J/ApJ/907/91 HAZMAT VII. Early M-dwarfs FUV em. line, Age and Prot (Loyd+, 2021)
HAZMAT.
VII. The Evolution of Ultraviolet Emission with Age and Rotation for Early
M Dwarf Stars.
Loyd R.O.P., Shkolnik E.L., Schneider A.C., Richey-Yowell T.,
Jackman J.A.G., Peacock S., Barman T.S., Pagano I., Meadows V.S.
<Astrophys. J., 907, 91 (2021)>
=2021ApJ...907...91L 2021ApJ...907...91L
ADC_Keywords: Stars, dwarfs; Stars, M-type; Spectra, ultraviolet; Stars, ages;
Spectral types
Keywords: Stellar activity ; Ultraviolet astronomy ; M dwarf stars ;
Stellar evolution
Abstract:
The ultraviolet (UV) emission from the most numerous stars in the
universe, M dwarfs, impacts the formation, chemistry, atmospheric
stability, and surface habitability of their planets. We have analyzed
the spectral evolution of UV emission from M0-M2.5 (0.3-0.6M☉)
stars as a function of age, rotation, and Rossby number using Hubble
Space Telescope observations of Tucana-Horologium (40Myr), Hyades
(650Myr), and field (2-9Gyr) objects. The quiescent surface flux of
their CII, CIII, CIV, HeII, NV, SiIII, and SiIV emission lines, formed
in the stellar transition region, remains elevated at a constant level
for 240±30Myr before declining by 2.1 orders of magnitude to an
age of 10Gyr. The MgII and far-UV pseudocontinuum emission, formed in
the stellar chromosphere, exhibits more gradual evolution with age,
declining by 1.3 and 1.7 orders of magnitude, respectively. The
youngest stars exhibit a scatter of 0.1dex in far-UV line and
pseudocontinuum flux attributable only to rotational modulation,
long-term activity cycles, or an unknown source of variability.
Saturation-decay fits to these data can predict an M0-M2.5 star's
quiescent emission in UV lines and the far-UV pseudocontinuum with an
accuracy of 0.2-0.3dex, the most accurate means presently available.
Predictions of UV emission will be useful for studying exoplanetary
atmospheric evolution and the destruction and abiotic production of
biologically relevant molecules and interpreting infrared and optical
planetary spectra measured with observatories like the James Webb
Space Telescope.
Description:
The HAZMAT HST survey (program ID 14784; PI: Shkolnik) collected data
using the Cosmic Origins Spectrograph (COS) with the G130M and G160M
(R=12000-20000) and G230L (R=2000-4000) gratings. Observations were
made of 21 M-stars, 12 from the Tucana-Horologium (Tuc-Hor, 40 Myr)
moving group, six from the Hyades cluster (650Myr), and three
unassociated field stars (2-10Gyr).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig3.dat 332 24 Surface fluxes of strong UV emission lines as a
function of rotation period
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)
J/A+A/331/81 : Hyades membership (Perryman+ 1998)
J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)
J/A+A/460/695 : Search for Associations Containing Young stars (Torres+, 2006)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/A+A/493/645 : Gl 176 radial velocities (Forveille+, 2009)
J/A+A/520/A15 : RACE-OC project; YSOs within 100pc (Messina+, 2010)
J/A+A/532/A10 : RACE-OC project. II. (Messina+, 2011)
J/ApJ/743/48 : Stars with rotation periods & Xray luminosities (Wright+, 2011)
J/ApJ/761/166 : Terrestrial exoplanet atmospheres. I. (Hu+, 2012)
J/MNRAS/422/2024 : Xray-age relation and exoplanet evaporation (Jackson+, 2012)
J/A+A/547/A13 : Homogeneous sample of F6-K4 Hyades stars (Tabernero+, 2012)
J/A+A/556/A126 : GJ667C Doppler & activity measurements (Anglada-Escude+, 2013)
J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)
J/MNRAS/431/2063 : UV/X-ray activity of M dwarfs within 10pc (Stelzer+, 2013)
J/MNRAS/443/2561 : CONCH-SHELL catalog of nearby M dwarfs (Gaidos+, 2014)
J/AJ/147/146 : Spectroscopy of Tuc-Hor candidate members (Kraus+, 2014)
J/AJ/148/64 : HAZMAT. I. FUV & NUV emission in early Mstars (Shkolnik+, 2014)
J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
J/ApJ/822/47 : K2 rotation periods for 65 Hyades members (Douglas+, 2016)
J/ApJ/821/93 : Rotation & Galactic kinematics of mid M dwarfs (Newton+, 2016)
J/A+A/600/A13 : HARPS M dwarf sample magnetic activity (Astudillo-Defru+, 2017)
J/AJ/153/128 : WOCS. LXXV. Hyades&Praesepe stellar Li data (Cummings+, 2017)
J/AJ/154/67 : HAZMAT. II. Low-mass stars with GALEX UV obs. (Miles+, 2017)
