Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-17T18:16:25.393Z Has data issue: false hasContentIssue false
  • English
  • Français

Enrichment of Heavy Elements in Chemo-Dynamical Simulations of Dwarf Galaxies

Published online by Cambridge University Press:  30 October 2019

Yutaka Hirai Open the ORCID record for Yutaka Hirai [Opens in a new window] ,
Takayuki R. Saitoh ,
Shinya Wanajo  and
Michiko S. Fujii
Yutaka Hirai
Affiliation:
RIKEN Center for Computational Science, 7-1-26 Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047, Japan email: yutaka.hirai@riken.jp
Takayuki R. Saitoh
Affiliation:
Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
Shinya Wanajo
Affiliation:
Department of Engineering and Applied Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan RIKEN iTHEMS Research Group, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Michiko S. Fujii
Affiliation:
Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Abundances of heavy elements in dwarf galaxies reflect their early evolutionary histories. Recent astronomical observations have shown that there are star-to-star scatters in the abundances of r-process elements and the decreasing trend of Zn toward higher metallicity in extremely metal-poor stars. However, the enrichment of heavy elements is not well understood. Here we performed a series of high-resolution N-body/smoothed particle hydrodynamics simulations of dwarf galaxies. We find that neutron star mergers can explain ratios of r-process elements to iron in dwarf galaxies due to their suppressed star formation rates. We also find that stars with [Zn/Fe] ≳ 0.5 reflect the ejecta from electron-capture supernovae. Inhomogeneity of the metals in the interstellar medium causes the scatters of heavy elements. We estimate that the timescale of metal mixing is ≲ 40 Myr using heavy element abundances in metal-poor stars.

Keywords

diffusiongalaxies: abundancesgalaxies: dwarfgalaxies: evolutionhydrodynamicsISM: abundancesmethods: numericalnucleosynthesisstars: abundancesLocal Group
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 14 , Symposium S344: Dwarf Galaxies: From the Deep Universe to the Present , August 2018 , pp. 197 - 200
Copyright
© International Astronomical Union 2019 

