Science Highlight





ALMA Tracing the Origins of Molecular In dUst-forming oxygen-rich M-type stars


ATOMIUM postcard
Gallery of AGB winds derived from the $^{12}$CO $J = 2 \rightarrow 1$ emission in the 14 AGB stars and 3 RSG stars observed in ATOMIUM. Emission that is redshifted with respect to the local standard of rest is shown in red, blueshifted emission is shown in blue, and emission around the systemic velocity is in white. The scale bars denote an angular extent of 1" (see the Supplementary Materials in Decin et al. 2020, Science, 369, 1497).

Project Summary:

The ATOMIUM Large Program (2018.1.00659.L) with the ALMA 12 m array is dedicated to an investigation of the interplay between the gas phase chemistry and dynamics, and the dust forming process in the winds of evolved asymptotic giant branch (AGB) and red supergiant (RSG). Seventeen oxygen rich AGB and RSG stars — spanning a range in (circum)stellar parameters and evolutionary phases — were observed in a series of homogeneous observations that covered 27 GHz in the 213-270 GHz range. The observations were done with 3 array configurations at an angular resolution of ~0.025" to ~1", a sensitivity of 1.5-5 mJy/beam, and a spectral resolution of ~1.3 km/s. The wind kinematics derived from the spectral line profiles reveal that the radial velocity described by the momentum equation for a spherical wind does not capture the complexity of the velocity field. The ATOMIUM observations are complemented by optical/IR studies, spectral and interferometric monitoring of some of the species, and maser and chemical kinetic modeling. Detailed maps of the distributions of the 24 molecules observed in the survey and the associated continuum emission, serve as a Legacy for the astronomical community by (i) providing the basis for new insights in the physicochemical processes that occur in other astrophysical environments; and (ii) serving as a crucial benchmark for establishing the wind dynamics of evolved stars in single and binary star systems.

Team Members:

Status Surname Name Affiliation
PI Decin Leen Institute of Astronomy, KU Leuven (Belgium)
CoPI Gottlieb Carl Harvard-Smithsonian Center for Astrophysics (MA, USA)


Surname Name Affiliation
Baudry Alain Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux (France)
De Beck Elvire Chalmers University of Technology, Onsala Space Observatory (Sweden)
Bolte Jan Institute of Astronomy, KU Leuven (Belgium)
Cannon Emily Institute of Astronomy, KU Leuven (Belgium)
Ceulemans Thomas Institute of Astronomy, KU Leuven (Belgium)
Danilovich Taissa School of Physics & Astronomy, Monash University (Australia)
De Ceuster Frederik Institute of Astronomy, KU Leuven (Belgium)
de Koter Alex Astronomical Institute Anton Pannekoek, University of Amsterdam (the Netherlands)
El Mellah Ileyk CIRAS, Universidad de Santiago de Chile (Chile)
Esseldeurs Mats Institute of Astronomy, KU Leuven (Belgium)
Etoka Sandra Jodrell Bank Centre for Astrophysics, University of Manchester (UK)
Gobrecht David Department of Chemistry & Molecular Biology, Gothenburg University (Sweden)
Gottlieb Elaine School of Engineering and Applied Sciences and Department of Earth and Planetary Sciences, Harvard University (US)
Grey Malcolm National Astronomical Research Institute of Thailand (Thailand)
Herpin Fabrice Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux (France)
Homan Ward Institut d’Astronomie et d’Astrophysique, ULB Brussels (Belgium)
Jeste Manali Max-Planck-Institut fĂĽr Radioastronomie (Germany)
Kee Dylan National Solar Observatory, (US)
Kervella Pierre LESIA, Observatoire de Paris (France)
Khouri Theo Chalmers University of Technology, Onsala Space Observatory (Sweden)
Lagadec Eric Lagrange, Observatoire de la Côte d’Azur (France)
Maes Silke Institute of Astronomy, KU Leuven (Belgium)
Malfait Jolien Institute of Astronomy, KU Leuven (Belgium)
Marinho Louise University of Bordeaux (France)
McDonald Iain Jodrell Bank Centre for Astrophysics, University of Manchester (UK)
Menten Karl Max-Planck-Institut fĂĽr Radioastronomie (Germany)
Millar Tom Astrophysics Research Centre, Queen’s University Belfast, (UK)
Montargès Miguel LESIA, Observatoire de Paris (France)
Müller Holger I. Physikalisches Institut, Universität zu Köln (Germany)
Pimpanuwat Bannawit National Astronomical Research Institute of Thailand (Thailand)
Plane John University of Leeds (UK)
Price Daniel Monash Centre for Astrophysics (Australia)
Steven Rieder Institute of Astronomy, KU Leuven (Belgium)
Richards Anita Jodrell Bank Centre for Astrophysics, University of Manchester (UK)
Sahai Raghvendra Jet Propulsion Laboratory (CA, USA)
Van de Sande Marie Leiden Observatory (Netherlands)
Siess Lionel Institut d’Astronomie et d’Astrophysique, ULB Brussels (Belgium)
Wallstrom Sofia Institute of Astronomy, KU Leuven (Belgium)
Waters Rens SRON Netherlands Institute for Space Research (Netherlands) Astronomical Institute Anton Pannekoek, University of Amsterdam (Netherlands)
Wong Ka Tat Deptartment of Physics & Astronomy, Uppsala University (Sweden)
Yates Jeremy Blackett Laboratory, Imperial College London (UK)
Zijlstra Albert Jodrell Bank Centre for Astrophysics, University of Manchester (UK)

ATOMIUM Publications:

ATOMIUM Large Program

Pimpanuwat B., Gray, M., Etoka, S., et al. ”ATOMIUM: Investigating the innermost regions of oxygen rich circumstellar envelopes with ALMA observations of millimeter wavelength SiO masers”, in preparation

Wallström, S. H. J., Danilovich, T., Müller, H.S.P., et al. ”ATOMIUM: Molecular inventory of 17 oxygen rich evolved stars observed with ALMA”, 2023, A&A, in press

Danilovich, T., Malfait, J., Van de Sande, M., et al. ”Chemical tracers of a highly eccentric binary orbit”, 2023, Nature Astronomy, in press

Baudry, A., Wong, K. T., Etoka, S., et al. “ATOMIUM: Probing the inner wind of evolved O-rich stars with new, highly excited H$_2$O and OH lines”, 2923, A&A, 674, A125; doi:10.48550/arXiv.2305.03171

Montargès, M., Cannon, E., de Koter, A., et al. “The VLT/SPHERE view of the ATOMIUM cool evolved star sample: I. Overview: Sample characterization through polarization analysis”, 2023, A&A, 671. A96; doi:10.1051/0004-6361/202245398

Decin, L., Gottlieb, C., Richards, A., et al. "ATOMIUM: ALMA Tracing the Origins of Molecules In dUst forming oxygen-rich M-type stars”, 2022, The Messenger, 189, 3; doi:10.18727/0722-6691/5283

Gottlieb, C. A., Decin, L., Richards, A. M. S., et al. “ATOMIUM: ALMA tracing the origins of molecules in dust forming oxygen rich M-type stars: Motivation, sample, calibration, and initial results”, 2022, A&A, 660, A94; doi:10.1051/0004-6361/202140431

Danilovich, T., Van de Sande, M., Plane, J. M. C., et al. “ATOMIUM: halide molecules around the S-type AGB star W Aquilae”, 2021, A&A, 655, A80; doi:10.1051/0004-6361/202141757

Homan, W., Pimpanuwat, B., Herpin, F., et al. “ATOMIUM: The astounding complexity of the near circumstellar environment of the M-type AGB star R Hydrae: I. Morpho-kinematical interpretation of CO and SiO emission”, 2021, A&A, 651, A82; doi:10.1051/0004-6361/202140512

