J/ApJ/960/62 Red dwarfs, Xray, UV, and CaII (Engle, 2024)
Living with a Red Dwarf:
X-Ray, UV, and Ca II Activity-Age Relationships of M Dwarfs.
Engle S.G.
<Astrophys. J. 960, 62 (2024)>
=2024ApJ...960...62E 2024ApJ...960...62E (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, variable ; Stars, M-type ; Stars, ages ;
X-ray sources ; Ultraviolet
Keywords: Stellar ages - Stellar atmospheres - Stellar coronae -
Stellar chromospheres - Stellar evolution - Stellar rotation -
X-ray astronomy - Ultraviolet astronomy - Low mass stars -
Late-type dwarf stars - M dwarf stars
Abstract:
The vast majority of stars in the nearby stellar neighborhood are M
dwarfs. Their low masses and luminosities result in slow rates of
nuclear evolution and minimal changes to the stars' observable
properties, even along astronomical timescales. However, they possess
relatively powerful magnetic dynamos and resulting X-ray to UV (X-UV)
activity, compared to their bolometric luminosities. This magnetic
activity does undergo an observable decline over time, potentially
making it a key age determinant for M dwarfs. Observing this activity
is important for studying the outer atmospheres of these stars, but
also for comparing the behaviors of different spectral type subsets of
M dwarfs; e.g., those with partially versus fully convective
interiors. Beyond stellar astrophysics, understanding the X-UV
activity of M dwarfs over time is a key component when studying the
atmospheres and habitability of any hosted exoplanets. Earth-sized
exoplanets, in particular, are more commonly found orbiting M dwarfs
than any other stellar type, and thermal escape (driven by the M dwarf
X-UV activity) is believed to be the dominant atmospheric loss
mechanism for these planets. Utilizing recently calibrated M dwarf
age-rotation relationships, also constructed as part of the Living
with a Red Dwarf program, we have analyzed the evolution of M dwarf
activity over time, in terms of coronal (X-ray), chromospheric
(Ly{alpha|, and CaII), and overall X-UV (5-1700Å) emissions. The
activity-age relationships presented here will be useful for studying
exoplanet habitability and atmospheric loss, and also for studying the
different dynamo and outer atmospheric heating mechanisms at work in M
dwarfs.
Description:
The Living with a Red Dwarf (LivRed) program has constructed
activity-age relationships for M dwarfs using three different
tracers of magnetic activity, along with a broad X-UV band
(5-1700Å). Multiple measures of each star's activity levels were
gathered whenever possible to help mitigate scatter due to stellar
variability, and many of the ages were calculated using the
age-rotation relationships presented in Engle & Guinan
(2023ApJ...954L..50E 2023ApJ...954L..50E).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 100 89 Early M Dwarf X-Ray Data
table3.dat 100 84 Mid-Late M Dwarf X-Ray Data
table4.dat 75 12 Early M Dwarf Lyα Data
table5.dat 75 22 Mid-Late M Dwarf Lyα Data
table6.dat 69 67 Early M Dwarf CaII Data
table7.dat 69 70 Mid-Late M Dwarf CaII Data
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Byte-by-byte Description of file: table2.dat table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Flag Flag (1)
3- 25 A23 --- Object Object Name
27- 34 A8 --- OName Other Name
36- 41 F6.2 d Prot ? Rotational Period, days
43- 46 F4.2 d e_Prot ? Uncertainty in Prot
48- 54 A7 --- r_Prot Reference for Prot (2)
56- 61 F6.3 [Gyr] logAge log, Age
63- 67 F5.3 [Gyr] e_logAge Uncertainty in logAge
69- 73 F5.2 [10-7W] logLX log, X-ray luminosity (in ergs/s)
75- 78 F4.2 [10-7W] e_logLX Uncertainty in logLx (in ergs/s)
80- 84 F5.2 --- LX/Lbol Ratio, X-ray to bolometric luminosity
86- 89 F4.2 --- e_LX/Lbol Uncertainty in Lx/Lbol
91-100 A10 --- XrayRef Reference for X-ray measurement(s) (3)
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Note (1): For all tables presented here, if (depending on the
spectral type source that was used) a target could have
potentially been placed in the other M dwarf subset, that
target is flagged with a value of Flag=1.
