We present a general method for identifying the pre-main-sequence population of any star-forming region, unbiased with respect to the presence or absence of disks, in contrast to samples selected primarily via their mid-infrared emission from Spitzer surveys. We have applied this technique to a new, deep, wide-field, near-infrared imaging survey of the ρ Ophiuchi cloud core to search for candidate low-mass members. In conjunction with published Spitzer IRAC photometry and least-squares fits of model spectra (COND, DUSTY, NextGen, and blackbody) to the observed spectral energy distributions, we have identified 948 candidate cloud members within our 90% completeness limits of J = 20.0, H = 20.0, and Ks = 18.50. This population represents a factor of ~3 increase in the number of known young stellar objects in the ρ Ophiuchi cloud. A large fraction of the candidate cluster members (81% ± 3%) exhibit infrared excess emission consistent with the presence of disks, thus strengthening the possibility of their being bona fide cloud members. Spectroscopic follow-up will confirm the nature of individual objects, better constrain their parameters, and allow an initial mass function to be derived.
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机译：与主要通过Spitzer调查通过中红外发射选择的样本相比，我们提供了一种通用的方法来识别任何恒星形成区域的主序列前种群，这些样本相对于磁盘的存在或不存在偏差。我们已将此技术应用于ρOphiuchi云核的新的深层，广域，近红外成像调查中，以寻找候选的低质量成员。结合已发布的Spitzer IRAC光度法和模型光谱的最小二乘拟合（COND，DUSTY，NextGen和黑体）与观察到的光谱能量分布，我们在90％的J = 20.0完整性极限内确定了948个候选云成员， H = 20.0，Ks = 18.50。这个种群代表了O蛇夫座云中已知的年轻恒星物体数量增加了约3倍。很大一部分候选簇成员（81％±3％）显示出与磁盘存在一致的红外过量发射，因此增强了它们成为真正的云成员的可能性。光谱跟踪将确认单个对象的性质，更好地约束其参数，并允许导出初始质量函数。
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