Young Stellar Object Candidates in the Aquila Rift Region

Using the 2m telescope of the Turingia State Observatory at Tauten-berg (TLS), imaging observations in 3 wavebands (Hα, R and I) are performed in the 16 fields in the Aquila Rift region. The observed fields cover about 7 square degrees. Excluding the 3 fields with unqualified data, the photometrical analysis is made for the remaining 13 fields, from which point sources are identified, and finally 7 Hα emission-line star candidates are identified by color-color diagrams. The 7 candidates are located in five fields. Three of them are located near the Galactic plane, while the galactic latitudes of the rest are greater than 4°. The 2 M ASS counterparts of the point sources are identified, and the properties of the 7 Hα emission-line star candidates are further analyzed by using the two-color diagrams. It is found that the near-infrared radiation from these Hα emission-line star candidates has no obvious infrared excess, one of them even falls on the main-sequence branch. This indicates that the Hα-emissive young stellar objects (YSOs) are not always accompanied with the infrared excess, and that the results of the Hα emission line observation and the infrared excess observation are mutually supplemented. If the 7 Hα emission-line star candidates are regarded as YSO candidates, then the number of YSOs in the Aquila Rift region is quite small. The further confirmation of these candidates needs subsequent spectral observations.