References

Abbott, B. P. et al. 2017, Phys. Rev. Lett., 119, 161101 CrossRefGoogle ScholarPubMed
Doherty, C. L., Gil-Pons, P., Siess, L., Lattanzio, J. C., & Lau, H. H. B. 2015, MNRAS, 446, 2599 CrossRefGoogle Scholar
Frebel, A., & Norris, J. E. 2015, ARAA, 53, 631 CrossRefGoogle Scholar
Geisler, D., Smith, V. V., Wallerstein, G., Gonzalez, G., & Charbonnel, C. 2005, AJ, 129, 1428 CrossRefGoogle Scholar
Ji, A. P., Frebel, A., Chiti, A., & Simon, J. D. 2016, Nature, 531, 610 CrossRefGoogle Scholar
Heger, A., & Woosley, S. E. 2002, ApJ, 567, 532 CrossRefGoogle Scholar
Hirai, Y., Ishimaru, Y., Saitoh, T. R., Fujii, M. S., Hidaka, J., & Kajino, T. 2015, ApJ, 814, 41 CrossRefGoogle Scholar
Hirai, Y., Ishimaru, Y., Saitoh, T. R., Fujii, M. S., Hidaka, J., & Kajino, T. 2017, MNRAS, 466, 2474 CrossRefGoogle Scholar
Hirai, Y., & Saitoh, T. R. 2017, ApJ (Letters), 838, L23 Google Scholar
Hirai, Y., Saitoh, T. R., Ishimaru, Y., & Wanajo, S. 2018, ApJ, 855, 63 CrossRefGoogle Scholar
Ishimaru, Y., Wanajo, S., & Prantzos, N. 2015, ApJ (Letters), 804, L35 Google Scholar
Kirby, E. N., & Cohen, J. G. 2012, AJ, 144, 168 CrossRefGoogle Scholar
Kirby, E. N., Guhathakurta, P., Bolte, M., Sneden, C., & Geha, M. C. 2009, ApJ, 705, 328 CrossRefGoogle Scholar
Kirby, E. N., Guhathakurta, P., Simon, J. D., Geha, M. C., Rockosi, C. M., Sneden, C., Cohen, J. G., Sohn, S. T., Majewski, S. R., & Siegel, M. 2010, ApJS, 191, 352 CrossRefGoogle Scholar
Kroupa, P. 2001, MNRAS, 322, 231 CrossRefGoogle Scholar
Nomoto, K., Kobayashi, C., & Tominaga, N. 2013, ARAA, 51, 457 CrossRefGoogle Scholar
Ojima, T., Ishimaru, Y., Wanajo, S., Prantzos, N., & François, P. 2018, ApJ in press, arXiv:1808.03390Google Scholar
Revaz, Y., & Jablonka, P. 2012, A&A, 538, A82 Google Scholar
Roederer, I. U., Mateo, M., Bailey, J. I., Song, Y., Bell, E. F., Crane, J. D., Loebman, S., Nidever, D. L., Olszewski, E. W., Shectman, S. A., Thompson, I. B., Valluri, M., & Walker, M. G 2016, AJ, 151, 82 CrossRefGoogle Scholar
Saito, Y.-J., Takada-Hidai, M., Honda, S., & Takeda, Y. 2009, PASJ, 61, 549 CrossRefGoogle Scholar
Saitoh, T. R. 2017, AJ, 153, 85 CrossRefGoogle Scholar
Saitoh, T. R., Daisaka, H., Kokubo, E., Makino, J., Okamoto, T., Tomisaka, K., Wada, K., & Yoshida, N. 2008, PASJ, 60, 667 CrossRefGoogle Scholar
Saitoh, T. R., Daisaka, H., Kokubo, E., Makino, J., Okamoto, T., Tomisaka, K., Wada, K., & Yoshida, N 2009, PASJ, 61, 481 CrossRefGoogle Scholar
Seitenzahl, I. R., Ciaraldi-Schoolmann, F., Röpke, F. K., Fink, M., Hillebrandt, W., Kromer, M., Pakmor, R., Ruiter, A. J., Sim, S. A., & Taubenberger, S. 2013, MNRAS, 429, 1156 CrossRefGoogle Scholar
Shen, S., Wadsley, J., & Stinson, G. 2010, MNRAS, 407, 1581 CrossRefGoogle Scholar
Shetrone, M., Venn, K. A., Tolstoy, E., Primas, F., Hill, V., & Kaufer, A. 2003, AJ, 125, 684 CrossRefGoogle Scholar
Simon, J. D., Jacobson, H. R., Frebel, A., Thompson, I. B., Adams, J. J., & Shectman, S. A. 2015, ApJ, 802, 93 CrossRefGoogle Scholar
Skúladóttir, Á., Tolstoy, E., Salvadori, S., Hill, V., & Pettini, M. 2017, A&A, 606, A71 Google Scholar
Suda, T., Hidaka, J., Aoki, W., Katsuta, Y., Yamada, S., Fujimoto, M. Y., Ohtani, Y., Masuyama, M., Noda, K., & Wada, K. 2017, PASJ, 69, 76 CrossRefGoogle Scholar
Suda, T., Katsuta, Y., Yamada, S., Suwa, T., Ishizuka, C., Komiya, Y., Sorai, K., Aikawa, M., & Fujimoto, M. Y. 2008, PASJ, 60, 1159 CrossRefGoogle Scholar
Wanajo, S., Müller, B., Janka, H.-T., & Heger, A. 2018, ApJ, 852, 40 CrossRefGoogle Scholar
Wanajo, S., Sekiguchi, Y., Nishimura, N., Kiuchi, K., Kyutoku, K., & Shibata, M. 2014, ApJ (Letters), 789, L39 Google Scholar