Hostname: page-component-7dd5485656-j7khd Total loading time: 0 Render date: 2025-11-01T07:26:08.840Z Has data issue: false hasContentIssue false
  • English
  • Français

Kinematics of The Tidally Disrupting Dwarf Galaxy Antlia II

Published online by Cambridge University Press:  30 October 2025

Alexander Ji Open the ORCID record for Alexander Ji [Opens in a new window]  and
the S5 Collaboration
Alexander Ji*
Affiliation:
University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637, USA
*
email: alexji@uchicago.edualexji@uchicago.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

The Milky Way satellite dwarf galaxy Antlia II is one of the lowest surface brightness galaxies known. It has a size comparable to the Large Magellanic Cloud, but only 106 solar masses of stars. We present kinematic and chemical measurements from the Southern Stellar Stream Spectroscopic Survey using the AAT/2dF that clearly demonstrate that Antlia II is tidally disrupting. The orbit and velocity gradient also clearly shows that the Milky Way has moved in response to the Large Magellanic Cloud. However, Antlia II currently lies on the galaxy mass-metallicity relation, suggesting that it has not lost too much stellar mass. These measurements illustrate the importance of full dynamic models when interpreting the masses of local group galaxies.

Keywords

Dwarf galaxiesstellar streamsLocal Group

Information

Type
Contributed Paper
Information
Proceedings of the International Astronomical Union , Volume 19 , Symposium S379: Dynamical Masses of Local Group Galaxies , December 2023 , pp. 141 - 146
Check for updates
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of International Astronomical Union

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Broadhurst, T., De Martino, I., Luu, H. N., Smoot, G. F., & Tye, S. H. H. 2020, Phys. Rev. D, 101(8), 083012.CrossRefGoogle Scholar
Caldwell, N., Walker, M. G., Mateo, M., Olszewski, E. W., Koposov, S., Belokurov, V., Torrealba, G., Geringer-Sameth, A., & Johnson, C. I. 2017, ApJ, 839(1), 20.CrossRefGoogle Scholar
Carrera, R., Pancino, E., Gallart, C., & del Pino, A. 2013, MNRAS, 434(2), 1681–1691.CrossRefGoogle Scholar
Collins, M. L. M., Tollerud, E. J., Rich, R. M., Ibata, R. A., Martin, N. F., Chapman, S. C., Gilbert, K. M., & Preston, J. 2020, MNRAS, 491(3), 3496–3514.CrossRefGoogle Scholar
Erkal, D., Belokurov, V., Laporte, C. F. P., Koposov, S. E., Li, T. S., Grillmair, C. J., Kallivayalil, N., Price-Whelan, A. M., Evans, N. W., Hawkins, K., Hendel, D., Mateu, C., Navarro, J. F., del Pino, A., Slater, C. T., Sohn, S. T., & Aspen Treasury Collaboration, Orphan 2019, MNRAS, 487(2), 2685–2700.CrossRefGoogle Scholar
Garavito-Camargo, N., Besla, G., Laporte, C. F. P., Johnston, K. V., Gómez, F. A., & Watkins, L. L. 2019, ApJ, 884(1), 51.CrossRefGoogle Scholar
Gómez, F. A., Besla, G., Carpintero, D. D., Villalobos, Á., O’Shea, B. W., & Bell, E. F. 2015, ApJ, 802(2), 128.CrossRefGoogle Scholar
Ji, A. P., Koposov, S. E., Li, T. S., Erkal, D., Pace, A. B., Simon, J. D., Belokurov, V., Cullinane, L. R., Da Costa, G. S., Kuehn, K., Lewis, G. F., Mackey, D., Shipp, N., Simpson, J. D., Zucker, D. B., Hansen, T. T., Bland-Hawthorn, J., & S5 Collaboration 2021, ApJ, 921(1), 32.CrossRefGoogle Scholar
Ji, A. P., Li, T. S., Hansen, T. T., Casey, A. R., Koposov, S. E., Pace, A. B., Mackey, D., Lewis, G. F., Simpson, J. D., Bland-Hawthorn, J., Cullinane, L. R., Da Costa, G. S., Hattori, K., Martell, S. L., Kuehn, K., Erkal, D., Shipp, N., Wan, Z., & Zucker, D. B. 2020, AJ, 160(4), 181.CrossRefGoogle Scholar
Koposov, S. E. 2019,. Astrophysics Source Code Library, record ascl:1907.013.Google Scholar
Li, T. S., Ji, A. P., Pace, A. B., Erkal, D., Koposov, S. E., Shipp, N., Da Costa, G. S., Cullinane, L. R., Kuehn, K., Lewis, G. F., Mackey, D., Simpson, J. D., Zucker, D. B., Ferguson, P. S., Martell, S. L., Bland-Hawthorn, J., Balbinot, E., Tavangar, K., Drlica-Wagner, A., De Silva, G. M., & Simon, J. D. 2022, ApJ, 928(1), 30.CrossRefGoogle Scholar
Li, T. S., Koposov, S. E., Zucker, D. B., Lewis, G. F., Kuehn, K., Simpson, J. D., Ji, A. P., Shipp, N., Mao, Y. Y., Geha, M., Pace, A. B., Mackey, A. D., Allam, S., Tucker, D. L., Da Costa, G. S., Erkal, D., Simon, J. D., Mould, J. R., Martell, S. L., Wan, Z., De Silva, G. M., Bechtol, K., Balbinot, E., Belokurov, V., Bland-Hawthorn, J., Casey, A. R., Cullinane, L., Drlica-Wagner, A., Sharma, S., Vivas, A. K., Wechsler, R. H., Yanny, B., & S5 Collaboration 2019, MNRAS, 490(3), 3508–3531.CrossRefGoogle Scholar
McGaugh, S. S. 2016, ApJ, 832(1), L8.CrossRefGoogle Scholar
Petersen, M. S. & Peñarrubia, J. 2021, Nature Astronomy, 5, 251–255.CrossRefGoogle Scholar
Sameie, O., Chakrabarti, S., Yu, H.-B., Boylan-Kolchin, M., Vogelsberger, M., Zavala, J., & Hernquist, L. 2020, arXiv e-prints, arXiv:2006.06681.Google Scholar
Sanders, J. L., Evans, N. W., & Dehnen, W. 2018, MNRAS, 478(3), 3879–3889.CrossRefGoogle Scholar
Torrealba, G., Belokurov, V., Koposov, S. E., Li, T. S., Walker, M. G., Sanders, J. L., Geringer-Sameth, A., Zucker, D. B., Kuehn, K., Evans, N. W., & Dehnen, W. 2019, MNRAS, 488(2), 2743–2766.CrossRefGoogle Scholar
Vivas, A. K., Martnez-Vázquez, C. E., Walker, A. R., Belokurov, V., Li, T. S., & Erkal, D. 2022, ApJ, 926(1), 78.CrossRefGoogle Scholar