The IGRINS YSO Survey. III. Stellar Parameters of Pre-main-sequence Stars in Ophiuchus and Upper Scorpius
The IGRINS YSO Survey. III. Stellar Parameters of Pre-main-sequence Stars in Ophiuchus and Upper Scorpius
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DOI：
10.3847/1538-4357/acab04
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发表时间：
2022-12
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通讯作者：
Ricardo López-Valdivia;G. Mace;E. Han;E. Sawczynec;Jesús Hernández;L. Prato;C. Johns–Krull;Heeyoung Oh;Jaejoon Lee;A. Kraus;J. Llama;D. Jaffe
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作者：
Ricardo López-Valdivia;G. Mace;E. Han;E. Sawczynec;Jesús Hernández;L. Prato;C. Johns–Krull;Heeyoung Oh;Jaejoon Lee;A. Kraus;J. Llama;D. Jaffe
我们使用浸没光栅红外光谱仪（IGRINS）测定了位于蛇夫座和天蝎座上部恒星形成区的61个K型和m型年轻恒星天体（YSOs）的基本参数。我们采用合成光谱和马尔可夫链蒙特卡罗方法拟合特定的K波段光谱区域，并确定光球温度(T)、表面重力（log）、磁场强度(B)、投影转速（vsini）和K波段遮蔽（r K）。我们在46%的样本中测定了B。我们将恒星参数与本系列第一篇论文中提出的金牛座-御夫座和长蛇座TW星群的结果进行了比较。我们对IGRINS巡天中所有的yso进行了分类，采用2微米全天巡天和广域红外巡天探测器的红外光谱指数在2 ~ 24 μm之间。我们发现II类yso通常比III类yso具有更低的logg和vsini，相似的B和更高的k波段覆盖度。此外，我们还确定了用IGRINS观测到的K和M场恒星样本的恒星参数。在IGRINS YSO调查中，我们通过对恒星参数的均匀测定，确定了不同演化阶段的内在相似性和差异性。考虑到对数作为年龄的代表，我们发现蛇夫座和金牛座样本的年龄相似。我们还发现，上天蝎座和TWA的YSOs年龄相似，并且比蛇夫座/金牛座的YSOs更进化。
We used the Immersion GRating Infrared Spectrometer (IGRINS) to determine fundamental parameters for 61 K- and M-type young stellar objects (YSOs) located in the Ophiuchus and Upper Scorpius star-forming regions. We employed synthetic spectra and a Markov chain Monte Carlo approach to fit specific K-band spectral regions and determine the photospheric temperature (T), surface gravity ( logg ), magnetic field strength (B), projected rotational velocity ( vsini ), and K-band veiling (r K ). We determined B for ∼46% of our sample. Stellar parameters were compared to the results from Taurus-Auriga and the TW Hydrae association presented in Paper I of this series. We classified all the YSOs in the IGRINS survey with infrared spectral indices from Two Micron All Sky Survey and Wide-field Infrared Survey Explorer photometry between 2 and 24 μm. We found that Class II YSOs typically have lower logg and vsini , similar B, and higher K-band veiling than their Class III counterparts. Additionally, we determined the stellar parameters for a sample of K and M field stars also observed with IGRINS. We have identified intrinsic similarities and differences at different evolutionary stages with our homogeneous determination of stellar parameters in the IGRINS YSO survey. Considering logg as a proxy for age, we found that the Ophiuchus and Taurus samples have a similar age. We also find that Upper Scorpius and TWA YSOs have similar ages, and are more evolved than Ophiuchus/Taurus YSOs.