J/MNRAS/489/2595 Spectro-interferometry of 8 evolved stars (Hadjara+, 2019)
A CO-multilayer outer atmosphere for eight evolved stars revealed with
VLTI/AMBER.
Hadjara M., Cruzalebes P., Nitschelm C., Chen X., Michael E.A., Moreno E.
<Mon. Not. R. Astron. Soc. 489, 2595-2614 (2019)>
=2019MNRAS.489.2595H 2019MNRAS.489.2595H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Stars, M-type ; Stars, variable ; Interferometry
Keywords: methods: numerical - methods: observational -
techniques: high angular resolution - stars: AGB and post-AGB -
stars: atmospheres - stars: fundamental parameters
Abstract:
We determine the physical parameters of the outer atmosphere of a
sample of eight evolved stars, including the red supergiant
α Scorpii, the red giant branch stars α Bootis and
γ Crucis, the K giant λ Velorum, the normal M giants
BK Virginis and SW Virginis, and the Mira star W Hydrae (in two
different luminosity phases) by spatially resolving the stars in the
individual carbon monoxide (CO) first overtone lines. We used the
Astronomical Multi-BEam combineR (AMBER) instrument at the Very Large
Telescope Interferometer (VLTI), in high-resolution mode
(λ/Δλ~=12000) between 2.28 and 2.31um in the K
band. The maximal angular resolution is 10mas, obtained using a
triplet telescope configuration, with baselines from 7 to 48m. By
using a numerical model of a molecular atmosphere in a spherical
shells (MOLsphere), called PAMPERO (an acronym for the 'physical
approach of molecular photospheric ejection at high angular resolution
for evolved stars'), we add multiple extended CO layers above the
photospheric MARCS model at an adequate spatial resolution. We use the
differential visibilities and the spectrum to estimate the size (R) of
the CO MOLsphere, its column density (NCO) and temperature (Tmol)
distributions along the stellar radius. The combining of the χ2
minimization and a fine grid approach for uncertainty analysis leads
to reasonable NCO and Tmol distributions along the stellar radius of
the MOLsphere.
Description:
VLTI/AMBER data of alpha Boo, alpha Scoo, BK Vir, gamma Cru,
lambda Vel, SW Vir and W Hya (for two different phases; 0.59 and 077)
obtained from 2.279 to 2.308 micron, including the spectrocopically
calibrated spectrum, visibilities and differential phases measured at
three baselines, and closure phase.
Objects:
------------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------------
14 15 39.67 +19 10 56.67 alpha Boo = HD 124897
16 29 24.46 -26 25 55.21 alpha Sco = HD 148478
12 30 21.02 +04 24 59.16 BK VIR = HD 108849
12 31 09.96 -57 06 47.57 gamma Cru = HD 108903
09 07 59.76 -43 25 57.32 lambda Vel = HD 78647
13 14 04.39 -02 48 25.16 SW Vir = HD 114961
13 49 02.00 -28 22 03.53 W Hya = HD 120285
------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 69 8 List of studied stars
alfboo.dat 320 318 alpha Boo spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
alfsco.dat 320 317 alpha Sco spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
bkvir.dat 320 508 BK Vir spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
gamcru.dat 320 318 gamma Cru spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
lamvel.dat 320 318 lambda Vel spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
swvir.dat 320 318 SW Vir spectrocopically calibrated spectrum,
visibilities and differential phases measured
at three baselines, and closure phase
whyap59.dat 320 318 W Hya (activity phase p=0.59) spectrocopically
calibrated spectrum, visibilities and differential
phases measured at three baselines, and closure phase
whyap77.dat 320 317 W Hya (activity phase p=0.77) spectrocopically
calibrated spectrum, visibilities and differential
phases measured at three baselines, and closure phase
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Star name
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 48 A12 --- FileName Name of the table with data
49- 69 A21 --- Note Note
--------------------------------------------------------------------------------
Byte-by-byte Description of file: *.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Index Index
6- 12 F7.5 um lambda [2.26326/2.30978] Wavelength
14- 26 E13.8 --- Flux Normalized flux
28- 40 E13.8 --- e_Flux Error in Normalized flux
42- 54 E13.8 --- Vis1 Visibility measured at baseline 1
56- 68 E13.8 --- e_Vis1 Error in visibility at baseline 1
70- 82 E13.8 deg DP1 Differential phase measured at baseline 1
84- 96 E13.8 deg e_DP1 [] Error in differential phase at baseline 1
98-110 E13.8 --- Vis2 Visibility measured at baseline 2
112-124 E13.8 --- e_Vis2 Error in visibility at baseline 2
126-138 E13.8 deg DP2 Differential phase measured at baseline 2
140-152 E13.8 deg e_DP2 [] Error in differential phase at baseline 2
154-166 E13.8 --- Vis3 Visibility measured at baseline 3
168-180 E13.8 --- e_Vis3 Error in visibility at baseline 3
182-194 E13.8 deg DP3 Differential phase measured at baseline 3
196-208 E13.8 deg e_DP3 [] Error in differential phase at baseline 3
210-222 E13.8 deg CP Closure phase
224-236 E13.8 deg e_CP [] Error in closure phase
238-250 E13.8 m BP1 Projected baseline 1
252-264 E13.8 deg PA1 [] Position angle of baseline 1
266-278 E13.8 m BP2 Projected baseline 2
280-292 E13.8 deg PA2 [] Position angle of baseline 2
294-306 E13.8 m BP3 Projected baseline 3
308-320 E13.8 deg PA3 [] Position angle of baseline 3
--------------------------------------------------------------------------------
Acknowledgements:
Massinissa Hadjara, massinissa.hadjara(at)gmail.com
(End) Massinissa Hadjara [UChile], Patricia Vannier [CDS] 10-Sep-2019