The OSACA database and a kinematic analysis of stars in the solar neighborhood

Бобылев, В. В.; Goncharov, G. A.; Bajkova, A. T.

doi:10.1134/s1063772906090071

Cited by 42 publications

(40 citation statements)

References 17 publications

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“…For example, Gontcharov and Vityazev (2005) showed that although many Galactic structures within 400 pc of the Sun (the Local Bubble, the Great Tunnel, Goulds Belt) consist of stars of different ages up to several hundred million years, they were formed recently, no earlier than 20 Myr ago in processes related to two stellar streams, Orion and Sirius. Based on the Milne-Ogorodnikov model, Bobylev et al (2006) have demonstrated significant differences in the kinematics of the nearest single and multiple main-sequence stars and accurately determined the Galactic rotation parameters from the motions of stars farther than 200 pc. …”

Section: Discussionmentioning

confidence: 99%

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Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system

2006

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The Pulkovo Compilation of Radial Velocities (PCRV) has been made to study the stellar kinematics in the local spiral arm. The PCRV contains weighted mean absolute radial velocities for 35 495 Hipparcos stars of various spectral types and luminosity classes over the entire celestial sphere mainly within 500 pc of the Sun. The median accuracy of the radial velocities obtained is 0.7 km s −1 . Results from 203 publications were used in the catalogue. Four of them were used to improve the radial velocities of standard stars from the IAU list. The radial velocities of 155 standard stars turned out to be constant within 0.3 km s −1 . These stars were used to analyze 47 768 mean radial velocities for 37 200 stars from 12 major publications (∼ 80% of all the data used). Zero-point discrepancies and systematic dependences on radial velocity, (B − V ) color index, right ascension, and declination were found in radial velocity differences of the form "publication minus IAU list of standards". These discrepancies and dependences were approximated and taken into account when calculating the weighted mean radial velocities. 1128 stars whose independent radial-velocity determinations were available at least in three of these publications and agreed within 3 km s −1 were chosen as the work list of secondary standards. Radial-velocity differences of the form "publication minus list of secondary standards" were used by analogy to correct the zero points and systematic dependences in the radial velocities from 33 more publications ( 13% of the data used). In addition, the radial * E-mail: georgegontcharov@yahoo.com 1 velocities from 154 minor publications (∼ 7% of the data used) pertaining to well-known instruments were used without any corrections. 2 INTRODUCTIONThe stellar kinematics in the solar neighborhood within the local spiral arm of the Galaxy is being studied at the Pulkovo Astronomical Observatory of the Russian Academy of Sciences and the Astronomical Institute of the St. Petersburg State University as part of the OSACA (Orion Spiral Arm Catalogue, http://www.geocities.com/orionspiral/) project (Gontcharov 2004). The study is based on six quantities that describe the stellar positions and velocities: α, δ, π, µ α , µ δ , and V r , as well as the coordinates X, Y , and Z and space velocities U, V , and W calculated from them in the standard Galactic rectangular coordinate system, where X, Y , and Z increase in the directions of the Galactic center, the Galactic rotation, and the Galactic North Pole, respectively.At present, the coordinates and proper motions are known for a larger number of stars and with a higher relative accuracy than the parallaxes and radial velocities. For example, the coordinates and proper motions of ∼ 96000 Hipparcos stars (ESA 1997) within 500 pc of the Sun are known with a relative accuracy higher than 10 −7 and an accuracy higher than 3 km s −1 , respectively, while the parallaxes of only ∼ 69000 Hipparcos stars are known with a relative accuracy higher than 0.3 and the radial velocities of ...

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Section: Discussionmentioning

confidence: 99%

“…Supplementing the PCRV by new observations and improving the weighted mean radial velocities are an important part of the long-term OSACA project. The size of this paper is too small to describe the kinematic studies using the PCRV that have been considered in other publications, for example, by Bobylev et al (2006).…”

Section: Introductionmentioning

confidence: 99%

Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system

2006

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“…This means that when using ZVSHs, either the effects of solar motion should be eliminated or it makes sense to perform the solution only for stars at approximately the same heliocentric distance; in this case, we will be able to determine the solar motion parameters only to within the factor 1/ r . Thus, using ZVSHs allow us: (1) to obtain the solution on a hemisphere, avoiding strong correlations between the parameters to be determined; (2) to use the derived decomposition coefficients to calculate the parameters of any kinematic model; (3) to test the model for consistency with the observations by comparing the main and alternative solutions; (4) to find the decomposition coefficients that are not predicted by the chosen model.…”

Section: Decomposition Of the Ogorodnikov-milne Model Equations Into mentioning

confidence: 99%

Kinematics of stars in the northern and southern galactic hemispheres

Vityazev

Tsvetkov

2012

Astron. Lett.

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“…The OSACA data base (Bobylev et al 2006) combines, as far as available, radial velocity data with the Hipparcos proper motions and parallaxes and readily provides the resulting stellar space velocities in galactic coordinates. We used the available OSACA vertical velocities of all stars in our spherical 150 pc sample and added a vertical solar velocity of +7.17 km s −1 (Dehnen & Binney 1998), to get the absolute vertical velocities σ z of each star relative to the Galactic plane.…”

Section: Observed Stellar Kinematics and Scaleheightsmentioning

confidence: 99%

“…Hence, the new empirical star counts for the r = 100 pc sample do not differ too much from the ones presented by Schröder & Pagel (2003), but they are now considered less biased. The last advance comes from improved synthetic population models. Radial velocity data from the OSACA data base (Bobylev, Gontcharov & Bajkova 2006) for our stellar subsamples have been used to derive an empirical velocity–age relation (see ). From this, a semi‐empirical scaleheight–age relation has been determined (calibrated from star counts over a range of subsamples; see ).…”

Section: Introductionmentioning

confidence: 99%

IMF, SFR and stellar depletion in the local Galactic plane, based on improved Hipparcos samples of single stars

Dawson

Schröder

2010

Monthly Notices of the Royal Astronomical Society

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We have used the recently reduced Hipparcos data and the Washington Double Star catalogue to derive two volume‐ and magnitude‐limited samples of single stars in the Galactic plane. The star count method has been used to compare synthetic to empirical samples of stars within both the main sequence and the evolved regions of the Hertzsprung–Russell diagram. Corrections have been made for unrecognized binaries and the residual incompleteness of the Hipparcos catalogue. Two methods of binary reduction have been compared, a flat 71 per cent binary fraction (including multiples) and a mass‐dependent binary fraction, which decreases with primary mass from 71 to 57 per cent. A semi‐empirical relation between the vertical scaleheight and stellar age has been derived from kinematic data provided by the OSACA data base. This relation is used to prescribe the loss of stellar content vertically from the plane due to heating. When employing the fixed binary ratio, we find that the best fit is provided by a Scalo initial mass function (IMF) with an exponent of 1.85 ± 0.15, together with an average Galactic thin‐disc star formation rate (SFR) of 618(±15) stars Myr−1 kpc−3 with 1211(±30) M⊙ Myr−1 kpc−3 for single stars with M* > 0.9 M⊙. The application of the mass‐dependent variable binary ratio yields more single stars at lower mass and hence a steeper (Γ= 2.2, … , 2.3) IMF and an increased SFR.

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The OSACA database and a kinematic analysis of stars in the solar neighborhood

Cited by 42 publications

References 17 publications

Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system

Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system

Kinematics of stars in the northern and southern galactic hemispheres

IMF, SFR and stellar depletion in the local Galactic plane, based on improved Hipparcos samples of single stars

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