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:

PI: Leen Decin (Institute of Astronomy, Ku Leuven, Belgium)
CO-PI: Carl A. Gottlieb (Harvard-Smithsonian Center for Astrophysics, US)

Consortium:

A.M.S. Richards (Jodrell Bank Centre for Astrophysics, Univ. of Manchester, UK), A. Baudry (Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux, France), E. De Beck (Chalmers Univ. of Technology, Onsala Space Observatory, Sweden), J. Bolte, E. Cannon (Inst. of Astronomy, KU Leuven, Belgium), T. Ceulemans (Inst. of Astronomy, KU Leuven, Belgium), F. De Ceuster (Inst. of Astronomy, KU Leuven, Belgium), T. Danilovich (School of Physics & Astronomy, Monash Univ., Australia), A. de Koter (Anton Pannekoek Inst. of Astronomy, Univ. of Amsterdam, Netherlands), Ileyk El Mellah (CIRAS, Universidad de Santiago de Chile, Chile), M. Esseldeurs (Inst. of Astronomy, KU Leuven, Belgium), S. Etoka (Jodrell Bank Centre for Astrophysics, Univ. of Manchester, UK), D. Gobrecht (Dept. of Chemistry & Molecular Biology, Gothenburg Univ., Sweden) E. Gottlieb (School of Engineering & Applied Sciences, Harvard Univ., US), M. Gray (National Astronomical Research Inst. of Thailand), F. Herpin (Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux, France), W. Homan (Institut d’Astronomie et d’Astrophysique, Belgium) M. Jeste (Max-Planck-Institut für Radioastronomie, Germany), D. Kee (National Solar Observatory, US), P. Kervella (LESIA, Observatoire de Paris, France), P. Kervella (LESIA, Observatoire de Paris, France), T. Khouri (Chalmers Univ. of Technology, Onsala Space Observatory, Sweden), E. Lagadec (Universite’ Côte d’Azur, Observatoire de la Côte d’Azur, France) S. Maes (Inst. of Astronomy, KU Leuven, Belgium), J. Malfait (Inst. of Astronomy, KU Leuven, Belgium), L. Marinho (Univ. of Bordeaux, France). I. McDonald (Jodrell Bank Centre for Astrophysics, Univ. of Manchester, UK), K.M. Menten (Max-Planck-Institut für Radioastronomie, Germany), T.J. Millar (Astrophysics Research Centre, Queen’s Univ. Belfast, UK), M. Montargès (LESIA,Observatoire de Paris - PSL, France), H.S.P. Müller (Universität zu Köln, I. Physikalisches Institut, Germany), J. Nuth (NASA/GSFC, US), B. Pimpanuwat (National Astronomical Research Inst. of Thailand), J.M.C. Plane (Univ. of Leeds, UK), D. Price (School of Physics & Astronomy, Monash University, Australia), S. Rieder (Institute of Astronomy, KU Leuven, Belgium), R. Sahai (Jet Propulsion Laboratory, US) M. Van de Sande (Leiden Observatory, Netherlands), L. Siess (Inst. of Astronomy & Astrophysics, ULB Brussels, Belgium) S.H.J. Wallström (Inst. of Astronomy, KU Leuven, Belgium), L.B.F.M. Waters (SRON Netherlands Inst. for Space Research, Anton Pannekoek Inst. of Astronomy Univ. of Amsterdam, Netherlands) K.T. Wong (Dept. of Physics & Astronomy, Uppsala Univ., Sweden), J. Yates (University College London, UK), A. Zijlstra (Jodrell Bank Centre for Astrophysics, Univ. 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

ATOMIUM Pilot

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

Chemistry

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**

Star	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