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Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some spiral responses, but spirals in many galaxies must be self-excited.
Sellwood, Jerry A., Masters, Karen
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Lopsided spiral galaxies [PDF]
The light distribution in the disks of many galaxies is non-axisymmetric or `lopsided' with a spatial extent much larger along one half of a galaxy than the other, as in M101. Recent near-IR observations show that lopsidedness is common. The stellar disks in nearly 30 % of galaxies have significant lopsidedness, greater than 10 % measured as the ...
Jog, Chanda J, Combes, Francoise
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SUPERLUMINOUS SPIRAL GALAXIES [PDF]
ABSTRACT We report the discovery of spiral galaxies that are as optically luminous as elliptical brightest cluster galaxies, with r-band monochromatic luminosity L r = 8–14L* (4.3–7.5 × 1044 erg s−1).
Lauranne Lanz+4 more
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Galaxy Zoo: dust in spiral galaxies★ [PDF]
We investigate the effect of dust on spiral galaxies by measuring the inclination-dependence of optical colours for 24,276 well-resolved SDSS galaxies visually classified in Galaxy Zoo. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4 magnitudes for the ugri passbands. We
Robert C. Nichol+15 more
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Let us consider an alternative perspective on climate change: The sum of solar radiation and heat generated by human activity result in a net energy input of 1.96 times that of the Sun on the Earth's surface. The expanding global population is expected to exacerbate this issue. Potential solutions are proposed, including replacement and heat recycling.
Martin Bertau, Gerald Steiner
wiley +1 more source
We study the role of asymptotic curves in supporting the spiral structure of a N-body model simulating a barred spiral galaxy. Chaotic orbits with initial conditions on the unstable asymptotic curves of the main unstable periodic orbits follow the shape of the periodic orbits for an initial interval of time and then they are diffused outwards ...
M. Harsoula, George Contopoulos
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Analysis of the escape in systems with four exit channels
In this paper, we have performed a numerical investigation of the escape of a particle from two different dynamical systems with the same number of exit channels. We have chosen specific values of the parameters of the systems so that the openings of the potential well in both systems are approximately of the same size.
Juan F. Navarro+2 more
wiley +1 more source
Genome‐wide identification and biological relevance of broccoli aquaporins
Abstract Broccoli (Brassica oleracea var. italica) is an important crop worldwide, and its regular consumption is associated with health benefits due to the presence of various bioactive compounds. An optimal water balance and homeostasis are needed for plant growth; in this sense, aquaporins play a crucial role.
Juan Nicolas‐Espinosa+1 more
wiley +1 more source
The spiral structure of galaxies [PDF]
Bernard J. T. Jones, Scott Tremaine
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Optimization of proposed micro grid system is done using physics based meta heuristic methods. A grid connected micro grid consist of solar PV system, wind turbine (WT), micro gas turbine (MT), fuel cell (FC) and battery energy storage system (BESS).
Jayati Vaish+2 more
wiley +1 more source