TY - JOUR
T1 - An APEX search for carbon emission from NGC 1977 proplyds
AU - Haworth, Thomas J.
AU - Kim, Jinyoung S.
AU - Qiao, Lin
AU - Winter, Andrew J.
AU - Williams, Jonathan P.
AU - Clarke, Cathie J.
AU - Owen, James E.
AU - Facchini, Stefano
AU - Ansdell, Megan
AU - Kama, Mikhel
AU - Ballabio, Giulia
N1 - Publisher Copyright:
© 2022 The Author(s).
PY - 2022/5/1
Y1 - 2022/5/1
N2 - 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 3σ 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.
AB - 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 3σ 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.
KW - accretion, accretion discs
KW - circumstellar matter
KW - planets and satellites: formation
KW - protoplanetary discs
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U2 - 10.1093/mnras/stac656
DO - 10.1093/mnras/stac656
M3 - Article
AN - SCOPUS:85128428954
SN - 0035-8711
VL - 512
SP - 2594
EP - 2603
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -