J/ApJ/768/128 K-band calibrated visibilities of 24 Be stars (Touhami+, 2013)
A CHARA array survey of circumstellar disks around nearby Be-type stars.
Touhami Y., Gies D.R., Schaefer G.H., McAlister H.A., Ridgway S.T.,
Richardson N.D., Matson R., Grundstrom E.D., ten Brummelaar T.A.,
Goldfinger P.J., Sturmann L., Sturmann J., Turner N.H., Farrington C.
<Astrophys. J., 768, 128 (2013)>
=2013ApJ...768..128T 2013ApJ...768..128T
ADC_Keywords: Interferometry ; Stars, Be ; Infrared sources
Keywords: circumstellar matter; infrared: stars;
instrumentation: interferometers; stars: emission-line, Be;
stars: rotation; techniques: high angular resolution
Abstract:
We report on a high angular resolution survey of circumstellar disks
around 24 northern sky Be stars. The K-band continuum survey was made
using the CHARA Array long baseline interferometer (baselines of
30-331m). The interferometric visibilities were corrected for the
flux contribution of stellar companions in those cases where the Be
star is a member of a known binary or multiple system. For those
targets with good (u, v) coverage, we used a four-parameter Gaussian
elliptical disk model to fit the visibilities and to determine the
axial ratio, position angle, K-band photospheric flux contribution,
and angular diameter of the disk's major axis. For the other targets
with relatively limited (u, v) coverage, we constrained the axial
ratio, inclination angle, and/or disk position angle where necessary
in order to resolve the degeneracy between possible model solutions.
We also made fits of the ultraviolet and infrared spectral energy
distributions (SEDs) to estimate the stellar angular diameter and
infrared flux excess of each target. The mean ratio of the disk
diameter (measured in K-band emission) to stellar diameter (from SED
modeling) is 4.4 among the 14 cases where we reliably resolved the
disk emission, a value which is generally lower than the disk size
ratio measured in the higher opacity Hα emission line. We
estimated the equatorial rotational velocity from the projected
rotational velocity and disk inclination for 12 stars, and most of
these stars rotate close to or at the critical rotational velocity.
Description:
The observations of the selected 24 Be stars were conducted between
2007 October and 2010 November using the CHARA Classic beam combiner
operating in the K-band (effective wavelength λ=2.1329um).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 24 Adopted stellar parameters
table3.dat 78 563 Calibrated visibilities
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See also:
B/wds : The Washington Visual Double Star Catalog (Mason+ 2001-2014)
III/251 : ELODIE library V3.1 (Prugniel+ 2007)
VI/102 : Geneva stellar evolution tracks and isochrones (Lejeune+, 2001)
II/220 : Polarisation of Be stars (McDavid, 1986-1999)
III/86 : SKYLAB S-019 Far-UV Objective-Prism Spectrophotometry (Henize+ 1979)
J/A+A/540/A53 : γ Cas radial velocity curve (Smith+, 2012)
J/A+A/537/A59 : Radial velocities of gamma Cas (Nemravov+, 2012)
J/ApJ/745/24 : A search for new companions with CHARA (Raghavan+, 2012)
J/ApJ/736/89 : Search for companions around nearby stars (Janson+, 2011)
J/ApJ/722/605 : A stellar rotation census of B stars (Huang+, 2010)
J/AJ/139/743 : Speckle interferometry in 2008-09 (Tokovinin+, 2010)
J/AJ/137/3358 : Speckle interferometry of massive stars (Mason+, 2009)
J/A+A/493/1099 : CaII HK emission in rapidly rotating stars (Schroeder+, 2009)
J/ApJ/689/461 : Circumstellar disk of χ Oph (Tycner+, 2008)
J/ApJ/654/527 : Interferometric obs. of northern Be stars (Gies+, 2007)
J/A+A/459/137 : Bright Be shell stars (Rivnius+, 2006)
J/A+A/450/735 : Effective temperatures and radii of stars (Masana+, 2006)
J/A+A/450/681 : Companions to close spectroscopic binaries (Tokovinin+, 2006)
J/A+A/440/305 : Fundamental param. of fast-rotating B stars (Fremat+, 2005)
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/AJ/127/1727 : Differential magnitudes of binary stars (Horch+, 2004)
J/AJ/124/1670 : Post-T Tauri Stars in Sco-Cen Association (Mamajek+, 2002)
J/A+A/368/912 : Polarization and rotational vel. of Be stars (Yudin, 2001)
J/A+A/328/551 : Spectroscopic data of 4 Herculis (Koubsky+ 1997)
J/A+A/290/609 : Be stars near-IR excess (Dougherty+, 1994)
J/AJ/106/637 : ICCD speckle observations. IX (Mason+, 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [HD]
4- 9 I6 --- HD HD number
11- 20 A10 --- Name Star name
22- 29 A8 --- SpT MK spectral type from Yudin (2001, J/A+A/368/912)
31- 35 I5 K Teff [9800/28783] Effective temperature (1)
37- 41 F5.3 [cm/s2] logg [3/4] Surface gravity (1)
43- 45 I3 deg PA [18/177] Disk position angle (2)
47- 51 F5.3 --- b/a [0/1] Ratio of minor to major disk axis (r) (3)
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Note (1): Stellar effective temperature and gravity logg from Fremat et al.
(2005, J/A+A/440/305). The stars HD 166014 and HD 202904 are not
listed by Fremat et al., so we used the parameters for these two from
Grundstrom (2007PhDT.........6G 2007PhDT.........6G).
Note (2): Prediction of the position angle of the projected major axis of the
disk that should be 90° different from the intrinsic polarization
angle (McDavid 1999, II/220; Yudin 2001, J/A+A/368/912).
Note (3): The ratio of the minor to major axis sizes according to the estimated
stellar inclination from Fremat et al. (2005, J/A+A/440/305).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number
8- 16 F9.3 d MJD Modified Julian Date
18- 22 A5 --- Tel Telescope Pair
24- 30 F7.3 arcsec-1 u u Coordinate (cycles/arcsec) (1)
32- 38 F7.3 arcsec-1 v v Coordinate (cycles/arcsec) (1)
40- 46 F7.3 m PBL [46/331] Projected Baseline
48- 54 F7.3 m EBL [7/330] Effective Baseline
56- 60 F5.3 --- Vis [0.1/1] Visibility
62- 66 F5.3 --- e_Vis Visibility uncertainty
68- 72 F5.3 --- CVis [0.5/1.2]? Corrected Visibility
74- 78 F5.3 --- e_CVis ? Corrected Visibility uncertainty
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Note (1): Spatial frequency of the interferometric observation is:
x = (u2+v2)0.5 (see section 5.1).
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Nov-2014