Massive stars have a strong impact on their local environments. However, how stellar feedback regulates star formation is still under debate. In this context, we studied the chemical properties of 80 dense cores in the Orion molecular cloud complex composed of the Orion A (39 cores), B (26 cores), and λ Orionis (15 cores) clouds using multiple molecular line data taken with the Korean Very Long Baseline Interferometry Network 21 m telescopes. The λ Orionis cloud has an H ii bubble surrounding the O-type star λ Ori, and hence it is exposed to the ultraviolet (UV) radiation field of the massive star. The abundances of C₂H and HCN, which are sensitive to UV radiation, appear to be higher in the cores in the λ Orionis cloud than in those in the Orion A and B clouds, while the HDCO to H₂CO abundance ratios show the opposite trend, indicating warmer conditions in the λ Orionis cloud. The detection rates of dense gas tracers such as the N₂H⁺, HCO⁺, and H¹³CO⁺ lines are also lower in the λ Orionis cloud. These chemical properties imply that the cores in the λ Orionis cloud are heated by UV photons from λ Ori. Furthermore, the cores in the λ Orionis cloud do not show any statistically significant excess in the infall signature of HCO⁺ (1–0), unlike those in the Orion A and B clouds. Our results support the idea that feedback from massive stars impacts star formation in a negative way by heating and evaporating dense materials, as in the λ Orionis cloud.

大质量恒星对其当地环境有很大的影响。然而，恒星反馈如何调节恒星形成仍存在争议。在此背景下，我们使用多个分子线数据研究了由猎户座 A（39 个核心）、B（26 个核心）和λ Orionis（15 个核心）云组成的猎户座分子云复合体中 80 个致密核心的化学性质。韩国甚长基线干涉测量网络 21 m 望远镜。所述λ猎户座云具有H II周围O型星气泡λ Ori的，因此它暴露于大质量恒星的紫外（UV）辐射场。对紫外线辐射敏感的 C ₂ H 和 HCN的丰度似乎在地核中更高。λ Orionis 云比 Orion A 和 B 云中的那些，而 HDCO 与 H ₂ CO 丰度比显示出相反的趋势，表明λ Orionis 云中的条件更温暖。在λ Orionis 云中，诸如 N ₂ H ⁺、HCO ⁺和 H ¹³ CO ⁺谱线等致密气体示踪剂的检测率也较低。这些化学性质意味着λ Orionis 云中的核心被来自λ Ori 的紫外线光子加热。此外，λ Orionis 云中的核心在HCO ⁺(1-0)，与猎户座 A 和 B 云中的不同。我们的结果支持这样一个观点，即来自大质量恒星的反馈通过加热和蒸发致密物质以负面方式影响恒星的形成，如猎户座λ云。