Note (2): For references preceded by a "1" the values derived using data
from one or more of the sources as follows:
1A = APT
1AS = APT
1AR = APT
1AR,3 = APT
1F = Feng et al. (2020ApJS..246...11F 2020ApJS..246...11F)
1M = MEarth
1H = Trifonov et al. (2020A&A...636A..74T 2020A&A...636A..74T)
1R = RCT
1S = Skynet
1T = not explained in the paper
1Z = ZTF
Literature references as follows:
AD17 = Astudillo-Defru et al. (2017A&A...600A..13A 2017A&A...600A..13A)
D19 = Diaz et al. (2019A&A...625A..17D 2019A&A...625A..17D)
F20 = France et al. (2020AJ....160..237F 2020AJ....160..237F)
F22 = Freundetal (2022A&A...664A.105F 2022A&A...664A.105F)
Fo22 = Fosteretal (2022A&A...661A..23F 2022A&A...661A..23F)
GA19 = Gonzalez-Alvarez et al. (2019A&A...624A..27G 2019A&A...624A..27G)
H11 = Hartman et al. (2011AJ....141..166H 2011AJ....141..166H)
K19 = Kueker et al. (2019A&A...622A..40K 2019A&A...622A..40K)
KS07 = Kiraga & Stepien (2007AcA....55..205K 2007AcA....55..205K)
M10 = Messina et al. (2010A&A...520A..15M 2010A&A...520A..15M)
M20 = Magaudda et al. (2020A&A...638A..20M 2020A&A...638A..20M)
M22 = Magaudda et al. (2022AN....34320049M 2022AN....34320049M].
N16 = Nunez & Agueros (2016ApJ...830...44N 2016ApJ...830...44N)
N18 = Newton et al. (2018AJ....156..217N 2018AJ....156..217N)
PL16 = Loyd et al. (2016ApJ...824..102L 2016ApJ...824..102L)
SM15 = Suarez Mascareno et al. (2015MNRAS.452.2745S 2015MNRAS.452.2745S)
T19 = Toledo-Padron et al. (2019MNRAS.488.5145T 2019MNRAS.488.5145T)
W18 = Wright et al. (2018MNRAS.479.2351W 2018MNRAS.479.2351W)
Note (3): For references preceded by a "1" the values derived using data
from one or more of the sources as follows:
W = not explained in the paper
F = Feng et al. (2020ApJS..246...11F 2020ApJS..246...11F)
G = not explained in the paper
X-ray data sources as follow:
C = Chandra
R = ROSAT
S = Swift
X = XMM
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Byte-by-byte Description of file: table4.dat table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Flag Flag (1)
3- 17 A15 --- Object Object Name
18- 23 A6 --- OName Other Name
25- 32 F8.4 d Prot Rotational Period
34- 39 F6.4 d e_Prot Uncertainty in Prot
41- 49 A9 --- r_Prot Reference of Prot (2)
51- 56 F6.3 [Gyr] logAge log, Age in Gyr
58- 62 F5.3 [Gyr] e_logAge Uncertainty in logAge
64- 69 F6.3 --- log(Lya/Lbol) log, Lyman-α 1216Å luminosity,
71- 75 F5.3 --- e_log(Lya/Lbol) Uncertainty in logLya
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Note (1): For all tables presented here, if (depending on the
spectral type source that was used) a target could have
potentially been placed in the other M dwarf subset, that
target is flagged with a value of Flag=1.
