J/ApJS/187/228 Hα profiles of Be stars (Silaj+, 2010)
A systematic study of Hα profiles of Be stars.
Silaj J., Jones C.E., Tycner C., Sigut T.A.A., Smith A.D.
<Astrophys. J. Suppl. Ser., 187, 228-250 (2010)>
=2010ApJS..187..228S 2010ApJS..187..228S
ADC_Keywords: Line Profiles ; Stars, Be ; Spectroscopy ; Models
Keywords: circumstellar matter - line: formation - line: profiles -
stars: emission-line, Be
Abstract:
We present a set of theoretical Hα emission-line profiles of Be
stars, created by systematically varying model input parameters over a
wide range of accepted values. Models were generated with a non-LTE
radiative transfer code that incorporates a non-isothermal disk
structure and a solar-type chemical composition. The theoretical Hα
emission-line profiles were compared to a large set of Be star spectra
with the aim of reproducing their global characteristics. We find that
the observed profile shapes cannot be used to uniquely determine the
inclination angle of Be star+disk systems. Drastically different
profile shapes arise at a given inclination angle as a direct result
of the state of the gas, and self-consistent disk physical conditions
are therefore crucial for interpreting the observations.
Description:
The spectra of the 69 Be star targets listed in Table 3 were obtained
between 2005 and 2008. The spectroscopic observations were acquired
using a fiber-fed echelle spectrograph connected to the 42inch John
S. Hall Telescope at the Lowell Observatory located in Flagstaff,
Arizona.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 68 69 Representative models
table4.dat 53 35328 Spectra
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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- 4 I4 --- HR ? HR number
6- 11 I6 --- HD HD number
13- 21 A9 --- OName Star name
22 A1 --- f_OName [ghi] Flag on object (1)
24- 31 A8 --- SpType SIMBAD MK spectral type
33- 38 F6.3 nm EWHa Hα equivalent width (2)
41- 42 A2 --- n_EWHa Observed Hα line profile shape (3)
44- 45 A2 --- Sp.M Representative model spectral type (4)
47- 48 I2 deg i ?=- Inclination angle of the star's pole to
the observer's line of sight (i.e., i=0°
is pole-on and i=90° is equator-on)
50- 52 F3.1 --- n ?=- Index of the radial power law
54- 58 E5.1 g/cm3 rho0 ?=- Disk base-density in the equatorial plane
60- 66 F7.4 nm EW.M ?=- Equivalent width value of the
representative model
68 A1 --- f_EW.M [f] Discrepancy in EW.M (5)
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Note (1): Flags as follows:
g = Due to the complexities of shell spectra, we have not applied a
representative axisymmetric model to this star.
For further discussion of shell spectra, see Section 5.
h = Recent work on this star has demonstrated that there are variable
overdense and underdense regions within the disk. Rotating spiral waves
and global disk oscillations have been proposed (Wisniewski et al.,
2007ApJ...656L..21W 2007ApJ...656L..21W; Carciofi et al., 2009A&A...504..915C 2009A&A...504..915C). Therefore,
we have not applied a representative axisymmetric model to this star.
i = Due to the highly asymmetric nature of this emission-line profile,
a representative axisymmetric model has not been applied to it.
Note (2): Hα equivalent width based on observation, not corrected for
tellurics. We adopt the standard convention that emission lines have
negative area.
Note (3): Shape is
s = single;
d = double;
tr = triple;
sh = shell
Note (4): All models were created assuming a main-sequence (V) central star.
Note (5): f means the discrepancy between the observed and calculated
equivalent width is due to the continuum rectification, as there is
significant cancellation between the positive and negative contributions.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- HR ? The HR number
6- 11 I6 --- HD The HD number
13- 21 A9 --- OName Star name
23- 31 F9.1 d JD Julian Date of the observation
33- 41 F9.5 nm lambda Wavelength
43- 53 F11.8 --- Flux Flux relative to the continuum flux
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 03-May-2010