MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4–5 μm
MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4–5 μm
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奇迹：直接成像的 4-5 μm 行星和次恒星伴星的大气特征
DOI：
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发表时间：
2019
影响因子：
6.5
通讯作者：
B. Lavie
中科院分区：
文献类型：
--
作者：
T. Stolker;S. Quanz;K. Todorov;Jonas Kuhn;P. Mollière;Michael R. Meyer;Thayne Currie;S. Daemgen;B. Lavie
PDS 70的拱星盘上有两颗正在形成的行星，它们正在积极地从环境中吸积气体。这些行星的物理和化学特征仍然模糊不清，因为它们与更进化的物体相比具有不寻常的光谱外观。在这项工作中，我们报告了使用VLT/纳科在Brα和M′过滤器中首次检测到PDS 70 B，在Brα中尝试检测到PDS 70 c，以及对存档的纳科L′和SPHERE H23和K12成像数据的再分析。圆盘的近侧也可以用Brα和M′滤波器分辨，表明散射光在这些波长下是不可忽略的。PDS 70 B b的光谱能量分布（SED）可用黑体辐射来描述，光球温度和光球半径分别为Teff = 1193 ± 20 K和R = 3.0 ± 0.2 RJ。相对较低的辐射热光度log（L scinL）= −3.79 ± 0.02，加上大半径，与完全对流天体的标准结构模型不相容。通过此类模型的预测，并采用最近对吸积率的估计，我们推导出行星质量和半径在Mp ≈ 0.5-1.5 MJ和Rp ≈ 1-2.5 RJ范围内，与行星的年龄和形成后的熵无关。黑体辐射，大光球半径，以及光球和行星半径之间的差异表明红外观测探测行星周围的扩展，尘埃环境，这模糊了其分子组成的观点。因此，SED有望追踪来自行星内部和/或部分来自吸积激波的再处理辐射。光球半径位于行星希尔球的深处，这意味着PDS 70 B不仅吸积气体，而且还不断补充尘埃。最后，我们得出了一个粗略的上限的温度和半径的潜在过剩排放从一个环行星盘，Teff 256 K和R 245 RJ，但我们确实找到了微弱的证据表明，目前的数据有利于一个模型与一个单一的黑体组件。
The circumstellar disk of PDS 70 hosts two forming planets, which are actively accreting gas from their environment. The physical and chemical characteristics of these planets remain ambiguous due to their unusual spectral appearance compared to more evolved objects. In this work, we report the first detection of PDS 70 b in the Brα and M′ filters with VLT/NACO, a tentative detection of PDS 70 c in Brα, and a reanalysis of archival NACO L′ and SPHERE H23 and K12 imaging data. The near side of the disk is also resolved with the Brα and M′ filters, indicating that scattered light is non-negligible at these wavelengths. The spectral energy distribution (SED) of PDS 70 b is well described by blackbody emission, for which we constrain the photospheric temperature and photospheric radius to Teff = 1193 ± 20 K and R = 3.0 ± 0.2 RJ. The relatively low bolometric luminosity, log(L∕L⊙) = −3.79 ± 0.02, in combination with the large radius, is not compatible with standard structure models of fully convective objects. With predictions from such models, and adopting a recent estimate of the accretion rate, we derive a planetary mass and radius in the range of Mp ≈ 0.5–1.5 MJ and Rp ≈ 1–2.5 RJ, independently of the age and post-formation entropy of the planet. The blackbody emission, large photospheric radius, and the discrepancy between the photospheric and planetary radius suggests that infrared observations probe an extended, dusty environment around the planet, which obscures the view on its molecular composition. Therefore, the SED is expected to trace the reprocessed radiation from the interior of the planet and/or partially from the accretion shock. The photospheric radius lies deep within the Hill sphere of the planet, which implies that PDS 70 b not only accretes gas but is also continuously replenished by dust. Finally, we derive a rough upper limit on the temperature and radius of potential excess emission from a circumplanetary disk, Teff ≲ 256 K and R ≲ 245 RJ, but we do find weak evidence that the current data favors a model with a single blackbody component.
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影响因子：
6.5
作者：
T. Schmidt;M. Mugrauer;R. Neuhauser;N. Vogt;S. Witte;P. Hauschildt;C. Helling;A. Seifahrt;A. I. U. Universitatssternwarte;Jena;H Germany;D. D. Astronom'ia-D.;Valpara'iso;Chile.;H. Sternwarte;S. O. Physics;Astronomy;S. Andrews;UK.;D. O. Astronomy;Astrophysics;Chicago.;Usa
通讯作者：
T. Schmidt;M. Mugrauer;R. Neuhauser;N. Vogt;S. Witte;P. Hauschildt;C. Helling;A. Seifahrt;A. I. U. Universitatssternwarte;Jena;H Germany;D. D. Astronom'ia-D.;Valpara'iso;Chile.;H. Sternwarte;S. O. Physics;Astronomy;S. Andrews;UK.;D. O. Astronomy;Astrophysics;Chicago.;Usa
DOI：
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发表时间：
2017-05
期刊：
arXiv: Instrumentation and Methods for Astrophysics
影响因子：
--
作者：
A. Carnall
通讯作者：
A. Carnall
双子座 NICI 行星搜寻活动：发现年轻碎片盘恒星 PZ Tel 的近恒星伴星
DOI：
10.1088/2041-8205/720/1/l82
发表时间：
2010
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Biller B
通讯作者：
Biller B
DOI：
10.3847/2041-8213/ab46b0
发表时间：
2019-09
期刊：
The Astrophysical Journal Letters
影响因子：
--
作者：
J. Bae;Zhaohuan Zhu;C. Baruteau;M. Benisty;C. Dullemond;S. Facchini;A. Isella;M. Keppler;L. P'ere
通讯作者：
J. Bae;Zhaohuan Zhu;C. Baruteau;M. Benisty;C. Dullemond;S. Facchini;A. Isella;M. Keppler;L. P'ere
DOI：
10.3847/2041-8213/ab2a12
发表时间：
2019-06
期刊：
The Astrophysical Journal Letters
影响因子：
--
作者：
A. Isella;M. Benisty;R. Teague;J. Bae;M. Keppler;S. Facchini;L. P'erez
通讯作者：
A. Isella;M. Benisty;R. Teague;J. Bae;M. Keppler;S. Facchini;L. P'erez