Terminal velocities of luminous, early-type SMC stars

Abstract

Ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) are used to determine terminal velocities for 11 O and B-type giants and supergiants in the Small Magellanic Cloud (SMC) from the Si IV and C IV resonance lines. Using archival data from observations with the Goddard High-Resolution Spectrograph and the International Ultraviolet Explorer telescope, terminal velocities are obtained for a further five B-type supergiants. We discuss the metallicity dependence of stellar terminal velocities, finding no evidence for a significant scaling between Galactic and SMC metallicities for Teff < 30,000 K, consistent with the predictions of radiation driven wind theory for supergiant stars. A comparison of the $v_{\infty }/v_{esc}$ ratio between the SMC and Galactic samples, while consistent with the above statement, emphasizes that the uncertainties in the distances to galactic O-stars are a serious obstacle to a detailed comparison with theory. For the SMC sample there is considerable scatter in this ratio at a given effective temperature, perhaps indicative of uncertainties in stellar masses.

arXiv comment28 pages, 8 figures, accepted by ApJ; minor revisions prior to acceptance

References in corpus (13)

• Mass-loss predictions for O and B stars as a function of metallicity
• A Hipparcos census of the nearby OB associations
• A UBVR CCD Survey of the Magellanic Clouds
• Quantitative Spectroscopy of O Stars at Low Metallicity. O Dwarfs in NGC 346
• Line-driven winds, ionizing fluxes and UV-spectra of hot stars at extremely low metallicity. I. Very massive O-stars
• Revised Stellar Temperatures for Magellanic Cloud O Supergiants from FUSE and VLT-UVES Spectroscopy
• On the effective temperature scale of O stars
• Fundamental parameters of Galactic luminous OB stars VI. Temperatures, masses and WLR of Cyg OB2 supergiants
• Understanding B-type Supergiants in the Low Metallicity Environment of the SMC
• Constraints on the Ionization Balance of Hot-Star Winds from FUSE Observations of O Stars in the Large Magellanic Cloud
• Quantitative spectral analysis of early B-type supergiants in the Sculptor galaxy NGC 300
• An Analysis of STIS HST UV Spectra of M33 early B Supergiants
• STIS UV spectroscopy of early B supergiants in M31

Cited by in corpus (31)

• Mass loss from hot massive stars
• On the metallicity dependence of Wolf-Rayet winds
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• The empirical metallicity dependence of the mass-loss rate of O- and early B-type stars
• Bright OB stars in the Galaxy IV. Stellar and wind parameters of early to late B supergiants
• Spitzer SAGE-SMC Infrared Photometry of Massive Stars in the Small Magellanic Cloud
• The VLT-FLAMES survey of massive stars: Mass loss and rotation of early-type stars in the SMC
• The VLT-FLAMES survey of massive stars: Wind properties and evolution of hot massive stars in the LMC
• Understanding B-type Supergiants in the Low Metallicity Environment of the SMC
• Quantitative studies of the optical and UV spectra of Galactic early B supergiants I. Fundamental parameters
• Understanding B-type supergiants in the low metallicity environment of the SMC II
• The Physical Properties and Effective Temperature Scale of O-type Stars as a Function of Metallicity. III. More Results from the Magellanic Clouds
• Interstellar H I and H_2 in the Magellanic Clouds: An Expanded Sample Based on UV Absorption-Line Data
• Winds of low-metallicity OB-type stars: HST-COS spectroscopy in IC1613
• X-Shooting ULLYSES: massive stars at low metallicity. I. Project Description
• NLTE models of line-driven stellar winds II. O stars in SMC
• X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars
• A Very Large Telescope imaging and spectroscopic survey of the Wolf-Rayet population in NGC 7793
• The ultraviolet and optical spectra of luminous B-type stars in the Small Magellanic Cloud
• Empirical mass-loss rates and clumping properties of O-type stars in the LMC
• Should I Stay or Should I Go: Stellar Wind Retention and Expulsion in Massive Star Clusters
• Mass loss rates from mid-IR excesses in LMC and SMC O stars
• Wind properties of variable B supergiants. Evidence of pulsations connected with mass-loss episodes
• Blue luminous stars in nearby galaxies - UIT005: a possible link to the luminous blue variable stage
• Modeling Gas Evacuation Mechanisms in Present-Day Globular Clusters: Stellar Winds from Evolved Stars and Pulsar Heating
• Optically-thick Structure in Early B Type Supergiant Stellar Winds at Low Metallicities
• OB-stars as extreme condition test beds
• The B-Supergiant Components of the Double-Lined Binary HD1383
• The Properties of Early-type Stars in the Magellanic Clouds
• Infrared properties of Active OB stars in the Magellanic Clouds from the Spitzer SAGE Survey
• UV Spectroscopy of Metal-Poor Massive Stars in the Small Magellanic Cloud