The SPHERE view of the Chamaeleon I star-forming region
C. Ginski, A. Garufi, M. Benisty, R. Tazaki, C. Dominik, A. Ribas, N. Engler, T. Birnstiel, G. Chauvin, G. Columba, S. Facchini, A. Goncharov, J. Hagelberg, T. … 展开作者
C. Ginski, A. Garufi, M. Benisty, R. Tazaki, C. Dominik, A. Ribas, N. Engler, T. Birnstiel, G. Chauvin, G. Columba, S. Facchini, A. Goncharov, J. Hagelberg, T. Henning, M. Hogerheijde, R. G. van Holstein, J. Huang, T. Muto, P. Pinilla, K. Kanagawa, S. Kim, N. Kurtovic, M. Langlois, C. Manara, J. Milli, M. Momose, R. Orihara, N. Pawellek, C. Pinte, C. Rab, T. O. B. Schmidt, F. Snik, Z. Wahhaj, J. Williams, A. Zurlo
本研究利用 VLT/SPHERE 近红外偏振散射光观测 Cha I 的 20 个系统，结合 ALMA 与恒星资料刻画星周盘，并发现近距双星与星周物质探测显著反相关。
摘要：
我们使用 VLT/SPHERE 在近红外偏振散射光中观测了 Cha I 云内的 20 个系统。我们将散射光观测与现有文献中关于恒星性质的数据以及存档的 ALMA 连续谱数据相结合，以研究随系统年龄和尘埃质量变化的趋势。我们还将分辨的近红外观测与这些系统的光谱能量分布联系起来。在本研究纳入的 20 个系统中，有 13 个系统我们探测到来自星周尘埃的分辨散射光信号。对于 CR Cha、CT Cha、CV Cha、SY Cha、SZ Cha 和 VZ Cha 系统，我们首次给出了散射光下盘的详细描述。观测发现，这些盘通常平滑或暗弱，往往几乎没有子结构；显著的例外是 SZ Cha，它显示出一个延展的多环盘，以及 WW Cha，它显示出与云环境的相互作用。我们巡测中 HD 97048 系统新的高信噪比 K 波段观测揭示出显著的亮度不对称，这可能指向盘未对准以及随后对外侧盘区域造成的阴影，或许与该盘中被提出的行星候选体有关。我们首次分辨出 CS Cha 系统中的恒星双星。对 CS Cha 周围盘的多波长观测表明，该系统含有可能强烈沉降的小而致密的尘埃颗粒，这与环双星盘的数值研究一致。我们在样本中发现，（近距）恒星伴星的存在与星周物质的探测之间存在强烈的反相关：我们的 7 个未探测对象中有 5 个位于双星系统中。
英文摘要：
We used VLT/SPHERE to observe 20 systems in the Cha I cloud in polarized scattered light in the near-infrared. We combined the scattered light observations with existing literature data on stellar properties and with archival ALMA continuum data to study trends with system age and dust mass. We also connected resolved near-infrared observations with the spectral energy distributions of the systems. In 13 of the 20 systems included in this study we detected resolved scattered light signals from circumstellar dust. For the CR Cha, CT Cha, CV Cha, SY Cha, SZ Cha, and VZ Cha systems we present the first detailed descriptions of the disks in scattered light. The observations found typically smooth or faint disks, often with little substructure, with the notable exceptions of SZ Cha, which shows an extended multiple-ringed disk, and WW Cha, which shows interaction with the cloud environment. New high S/N K- band observations of the HD 97048 system in our survey reveal a significant brightness asymmetry that may point to disk misalignment and subsequent shadowing of outer disk regions, possibly related to the suggested planet candidate in the disk. We resolve for the first time the stellar binary in the CS Cha system. Multiple wavelength observations of the disk around CS Cha have revealed that the system contains small, compact dust grains that may be strongly settled, consistent with numerical studies of circumbinary disks. We find in our sample that there is a strong anti-correlation between the presence of a (close) stellar companion and the detection of circumstellar material with five of our seven nondetections located in binary systems.
Dust masses of Upper Scorpius disks and their statistics
School of Physical Science and Technology, Southwest Jiaotong University（西南交通大学物理科学与技术学院）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）
Luminosity Functions of Spitzer Identified Protostars in Nine Nearby Molecular Clouds
We identify protostars in Spitzer surveys of nine star-forming molecular clouds within 1 kpc: Serpens, Perseus, Ophiuchus, Chamaeleon, Lupus, Taurus, Orion, Cep OB3, and Mon R2, which combined host over 700 protostar candidates. Our diverse cloud sample allows us to compare protostar luminosity functions in these varied environments. We combine photometry from 2MASS J, H, and Ks bands and Spitzer IRAC and MIPS 24 micron bands to create 1 - 24 micron spectral energy distributions (SEDs). Using protostars from the c2d survey with well-determined bolometric luminosities (Lbol), we derive a relati…
