J/ApJ/817/1 Palomar/MSU and SDSS-DR7 M dwarfs with GALEX obs. (Jones+, 2016)
A catalog of GALEX ultraviolet emission from spectroscopically confirmed
M dwarfs.
Jones D.O., West A.A.
<Astrophys. J., 817, 1 (2016)>
=2016ApJ...817....1J 2016ApJ...817....1J (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Photometry, ultraviolet ; Equivalent widths ;
Proper motions ; Spectral types ; Stars, distances
Keywords: stars: activity; stars: late-type; stars: low-mass
Abstract:
We present a catalog of Galaxy Evolution Explorer Near-UV (NUV) and
Far-UV (FUV) photometry for the Palomar/MSU and SDSS DR7 spectroscopic
M dwarf catalogs. The catalog contains NUV measurements matched to 577
spectroscopically confirmed M dwarfs and FUV measurements matched to
150 spectroscopically confirmed M dwarfs. Using these data, we find
that NUV and FUV luminosities strongly correlate with Hα
emission, a typical indicator of magnetic activity in M dwarfs. We
also examine the fraction of M dwarfs with varying degrees of strong
line emission at NUV wavelengths. Our results indicate that the
frequency of M dwarf NUV emission peaks at intermediate spectral
types, with at least ∼30% of young M4-M5 dwarfs having some level of
activity. For mid-type M dwarfs, we show that NUV emission decreases
with distance from the Galactic plane, a proxy for stellar age. Our
complete matched source catalog is available online.
Description:
To compare magnetic activity in the optical with UV activity, we
matched the SDSS Data Release 7 (DR7; Abazajian et al. 2009, II/294)
M dwarf spectroscopic catalog (West et al. 2011, J/AJ/141/97; R∼2000)
to GALEX data from Data Releases 6 and 7 (NUV: ∼1750-2750Å and FUV:
∼1350-1750Å; see II/312). The DR7 M dwarf catalog consists of 70841
SDSS M dwarfs with spectral types verified by eye. We supplemented the
SDSS sample with the Palomar/MSU Nearby-Star Spectroscopic Survey
(PMSU; Reid et al. 1995, III/198), which contains 1684 nearby low-mass
stars (1415 M dwarfs) as part of the northern sample (δ>-30°)
and 282 nearby low-mass stars (228 M dwarfs) as part of the southern
sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 280 186 DR7 M dwarfs found in GALEX
table3.dat 243 371 Palomar/MSU M dwarfs found in GALEX
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)
J/ApJ/798/41 : GALEX NUV observations of bright M-type stars (Ansdell+, 2015)
J/AJ/148/64 : HAZMAT I. FUV/NUV emission in early M stars (Shkolnik+, 2014)
J/AJ/147/94 : Solar neighborhood. XXXII. L and M dwarfs (Dieterich+, 2014)
J/ApJ/779/188 : Spectra of nearby late K and M Kepler stars (Mann+, 2013)
J/MNRAS/431/2063 : UV/X-ray activity of M dwarfs within 10pc (Stelzer+, 2013)
J/AJ/144/93 : Close white dwarf + M dwarf binaries (WD+dM) (Morgan+, 2012)
J/ApJ/746/23 : Radio observations of ultracool dwarf stars (McLean+, 2012)
J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)
J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/ApJS/178/339 : ChaMP extended stellar survey (ChESS) (Covey+, 2008)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/ApJS/173/673 : M dwarf UV flares in GALEX (Welsh+, 2007)
J/AJ/133/2825 : Star beyond the NLTT catalog (Reid+, 2007)
J/ApJS/169/401 : ChaMP X-ray point source catalog (Kim+, 2007)