Homan, W., Montargès, M., Pimpanuwat, B., et al. “ATOMIUM: A high-resolution view of the highly asymmetric wind of the AGB star $\pi^1$ Gruis: I. First detection of a new companion and its effect on the inner wind”, 2020, A&A, 644, A61; doi:10.1051/0004-6361/202039185

Decin, L., Montargès, M., Richards, A. M. S., et al. “(Sub)stellar companions shape the winds of evolved stars”, 2020, Science, 369, 1497; doi:10.1126/science.abb1229


Decin, L.; Richards, A. M. S.; Danilovich, T. , et al. “ALMA spectral line and imaging survey of a low and a high mass-loss rate AGB star between 335 and 362 GHz”, 2018, A&A 615, A28; doi:10.1051/0004-6361/201732216

Decin, L.; Richards, A. M. S.; Waters, L. B. F. M., et al. “Study of the aluminium content in AGB winds using ALMA Indications for the presence of gas-phase (Al$_2$O$_3$)$_n$ clusters”, 2017, A&A, 608, A55; doi:10.1051/0004-6361/201730782

Danilovich, T., Gottlieb, C. A., Decin, L., et al. “Rotational Spectra of Vibrationally Excited AlO and TiO in Oxygen-rich Stars”, 2020, ApJ, 904, 110; doi:10.3847/1538-4357/abc079

Homan, W., Boulangier, J., Decin, L.., and de Koter, A. ”Simplified models of circumstellar morphologies for interpreting high-resolution data. Analytical approach to the equatorial density enhancement”, 2016, A&A, 596, A91; doi:10.1051/0004-6361/201528000

ATOMIUM Motivated


Gobrecht, D., Hashemi, S. R., Plane, J. M. C., et al., “Bottom-up dust nucleation theory in oxygen-rich evolved stars. II. Magnesium and calcium aluminate clusters”. 2023, A&A, in press

Maes, S.; Van de Sande, M.; Danilovich, T. et al., ”Sensitivity study of chemistry in AGB outflows using chemical kinetics”, 2023, MNRAS,522, 4654; doi:10.1093/mnras/stad1152

Gobrecht, D., Plane, J. M. C.. Bromley, S. T., et al., ”Bottom-up dust nucleation theory in oxygen-rich evolved stars. I. Aluminum oxide clusters”. 2022, A&A, 658, 167; doi:10.1051/0004-6361/202141976

Van de Sande, M. and Millar, T. J., ”The impact of stellar companion UV photons on the chemistry of the circumstellar environments of AGB stars”, 2022, MNRAS, 510, 1204; doi:10.1093/mnras/stab3282

Douglas, K. M., Gobrecht, D., Plane, J. M. C., ”Experimental study of the removal of excited state phosphorus atoms by H$_2$O and H$_2$: implications for the formation of PO in stellar winds”, 2022, MNRAS, 515. 99; doi:10.1093/mnras/stac1684

Plane, J. M. C., and Robertson, S. H.. ”Master equation modelling of non-equilibrium chemistry in stellar outflows”, 2022, Faraday Discuss., 238, 461; doi:10.1039/D2FD00025C

Hydrodynamical simulations

Esseldeurs, M., Siess, L., De Ceuster, F., et al. “3D simulations of AGB stellar winds. II. Ray-tracer implementation and impact of radiation on the outflow morphology”, 2023, A&A, 674, A122; doi:10.1051/0004-6361/202346282

Siess, L., Homan, W., Toupin, S., et al. “3D simulations of AGB stellar winds. I. Steady winds and dust formation”, 2022, A&A, 667, A75; doi:10.1051/0004-6361/202243540

Maes, S., Homan, W., Malfait, J., et al., ”SPH modelling of companion-perturbed AGB outflows including a new morphology classification scheme”, 2021, A&A, 653, A25; doi:10.1051/0004-6361/202140823

Malfait, J., Homan, W., Maes, S., et al., ”SPH modelling of wind-companion interactions in eccentric AGB binary systems”, 2021, A&A, 652, A51; doi:10.1051/0004-6361/202141161

