中文

与小麦哲伦云相关的恒星超密度区

星系天体物理 2017-07-17 v2

摘要

我们利用暗能量巡天 (DES) 前两年和麦哲伦卫星巡天 (MagLiteS) 第一年的数据,报告在麦哲伦云中心以北 8^{\circ} 处发现了一个恒星超密度区(小麦哲伦云北部超密度区;SMCNOD)。SMCNOD 在年龄、金属丰度和距离上与邻近的 SMC 恒星无法区分,主要由中等年龄恒星(6 Gyr, Z=0.001)组成,并包含一小部分年轻恒星(1 Gyr, Z=0.01)。SMCNOD 呈椭率 0.6 的拉长形状,大小约为 6x2 度。其绝对星等为 MVM_V \cong -7.7,rh=2.1r_h = 2.1 kpc,μV(r<rh)\mu_V(r<r_h) = 31.2 mag arcsec2^{-2}。我们遵循 Kroupa 质量函数,估算其恒星质量约为 105\sim 10^5 MM_{\odot}。SMCNOD 很可能因潮汐剥离而从 SMC 盘中被移除,因为它位于麦哲伦流的前端附近,且文献表明近期可能发生过 LMC-SMC 相互作用。缺乏显著的 HI 气体支持了这一图景。SMCNOD 起源的其他可能情形是 SMC 潮汐半径内的瞬态超密度区,或是一个处于瓦解后期的原初 SMC 卫星。

关键词

引用

@article{arxiv.1612.03938,
  title  = {A stellar over-density associated with the Small Magellanic Cloud},
  author = {A. Pieres and B. X. Santiago and A. Drlica-Wagner and K. Bechtol and R. P. van der Marel and G. Besla and N. F. Martin and V. Belokurov and C. Gallart and D. Martinez-Delgado and J. Marshall and N. E. D. Noel and S. R. Majewski and M. -R. L. Cioni and T. S. Li and W. Hartley and E. Luque and B. C. Conn and A. R. Walker and E. Balbinot and G. S. Stringfellow and K. A. G. Olsen and L. N. da Costa and R. Ogando and M. Maia and A. Fausti Neto and T. M. C. Abbott and F. B. Abdalla and S. Allam and J. Annis and A. Benoit-Levy and A. Carnero Rosell and M. Carrasco Kind and J. Carretero and C. E. Cunha and C. B. DAndrea and S. Desai and H. T. Diehl and P. Doel and B. Flaugher and P. Fosalba and J. Garcia-Bellido and D. Gruen and R. A. Gruendl and J. Gschwend and G. Gutierrez and K. Honscheid and D. James and K. Kuehn and N. Kuropatkin and F. Menanteau and R. Miquel and A. A. Plazas and A. K. Romer and M. Sako and E. Sanchez and V. Scarpine and M. Schubnell and I. Sevilla-Noarbe and R. C. Smith and M. Soares-Santos and F. Sobreira and E. Suchyta and M. E. C. Swanson and G. Tarle and D. L. Tucker and W. Wester},
  journal= {arXiv preprint arXiv:1612.03938},
  year   = {2017}
}

备注

14 pages, 10 color figures