Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1B039

The Massive Stellar Population of W49: a Spectroscopic Survey

Wu, Shiwei (MPIA, Heidelberg)
Bik, Arjan (MPIA, Heidelberg)
Henning, Thomas (MPIA, Heidelberg)
Pasquali, Anna (ARI, Heidelberg)
Alves, Joao (Universitaet Wien)
Stolte, Andrea (AIfA, Bonn)
Brandner, Wolfgang (MPIA, Heidelberg)
Gennaro, Mario (Space Telescope Science Institute)
Rochau, Boyke (MPIA, Heidelberg)
Gouliermis, Dimitrios (MPIA, Heidelberg)
Beuther, Henrik (MPIA, Heidelberg)
Wang, Yuan (PMO, China)

As a part of LOBSTAR project (Luci OBservations of STARburst regions) which aims at understanding the stellar content of young star-forming regions, we present our first result on the high-mass stellar content of W49. Near-infrared imaging observations are obtained with LUCI at the Large Binocular Telescope and SOFI of New Technology Telescope (NTT). The K-band spectra (ISAAC/VLT) of the candidate massive stars provide us with more reliable spectral types than photometry alone. Four massive stars are identified as O3V-O5V stars while indications for an O2If*/WN6 star are found for a possible very massive star. After spectroscopic classification (and applying the proper extinction law), the objects can be placed in a Hertzsprung¨CRussell diagram. With comparison to stellar evolution models, the age of the cluster is estimated as lower than 2Myrs and the mass of the massive stars are calculated.

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