Isolated Hot Stars in the Galactic Center Vicinity
نویسندگان
چکیده
Using near-infrared imaging and spectroscopy, we discuss the discovery of six emission-line sources within D20 pc of Sgr A West but outside of the central parsec. The objects are coincident with stars seen in the J, H, and K@ images ; all have Brc (2.166 km) in emission, several also have He I (2.058 and 2.112/3 km), and some have He II (2.189 km) emission lines. Comparison of the Hand K-band spectra of the newly discovered stars with recently published infrared spectral atlases of optically classiÐed stars suggests that most of these stars are similar to massive stars in transition (e.g., Ofpe/WN9, B[e], and LBV), although one is deÐnitely a WN6 star. Two of the potential stars are associated with the radio emission regions AÈD near Sgr A East, three are near or within the radio emission regions H1ÈH8 (nomenclature from Yusef-Zadeh & Morris), the last is near G0.10]0.02 and is likely to be associated with the G0.12]0.02 (Arches) cluster of stars, discussed in a previous paper. The stars are shown to be signiÐcant sources of ionization for their associated radio emission regions, with several capable of completely ionizing the regions. These results provide additional support for the idea that these thermal radio regions, and similar such regions in the Galactic center, are indeed photoionized by hot young stars. Subject headings : Galaxy : center È infrared : stars È stars : early-type È stars : Wolf-Rayet
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