J/other/RAA/19.98 X-ray activity from different types of stars (He+, 2019)
X-ray activity from different types of stars.
He L., Wang S., Xu X.-J., Soria R., Liu J.-F., Li X.-D., Bai Y., Bai Z.-R.,
Guo J.-C., Qiu Y.-L., Zhang Y., Xu R.-C., Qian K.-C.
<Res. Astron. Astrophys., 19, 98-98 (2019)>
=2019RAA....19...98H 2019RAA....19...98H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; X-ray sources
Keywords: X-rays: stars - stars: activity - stars: late-type
Abstract:
X-ray emission is an important indicator of stellar activity. In this
paper, we study stellar X-ray activity using the XMM-Newton and LAMOST
data for different types of stars. We provide a sample including 1259
X-ray-emitting stars, of which 1090 have accurate stellar parameter
estimations. Our sample size is much larger than those used in
previous works. We find a bimodal distribution of the X-ray to optical
flux ratio (log(fX/fV)) for G and K stars. We interpret that this
bimodality is due to two subpopulations with different coronal heating
rates. Furthermore, using the full widths at half maxima calculated
from Hα and Hβ lines, we show that these stars in the
inactive peaks have smaller rotational velocities. This is consistent
with the magnetic dynamo theory that presumes stars with low
rotational velocities have low levels of stellar activity. We also
examine the correlation between log(fX/fV) and luminosity of the
excess emission in the Hα line, and find a tight relation
between the coronal and chromospheric activity indicators.
Description:
The XMM-Newton and LAMOST data allow us to identify X-ray emitters and
probe stellar X-ray activity over a wide range of stellar parameters.
By cross matching the 3XMM-DR5 catalog and the LAMOST DR3 catalog, we
provide a sample of X-ray emitting stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 887 The X-ray information for the sample sources
table2.dat 98 1001 Stellar parameters for the sample sources
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See also:
IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5 (XMM-SSC, 2016)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ObsID Spectral ID in LAMOST catalog
11- 18 E8.3 mW/m2 FX Unabsorbed flux in band 0.3-3.5keV
20- 27 E8.3 mW/m2 e_FX rms uncertainty on FX
29- 33 F5.2 [-] log(FX/FV) X-ray to optical flux ratio
35- 38 F4.2 [-] e_log(FX/FV) rms uncertainty on log(FX/FV)
40- 44 F5.2 --- HR ?=- EPIC HR using the bands of 0.5-1keV and
1-2keV derived from the 3XMM-DR5 catalog
46- 50 F5.2 --- e_HR ?=- rms uncertainty on HR
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ObsID Spectral ID in LAMOST catalog
11- 21 F11.7 deg RAdeg Right ascension (J2000)
23- 32 F10.7 deg DEdeg Declination (J2000)
34- 38 A5 --- Type Stellar subclass
39- 43 F5.2 mag Vmag V-band magnitude
45- 48 F4.2 mag e_Vmag rms uncertainty on Vmag
50- 53 F4.2 mag AV Extinction in the V band
55- 62 E8.3 cm-2 NH Hydrogen column density converted from
optical extinction
64- 70 F7.2 K Teff Effective temperature
72- 77 F6.2 K e_Teff rms uncertainty on Teff
79- 82 F4.2 [cm/s2] logg Surface gravity
84- 87 F4.2 [cm/s2] e_logg rms uncertainty on logg
89- 93 F5.2 [-] [Fe/H] Metallicity
95- 98 F4.2 [-] e_[Fe/H] rms uncertainty on [Fe/H]
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 08-Aug-2019