Bibcode
                                    
                            DOI
                                    
                            Garzon, F.; Lopez-Corredoira, M.; Hammersley, P.; Mahoney, T. J.; Calbet, X.; Beckman, J. E.
    Bibliographical reference
                                    Astrophysical Journal Letters v.491, p.L31
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                        12
            
                        1997
            
  Citations
                                    35
                            Refereed citations
                                    31
                            Description
                                    We present an analysis of the optical spectroscopy of 58 stars in the
Galactic plane at l=27^° , where a prominent excess in the flux
distribution and star counts have been observed in several spectral
regions, in particular in the Two-Micron Galactic Survey (TMGS) catalog.
The sources were selected from the TMGS to have a K magnitude brighter
than +5 mag and to be within 2 deg of the Galactic plane. More than 60%
of the spectra correspond to stars of luminosity class I, and a
significant proportion of the remainder are very late and fast-evolving
giants. This very high concentration of young sources points to the
existence of a major star formation region in the Galactic plane,
located just inside the assumed origin of the Scutum spiral arm. Such
regions can form because of the concentrations of shocked gas where a
galactic bar meets a spiral arm, as is observed at the ends of the bars
of face-on external galaxies. Thus, the presence of a massive star
formation region is very strong supporting evidence for the presence of
a bar in our Galaxy.