J/A+A/626/A126 RMC143 ALMA images (Agliozzo+, 2019)
A massive nebula around the luminous blue variable star RMC143 revealed by ALMA.
Agliozzo C., Menher A., Phillips N. M., Leto P., Groh J.H.,
Noriega-Crespo A., Buemi C., Cavallaro F., Cerrigone L., Ingallinera A.,
Paladini R., Pignata G., Trigilio C., Umana G.
<Astron. Astrophys. 626, A126 (2019)>
=2019A&A...626A.126A 2019A&A...626A.126A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Millimetric/submm sources
Keywords: stars: massive - stars: variables: S Doradus -
stars: evolution - stars: individual: RMC 143 - stars: mass-loss -
dust, extinction
Abstract:
The luminous blue variable (LBV) RMC143 is located in the outskirts of
the 30∼Doradus complex, a region rich with interstellar material and
hot luminous stars. We report the 3σ sub-millimetre detection
of its circumstellar nebula with ALMA. The observed morphology in the
sub-millimetre is different than previously observed with HST and ATCA
in the optical and centimetre wavelength regimes. The spectral energy
distribution (SED) of RMC suggests that two emission mechanisms
contribute to the sub-mm emission: optically thin bremsstrahlung and
dust. Both the extinction map and the SED are consistent with a dusty
massive nebula with a dust mass of 0.055±0.018M☉ (assuming
κ850=1.7cm2/g). To date, RMC143 has the most dusty LBV
nebula observed in the Magellanic Clouds. We have also re-examined the
LBV classification of RMC143 based on VLT/X-shooter spectra obtained
in 2015/16 and a review of the publication record. The radiative
transfer code CMFGEN is used to derive its fundamental stellar
parameters. We find an effective temperature of ∼8500K, luminosity of
log(L/L☉)=5.32, and a relatively high mass-loss rate of
1.0x10-5M☉/yr. The luminosity is much lower than previously
thought, which implies that the current stellar mass of ∼8M☉ is
comparable to its nebular mass of ∼5.5∼M☉ (from an assumed
gas-to-dust ratio of 100), suggesting that the star has lost a large
fraction of its initial mass in past LBV eruptions or binary
interactions. While the star may have been hotter in the past, it is
currently not hot enough to ionize its circumstellar nebula. We
propose that the nebula is ionized externally by the hot stars in the
30 Doradus star-forming region.
Description:
Photometry used to fit the free-free emission of RMC143, extracted
from the ALMA 343GHz map, the ATCA 17GHz map and the reprocessed
ATCA 5.5 and 9GHz maps. Photometry used to fit the dust grey-body
emission of RMC143.
Objects:
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RA (2000) DE Designation(s)
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05 38 51.62 -69 08 07.3 RMC143 = CPD -69 463
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 5 ALMA and ATCA maps properties and photometry
table4.dat 39 4 Photometry used for dust grey-body fit
list.dat 280 4 List of fits files
fits/* . 4 Individual fits files
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "date" DateS Start of date of observations
12- 21 A10 "date" DateE End of date of observations
23- 26 A4 --- Array Interferometer
28- 32 F5.1 GHz Freq Central frequency
34- 36 F3.1 arcsec LAS LAS in the final map (1)
38- 41 F4.2 arcsec HPBW1 Half Power Beam Width 1 (1)
43- 46 F4.2 arcsec HPBW2 Half Power Beam Width 2 (1)
48- 53 F6.1 deg PA [] Position Angle
55 A1 --- l_F Limit flag on F
56- 60 F5.3 mJy F Peak flux density
62- 66 F5.3 mJy e_F ? Peak flux density error
68- 70 F3.1 mJy S ? Spatially integrated flux density
72- 74 F3.1 mJy e_S ? Spatially integrated flux density error
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Note (1): In the re-processed ATCA 5.5 and 9GHz maps the visibilities with
uv-distance <17klambda where filtered out in order to match the LAS at
17GHz.
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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- 8 A8 --- Tel Telescope
10- 14 A5 --- Inst Instrument
16- 22 F7.3 um lambda Wavelength
24- 27 F4.1 arcsec FWHM FWHM
29- 33 F5.1 mJy S Flux density (1)
35- 39 F5.1 mJy e_S Flux density error (2)
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Note (1): ALMA measurement is integrated over the nebula.
MIPS24 value is the weighted average of two SAGE epoch measurements.
Note (2): MIPS24 uncertainty set to 20% to account for confusion.
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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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- 53 A26 "datime" Obs.date Observation date
55- 65 E11.6 Hz Freq Observed frequency
67- 69 I3 Kibyte size Size of FITS file
71- 83 A13 --- FileName Name of FITS file, in subdirectory fits
85-280 A196 --- Title Title of the FITS file
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Acknowledgements:
Claudia Agliozzo, cagliozzo(at)gmail.com
References:
Agliozzo et al., 2012MNRAS.426..181A 2012MNRAS.426..181A, Radio detection of nebulae around four
luminous blue variable stars in the Large Magellanic Cloud
Meixner et al., 2006AJ....132.2268M 2006AJ....132.2268M, Cat. J/AJ/132/2268
Spitzer Survey of the Large Magellanic Cloud: Surveying the Agents of a
Galaxy's Evolution (SAGE). I. Overview and Initial Results
(End) Patricia Vannier [CDS] 28-May-2019