Parameters of OB stars & their bow shock nebulae

DOI

Second only to initial mass, the rate of wind-driven mass loss determines the final mass of a massive star and the nature of its remnant. Motivated by the need to reconcile observational values and theory, we use a recently vetted technique to analyze the mass-loss rates in a sample of OB stars that generate bow shock nebulae. We measure peculiar velocities from new Gaia parallax and proper motion data and their spectral types from new optical and infrared spectroscopy. For our sample of 70 central stars in morphologically selected bow shock nebulae, 67 are OB stars. The median peculiar velocity is 11 km/s, significantly smaller than classical "runaway star" velocities. Mass-loss rates for these O and early B stars agree with recently lowered theoretical predictions, ranging from ~10^-7^ M_{sun}/yr for mid-O dwarfs to 10^-9^ M{sun}/yr for late O dwarfs - a factor of about 2.7 lower than the often-used Vink et al. (2000A&A...362..295V, 2001A&A...369..574V) formulation. Our results provide the first observational mass-loss rates for B0-B3 dwarfs and giants - 10^-9^ to 10^-8^ M{sun}/yr. We find evidence for an increase in the mass-loss rates below a critical effective temperature, consistent with predictions of the bistability phenomenon in the range T_eff=19000-27000 K. The sample exhibits a correlation between modified wind momentum and luminosity, consistent in slope but lower by 0.43 dex in magnitude compared to canonical wind-luminosity relations. We identify a small subset of objects deviating most significantly from theoretical expectations as probable radiation-driven bow wave nebulae by virtue of their low stellar-to-nebular luminosity ratios. For these, the inferred mass-loss rates must be regarded as upper limits.

Cone search capability for table J/AJ/158/73/catalog (Measured and adopted parameters (table 1) , kinematic data (table 2) and derived parameters (table 3) for stars and their bow shock nebulae)

Identifier
DOI http://doi.org/10.26093/cds/vizier.51580073
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/158/73
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/158/73
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/158/73
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/158/73
Provenance
Creator Kobulnicky H.A.; Chick W.T.; Povich M.S.
Publisher CDS
Publication Year 2019
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Interdisciplinary Astronomy; Interstellar medium; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy