Data di Pubblicazione:
2022
Citazione:
An APEX search for carbon emission from NGC 1977 proplyds / T.J. Haworth, J.S. Kim, L. Qiao, A.J. Winter, J.P. Williams, C.J. Clarke, J.E. Owen, S. Facchini, M. Ansdell, M. Kama, G. Ballabio. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 512:2(2022 Mar 29), pp. 2594-2603. [10.1093/mnras/stac656]
Abstract:
We used the Atacama Pathfinder Experiment (APEX) telescope to search for C I 1-0 (492.16 GHz) emission towards eight proplyds in NGC 1977, which is an FUV radiation environment two orders of magnitude weaker than that irradiating the Orion Nebular Cluster (ONC) proplyds. C I is expected to enable us to probe the wind launching region of externally photo-evaporating discs. Of the eight targets observed, no 3 sigma detections of the C I line were made despite reaching sensitivities deeper than the anticipated requirement for detection from prior APEX CI observations of nearby discs and models of external photo-evaporation of quite massive discs. By comparing both the proplyd mass loss rates and C I flux constraints with a large grid of external photo-evaporation simulations, we determine that the non-detections are in fact fully consistent with the models if the proplyd discs are very low mass. Deeper observations in C I and probes of the disc mass with other tracers (e.g. in the continuum and CO) can test this. If such a test finds higher masses, this would imply carbon depletion in the outer disc, as has been proposed for other discs with surprisingly low C I fluxes, though more massive discs would also be incompatible with models that can explain the observed mass loss rates and C I non-detections. The expected remaining lifetimes of the proplyds are estimated to be similar to those of proplyds in the ONC at 0.1 Myr. Rapid destruction of discs is therefore also a feature of common, intermediate UV environments.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
accretion, accretion discs; circumstellar matter; planets and satellites: formation; protoplanetary discs;
Elenco autori:
T.J. Haworth, J.S. Kim, L. Qiao, A.J. Winter, J.P. Williams, C.J. Clarke, J.E. Owen, S. Facchini, M. Ansdell, M. Kama, G. Ballabio
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