Paschen α Observations of Be Stars Toward the SMC Cluster NGC 330
| Autor: | Masahiro Konishi, Natsuko Kato, Noriyuki Matsunaga, Koji Toshikawa, Yuzuru Yoshii, Ken Tateuchi, Yoshifusa Ita, Kentaro Motohara, Toshihiko Tanabe |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Publications of the Astronomical Society of Japan. 65:55 |
| ISSN: | 2053-051X 0004-6264 |
| DOI: | 10.1093/pasj/65.3.55 |
| Popis: | We made imaging observations of the young SMC cluster NGC 330 in the near-infrared $ J$ , $ H$ , $ K_{\rm s}$ as well as two narrow-band Pa $ \alpha $ and Pa $ \alpha $ -off filters. The observations were carried out at a high-altitude site, 5640 m, where the atmospheric extinction is small enough to make the spectral range around Pa $ \alpha $ transparent. We present the calibration of specially designed narrow-band filters, and the method used to identify Pa $ \alpha $ emission using photometric colors. We have successfully detected Pa $ \alpha $ emission from almost all Be stars within the detection limit of the small telescope and the narrow-band filters. The strength of Pa $ \alpha $ emission well correlates with that of H $ \alpha $ , which also confirms the proper detection of Pa $ \alpha $ emission. This was the first systematic detection of the Pa $ \alpha $ emission line from Be stars. We also found new candidates of Pa $ \alpha $ emission-line objects. This work demonstrates that the photometric colors, including the Pa $ \alpha $ band, can be used to detect the Pa $ \alpha $ line when observed from high-altitude sites. |
| Databáze: | OpenAIRE |
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