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Rediscovering the Galactic outer disk with LAMOST data

Published online by Cambridge University Press:  02 August 2018

Chao Liu Open the ORCID record for Chao Liu [Opens in a new window] ,
Yan Xu ,
Haifeng Wang Open the ORCID record for Haifeng Wang [Opens in a new window]  and
Junchen Wan
Chao Liu
Affiliation:
Key Lab of Optical Astronomy, National Astronomical Observatories, CAS 20A Datun Road, 100012, Beijing, China email: liuchao@nao.cas.cn
Yan Xu
Affiliation:
Key Lab of Optical Astronomy, National Astronomical Observatories, CAS 20A Datun Road, 100012, Beijing, China email: liuchao@nao.cas.cn
Haifeng Wang
Affiliation:
Key Lab of Optical Astronomy, National Astronomical Observatories, CAS 20A Datun Road, 100012, Beijing, China email: liuchao@nao.cas.cn University of Chinese Academy of Sciences, 100049, Beijing, China
Junchen Wan
Affiliation:
Key Lab of Optical Astronomy, National Astronomical Observatories, CAS 20A Datun Road, 100012, Beijing, China email: liuchao@nao.cas.cn
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Abstract

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From the derived stellar density profile using LAMOST giant stars, we find that the Galactic disk does not show truncation or break, but smoothly transit to the halo from 19 kpc. The scale length of the outer disk is only 1.6 ± 0.1 kpc, substantially smaller than previous results. This implies that the shapes of the inner and outer disk are different. Meanwhile, the disk flaring is not only found in older populations, but also in younger population. Moreover, the vertical oscillations of the disk are identified in a wide range or R from 8 to 14 kpc. We also find that the velocity dispersion profile as a function of the Galactocentric radius is flat with scale length of 26.3 ± 3.2 kpc. We confirm that the radial velocity profile in outer disk is significantly affected by asymmetric motion. The bar with either a slower or a faster pattern speed can induce the similar radial asymmetric motion.

Keywords

Galaxy: generalGalaxy: structureGalaxy: diskGalaxy: kinematics and dynamics
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 13 , Symposium S334: Rediscovering our Galaxy , July 2017 , pp. 109 - 115
Copyright
Copyright © International Astronomical Union 2018 

References

Bland-Hawthorn, J. & Gerhard, O., 2016, ARA&A, 54, 529Google Scholar
Bovy, J., 2015, ApJS, 216, 29Google Scholar
Carlin, J. L., DeLaunay, J., Newberg, H. J., et al. 2013, ApJL, 777, L5Google Scholar
Cui, X.-Q., et al. 2012, RAA, 12, 1197Google Scholar
Debattista, V. P., 2014, MNRAS, 443, L1Google Scholar
Dehnen, W., 1998, AJ, 115, 2384Google Scholar
Dehnen, W., 2000, AJ, 119, 800Google Scholar
Deng, L.-C. et al., RAA, 12, 735Google Scholar
Faure, C., Siebert, A., & Famaey, B., 2014, MNRAS, 440, 2564Google Scholar
Gilmore, G. & Reid, N., 1983, MNRAS, 202, 1025Google Scholar
Gómez, F. A., Minchev, I., O’Shea, B. W., et al. 2013, MNRAS, 429, 159Google Scholar
Grand, R. J. J., Bovy, J., Kawata, D., et al. 2015, MNRAS, 453, 1867Google Scholar
Jurić, M., Ivezić, Ž., Brooks, A., et al. 2008, ApJ, 673, 864-914Google Scholar
van der Kruit, P. C., 1988, A&A, 192, 117Google Scholar
Lewis, J. R. & Freeman, K. C., 1989, AJ, 97, 139Google Scholar
Liu, C., Xue, X., Fang, M., et al. 2012, ApJL, 753, L24Google Scholar
Liu, C., Deng, L.-C., Carlin, J. L., et al. 2014, ApJ, 790, 110Google Scholar
Liu, C., Xu, Y., Wan, J.-C., et al. 2017, Research in Astronomy and Astrophysics, 17, 96Google Scholar
Liu, C., Wang, Y.-G., Shen, J., et al. 2017, ApJL, 835, L18Google Scholar
López-Corredoira, M., Cabrera-Lavers, A., Garzón, F., & Hammersley, P. L., 2002, A&A, 394, 883Google Scholar
López-Corredoira, M. & Molgó, J., 2014, A&A, 567, A106Google Scholar
Minniti, D., Saito, R. K., Alonso-García, J., Lucas, P. W., & Hempel, M., 2011, ApJL, 733, L43Google Scholar
Momany, Y., Zaggia, S., Gilmore, G., et al. 2006, A&A, 451, 515Google Scholar
Newberg, H. J., Yanny, B., Rockosi, C., et al. 2002, ApJ, 569, 245Google Scholar
Pérez-Villegas, A., Portail, M., Wegg, C., & Gerhard, O., 2017, ApJL, 840, L2Google Scholar
Siebert, A., Famaey, B., Minchev, I., et al. 2011, MNRAS, 412, 2026Google Scholar
Tian, H.-J. et al., 2016, arXiv:1603.06262Google Scholar
Wan, J.-C., et al. 2015, Research in Astronomy and Astrophysics, 15, 1166Google Scholar
Wan, J.-C., Liu, C., & Deng, L.-C., 2017, Research in Astronomy and Astrophysics, 17, 079Google Scholar
Wang, Q., Wang, Y., Liu, C., Mao, S., & Long, R. J., 2017, MNRAS, 470, 2949Google Scholar
Widrow, L. M., Gardner, S., Yanny, B., Dodelson, S., & Chen, H.-Y., 2012, ApJL, 750, L41Google Scholar
Williams, M. E. K., Steinmetz, M., Binney, J., et al. 2013, MNRAS, 436, 101Google Scholar
Xu, Y., Newberg, H. J., Carlin, J. L., et al. 2015, ApJ, 801, 105Google Scholar
Yao, S. et al., Research in Astronomy and Astrophysics, 12, 772Google Scholar
Zhao, G., et al. 2012, Research in Astronomy and Astrophysics, 12, 723Google Scholar