高角分辨率 ALMA 对 HL Tau 区域观测的初步结果
太阳与恒星天体物理
2016-09-30 v3
摘要
我们展示了阿塔卡马大型毫米波/亚毫米波阵列(ALMA)在2014年长基线战役中对 HL Tau 区域的尘埃连续谱和谱线发射的观测结果。波长为 2.9、1.3 和 0.87 mm 的连续谱图像具有前所未有的角分辨率，从 0.075 角秒(10 AU)到 0.025 角秒(3.5 AU)，揭示了围绕年轻类太阳天体 HL Tau 的星周盘中令人惊叹的细节，在所有波长上均观测到亮环与暗环相间的图样。通过对最显著的环拟合椭圆，我们精确测量了盘倾角(46.72±0.05 度)和位置角(+138.02±0.07 度)。我们获得了 1.0 mm 谱指数()的高保真图像，该指数在光学厚的中心峰和两个最亮环中约为 ，在暗环中增加至 2.3-3.0。暗环并非没有发射，我们估计最内暗环的尘埃发射率指数为 0.8，后续暗环更低，这与一定程度的尘埃生长和演化一致。环源自行星形成的其他线索包括其中心偏移随半径增加而增大，以及存在众多轨道共振。在 35 AU 分辨率下，我们分辨了盘中 HCO+ (1-0) 的分子成分，其展示的 LSR 速度从 2-12 km/s 的图样与围绕一颗约 1.3 太阳质量恒星的开普勒运动一致，尽管在低蓝移速度处的吸收使其复杂化。我们还偶然探测并分辨了附近原恒星 XZ Tau (A/B) 和 LkHa358 在 2.9 mm 处的辐射。
引用
@article{arxiv.1503.02649,
title = {First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region},
author = {ALMA Partnership and C. L. Brogan and L. M. Perez and T. R. Hunter and W. R. F. Dent and A. S. Hales and R. Hills and S. Corder and E. B. Fomalont and C. Vlahakis and Y. Asaki and D. Barkats and A. Hirota and J. A. Hodge and C. M. V. Impellizzeri and R. Kneissl and E. Liuzzo and R. Lucas and N. Marcelino and S. Matsushita and K. Nakanishi and N. Phillips and A. M. S. Richards and I. Toledo and R. Aladro and D. Broguiere and J. R. Cortes and P. C. Cortes and D. Espada and F. Galarza and D. Garcia-Appadoo and L. Guzman-Ramirez and E. M. Humphreys and T. Jung and S. Kameno and R. A. Laing and S. Leon and G. Marconi and A. Mignano and B. Nikolic and L. -A. Nyman and M. Radiszcz and A. Remijan and J. A. Rodon and T. Sawada and S. Takahashi and R. P. J. Tilanus and B. Vila Vilaro and L. C. Watson and T. Wiklind and E. Akiyama and E. Chapillon and I. de Gregorio-Monsalvo and J. Di Francesco and F. Gueth and A. Kawamura and C. -F. Lee and Q. Nguyen Luong and J. Mangum and V. Pietu and P. Sanhueza and K. Saigo and S. Takakuwa and C. Ubach and T. van Kempen and A. Wootten and A. Castro-Carrizo and H. Francke and J. Gallardo and J. Garcia and S. Gonzalez and T. Hill and T. Kaminski and Y. Kurono and H. -Y. Liu and C. Lopez and F. Morales and K. Plarre and G. Schieven and L. Testi and L. Videla and E. Villard and P. Andreani and J. E. Hibbard and K. Tatematsu},
journal= {arXiv preprint arXiv:1503.02649},
year = {2016}
}
备注
11 pages, 5 figures, 2 tables, accepted for publication in the Astrophysical Journal Letters