[O i] 6300 angstrom emission as a probe of external photoevaporation of protoplanetary discs
Por:
Ballabio, Giulia, Haworth, Thomas J., Henney, W. J.
Publicada:
8 dic 2022
Resumen:
We study the utility of the [O i] 6300 angstrom forbidden line for
identifying and interpreting externally driven photoevaporative winds in
different environments and at a range of distances. Thermally excited
[O i] 6300 angstrom is a well-known tracer of inner disc winds, so any
external contribution needs to be distinguishable. In external winds,
the line is not thermally excited and instead results from the
dissociation of OH, and we study how the line luminosity resulting from
that process scales with the disc/environmental parameters. We find that
the line luminosity increases dramatically with FUV radiation field
strength above around 5000 G(0). The predicted luminosities from our
models are consistent with measurements of the line luminosity of
proplyds in the Orion Nebula Cluster. The high luminosity in strong UV
environments alone may act as a diagnostic, but a rise in the [O
i]-to-accretion luminosity ratio is predicted to better separate the two
contributions. This could provide a means of identifying external
photoevaporation in distant clusters where the proplyd morphology of
evaporating discs cannot be spatially resolved.
Filiaciones:
Ballabio, Giulia:
Queen Mary Univ London, Sch Phys & Astron, Astron Unit, London E1 4NS, England
Haworth, Thomas J.:
Queen Mary Univ London, Sch Phys & Astron, Astron Unit, London E1 4NS, England
Henney, W. J.:
Univ Nacl Autonoma Mexico, Inst Radioastron & Astrofis, Apartado Postal 3 72, Morelia 58090, Michoacan, Mexico
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