El Mellah, I., Bolte, J., Decin, L., et al., ”Wind morphology around cool evolved stars in binaries. The case of slowly accelerating oxygen-rich outflows”, 2020, A&A, 637, A91; doi:10.1051/0004-6361/202037492

ATOMIUM products:

See Gottlieb et al. 2022A&A...660A..94G for details of ATOMIUM observations and data processing. For each of 17 stars, 16 frequency tunings were used to make spectral image cubes numbered 00 - cube15 as shown in the table below. The compact, mid and extended configurations give resolutions around 1", 0".3, 0".03, which were also combined.
Cube 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
Nch 1920 1920 1920 1920 1920 1920 1920 960 960 1920 1920 1920 1920 960 1920 1920
Min 213.9 216.1 220.3 223.7 227.3 229.6 235.5 239.2 244.1 245.4 251.6 254.0 258.7 262.1 265.6 267.8
Max 215.7 217.9 222.1 225.5 229.1 231.5 237.3 240.1 245.0 247.3 253.5 255.8 260.6 263.1 267.4 269.7

The minimum and maximimum frequencies are in GHz, the exact values depend on the stellar velocity. All channels are 0.9765 MHz wide, but for some cubes the original channel numbering is from high to low frequencies.
All cubes were observed in Mid and Extended configurations, 00,01,04,05,08,09,12,13 also in Compact configuration.
All data were processed by the ALMA pipeline. We performed additional calibration and the resulting measurement sets, continuum images and spectral cubes are available along with the original data from the ALMA Science Archive. Data reduction scripts and spectra extracted from each cube are also available.

product list:

Start by downloading the README.txt summary of the LP products wget https://almascience.eso.org/dataPortal/**MAKE LINKS**
AH_Sco group.uid___A001_X133d_X131f.lp_ldecin.README.txt
GY_Aql group.uid___A001_X133d_X1237.lp_ldecin.README.txt
IRC+10011 group.uid___A001_X133d_X1293.lp_ldecin.README.txt
IRC_10529 group.uid___A001_X133d_X1298.lp_ldecin.README.txt
KW_Sgr group.uid___A001_X133d_X1307.lp_ldecin.README.txt
pi1_Gru group.uid___A001_X133d_X1254.lp_ldecin.README.txt
RW_Sco group.uid___A001_X133d_X12bf.lp_ldecin.README.txt
R_Aql group.uid___A001_X133d_X1210.lp_ldecin.README.txt
R_Hya group.uid___A001_X133d_X127b.lp_ldecin.README.txt
SV_Aqr group.uid___A001_X133d_X12ef.lp_ldecin.README.txt
S_Pav group.uid___A001_X133d_X11c6.lp_ldecin.README.txt
T_Mic group.uid___A001_X133d_X120b.lp_ldecin.README.txt
U_Del group.uid___A001_X133d_X11b7.lp_ldecin.README.txt
U_Her group.uid___A001_X133d_X124f.lp_ldecin.README.txt
VX_Sgr group.uid___A001_X133d_X12e9.lp_ldecin.README.txt
V_PsA group.uid___A001_X133d_X11c1.lp_ldecin.README.txt
W_Aql group.uid___A001_X133d_X11bc.lp_ldecin.README.txt
The files can be downloaded individually using the command line in a format such as
wget https://almascience.eso.org/dataPortal/group.uid___A001_X133d_X131f.lp_ldecin.README.txt
The description.pdf describes the data reduction and products in more detail. This is for VX Sgr; you can download for every star but the methods are general:
wget https://almascience.eso.org/dataPortal/group.uid___A001_X133d_X12e9.lp_ldecin.description.pdf Script atomium_asa.py**LINK** provides downloading of multiple data products. atomium_filesizes.tab **LINK** lists all the available LP products along with the file sizes. In summary: Documentation <1 MB; Spectra <10 MB (text files) Images (fits) continuum <5 GB; cubes: compact <1 GB; mid < 11GB; extended <8 GB; combined <19 GB Visibility data (measurement sets): continuum <65 GB; line and contsub MS 7 to 70 GB