THE GEMINI/NICI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF PLANETS AROUND YOUNG MOVING GROUP STARS
THE GEMINI/NICI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF PLANETS AROUND YOUNG MOVING GROUP STARS
复制标题
DOI：
10.1088/0004-637x/777/2/160
复制
发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
B. Biller;Michael C. Liu;Z. Wahhaj;E. Nielsen;Thomas L. Hayward;J. Males;A. Skemer;L. Close;M. Chun;C. Ftaclas;F. Clarke;N. Thatte;E. Shkolnik;I. N. Reid;M. Hartung;A. Boss;D. Lin;S. Alencar;E. M. de Gouveia Dal Pino;J. Gregorio-Hetem;D. Toomey
中科院分区：
文献类型：
--
作者：
B. Biller;Michael C. Liu;Z. Wahhaj;E. Nielsen;Thomas L. Hayward;J. Males;A. Skemer;L. Close;M. Chun;C. Ftaclas;F. Clarke;N. Thatte;E. Shkolnik;I. N. Reid;M. Hartung;A. Boss;D. Lin;S. Alencar;E. M. de Gouveia Dal Pino;J. Gregorio-Hetem;D. Toomey
我们报告了对β Pic，TW Hya，Tucana-Horologium，AB Dor和Hercules-Lyra移动群的80个成员周围的巨行星进行直接成像调查的结果，作为Gemini/NICI行星发现活动的一部分。对于该样品，我们在CH 4窄带ADI+SDI组合模式下获得了1″处的中值对比度ΔH = 13.9 mag，在H波段ADI模式下获得了2″处的中值对比度ΔH = 15.1 mag。我们在调查图像中发现了许多（>70）候选同伴。其中一些候选者被拒绝作为共同的自行同伴使用档案数据;我们用近红外日冕成像仪（NICI）重新观察了所有其他候选者，这些候选者位于星星的400 Au范围内，并且不在密集的恒星场中。绝大多数候选同伴被证实为档案观察和/或专门的NICI运动后续的背景对象。在这个移动的群体样本中发现了四个共同移动的褐矮星或恒星质量的同伴：PZ电话B（36 ± 6兆焦耳，16.4 ± 1.0 Au），CD−35 2722 B（31 ± 8 MJ，67 ± 4 Au），HD 12894 B（0.46 ± 0.08 M，15.7 ± 1.0 Au）和BD+07 1919 C（0.20 ± 0.03 M，12.5 ± 1.4 Au）。通过对H波段ADI和ASDI对比的贝叶斯分析，使用行星分布的幂律模型和热启动进化模型，我们将半长轴10-150 Au处1-20 MJup伴星的频率限制在使用DUSTY模型的95.4%置信水平下<18%，使用COND模型的95.4%置信水平下<6%。我们的研究结果强烈限制半长轴50 Au内的行星的频率。我们使用DUSTY模型在95.4%置信水平下将半长轴上1-20 MJup伴星的频率从10-50 Au限制为<21%，使用COND模型在95.4%置信水平下限制为<7%。这次调查是迄今为止对年轻移动群恒星周围巨行星的最深搜索。
We report results of a direct imaging survey for giant planets around 80 members of the β Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the Gemini/NICI Planet-Finding Campaign. For this sample, we obtained median contrasts of ΔH = 13.9 mag at 1″ in combined CH4 narrowband ADI+SDI mode and median contrasts of ΔH = 15.1 mag at 2″ in H-band ADI mode. We found numerous (>70) candidate companions in our survey images. Some of these candidates were rejected as common-proper motion companions using archival data; we reobserved with Near-Infrared Coronagraphic Imager (NICI) all other candidates that lay within 400 AU of the star and were not in dense stellar fields. The vast majority of candidate companions were confirmed as background objects from archival observations and/or dedicated NICI Campaign followup. Four co-moving companions of brown dwarf or stellar mass were discovered in this moving group sample: PZ Tel B (36 ± 6 MJup, 16.4 ± 1.0 AU), CD−35 2722B (31 ± 8 MJup, 67 ± 4 AU), HD 12894B (0.46 ± 0.08 M☉, 15.7 ± 1.0 AU), and BD+07 1919C (0.20 ± 0.03 M☉, 12.5 ± 1.4 AU). From a Bayesian analysis of the achieved H band ADI and ASDI contrasts, using power-law models of planet distributions and hot-start evolutionary models, we restrict the frequency of 1–20 MJup companions at semi-major axes from 10–150 AU to <18% at a 95.4% confidence level using DUSTY models and to <6% at a 95.4% using COND models. Our results strongly constrain the frequency of planets within semi-major axes of 50 AU as well. We restrict the frequency of 1–20 MJup companions at semi-major axes from 10–50 AU to <21% at a 95.4% confidence level using DUSTY models and to <7% at a 95.4% using COND models. This survey is the deepest search to date for giant planets around young moving group stars.