J/AJ/132/866 : New M dwarfs in solar neighborhood (Riaz+, 2006)
J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)
J/AJ/127/3034 : Proper-motion catalog combining USNO-B and SDSS (Munn+, 2004)
J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)
J/AJ/124/1190 : Northern high proper motion stars in DSS (Lepine+, 2002)
http://www.sdss.org/ : SDSS home page
http://galex.stsci.edu/GR6/ : GALEX GR6/7 Data Release home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- objidG GALEX source identifier
21- 38 A18 --- ObjID SDSS DR7 source identifier
40- 40 I1 --- SpT [0/8] Numeric M-type spectral subtype
from West+, 2011, J/AJ/141/97
42- 52 F11.7 deg RAGdeg GALEX NUV Right Ascension (J2000)
54- 64 F11.7 deg DEGdeg GALEX NUV Declination (J2000)
66- 76 F11.7 deg RAdeg SDSS DR7 Right Ascension (J2000)
78- 88 F11.7 deg DEdeg SDSS DR7 Declination (J2000)
90- 92 F3.1 arcsec Sep [0/2] SDSS-GALEX NUV positional separation
94- 96 F3.1 arcsec PosErr [0.5/2.1] GALEX NUV positional error
98-103 F6.3 mag NUVmag [15.9/25.4] GALEX NUV band
(∼1750-2750Å) magnitude
105-109 F5.3 mag e_NUVmag Uncertainty in NUVmag
111-117 F7.3 mag FUVmag [/24.6]?=-99 GALEX FUV band
(∼1350-1750Å) magnitude (G1)
119-124 F6.3 mag e_FUVmag ?=99 Uncertainty in FUVmag (G1)
126-132 F7.1 s NUVexp [93/38167] GALEX NUV exposure time
134-140 F7.1 s FUVexp [0/24269] GALEX FUV exposure time
142-144 A3 --- GName GALEX survey identifier
146-149 I4 --- Plate SDSS spectrum plate number
151-155 I5 d MJD [51609/54629] Modified Julian Date of
SDSS spectrum observation
157-159 I3 --- Fiber SDSS spectrum fiber identifier
161-163 I3 --- ActHa [-99/1]? Hα activity (G2)
165-170 F6.3 0.1nm EWHa [-2.3/9.2] Hα equivalent width (Å)
172-176 F5.3 0.1nm e_EWHa [0.02/5] Uncertainty in EWHa
178-187 E10.3 --- LHa [-0.0002/0.0005] Hα luminosity (G3)
189-197 E9.3 --- e_LHa [0/0.0002] Uncertainty in LHa
199-207 E9.3 --- LNUV [0.0001/0.2] GALEX NUV luminosity (G3)
209-217 E9.3 --- e_LNUV [0/0.03] Uncertainty in LNUV
219-228 E10.3 --- LFUV [0.0001/0.2]?=-99 GALEX FUV luminosity (G3)
230-238 E9.3 --- e_LFUV [0/0.03]?=99 Uncertainty in LFUV (G1)
240-244 F5.1 pc Dist [39/993] Photometric parallax distance (1)
246-250 F5.1 pc e_Dist [7/191] Uncertainty in Dist (1)
252-258 F7.2 uarcsec/yr pmRA [-166/98] Proper motion in RA (2)
260-264 F5.2 uarcsec/yr e_pmRA [0/28] Uncertainty in pmRA (2)
266-272 F7.2 uarcsec/yr pmDE [-178/132] Proper motion in DE (2)
274-278 F5.2 uarcsec/yr e_pmDE [0/28] Uncertainty in pmDE (2)
280 I1 --- Good [0/1]? Good FUV flag (0=FUV does not
pass quality cuts) (G4)
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Note (1): Typical uncertainty is ∼20%, plus photometric error.
Distances were measured for all stars using the photometric parallax
technique described in Bochanski et al. (2010AJ....139.2679B 2010AJ....139.2679B) and
corrected for dust (Jones et al. 2011AJ....142...44J 2011AJ....142...44J).
Note (2): Some SDSS stars had multiple GALEX counterparts; to eliminate chance
alignments and remove multiple detections, we used the proper motions
in the DR7 M dwarf sample (Munn et al. 2004AJ....127.3034M 2004AJ....127.3034M) to
determine the position for each star on a given observation date.