Note (2): For references preceded by a "1" the values derived using data
from one or more of the sources as follows:
1AR = APT
1M = MEarth
1R = RCT
1S = Skynet
1Z = ZTF
1H = Trifonov et al. (2020A&A...636A..74T 2020A&A...636A..74T)
Literature references as follows:
AD17 = Wargelin et al. (2017MNRAS.464.3281W 2017MNRAS.464.3281W)
DA19 = Diez Alonso et al. (2019A&A...621A.126D 2019A&A...621A.126D)
K19 = Kueker et al. (2019A&A...622A..40K 2019A&A...622A..40K)
KS07 = Kiraga & Stepien (2007AcA....55..205K 2007AcA....55..205K)
KS13 = Kiraga & Stepien (2013AcA....63...53K 2013AcA....63...53K)
Ko19 = Kosiarek et al. (2019AJ....157...97K 2019AJ....157...97K)
M10 = Messina et al. (2010A&A...520A..15M 2010A&A...520A..15M)
Ma18 = Mallonn et al. (2018A&A...614A..35M 2018A&A...614A..35M)
Mo08 = Morin et al. (2008MNRAS.390..567M 2008MNRAS.390..567M)
N16 = Newton et al. (2016ApJ...821...93N 2016ApJ...821...93N)
N18 = Newton et al. (2018AJ....156..217N 2018AJ....156..217N)
SM15 = Suarez Mascaremo et al. (2015MNRAS.452.2745S 2015MNRAS.452.2745S)
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Byte-by-byte Description of file: table6.dat table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Flag Flag (1)
3- 18 A16 --- Object Object Name
20- 25 A6 --- OName Other Name
27- 32 F6.2 d Prot ? Rotational Period
34- 38 F5.2 d e_Prot ? Uncertainty in Prot
40- 43 A4 --- r_Prot References for Prot (2)
45- 50 F6.3 [Gyr] logAge log, Age
52- 56 F5.3 [Gyr] e_logAge Uncertainty in logAge
58- 63 F6.3 [-] logRHK log, R'HK activity indicator
65- 69 F5.3 [-] e_logRHK Uncertainty in logRHK (3)
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Note (1): For all tables presented here, if (depending on the
spectral type source that was used) a target could have
potentially been placed in the other M dwarf subset, that
target is flagged with a value of Flag=1.
Note (2): For references preceded by a "1" the values derived using data
from one or more of the sources as follows:
1A = APT
1AS = APT
1F = Feng et al. (2020ApJS..246...11F 2020ApJS..246...11F)
1H = Trifonov et al. (2020A&A...636A..74T 2020A&A...636A..74T)
1R = RCT
1S = Skynet
1T = not explained in the paper
Literature references as follows:
AD17 = Astudillo-Defru et al. (2017A&A...600A..13A 2017A&A...600A..13A)
B22 = Boudreaux et al. (2022ApJ...929...80B 2022ApJ...929...80B)
DA19 = Diez Alonso et al. (2019A&A...621A.126D 2019A&A...621A.126D)
K19 = Kueker et al. (2019A&A...622A..40K 2019A&A...622A..40K)
KS07 = Kiraga & Stepien (2007AcA....55..205K 2007AcA....55..205K)
KS13 = Kiraga & Stepien (2013AcA....63...53K 2013AcA....63...53K)
M20 = Magaudda et al. (2020A&A...638A..20M 2020A&A...638A..20M)
N16 = Newton et al. (2016ApJ...821...93N 2016ApJ...821...93N)
N18 = Newton et al. (2018AJ....156..217N 2018AJ....156..217N)
SM15 = Suarez Mascareno et al. (2015MNRAS.452.2745S 2015MNRAS.452.2745S)
SM16 = Suarez Mascareno et al. (2016A&A...595A..12S 2016A&A...595A..12S)
SM17 = Suarez Mascareno et al. (2017MNRAS.468.4772S 2017MNRAS.468.4772S)
SM18 = Suarez Mascareno et al. (2018A&A...612A..89S 2018A&A...612A..89S)
Note (3): Each star's logRHK value was determined using the combined
data (depending on availability) from
Pace (2013A&A...551L...8P 2013A&A...551L...8P)
Suarez Mascareno et al. (2015MNRAS.452.2745S 2015MNRAS.452.2745S, 2016A&A...595A..12S 2016A&A...595A..12S)
Astudillo-Defru et al. (2017A&A...600A..13A 2017A&A...600A..13A)
Suarez Mascareno et al. (2017MNRAS.468.4772S 2017MNRAS.468.4772S)
Boro Saikia et al. (2018A&A...616A.108B 2018A&A...616A.108B)
Suarez Mascareno et al. (2018A&A...612A..89S 2018A&A...612A..89S)
Melbourne et al. (2020AJ....160..269M 2020AJ....160..269M)
Perdelwitz et al. (2021A&A...652A.116P 2021A&A...652A.116P)
Boudreaux et al. (2022ApJ...929...80B 2022ApJ...929...80B)
Ibanez Bustos et al. (2023A&A...672A..37I 2023A&A...672A..37I)
Marvin et al. (2023A&A...671A.162M 2023A&A...671A.162M]
The Pleiades and Hyades values were obtained from
Fang et al. (2018MNRAS.476..908F 2018MNRAS.476..908F]
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Acknowledgements:
Scott Engle, scott.engle(at)villanova.edu
(End) Patricia Vannier [CDS] 02-Jan-2026