An APEX search for carbon emission from NGC 1977 proplyds

Thomas J. Haworth, Jinyoung S. Kim, Lin Qiao, Andrew J. Winter, Jonathan P. Williams, Cathie J. Clarke, James E. Owen, Stefano Facchini, Megan Ansdell, Mikhel Kama, Giulia Ballabio

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)2594-2603
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - May 1 2022


  • accretion, accretion discs
  • circumstellar matter
  • planets and satellites: formation
  • protoplanetary discs

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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