Near-and far-infrared counterparts of millimeter dust cores in the Vela molecular ridge cloud D
Near-and far-infrared counterparts of millimeter dust cores in the Vela molecular ridge cloud D
复制标题
Vela 分子脊云 D 中毫米级尘埃核的近红外和远红外对应物
DOI：
10.1051/0004-6361:20077235
复制
发表时间：
2007
影响因子：
6.5
通讯作者：
B. Nisini
中科院分区：
文献类型：
--
作者：
M. Luca;T. Giannini;D. Lorenzetti;F. Massi;D. Elia;B. Nisini
目标。通过新的红外观测（2.12 μ m的H2窄带和10.4 μ m的N宽带）沿着对现有红外星表的研究，确定船帆座分子脊云D尘埃毫米核的年轻原恒星对应物。方法.根据空间重合、红外颜色和光谱能量分布，建立了毫米连续辐射与目录（IRAS、MSX、2 MASS）、文献中的JHK数据和新观测的红外源的关联。结果29个分辨的毫米核中只有7个（26个未分辨的核中有16个）没有显示出星星形成活动的标志。其他的明显与：远红外源，H2喷流指向嵌入的物体（尚未）检测或近红外物体显示出高内在的颜色过剩。与相关源有关的谱指数的分布在I类对象的典型值处达到峰值，而三个对象被信号通知为候选0类源。具有类似于金牛座T星和赫比格Ae/Be星的远红外颜色的天体似乎很少。另外一群年轻天体的存在与毫米核无关，但与弥漫的暖尘排放和气体细丝有关。我们指出，高检测率（30%）的氢喷流驱动的源位于毫米核心。它们似乎不是由场中最明亮的天体驱动的，而是由年轻星团中较不明亮的天体驱动的，这证明了低质量和中等质量星星形成的共存。结论.所提供的结果可靠地描述了VMR-D的年轻人群。然而，活动与所研究的核心的不活动性，甚至与其他星星形成区的结果很好地一致，似乎反映了可用设施的极限灵敏度，而不是mm凝聚的任何固有性质。
Aims. Identify the young protostellar counterparts associated with dust millimeter cores of the Vela Molecular Ridge Cloud D through new IR observations (H 2 narrow-band at 2.12 μ m and N broad band at 10.4 μ m) along with an investigation performed on the existing IR catalogues. Methods. The association of mm continuum emission with infrared sources from catalogues (IRAS, MSX, 2MASS), JHK data from the literature, and new observations, was established according to spatial coincidence, infrared colours and spectral energy distributions. Results. Only 7 out of 29 resolved mm cores (and 16 out of the 26 unresolved ones) do not exhibit signposts of star formation activity. The other ones are clearly associated with: far-IR sources, H 2 jets pointing back to embedded objects not (yet) detected or near-IR objects showing a high intrinsic colour excess. The distribution of the spectral indices pertaining to the associated sources is peaked at values typical of Class I objects, while three objects are signalled as candidates Class 0 sources. Objects with far-IR colours similar to those of T-Tauri and Herbig Ae/Be stars seem to be very few. An additional population of young objects exists associated not with the mm -cores, but with both the diffuse warm dust emission and the gas filaments. We point out the high detection rate (30%) of H 2 jets driven by sources located inside the mm -cores. They do not appear to be driven by the most luminous objects in the field, but rather by less luminous objects in young clusters, testifying the co-existence of both low- and intermediate-mass star formation. Conclusions. The presented results reliably describe the young population of VMR-D. However, the statistical evaluation of activity vs. inactivity of the investigated cores, even in good agreement with results found for other star forming regions, seems to reflect the limiting sensitivity of the available facilities rather than any property intrinsic to the mm -condensations.