Spectral Classification and Properties of the OVz Stars in the Galactic O Star Spectroscopic Survey (GOSSS)

ARIAS, J.; WALBORN, N. R.; SIMÓN-DÍAZ, S.; BARBÁ, R.; MAÍZ APELLÁNIZ, J.; SABÍN-SANJULIÁN, C.; GAMEN, R. C.; MORRELL, N. I.; SOTA, A.; MARCO, A.; NEGUERUELA, I.; LEAO, J.R.S.; HERRERO, A.; ALFARO, E. J.

ASTRONOMICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016 vol. 152 p. 31 - 50

0004-6256

On the basis of the Galactic O Star Spectroscopic Survey (GOSSS), wepresent a detailed systematic investigation of the O Vz stars. Thecurrently used spectral classification criteria are rediscussed, and theVz phenomenon is recalibrated through the addition of a quantitativecriterion based on the equivalent widths of the He i λ4471, He iiλ4542, and He ii λ4686 spectral lines. The GOSSS O Vz andO V populations resulting from the newly adopted spectral classificationcriteria are comparatively analyzed. The locations of the O Vz stars areprobed, showing a concentration of the most extreme cases toward theyoungest star-forming regions. The occurrence of the Vz spectralpeculiarity in a solar-metallicity environment, as predicted by thefastwind code, is also investigated, confirming the importance of takinginto account several processes for the correct interpretation of thephenomenon.