J/MNRAS/485/2417 CO J=2-1 NOEMA observations of mu Cep (Montarges+, 2019)
NOEMA maps the CO J = 2-1 environment of the red supergiant mu Cep.
Montarges M., Homan W., Keller D., Clementel N., Shetye S., Decin L.,
Harper G.M., Royer P., Castro-Carrizo A., Winters J.M., Le Bertre T.,
Richards A.M.S.
<Mon. Not. R. Astron. Soc. 485, 2417-2430 (2019)>
=2019MNRAS.485.2417M 2019MNRAS.485.2417M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, supergiant ; Carbon monoxide ; Radio lines
Keywords: circumstellar matter - stars: imaging - stars: individual: mu Cep -
stars: mass-loss - supergiants - radio lines: stars
Abstract:
Red supergiant stars are surrounded by a gaseous and dusty
circumstellar environment created by their mass loss which spreads
heavy elements into the interstellar medium. The structure and the
dynamics of this envelope are crucial to understand the processes
driving the red supergiant mass loss and the shaping of the
pre-supernova ejecta. We have observed the emission from the CO J=2-1
line from the red supergiant star µ Cep with the NOEMA
interferometer. In the line the synthesized beam was 0.92x0.72-arcsec
(590x462au at 641pc). The continuum map shows only the unresolved
contribution of the free-free emission of the star chromosphere. The
continuum-subtracted channel maps reveal a very inhomogeneous and
clumpy circumstellar environment. In particular, we detected a bright
CO clump, as bright as the central source in the line, at 1.80-arcsec
south-west from the star, in the blue channel maps. After a
deprojection of the radial velocity assuming two different constant
wind velocities, the observations were modelled using the 3D radiative
transfer code LIME to derive the characteristics of the different
structures. We determine that the gaseous clumps observed around
µ Cep are responsible for a mass loss rate of
(4.9±1.0)x10-7M[sun/yr, in addition to a spatially unresolved
wind component with an estimated mass-loss rate of
2.0x10-6M[sun/yr. Therefore, the clumps have a significant role in
µ Cep's mass loss (≥25%). We cannot exclude that the unresolved
central outflow may be made of smaller unresolved clumps.
Description:
Cleaned continuum and line images of mu Cep from NOEMA CO J=2-1
observations and stellar and derived basic stellar parameters from
updated distance estimation.
Objects:
---------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------
21 43 30.46 +58 46 48.2 mu Cep = HR 8316
---------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 65 1 mu Cep and stellar and derived basic stellar
parameters from updated distance estimation
list.dat 132 2 List of fits file
fits/* . 2 Individual fits files
--------------------------------------------------------------------------------
See also:
II/237 : Stellar Photometry in Johnson's 11-color system (Ducati, 2002)
J/A+A/537/A146 : Stellar models with rotation. 0.8<M<120, Z=0.014
(Ekstrom+, 2012)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 pc Dist Distance of the star
5- 7 I3 pc E_Dist Upper error of the distance
9- 11 I3 pc e_Dist Lower error of the distance
13- 15 I3 Rsun Rad Stellar radius
17- 19 I3 Rsun e_Rad Error on the stellar radius
21- 27 E7.2 W/m2 Fbol Bolometric flux
29- 35 E7.2 W/m2 e_Fbol Error on the bolometric flux
37- 40 I4 K Teff Effective temperature
42- 44 I3 K e_Teff Error on the effective temperature
46- 49 F4.2 [Lsun] logL log of the luminosity
51- 54 F4.2 [Lsun] E_logL Upper error on the luminosity
56- 59 F4.2 [Lsun] e_logL Lower error on the luminosity
61- 62 I2 Msun b_Mass Lower limit on the initial mass
64- 65 I2 Msun B_Mass Upper limit on the initial mass
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz ? Number of slices for the datacube
32- 39 F8.1 m/s bVRAD Radial velocity or lower value of
radial velocity for the datacube
41- 46 I6 m/s BVRAD ? Upper value of radial velocity for the
datacube
48- 54 F7.3 m/s dVRAD ? Velocity resolution for the datacube
56- 61 I6 Kibyte size Size of FITS file
63- 74 A12 --- FileName Name of FITS file, in subdirectory fits
76-132 A57 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Miguel Montarges, miguel.montarges(at)kuleuven.be
(End) Miguel Montarges [KU Leuven, Belgium], Patricia Vannier [CDS] 27-Feb-2019