Authors

Abstract

Our galaxy is a spiral galaxy and its stars are mostly in a thin disk and rotate around the galactic center. The vertical component of the dispersion velocity of stars is a function of the galactic latitude and decreases with increasing it. In the galactic Besancon model, this dependence is ignored and they just consider the dependence of dispersion velocity on the stellar age. Becanson model is mostly applied to interpret the observational data of gravitational microlensing events to indicate the power index of the power-law number density of mass into the galactic disk. In this paper, we explain that ignoring the dependence of the dispersion velocity on the galactic latitude causes an overestimation of the number of low-mass objects in the galactic disk.
 
 

Keywords

1. B Paczynski, ApJ. 301 (1986) 503.
2. I Soszynski, A Udalski, and M K Szymanski, et al., “The Optical Gravitational Lensing Experiment.The OGLE- III Catalog of Variable Stars. IX. RR Lyr Stars in the Small Magellanic Cloud”, AcA. 60 (2010) 165.
3. I A Bond, F Abe, and R J Dodd, et al., MNRAS 327 (2001) 868.
4. S L Kim, C -UK Lee, and B Park, et al., JKAS 49 (2016) 37.
5. G Kim, N Safizadeh, ApJ. 500 (1998) 37.
6. T Lasserre, C Afonso, and J N Albert, et al., A &A. 355 (2000) 39.
7. P Tisserand, L Le Guillou, and C Afonso, et al., A & A. 469 (2007) 387.
8. A C Robin, C Reyle, S Derriere, and S Picaud, A& A. 409 (2003) 523.
9. J Binney and S Tremaine, “Galactic Dynamics”, Princeton University Press, Second Edition (1987).
10. P Vermaak, MNRAS, 319, 4 (2000) 1011.
11. L Wyrzykowski, A E Rynkiewicz, and J Skowron, et al., ApJS. 216 (2015) 12.
12. S Sajadian, AJ. 149 (2015) 4.
13. S Sajadian and P Radek, “Prediction on Detection and Characterization of Galactic Disk Microlensing Events by LSST”, arXiv: 1806 (2018) 06372.
14. S Sajadian, MNRAS 452 (2015) 2587.
15. M Moniez, S Sajadian, and M Karami, et al., A& A. 604 (2017) 124.
16. S Awiphan, E Kerins, and A C Robin, MNRAS 456 (2016) 166.
17. T Sumi, K Kamiya, and A Udalski, Nature 473 (2011) 349.
18. P Mroz, A Udalski, and J Skowron, et al., Nature 548 (2017) 7666.

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