The massive stellar population of W49: a spectroscopic survey

Author(s)

S. Wu, A. Bik, Th. Henning, A. Pasquali, J. Alves, A. Stolte, W. Brandner, M. Gennaro, B. Rochau, A. D. Gouliermis, H. Beuther, Y. Wang

Abstract

Where and how are massive stars forming in the Galaxy? Answering this

question is hampered by their high extinction and short life times.

Starburst clusters such as W49 where 100s of OB-type stars are present

are exceptional laboratories to address these issues. W49 is one of the

most luminous and youngest HII regions in our galaxy located at a

distance of 11.4 kpc. The region consists of over 40 ultra-compact HII

regions as well as a more extended Giant HII region. We present

observations made by applying imaging and multi-object spectroscopy in

the K-band of the high-mass stellar content of W49. These near-infrared

observations are obtained with LUCI at the Large Binocular Telescope.

The K-band spectra of the candidate massive stars provide us with more

reliable spectral types than photometry alone. After spectroscopic

classification (and applying the proper extinction law), the objects can

be placed in a Hertzsprung-Russell diagram. With comparison to stellar

evolution models, the age as well as the mass of the stellar population

can be estimated. We present the first results of our spectroscopic

campaign of W49 in this poster.

Organisation(s)

Department of Astrophysics

Publication date

06-2013

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

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