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相关论文: The local stellar velocity field via vector spheri…

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We measure the line-of-sight accelerations of 26 binary pulsars due to the Milky Way's gravitational potential, and produce a 3-dimensional map of the acceleration field of the Galaxy. Acceleration measurements directly give us the change…

Radial motions of stars in nearby moving clusters are determined from accurate proper motions and trigonometric parallaxes, without any use of spectroscopy. Assuming that cluster members share the same velocity vector (apart from a random…

天体物理学 · 物理学 2009-11-07 S. Madsen , D. Dravins , L. Lindegren

A stability analysis of a spherically symmetric star in scalar-tensor theories of gravity is given in terms of the frequencies of quasi-normal modes. The scalar-tensor theories have a scalar field which is related to gravitation. There is…

广义相对论与量子宇宙学 · 物理学 2010-11-19 Tomohiro Harada

An analysis of the residual-velocity field of OB associations within 3 kpc of the Sun has revealed periodic variations in the radial residual velocities along the Galactic radius vector with a typical scale length of lambda=2.0(+/-0.2) kpc…

天体物理学 · 物理学 2008-09-22 A. M. Mel'nik , A. K. Dambis , A. S. Rastorguev

Based on published data, we have collected information about Galactic maser sources with measured distances. In particular, 44 Galactic maser sources located in star-forming regions have trigonometric parallaxes, proper motions, and radial…

星系天体物理 · 物理学 2013-02-07 A. S. Stepanishchev , V. V. Bobylev

Local nonlinear approximations to the growth of cosmic perturbations are developed, resulting in relations, at a given epoch, between the peculiar velocity and gravity fields and their gradients. Only the equation of motion is approximated,…

天体物理学 · 物理学 2009-10-22 Paul J. Mancinelli , Amos Yahil

We have constructed a catalog containing best available astrometric, photometric, radial velocity and astrophysical data for mainly F-type and G-type stars (called the Astrometric catalog associated with Astrophysical Data, ACAD), which…

星系天体物理 · 物理学 2014-05-23 Zong-Bo Huyan , Zi Zhu , Jia-Cheng Liu

The Oort constants describe the local variations of the stellar streaming field. Classically, they are determined from stellar proper motions. We discuss problems arising in this procedure. A large, hitherto overlooked, source of systematic…

天体物理学 · 物理学 2009-11-07 Rob P. Olling , Walter Dehnen

The Milagro hot spot A, close to the Galactic anticenter direction, has been tentatively attributed to cosmic rays from a local reservoir (at a distance ~100 pc), freely streaming along diverging and smooth magnetic field lines. This is at…

高能天体物理现象 · 物理学 2015-05-18 M. Salvati

In many astronomical works, the structure of vector fields is analyzed, such as the differences in the celestial object coordinates in catalogs or the celestial object velocities, by decomposition into vector spherical harmonics (VSH). This…

天体物理仪器与方法 · 物理学 2024-10-10 Zinovy Malkin

We study the impact on the galaxy correlation function of the presence of a vector component in the tracers' peculiar velocities, in the case in which statistical isotropy is violated. We present a general framework - based on the bipolar…

宇宙学与河外天体物理 · 物理学 2018-11-21 Vittorio Tansella , Camille Bonvin , Giulia Cusin , Ruth Durrer , Martin Kunz , Ignacy Sawicki

We try to determine the Galactic structure by comparing the observed and modeled velocities of OB-associations in the 3 kpc solar neighborhood. We made N-body simulations with a rotating stellar bar. The galactic disk in our model includes…

星系天体物理 · 物理学 2015-05-19 Pertti Rautiainen , Anna Mel'nik

The large sample of main sequence stars with Hipparcos parallaxes and estimates of the radial velocity has been used to study the relations among kinematics, age and heavy element content for the solar neighbourhood. The samples with V> -30…

天体物理学 · 物理学 2007-05-23 V. Caloi , D. Cardini , F. D'Antona , M. Badiali , A. Emanuele , I. Mazzitelli

Previous analyses of large databases of Milky Way stars have revealed the stellar disk of our Galaxy to be warped and that this imparts a strong signature on the kinematics of stars beyond the solar neighborhood. However, due to the…

We present the results of the kinematic investigations carried out with the use of spatial velocities of red giants and sub-giants containing in the $Gaia$~EDR3 catalogue. The twelve kinematic parameters of the Ogorodnikov--Milne model have…

星系天体物理 · 物理学 2021-10-13 P. N. Fedorov , V. S. Akhmetov , A. B. Velichko , A. M. Dmytrenko , S. I. Denischenko

This work presents the results from extending the long-term monitoring program of stellar motions within the Galactic Center to include stars with separations of 2 - 7 arcseconds from the compact radio source, Sgr A*. In comparison to the…

A class of harmonic solutions to the steady Euler equations for incompressible fluids is presented in two dimensions in circular, elliptic and bipolar coordinates. Since the velocity field is solenoidal in this case, it can be written as…

流体动力学 · 物理学 2014-08-06 Pablo Luis Rendón , Eugenio Ley-Koo

Plaskett's "star" appears to be one of a small number of short-period binary systems known to contain a hot, massive, magnetic star. Building on the 2013 discovery investigation, we combine an extensive spectropolarimetric (Stokes $V$)…

太阳与恒星天体物理 · 物理学 2022-04-06 J. H. Grunhut , G. A. Wade , C. P. Folsom , C. Neiner , O. Kochukhov , E. Alecian , M. Shultz , V. Petit , the MiMeS , BinaMIcS collaborations

Context: A radial velocity survey of about 380 G and K giant stars is ongoing at Lick observatory. For each star we have a high signal to noise ratio template spectrum, which we use to determine spectroscopic stellar parameters. Aim: The…

天体物理学 · 物理学 2009-11-13 S. Hekker , J. Meléndez

We present the results of an automated variability analysis of the Kepler public data measured in the first quarter (Q1) of the mission. In total, about 150 000 light curves have been analysed to detect stellar variability, and to identify…

太阳与恒星天体物理 · 物理学 2015-05-27 J. Debosscher , J. Blomme , C. Aerts , J. De Ridder