Results 1 to 10 of about 25,712 (75)
Stellar winds and photoionization in a spiral arm [PDF]
Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT The role of different stellar feedback mechanisms in giant molecular clouds is not well understood. This is especially true for regions with many interacting clouds as would be found in a galactic spiral arm. In this paper, building on previous work by Bending et al., we extract a $500{\, \mathrm{pc}}\times 500{\, \mathrm{pc ...
Ahmad A Ali +2 more
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Superposing the Magnetic spiral structure of the Milky Way, on the stellar spiral arms -- Matching the unique galactic magnetic field reversal Zone with two galactic spiral arm Segments [PDF]
2022 December, International Journal of Astronomy & Astrophysics,
volume 12, pages 281-300, 2022 To pinpoint the peak location of the synchrotron total intensity emission in a spiral arm, we use a map of the spiralarm locations (from the observed arm tangent). Thus In a typical spiral arm in Galactic Quadrant I, we find the peak of the synchrotron radiation to be located about 220 +/-40 pc away from the inner arm edge (hot dust lane) inside the ...
arxiv +1 more source
The evolution of pitch angles of spiral arms [PDF]
Monthly Notices of the Royal Astronomical Society, 2019 ABSTRACTIn spiral galaxies, the pitch angle, α, of the spiral arms is often proposed as a discriminator between theories for the formation of the spiral structure. In Lin–Shu density wave theory, α stays constant in time, being simply a property of the underlying galaxy. In other theories (e.g.
Pringle, J E, Dobbs, C L
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Kinematic structure of the Milky Way galaxy, near the spiral arm tangents [PDF]
International Journal of Astronomy and Astrophysics, 2022
December, volume 12, pages 382-392, 2023 We compare the observed radial velocity of different arm tracers, taken near the tangent to a spiral arm. A slight difference is predicted by the density wave theory, given the shock predicted at the entrance to the inner spiral arm. In many of these spiral arms, the observed velocity offset confirms the prediction of the density wave theory (with a ...
arxiv +1 more source
Tracing the spiral arms in IP Pegasi [PDF]
Astronomy & Astrophysics, 2005 We report the analysis of time-resolved spectroscopy of IP Pegasi in outburst with eclipse mapping techniques to investigate the location and geometry of the observed spiral structures. We were able to obtain an improved view of the spiral structures with the aid of light curves extracted in velocity bins matching the observed range of velocities of ...
Baptista, R. +4 more
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Triggered star formation in spiral arms [PDF]
Proceedings of the International Astronomical Union, 2006 AbstractWe present preliminary results for six spiral galaxies from a sample of 25, where we have used the method developed by González & Graham (1996) to search for and analyze azimuthal color gradients across spiral arms. The six galaxies analyzed here are NGC 1703 (SBrb), NGC 3001 (SABrsbc), NGC 3059 (SBrsbc), NGC 3513 (SBrsc), NGC 4593 (RSBrsb),
E. E. Martínez-García +2 more
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Bulletin of the Seismological Society of America, 2015 Seismic arrays have many uses for signal enhancement, from surface-wave characterization of the near surface to teleseismic detection in the context of monitoring nuclear tests. Many variants of the geometrical configuration of stations have been used with the objective of maximizing potential resolution of the incoming wavefronts di- rection of ...
Kennett, Brian +2 more
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GALACTIC SPIRAL ARMS BY SWING AMPLIFICATION [PDF]
The Astrophysical Journal, 2016 ABSTRACT Based on the swing amplification model of Julian & Toomre, we investigate the formation and structure of stellar spirals in disk galaxies. We calculate the pitch angle, wavelengths, and amplification factor of the most amplified mode.
Eiichiro Kokubo, Shugo Michikoshi
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Spiral-arm instability: giant clump formation via fragmentation of a galactic spiral arm [PDF]
Monthly Notices of the Royal Astronomical Society, 2017 Fragmentation of a spiral arm is thought to drive the formation of giant clumps in galaxies. Using linear perturbation analysis for self-gravitating spiral arms, we derive an instability parameter and define the conditions for clump formation. We extend our analysis to multi-component systems that consist of gas and stars in an external potential.
Naoki Yoshida +3 more
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Magnetic spiral arms and galactic outflows [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2014 Abstract Galactic magnetic arms have been observed between the gaseous arms of some spiral galaxies; their origin remains unclear. We suggest that magnetic spiral arms can be naturally generated in the interarm regions because the galactic fountain flow or wind is likely to be weaker there than in the arms.
Anvar Shukurov +3 more
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