Spectrum of Lin-Shu-type density waves in the galaxy

• Verfasst von: Griv, Evgeny [VerfasserIn]
• Verfasst von: Kharchenko, Nina V. [VerfasserIn]
• Verfasst von: Piskunov, Anatoly E. [VerfasserIn]
• Verfasst von: Hou, Li-Gang [VerfasserIn]
• Verfasst von: Jiang, Ing-Guey [VerfasserIn]
• Titel: Spectrum of Lin-Shu-type density waves in the galaxy
• Titelzusatz: a number of discrete spiral modes of collective oscillations?
• Verf.angabe: Evgeny Griv, Nina V. Kharchenko, Anatoly E. Piskunov, Li-Gang Hou and Ing-Guey Jiang
• E-Jahr: 2015
• Jahr: 27 August 2015
• Umfang: 9 S.
• Fussnoten: Gesehen am 07.01.2021
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2015
• Band/Heft Quelle: 453(2015), 2, Seite 1981-1989
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stv1636
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1744157839

Abstract

Measurements of great importance of photometric/trigonometric distances and velocities have recently done for 2859 open clusters and 103 masers associated with young high-mass stars in the disc of our Galaxy by Kharchenko et al. and Reid et al. We use these new high-precision data to determine the spectrum of Lin-Shu-type density waves in the system. The kinematics of 472 clusters and 65 masers selected within 4 kpc from the Sun is analysed on the assumption that the Galaxy is subject to moderately unstable, tightly-wound, small-amplitude density waves. For a given number of spiral arms, several minima of a least-squares estimator S of measured and predicted line-of-sight velocities of both clusters and masers with respect to the pitch angle p and the phase of the wave at the Sun's location are apparent from our calculation as |p| increases from 1° to 20°. The appearance of the minima of S is explained in terms of a number of discrete spiral modes of collective oscillations developing in the solar vicinity as suggested analytically by Lau, Lin & Mark, Bertin & Mark, Lau & Bertin and others in the late 1970s.