Working packages

The project has been divided in the six working packages described below, also quoting a brief summary of aims and tasks:

[WP1] The IACOB spectroscopic database

(1) Compile the largest multi-epoch, high-resolution spectroscopic database of Northern Galactic OB stars. (2) Prepare the IACOB database for its scientific exploitation. (3) Create the web-page of the IACOB project and incorporate the spectroscopic database (in VO format) to make it available for the scientific community. (4) Place the IACOB database in the context of other on-going surveys of massive stars (GOSSS, NoMaDS, CAFÉ-BEANS, MiMeS, VFTS ...) and the Gaia mission.

[WP2] Line-broadening in OB stars

(1) Develop techniques to disentangle the rotational (vsini) and macroturbulent (QRT) broadening contributions to the line-profiles, (2) Measure the vsini and QRT in the whole IACOB sample. (3) Connect the Galactic results with those derived by the VLT-FLAMES Tarantula survey consortium. (4) Use the derived vsini to impose constraints on the rotational properties of massive stars in different evolutionary phases as a function of metallicity. (4) Gather and analyse time-series spectroscopic observations of selected candidates to investigate possible QRT – line-profile variability correlations, (5) Investigate the pulsational hypothesis to explain the macroturbulent broadening in OB stars.

[WP3] Quantitative spectroscopic analyses (I): stellar and wind parameters

(1) Analyse the whole sample of IACOB spectra using the IACOB-GBAT. (2) Create the most complete homogeneous database of stellar and wind parameters of Galactic OB stars – in preparation for the Gaia era –. (3) Connect the Galactic results with those derived by the VFTS consortium (30 Dor, LMC) and other ongoing extra-galactic studies by the Blue Massive Stars group at the IAC. (4) Use the outcome from the spectroscopic analysis to investigate old-standing (and new) puzzling questions in the field of massive stars (e.g. the mass discrepancy problem, the temperature of the early O-type stars, the calibration of stellar parameters with spectral type and luminosity class, the nature of the O Vz stars, the origin and evolution of fast rotators, the weak-wind problem, the effect of rotation, stellar winds, binarity and stellar pulsations on the evolution of massive stars).

[WP4] Quantitative spectroscopic analyses (II): stellar abundances

(1) Determine C, N, O, Si, Mg, Ne, Ar, and S abundances in the whole sample of IACOB OB-type stars – i.e. B main sequence and B supergiants –. (2) Determine He, C, N, and O abundances in the whole sample of IACOB O-type stars. (3) Complement the IACOB catalogue with the set of derived abundances. (4) Use the derived abundances impose observational constraints to modern evolutionary models of massive stars. (5) Create a 2D map of the present-day chemical composition of the Solar Neighbourhood using OB main sequence stars.

[WP5] Binary/multiple systems

(1) Detect massive binary/multiple systems included in the IACOB database (2) Use this information for the elimination of possible biases due to undetected binarity in the results from the quantitative spectroscopic analysis of the IACOB sample (3) Participate in the CAFÉ-BEANS project – follow up observations of detected binaries – (4) Investigate the mass discrepancy problem in massive stars by means of the study of a sample of massive eclipsing binaries (5) Obtain observational constraints to investigate the effect of binaries on the evolution of massive stars (i.e detection of possible mergers and mass transfer episodes).

[WP6] Massive OB stars and the ISM

(1) Investigate the agreement between stellar (B-type stars) and nebular (HII region) abundances in the same Galactic site (2) Check the ionizing spectral energy distributions predicted by modern stellar atmosphere codes by means of a combined stellar/nebular study of selected Galactic HII regions