Using these positions, we were able to eliminate most of the multiple
matches, keeping only the UV source that was closest to the position
of the DR7 M dwarf at the date that GALEX observed it.
See section 3 for further explanations.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- objidG GALEX source identifier
21- 29 A9 --- Name PMSU source identifier (Hawley+, 1997,
III/198; <[RHG95] NNNN> in Simbad)
31- 33 F3.1 --- SpT Numeric M-type spectral subtype
35- 45 F11.7 deg RAGdeg GALEX NUV Right Ascension (J2000)
47- 57 F11.7 deg DEGdeg GALEX NUV Declination (J2000)
59- 69 F11.7 deg RAdeg PMSU Right Ascension (J2000)
71- 81 F11.7 deg DEdeg PMSU Declination (J2000)
83- 85 F3.1 arcsec Sep [0/2] PMSU-GALEX NUV positional separation
87- 89 F3.1 arcsec PosErr [0.5/1.7] GALEX NUV positional error
91- 96 F6.3 mag NUVmag [15.2/23.6] GALEX NUV band magnitude
98-102 F5.3 mag e_NUVmag [0.003/0.4] Uncertainty in NUVmag
104-110 F7.3 mag FUVmag [16.8/23.8]?=-99 GALEX FUV band magnitude (G1)
112-118 F7.3 mag e_FUVmag [0.03/]?=99 Uncertainty in FUVmag (G1)
120-126 F7.1 uJy NUV3sig [48/51725] NUV 3σ detection threshold
128-134 F7.1 uJy FUV3sig [0/51725] NUV 3σ detection threshold
136-138 A3 --- GName GALEX survey identifier
140-142 I3 --- ActHa [-99/1]? Hα activity (G2)
144-150 F7.3 0.1nm EWHa [-0.3/6]?=-99 Hα equivalent width (Å)
152-161 E10.3 --- LHa [-0.0001/0.0004]?=-999 Hα
luminosity (G3)(1)
163-171 E9.3 --- e_LHa [0/0.0002] Uncertainty in LHa
173-181 E9.3 --- LNUV [0/0.002] GALEX NUV luminosity (G3)
183-191 E9.3 --- e_LNUV [0/0.0009] Uncertainty in LNUV
193-202 E10.3 --- LFUV [0/0.0003]?=-99 GALEX FUV luminosity (G3)
204-213 E10.3 --- e_LFUV [0/99]?=99 Uncertainty in LFUV
215-218 F4.1 pc Dist [1/58] Trigonometric/photometric parallax
distance (2)
220-223 F4.1 % e_Dist [0/30] Percent uncertainty in Dist
225-232 F8.2 mas/yr pmRA [-3776/2314] Proper motion in RA (3)
234-241 F8.2 mas/yr pmDE [-1773/2295] Proper motion in DE (3)
243 I1 --- Good [0/1]? Good FUV flag (0=FUV does not
pass quality cuts) (G4)
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Note (1): A negative LHa value indicates Hα is in absorption rather
than emission.
Note (2): PMSU distances come from a variety of sources; many were measured by
the Hipparcos Satellite, while others were derived using
spectrophotometric parallax.
Note (3): To match GALEX to the PMSU sample, we first corrected the PMSU
positions and proper motions using the SIMBAD Astronomical Database
and the Lepine & Gaidos (2011, J/AJ/142/138) M dwarf catalog.
See section 3 for further explanations.
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Global notes:
Note (G1): A FUV value and uncertainty of -99.000±99.000 implies
either that the object was not observed in the FUV or that it
was not detected.
Note (G2): Hα activity as follows:
0 = No Hα activity;
1 = Hα activity;
-99 = Uncertain Hα activity due to noise in the spectrum.
Note (G3): As a fraction of the bolometric luminosity.
Note (G4): Good FUV flag as follows:
1 = FUV passes quality cuts (FOVRADIUS<0.55, artifact ≤1).
0 = FUV does not pass quality cuts.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Mar-2016