Young Massive Clusters/Associations in the GMC G23.3-0.3
  An overview of a spectroscopic survey for massive stars in the direction of the Galactic giant molecular complex G23.3-0.3 is presented (Messineo et al. 2010, and 2014 A&A submitted). This region is interesting because it is rich in HII regions and supernova remnants (SNRs). A number of 38 early-type stars, a new luminous blue variable, and a dozen of red supergiants were detected. We identified the likely progenitors of the SNRs W41, G22.7-00.2, and G22.7583-0.4917. 
M. Messineo, K. M. Menten, D. Figer, B. Davies, J.S. Clark, V.D.   Ivanov, R.P. Kudritzki, R.M. Rich, J. MacKenty, and C. Tr...
astro-ph.GA