Access to Astronomical Catalogues

← Click to display the menu
J/AJ/134/1570       Rotational velocities of OB stars        (Daflon+, 2007)

The projected rotational velocity distribution of a sample of OB stars from a calibration based on synthetic He I lines. Daflon S., Cunha K., De Araujo F.X., Wolff S., Przybilla N. <Astron. J., 134, 1570-1578 (2007)> =2007AJ....134.1570D
ADC_Keywords: Associations, stellar ; Stars, OB ; Rotational velocities Keywords: line: profiles - stars: early-type - stars: rotation Abstract: We derive projected rotational velocities (vsini) for a sample of 156 Galactic OB star members of 35 clusters, HII regions, and associations. The HeI lines at 4026, 4388, and 4471Å were analyzed in order to define a calibration of the synthetic HeI full widths at half-maximum (FWHMs) versus stellar vsini. A grid of synthetic spectra of HeI line profiles was calculated in non-LTE using an extensive helium model atom and updated atomic data. The vsini values for all stars were derived using the HeI FWHM calibrations, but also, for those target stars with relatively sharp lines, vsini values were obtained from best-fit synthetic spectra of up to 40 lines of CII, NII, OII, AlIII, MgII, SiIII, and SIII. This calibration is a useful and efficient tool for estimating the projected rotational velocities of O9-B5 main-sequence stars. The distribution of vsini for an unbiased sample of early B stars in the unbound association Cep OB2 is consistent with the distribution reported elsewhere for other unbound associations. Description: The observational data for this study are high-resolution spectra of late O and early B type stars that were obtained during several observing runs between the years 1994 and 2000. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 78 156 vsin(i) Results
See also: J/MNRAS/284/265 : Rotational velocities of 373 OB stars (Howarth+ 1997) J/A+A/457/265 : The VLT-FLAMES survey of massive stars (Dufton+, 2006) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 9 A9 --- CName Cluster name 11- 26 A16 --- SName Star name 28- 29 A2 --- n_SName Remark on binarity (1) 31- 35 I5 K Teff Effective temperature 36 A1 --- u_Teff Uncertainty flag on Teff 37 A1 --- f_Teff [1]? Assumed Teff=30000K to calculate vsin(i) 39- 41 I3 km/s <vsini> ? Mean vsin(i) velocity from weak metal lines 43- 44 I2 km/s e_<vsini> ? Uncertainty in <vsiniM> 46- 48 F3.1 --- W4026 ? The He I (4026) FWHM 49 A1 --- u_W4026 ? Uncertainty flag on W4026 51- 53 I3 km/s vsini4026 ? The He I (4026) vsin(i) 55- 57 F3.1 --- W4387 ? The He I (4387) FWHM 58 A1 --- u_W4387 ? Uncertainty flag on W4387 60- 62 I3 km/s vsini4387 ? The He I (4387) vsin(i) 64- 66 F3.1 --- W4471 ? The He I (4471) FWHM 67 A1 --- u_W4471 ? Uncertainty flag on W4471 69- 71 I3 km/s vsini4471 ? The He I (4477) vsin(i) 73- 75 I3 km/s <vsiniHe> Mean He I derived vsin(i) 77- 78 I2 km/s e_<vsiniHe> ? Uncertainty in <vsiniHe>
Note (1): Flag as follows: dg = Asymmetric line profiles: possible spectroscopic binary? dd = Single-lined spectroscopic binary (SB1) * = Double-lined spectroscopic binary (SB2)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 11-Nov-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service