J/AJ/166/196 V1298 Tau high energy spectrum (Duvvuri+, 2023)
The High-energy Spectrum of the Young Planet Host V1298 Tau.
Duvvuri G.M., Cauley P.W., Aguirre F.C., Kilgard R., France K.,
Berta-Thompson Z.K., Pineda J.S.
<Astron. J., 166, 196 (2023)>
=2023AJ....166..196D 2023AJ....166..196D
ADC_Keywords: YSOs; Spectra, infrared; Spectra, optical; Spectra, ultraviolet;
X-ray sources
Keywords: Pre-main sequence stars ; X-ray astronomy ; Ultraviolet
astronomy ; Stellar atmospheres ; Stellar chromospheres ;
Stellar coronae ; Atmospheric evolution ; Stellar magnetic
fields
Abstract:
V1298 Tau is a young pre-main-sequence star hosting four known
exoplanets that are prime targets for transmission spectroscopy with
current-generation instruments. This work pieces together observations
from the NICER X-ray telescope, the Space Telescope Imaging
Spectrograph and Cosmic Origins Spectrograph instruments aboard Hubble
Space Telescope, and empirically informed models to create a
panchromatic spectral energy distribution for V1298 Tau spanning
1-105Å. We describe the methods and assumptions used to assemble
the panchromatic spectrum and show that despite this star's
brightness, its high-energy spectrum is near the limit of present
X-ray and ultraviolet observatories' abilities to characterize. We
conclude by using the V1298 Tau spectrum as a benchmark for the
activity saturation stage of high-energy radiation from solar-mass
stars to compare the lifetime cumulative high-energy irradiation of
the V1298 Tau planets to other planets orbiting similarly massive
stars.
Description:
From 2020 through early 2022 we obtained observations of V1298 Tau's
high-energy spectrum using the Space Telescope Imaging Spectrograph
(STIS) and Cosmic Origins Spectrograph (COS) instruments on the Hubble
Space Telescope (HST) and NASA's Neutron Star Interior Composition
ExploreR (NICER) mission aboard the International Space Station. The
ultraviolet observations cover the wavelength range 1140-3150Å and
the X-ray observations span the energy range 0.1-10keV (∼5-55Å).
We detail the individual instrument settings and observations in the
two subsections below, including a summary in Table 1.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------------------
04 05 19.59 +20 09 25.5 V1298 Tau = 1RXS J040518.6+200919
------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 54 6 Summary of NICER and HST observations
fig1.dat 46 384852 The composite spectrum
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+AS/125/149 : CHIANTI An Atomic Database For Emission Lines I. (Dere+ 1997)
J/A+A/416/281 : X-ray spectra of 4 cool stars (Sanz-forcada+, 2004)
J/ApJ/743/48 : Stars with rot periods and X-ray luminosities (Wright+, 2011)
J/ApJ/756/171 : HST far-UV survey of H2 emission of TTau stars (France+, 2012)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/AJ/154/109 : California-Kepler Survey. III. Planet radii (Fulton+, 2017)
J/AJ/164/110 : HST/COS far-UV spectra AUMicroscopii flares (Feinstein+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Tel Telescope used
7- 16 A10 --- Inst Instrument setting
18- 21 I4 yr Obs.Y [2020/2022] UT year of observation
23- 24 I2 "month" Obs.M UT month of observation
26- 27 I2 d Obs.D UT day of observation
29- 30 I2 h Obs.H UT hour of observation
32- 33 I2 min Obs.m UT minute of observation
35- 39 I5 s Texp [1880/21924] Exposure time
41- 44 I4 0.1nm lambda1 [5/1600] Starting wavelength (angstrom)
46- 49 I4 0.1nm lambda2 [55/3150] Ending wavelength (angstrom)
51- 54 F4.2 0.1nm Res [0.09/3] Resolution (1)
--------------------------------------------------------------------------------
Note (1): Resolutions vary across the free spectral range. We report
the approximate value at the central wavelength of the recorded
spectrum
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 E11.5 10-13m Wave [1/499965] Wavelength; Angstroms
13- 22 E10.3 cW/m2/nm Flux [-4e-16/5e-13] Flux density;
erg/s/cm2/Angstrom
24- 30 E7.1 cW/m2/nm e_Flux [0/2e-13] Lower uncertainty in Flux
32- 38 E7.1 cW/m2/nm E_Flux [0/2e-13] Upper uncertainty in Flux
40- 46 A7 --- Source Data source (1)
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Note (1): Sources as follows:
XSPEC = XSPEC model, 1-100 Angstroms;
DEM = Differential Emission Measure model, 100-1150 Angstroms;
COS = HST/COS, 1150-1700 Angstroms;
Scaled = 1214.63-1216.78 Angstroms (Lyman-α) and
1519.42-1530.78 Angstroms replaced with scaled excerpts
from the MUSCLES SED for ε Eridani;
STIS = HST/STIS, 1700-3100 Angstroms;
PHOENIX = PHOENIX model, 3100-1e5 Angstroms.
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Acknowledgements:
Girish Duvvuri <girish.duvvuri at colorado.edu>
History:
From electronic version of the journal
* 13-May-2024: Insert into VizieR
* 22-Jul-2024: Description of error columns of Figure 1 corrected
(upper and lower errors were inverted)
(End) Prepared by [AAS]; Coralie Fix [CDS], 09-Apr-2024