J/AJ/162/235 HST/STIS near-UV spectrum of η Telescopii (Youngblood+, 2021)
A Radiatively Driven Wind from the ηTel Debris Disk
Youngblood A., Roberge A., MacGregor M.A., Brandeker A., Weinberger A.J.,
Perez S., Grady C., Welsh B.
<Astron. J., 162, 235 (2021)>
=2021AJ....162..235Y 2021AJ....162..235Y
ADC_Keywords: Stars, A-type; Spectra, ultraviolet; Abundances
Keywords: A stars ; Circumstellar matter ; Ultraviolet astronomy ;
Protoplanetary disks
Abstract:
We present far- and near-ultraviolet absorption spectroscopy of the
∼23Myr edge-on debris disk surrounding the A0V star ηTelescopii,
obtained with the Hubble Space Telescope Space Telescope Imaging
Spectrograph. We detect absorption lines from CI, CII, OI, MgII, AlII,
SiII, SII, MnII, FeII, and marginally NI. The lines show two clear
absorption components at -22.7±0.5km/s and -17.8±0.7km/s,
which we attribute to circumstellar (CS) and interstellar gas,
respectively. CO absorption is not detected, and we find no evidence
for star-grazing exocomets. The CS absorption components are
blueshifted by -16.9±2.6km/s in the star's reference frame,
indicating that they are outflowing in a radiatively driven disk wind.
We find that the C/Fe ratio in the ηTel CS gas is significantly
higher than the solar ratio, as is the case in the βPic and 49Cet
debris disks. Unlike those disks, however, the measured C/O ratio in
the ηTel CS gas is consistent with the solar value. Our analysis
shows that because ηTel is an earlier type star than βPic and
49Cet, with more substantial radiation pressure at the dominant CII
transitions, this species cannot bind the CS gas disk to the star as
it does for βPic and 49Cet, resulting in the disk wind.
Description:
We observed the ηTel debris disk with Hubble Space Telecscope
Space Telescope Imaging Spectrograph (HST/STIS) on 2016 October 3 and
2016 October 6. The wavelength coverage of the STIS spectra is
1164-1951Å and 2587-2851Å. The spectra were obtained with the
E140H and E230H echelle gratings (grating settings i1271, c1416,
c1598, i1813, and i2713), providing an average dispersion of
λ/228000Å/pixel.
Objects:
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RA (2000) DE Designation(s)
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19 22 51.21 -54 25 26.1 * eta Tel = * eta Tel
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 75 142094 Co-added spectrum of ηTelescopii from HST STIS
E140H and E230H observations
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See also:
III/254 : 2nd Cat. Radial Velocities with Astrometric Data (Kharchenko+, 2007)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/497/330 : Candidate main-sequence stars (Mannings+, 1998)
J/AN/328/889 : Mean Radial Velocities of open clusters (Kharchenko+, 2007)
J/ApJ/660/1556 : Characterization of dusty debris disks (Rhee+, 2007)
J/AJ/143/134 : Candidate members of βPic/ABDor groups (McCarthy+, 2012)
J/PASP/125/477 : Gas Survey of Protoplanetary Systems. I. (Dent+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/ApJS/211/25 : Spitzer/IRS debris disk catalog. I. (Chen+, 2014)
J/MNRAS/469/521 : CO, C & O gas content debris discs predictions (Kral+, 2017)
J/A+A/614/A3 : 6 cold-gas-bearing debris-disc stars spectra (Rebollido+, 2018)
J/ApJ/896/24 : Properties of atomic lines 51 Oph UV spectra (Jenkins+, 2020)
J/A+A/639/A11 : Exocomets. A Spectroscopic Survey (Rebollido+, 2020)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 24 E24.18 0.1nm lambda [1163/2835] Wavelength, Angstroms
26- 50 E25.18 10mW/m2/nm Flux Flux Density, erg/cm2/s/Ang
52- 75 E24.18 10mW/m2/nm e_Flux Flux Density Error, erg/cm2/s/Ang
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 18-Feb-2022