J/ApJ/843/31 : MUSCLES Treasury Survey IV Mdwarf UV fluxes (Youngblood+, 2017)
J/ApJ/862/33 : Improved & expanded membership cat. for NGC752 (Agueros+, 2018)
J/AJ/155/265 : The solar neighborhood. XLIV. RECONS discoveries (Henry+, 2018)
J/AJ/156/217 : Stellar properties for M dwarfs in MEarth-South (Newton+, 2018)
J/AJ/155/39 : Variability properties TIC sources with KELT (Oelkers+, 2018)
J/AJ/155/122 : HAZMAT. III. Low-mass stars GALEX photometry (Schneider+, 2018)
J/AJ/158/77 : Candidates & members of Pisces-Eridanus stream (Curtis+, 2019)
J/ApJ/879/100 : K2 rotation periods Hyades & Praesepe members (Douglas+, 2019)
J/ApJ/872/17 : HAZMAT. V. UV & X-ray evolution K stars (Richey-Yowell+, 2019)
J/AJ/160/90 : Stellar parameters for 13196 Kepler dwarfs (Angus+, 2020)
J/ApJ/904/140 : Ruprecht 147 members & rot. data for 5 other cl (Curtis+, 2020)
Byte-by-byte Description of file: fig3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Stellar identifier
10- 26 A17 --- 2MASS 2MASS identifier
28- 35 E8.2 yr Age [4e+07/8.71e+09] Age
37- 44 E8.2 yr e_Age [5e+06/6e+09] Lower uncertainty in Age
46- 53 E8.2 yr E_Age [5e+06/9e+09] Upper uncertainty in Age
55- 61 F7.3 d Prot [0.57/104]? Rotation period
63- 67 F5.3 d e_Prot [1.57/9.3]? Uncertainty in Prot
69- 73 F5.3 --- Ro [0.01/2.09]? Rossby number
75- 79 F5.3 --- e_Ro [0.02/0.2]? Uncertainty in Ro
81- 84 A4 --- SpType Spectral type (1)
86- 89 A4 --- ASpType Alternate spectral type (1)
91- 98 E8.2 mW/m2 SFMg2 [60200/1.68e+06]? Mg II 2796,2803A surface flux;
erg/s/cm2
100-107 E8.2 mW/m2 E_SFMg2 [357/134000]? Upper uncertainty in SF-Mg2
109-116 E8.2 mW/m2 e_SFMg2 [472/143000]? Lower uncertainty in SF-Mg2
118-125 E8.2 mW/m2 SFC2 [1060/126000]? C II 1334,1335A surface flux;
erg/s/cm2
127-134 E8.2 mW/m2 E_SFC2 [10.5/9450]? Upper uncertainty in SF-C2
136-143 E8.2 mW/m2 e_SFC2 [12.3/15000]? Lower uncertainty in SF-C2
145-152 E8.2 mW/m2 SFSi3 [354/59300]? Si III 1206A surface flux;
erg/s/cm2
154-161 E8.2 mW/m2 E_SFSi3 [6.86/7800]? Upper uncertainty in SF-Si3
163-170 E8.2 mW/m2 e_SFSi3 [6.72/8200]? Lower uncertainty in SF-Si3
172-179 E8.2 mW/m2 SFC3 [471/94500]? C III 1175A surface flux;
erg/s/cm2
181-188 E8.2 mW/m2 E_SFC3 [10.9/12900]? Upper uncertainty in SF-C3
190-197 E8.2 mW/m2 e_SFC3 [7.68/8850]? Lower uncertainty in SF-C3
199-206 E8.2 mW/m2 SFSi4 [533/65300]? Si IV 1393,1402A surface flux;
erg/s/cm2
208-215 E8.2 mW/m2 E_SFSi4 [8.82/19500]? Upper uncertainty in SF-Si4
217-224 E8.2 mW/m2 e_SFSi4 [8.39/8920]? Lower uncertainty in SF-Si4
226-233 E8.2 mW/m2 SFHe2 [1400/180000]? He II 1604A surface flux;
erg/s/cm2
235-242 E8.2 mW/m2 E_SFHe2 [20/36300]? Upper uncertainty in SF-He2
244-251 E8.2 mW/m2 e_SFHe2 [15/64000]? Lower uncertainty in SF-He2
253-260 E8.2 mW/m2 SFC4 [1670/266000]? C IV 1548,1550A surface flux;
erg/s/cm2
262-269 E8.2 mW/m2 E_SFC4 [35.7/22200]? Upper uncertainty in SF-C4
271-278 E8.2 mW/m2 e_SFC4 [31.4/20400]? Lower uncertainty in SF-C4
280-287 E8.2 mW/m2 SFN5 [522/56600]? N V 1238,1242A surface flux;
erg/s/cm2
289-296 E8.2 mW/m2 E_SFN5 [10.4/10000]? Upper uncertainty in SF-N5
298-305 E8.2 mW/m2 e_SFN5 [10.3/4380]? Lower uncertainty in SF-N5
307-314 E8.2 mW/m2 SFCont [4900/330000]? FUV pseudocontinuum surface flux;
erg/s/cm2
316-323 E8.2 mW/m2 E_SFCont [110/13000]? Upper uncertainty in Cont
325-332 E8.2 mW/m2 e_SFCont [110/13000]? Lower uncertainty in Cont
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Note (1): All spectral types of the 40Myr stars are from
Kraus+, 2014, J/AJ/147/146. The first are based on SED fitting while
the alternates are based on optical spectral indices. See text for
spectral type references of older stars.
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History:
From electronic version of the journal
References:
Shkolnik et al. Paper I : 2014AJ....148...64S 2014AJ....148...64S Cat. J/AJ/148/64
Miles et al. Paper II : 2017AJ....154...67M 2017AJ....154...67M Cat. J/AJ/154/67
Schneider et al. Paper III : 2018AJ....155..122S 2018AJ....155..122S Cat. J/AJ/155/122
Loyd et al. Paper IV : 2018ApJ...867...70L 2018ApJ...867...70L
Richey-Yowell et al. Paper V : 2019ApJ...872...17R 2019ApJ...872...17R Cat. J/ApJ/872/17
Peacock et al. Paper VI : 2020ApJ...895....5P 2020ApJ...895....5P
(End) Prepared by [AAS], Coralie Fix [CDS], 03-Jun-2022