Difference In Position Angle Research Articles

パラレルメカニズムを用いた６自由度精密運動機構 リンク配置の検討

This paper describes a link layout design problem for six degree-of-freedom fine motion stage using Stewart platform mechanism. Isotropies of the translational and rotational stiffness, the generated force of the stage, the force acting on the link and the positioning resolution are investigated by singular value decomposition in various link layout. The obtained main results are as follows. (1) The translational stage stiffness in XYZ directions is unified at optimum stage height. The height is dependent on position angle difference between the stage joint and the base joint and is independent of the stage radius. (2) The translational positioning resolution, the generated force of the stage and the force acting on the link are unified with optimum stage radius, when the angle between the links and the base plane is 35.23°. (3) Optimum relation between the stage height and the stage radius exists to make the rotational stiffness in αβγ directions equal, when the angle between the links and the base plane is 54.7°. (4) The link layout which unifies simultaneously the translational stiffness and the rotational stiffness has not been found.

Polarimetry of the millisecond pulsar

The millisecond pulsar1 PSR1937 + 21 might be expected to have unique waveform and polarization properties as a result of its remarkably short period and small spin-down rate2,3. The proximity of the velocity of light cylinder to the star (RLC = 7.4 × 106 cm) and the low value of inferred magnetic field (∼108 G, 10−4 that of the Crab pulsar) should strongly influence the magnetospheric structure and particle density of this pulsar. And yet the waveform is similar to that of the Crab pulsar4 and PSR1055 − 52 (ref. 5), which have interpulses that are comparable in strength to the main pulse, and the polarization properties are at first sight unexceptional2. I present here polarization observations of the main pulse and interpulse at 1,415 and 2,380 MHz that have higher time resolution than previously available. The main pulse depolarizes substantially over this frequency range whereas the interpulse polarization almost doubles. There is evidence that orthogonally polarized radiation is present on the leading edge of the main pulse and the trailing edge of the interpulse and that it accounts for the ∼90° difference in position angle between the main pulse and interpulse. The interpulse decreases in intensity relative to the main pulse as f−1, indicating (if the trend continues to lower frequency) that the high frequency interpulse dominates the main pulse below ∼700 MHz. The main pulse is found to consist of two closely spaced components.

Observable properties of non-axisymmetryc galaxies

We analyse the simple geometrical theory of the triaxial, coaxial ellipsoids with different intrinsic axial ratios, suggesting that some observed properties of the isophotes could be interpreted as resulting from a similar distribution of the stars. The general analytical solutions for the apparent ellipticity and the difference in position angle of the major axes between each projected shell are also applied to composite structures formed by two subsystems of different shape. In comparison with the observable structures we considered three cases: (i) completely triaxial shells; (ii) barred discs; (iii) prolate-like systems. Some geometrical tests applying to these systems are also suggested in order to bring a better under-standing of their spatial structure.

Misalignment in the radio jets of NGC 6251

view Abstract Citations (35) References (8) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Misalignment in the radio jets of NGC 6251. Cohen, M. H. ; Readhead, A. C. S. Abstract The compact nuclear source in NGC 6251 has been observed with VLBI techniques at 2.8 and 13 cm. The source is asymmetric with a bright optically thick core and an optically thin jet. The jet has a small but significant difference in position angle from the outer jet. Publication: The Astrophysical Journal Pub Date: November 1979 DOI: 10.1086/183085 Bibcode: 1979ApJ...233L.101C Keywords: Galactic Nuclei; Galactic Structure; Radio Jets (Astronomy); Very Long Base Interferometry; Astronomical Maps; Centimeter Waves; Jets; Optical Thickness; Radio Interferometers; Astronomy; Galactic Nuclei:Radio Jets; Interferometry:Radio Sources full text sources ADS | data products SIMBAD (5) NED (1)

Triaxial Models of the Bulge of M31

view Abstract Citations (227) References (8) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Triaxial Models of the Bulge of M31 Stark, Antony A. Abstract A solution is derived for the problem of finding the volume brightness distribution of a stellar system whose isophotes are similar ellipses. This solution consists of similar triaxial ellipsoids. A one-parameter family of models is found for the inner 2 kpc of M3 1. One axis of the ellipsoids of constant volume brightness is assumed to be perpendicular to the disk of the galaxy. The models reproduce the observed surface brightness distribution, including the difference in position angle between the isophotes of the disk and the isophotes of the bulge. All of the models are barlike (the ratio of the two axes in the plane of the disk is 1.5 or larger). For a star in the disk at 5 kpc from the center, the nonaxisymmetric force due to the quadrupole moment of the bulge is typically about 5% of the radial force. Subject headings: galaxies: individual - galaxies: structure Publication: The Astrophysical Journal Pub Date: April 1977 DOI: 10.1086/155164 Bibcode: 1977ApJ...213..368S full text sources ADS |