. Their dual role as essential host enzymes and pathogen cofactors makes them promising drug targets.
Ana C. Mendes +3 more
wiley +1 more source