J/A+A/341/751 ROSAT HRI observations of the Pleiades (Micela+ 1999)
Deep ROSAT HRI observations of the Pleiades
Micela G., Sciortino S., Harnden, F.R.Jr., Kashyap V., Rosner R.,
Prosser C.F., Damiani F., Stauffer J., Caillault J.-P.
<Astron. Astrophys. 341, 751 (1999)>
=1999A&A...341..751M 1999A&A...341..751M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; X-ray sources ; Rotational velocities ;
Photometry
Mission_Name: ROSAT
Keywords: open clusters and associations: Pleiades - stars: coronae -
X-rays: stars
Abstract:
In a deep X-ray survey of the Pleiades open cluster, we use the ROSAT
High Resolution Imager to explore a region of the cluster formerly
surveyed with the PSPC. These new observations substantially improve
upon both the sensitivity and the spatial resolution for this region
of the Pleiades, allowing us to detect 18 cluster members not detected
before and 16 members not included in the catalogs used in previous
surveys. The high sensitivity of the present observations permits us
to obtain more stringent upper limits for 72 additional members and
also provides sufficient numbers of stars to enable us to explore the
dependence of Lx on stellar rotation for the slow rotators of the
Pleiades. Using the new high sensitivity X-ray observations and the
recent rotational measurements we discuss the activity-rotation
relationship in the Pleiades solar type stars.
We also present new photometric observations of optical counterparts
of a number of X-ray sources detected in previous surveys but not yet
identified.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 77 260 Optical properties of the observed Pleiades
table3.dat 67 260 X-ray properties of the observed Pleiades
tables.tex 114 667 LaTeX version of the tables
tables.ps 72 1412 PostScript version of the tables
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See also:
I/90 : Positions of 502 Stars in Pleiades Region (Eichhorn+ 1970)
I/163 : US Naval Observatory Pleiades Catalog (Van Flandern 1969)
J/ApJS/91/625 : ROSAT survey of the Pleaides (Stauffer+ 1994)
J/ApJS/102/75 : ROSAT Observations of the Pleiades (Micela+ 1996)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running Number
5- 12 A8 --- Name Name
14- 15 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
20- 24 F5.2 s RAs Right ascension (J2000)
26 A1 --- DE- Declination sign
27- 28 I2 deg DEd Declination (J2000)
30- 31 I2 arcmin DEm Declination (J2000)
33- 34 I2 arcsec DEs Declination (J2000)
36- 40 F5.2 mag Vmag ? Visual Magnitude
41 A1 --- u_Vmag Uncertainty flag on Vmag
43- 46 F4.2 mag B-V ? B-V color index
48- 51 F4.2 mag V-Ik ? V-Ik color index
53- 57 A5 --- SpType Spectral type
59 A1 --- l_vsini Limit flag on vsini
60- 64 F5.2 km/s vsini ? Projected rotational velocity
66- 71 F6.2 h Per ? Rotational period
73- 77 F5.2 mag E(B-V) ? Color excess (E(B-V))
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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- 3 I3 --- Seq Running Number
5- 12 A8 --- Name Name
14- 18 F5.1 arcsec oRA ? Offset in right ascension
20- 25 F6.2 arcsec oDE ? Offset in declination
27- 30 F4.1 --- S/N ? Detection significance in sigma equivalent
32 A1 --- l_Rate Limit flag on Rate
33- 37 F5.2 ct/ks Rate X-ray count rate
39- 42 F4.2 ct/ks e_Rate ? Error in X-ray count rate
44 A1 --- l_log(Lx) Limit flag on log(Lx)
45- 49 F5.2 [10-7W] log(Lx) X-ray luminosity
50 A1 --- n_log(Lx) [)] Note on log(Lx) (1)
52 A1 --- l_log(Lx/Lb) Limit flag on log(Lx/Lb)
53- 57 F5.2 --- log(Lx/Lb) ? X-ray to bolometric luminosity ratio
58 A1 --- n_log(Lx/Lb) [)] Note on log(Lx/Lb) (1)
60- 62 A3 --- Field Field where the source has been detected
64- 67 F4.1 arcmin offaxis Distance from the center of the field
of view
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Note (1): ): when we believe that the luminosity suffer UV leak contamination.
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Acknowledgements: Giuseppina Micela
(End) Patricia Bauer [CDS] 22-Oct-1998