TY  - JOUR
A1  - Meyer, Dominique M.-A.
A1  - Kreplin, Alexander
A1  - Kraus, S.
A1  - Vorobyov, E. I.
A1  - Haemmerlé, Lionel
A1  - Eislöffel, Jochen
T1  - On the ALMA observability of nascent massive multiple systems formed by gravitational instability
T2  - Monthly notices of the Royal Astronomical Society
N2  - Massive young stellar objects (MYSOs) form during the collapse of high-mass pre-stellar cores, where infalling molecular material is accreted through a centrifugally balanced accretion disc that is subject to efficient gravitational instabilities. In the resulting fragmented accretion disc of the MYSO, gaseous clumps and low-mass stellar companions can form, which will influence the future evolution of massive protostars in the Hertzsprung-Russell diagram. We perform dust continuum radiative transfer calculations and compute synthetic images of disc structures modelled by the gravito-radiation-hydrodynamics simulation of a forming MYSO, in order to investigate the Atacama Large Millimeter/submillimeter Array (alma) observability of circumstellar gaseous clumps and forming multiple systems. Both spiral arms and gaseous clumps located at similar or equal to a few from the protostar can be resolved by interferometric alma Cycle 7 C43-8 and C43-10 observations at band 6 (), using a maximal 0.015 aracsec beam angular resolution and at least exposure time for sources at distances of . Our study shows that substructures are observable regardless of their viewing geometry or can be inferred in the case of an edge-viewed disc. The observation probability of the clumps increases with the gradually increasing efficiency of gravitational instability at work as the disc evolves. As a consequence, large discs around MYSOs close to the zero-age-main-sequence line exhibit more substructures than at the end of the gravitational collapse. Our results motivate further observational campaigns devoted to the close surroundings of the massive protostars S255IR-NIRS3 and NGC 6334I-MM1, whose recent outbursts are a probable signature of disc fragmentation and accretion variability.
KW  - radiative transfer
KW  - methods: numerical
KW  - stars: circumstellar matter
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/48592
SN  - 0035-8711
SN  - 1365-2966
VL  - 487
IS  - 4
SP  - 4473
EP  - 4491
PB  - Oxford Univ. Press
CY  - Oxford
ER  -