J/AJ/167/127 JWST MIRI spectrum of T Cha (Bajaj+, 2024)
JWST MIRI MRS Observations of T Cha: Discovery of a Spatially Resolved Disk
Wind.
Bajaj N.S., Pascucci I., Gorti U., Alexander R., Sellek A., Morrison J.,
Gaspar A., Clarke C., Xie C., Ballabio G., Deng D.
<Astron. J., 167, 127 (2024)>
=2024AJ....167..127B 2024AJ....167..127B
ADC_Keywords: Stars, G-type; Spectra, infrared
Keywords: Planet formation ; Protoplanetary disks ; T Tauri stars ;
Infrared spectroscopy
Abstract:
Understanding when and how circumstellar disks disperse is crucial to
constrain planet formation and migration. Thermal winds powered by
high-energy stellar photons have long been theorized to drive disk
dispersal. However, evidence for these winds is currently based only
on small (∼3-6km/s) blueshifts in [NeII] 12.81µm lines, which does
not exclude MHD winds. We report JWST MIRI MRS spectro-imaging of
TCha, a disk with a large dust gap (∼30au in radius) and blueshifted
[NeII] emission. We detect four forbidden noble gas lines, [ArII],
[ArIII], [NeII], and [NeIII], of which [ArIII] is the first detection
in any protoplanetary disk. We use line flux ratios to constrain the
energy of the ionizing photons and find that argon is ionized by
extreme ultraviolet, whereas neon is most likely ionized by X-rays.
After performing continuum and point-spread function subtraction on
the integral field unit cube, we discover a spatial extension in the
[NeII] emission off the disk continuum emission. This is the first
spatially resolved [NeII] disk wind emission. The mostly ionic
spectrum of TCha, in combination with the extended [NeII] emission,
points to an evolved stage for any inner MHD wind and is consistent
with the existence of an outer thermal wind ionized and driven by
high-energy stellar photons. This work acts as a pathfinder for future
observations aiming at investigating disk dispersal using JWST.
Description:
TCha was observed as part of the Cycle 1 General Observer program
(proposal ID: 2260; PI: I. Pascucci) using the MIRI MRS instrument on
board the James Webb Space Telescope (JWST). It was observed on 2022
August 13-14 for 3.24hr on-source and 4.48hr including the
overheads.
Objects:
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RA (2000) DE Designation(s)
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11 57 13.52 -79 21 31.5 T Cha = V* T Cha
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 18 11068 The JWST MIRI MRS spectrum of T Cha
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See also:
J/A+A/480/735 : Young local stellar associations (Fernandez+, 2008)
J/MNRAS/435/1325 : Membership of the ε Cha association (Murphy+, 2013)
J/A+A/620/A87 : Ejection processes in NGC 2264 (McGinnis+, 2018)
J/AJ/161/87 : Gaia data for members of eCha (Dickson-Vandervelde+, 2021)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.6 um Wave [4.9/28.8] Wavelength
11- 18 F8.6 Jy Flux [0/4.58]? Flux density
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 17-May-2024