J/ApJS/91/625 ROSAT survey of the Pleiades (Stauffer+ 1994)
A deep imaging survey of the Pleiades with ROSAT.
Stauffer J.R., Caillault J.-P., Gagne M., Prosser C.F., Hartmann L.W.
<Astrophys. J. Suppl. 91, 625 (1994)>
=1994ApJS...91..625S 1994ApJS...91..625S
ADC_Keywords: X-ray sources ; Clusters, open
Mission_Name: ROSAT
Keywords: open clusters and associations: individual (Pleiades) -
stars: late-type - surveys
Description:
We have obtained deep ROSAT images of three regions within the
Pleiades open cluster. We have detected 317 X-ray sources in these
ROSAT PSPC images, 171 of which we associate with certain or probable
members of the Pleiades cluster. We detect nearly all Pleiades members
with spectral types later than G0 and within 25 arcminutes of our
three field centers where our sensitivity is highest. This has allowed
us to derive for the first time the luminosity function for the G, K,
and M dwarfs of an open cluster without the need to use statistical
techniques to account for the presence of upper limits in the data
sample. Because of our high X-ray detection frequency down to the
faint limit of the optical catalog, we suspect that some of our
unidentified X-ray sources are previously unknown, very low-mass
members of the Pleiades.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 127 307 Detected X-ray sources
table2.tex 163 536 LaTeX version of table2
table3.dat 93 10 X-ray sources detected between 40' and 50' off-axis
table3.tex 113 34 LaTeX version of table3
table7.dat 69 238 Optical and X-ray data for known Pleiades members
table7.tex 133 397 LaTeX version of table7
table8.dat 57 16 Optical data for known Pleiades members with
blended X-ray emission
table8.tex 96 50 LaTeX version of table8
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See also:
I/163 : US Naval Observatory Pleiades Catalog
II/131 : Tonantzintla Pleiades Flare Stars (Haro+ 1982)
J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)
J/A+A/299/696 : Pleiades field Membership probabilities (Schilbach+, 1995)
J/A+A/341/751 : ROSAT HRI observations of the Pleiades (Micela+ 1999)
Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- NoX X-ray number
5- 6 I2 h RAh Right ascension (J2000) of the source
8- 9 I2 min RAm Right ascension (J2000) of the source
11- 14 F4.1 s RAs Right ascension (J2000) of the source
16 A1 --- DE- Declination sign
17- 18 I2 deg DEd Declination (J2000) of the source
20- 21 I2 arcmin DEm Declination (J2000) of the source
23- 24 I2 arcsec DEs Declination (J2000) of the source
26- 31 F6.4 ct/s Rate1 ? Centre field rate
33- 38 F6.4 ct/s e_Rate1 ? rms uncertainty on Rate1
40- 41 I2 arcmin Dist1 ? Center Field distance
43- 48 F6.4 ct/s Rate2 ? Northeast Field rate
50- 55 F6.4 ct/s e_Rate2 ? rms uncertainty on Rate2
57- 58 I2 arcmin Dist2 ? Northeast Field distance
60- 65 F6.4 ct/s Rate3 ? Northwest field rate
67- 72 F6.4 ct/s e_Rate3 ? rms uncertainty on Rate3
74- 75 I2 arcmin Dist3 ? Northwest field distance
77- 84 A8 --- Source Optical candidate (1)
85 A1 --- n_Source [a-i] Note on Source (2)
87- 89 I3 arcsec DRA ? Offset in right ascension
91- 93 I3 arcsec DDE ? Offset in declination
95-101 A7 --- Source2 Second optical candidate (1)
102 A1 --- n_Source2 [a-i] Note on Source2 (2)
104-106 I3 arcsec DRA2 ? Offset in right ascension of Source2
108-110 I3 arcsec DDE2 ? Offset in Declination of Source2
112-118 A7 --- Source3 Third optical candidate (1)
120-122 I3 arcsec DRA3 ? Offset in right ascension of Source3
124-126 I3 arcsec DDE3 ? Offset in Declination of Source3
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Note (1): HCG numbers are from Haro et al. (1982) II/131
H II numbers are from Hertzsprung (1947)
Note (2): the letters correspond to the following notes:
a = Although the signal-to-noise ratio of this source is below our
threshold of 2.5, it was retained after visual inspection of the image
b = Star position from Hambly et al. (1993). We have assumed HII 996
is the optical counterpart.
c = This source has been identified with Alcyone (HII 1432), the
brightest Pleiades at V0=2.75. This source may in fact be two
sources, with the softer component to the south being closer to Alcyone.
d = Star position from Hambly et al. (1993). We have assumed HCG 311
is the optical counterpart.
e = Both HII 1797 and HCG 315 are too far from the X-ray centroid to be
likely optical counterparts. As a result, upper limits were
determined for both these stars.
f = Star position from Hambly et al. (1993). We have assumed HCG 327
is the optical counterpart.
g = Star position from Hambly et al. (1993). We have assumed HCG 337
is the optical counterpart.
h = Hyades cluster member.
i = Not a Pleiades cluster member.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- NoO Optical catalog index number
5- 7 I3 --- NoX ? X-ray source number
9- 15 A7 --- Name Star name
17- 21 F5.2 mag V0 Absolute V magnitude
23- 26 F4.2 mag (B-V)0 ? Absolute B-V color index
28- 31 F4.2 mag (V-I)0 ? Absolute V-I color index
33 A1 --- l_vsini Limit flag on vsini
34- 36 I3 km/s vsini ? Rotational velocity
38 A1 --- l_logLX Limit flag on logLX
39- 43 F5.2 [10-7W] logLX X-ray luminosity
44 A1 --- n_logLX [v] v when X-ray emission is variable
46- 49 F4.2 [10-7W] e_logLX ? rms uncertainty on logLX
51 A1 --- l_log(LX/Lbol) Limit flag on log(LX/Lbol)
52- 56 F5.2 --- log(LX/Lbol) X-ray luminosity versus bolometric
luminosity ratio
58- 63 A6 --- Name2 Other name
65- 69 A5 --- Name3 Other name
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- NoO Optical number
5- 7 I3 --- NoX ? X-ray number
9- 15 A7 --- Name Star name
16 A1 --- f_Name blended (1)
18- 22 F5.2 mag V0 Absolute V magnitude
24- 27 F4.2 mag (B-V)0 ? Absolute B-V color index
29- 32 F4.2 mag (V-I)0 ? Absolute V-I color index
34 A1 --- l_vsini Limit flag on vsini
35- 37 I3 km/s vsini ? Rotational velocity
39- 43 F5.2 [10-7W] logLbol Bolometric luminosity
45- 50 A6 --- Name2 Other name
52- 56 A5 --- Name3 Other name
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Note (1):
a = Blended with HCG 125. See table4 of paper
b = Blended with HCG 128. See table4 of paper
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Courtesy: Marc Gagne
Historycal notes:
The first version of table7 was erroneous in X-ray number.
The right version was installed on 24-Feb-1998
References:
Hambly N.C et al. 1993, A&AS 100, 607 =Cat J/A+AS/100/607
Haro G. et a. 1982, Bol. Inst. Tonantzintla 3, 3 =Cat II/131
Hertzsprung E. 1947 Ann. Sternw. Leiden, 19, 1 =1947AnLei..19a...1H 1947AnLei..19a...1H
(End) Patricia Bauer [CDS] 14-Aug-1996