J/A+AS/131/197 F, G and K stars BVRI photometry (Metanomski+ 1998)
F, G and K stars in the ROSAT all-sky survey. I. Photometry.
Metanomski A.D.F., Pasquini L., Krautter J., Cutispoto G., Fleming T.A.
<Astron. Astrophys. Suppl. Ser. 131, 197 (1998)>
=1998A&AS..131..197M 1998A&AS..131..197M (SIMBAD/NED BibCode)
ADC_Keywords: Radio sources ; Stars, late-type ; Photometry, UBVRI
Mission_Name: ROSAT
Keywords: stars: late-type - X-ray: stars - surveys
Abstract:
We present accurate BV(RI)c photometry for a sample of F, G and K
stars detected in selected areas of the ROSAT all-sky survey (RASS).
We have used the photometry, in addition to low-resolution
spectroscopy, to estimate spectral classifications, distances and
X-ray luminosities. The log(LX/LV) in the sample lies below -2.
Although the sample contains also nearby, inactive stars, it is
dominated by active objects. The median X-ray luminosity in our sample
is <LX≥29.88 and the mean value of the hardness ratios
=0.13±0.35. We compare the derived X-ray luminosity function
with similar functions obtained from the serendipitous samples of the
Einstein Observatory medium sensitivity survey (EMSS, Cat. IX/15)
and EXOSAT (Cat. J/A+AS/115/41). Our
sample is completely consistent with the EMSS sample of solar type
stars, indicating that both our sources and the EMSS sources are
representative of the high galactic latitude X-ray stellar population.
We do not find extremely active stars (log(LX)≥32), as are found in
the EMSS sample, and we argue that these objects are rare.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 195 107 Summary of X-ray and observational data as well
as results for the studied sample
notes.dat 80 86 Individual notes
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1996)
IX/15 : Einstein EMSS Survey (Gioia+ 1990, Stocke+ 1991)
J/ApJS/99/701 : EMSS (Fleming+ 1995)
J/A+AS/115/41 : UBV(RI) photometry of cool stars (Cutispoto+, 1996)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- RXJ ROSAT name
16 A1 --- n_RXJ [*] *: see note detailed in file notes.dat
17- 18 I2 h RAXh X-ray source right ascension (J2000.0)
20- 21 I2 min RAXm X-ray source right ascension (J2000.0)
23- 26 F4.1 s RAXs X-ray source right ascension (J2000.0)
28 A1 --- DEX- X-ray source declination sign
29- 30 I2 deg DEXd X-ray source declination (J2000.0)
32- 33 I2 arcmin DEXm X-ray source declination (J2000.0)
35- 36 I2 arcsec DEXs X-ray source declination (J2000.0)
38- 44 F7.5 ct/s Counts Count-rate for the X-ray source
46- 52 F7.2 s Texp Total exposition time
54- 58 F5.2 --- HR1 ? Hardness Ratio 1 (1)
60- 61 I2 h RAh Counterpart right ascension (J2000.0)
63- 64 I2 min RAm Counterpart right ascension (J2000.0)
66- 69 F4.1 s RAs Counterpart right ascension (J2000.0)
71 A1 --- DE- Counterpart declination sign
72- 73 I2 deg DEd Counterpart declination (J2000.0)
75- 76 I2 arcmin DEm Counterpart declination (J2000.0)
78- 79 I2 arcsec DEs Counterpart declination (J2000.0)
81- 84 F4.1 arcsec DX-C Distance between X-ray and counterpart
positions
86- 94 A9 --- SpType Spectral type
96- 98 A3 --- n_SpType Note on Spectral type for binaries (2)
100-102 I3 pc Dist Distance of the star from the Sun
104-106 I3 pc E_Dist ? Error in Distance (upper limit)
108-109 I2 pc e_Dist ? Error in Distance (lower limit)
111-115 F5.2 10-15W/m2 fX X-ray flux
117-120 F4.2 10-15W/m2 E_fX Error in fX (upper limit)
122-125 F4.2 10-15W/m2 e_fX Error in fX (lower limit)
127-133 F7.3 10+22W LX X-ray luminosity
135-140 F6.2 10+22W E_LX Error in LX (upper limit)
142-147 F6.2 10+22W e_LX Error in Lx (lower limit)
149-162 A14 --- Name Counterpart name
164-171 A8 --- SpTypeO Counterpart spectral type
173-177 F5.2 mag Vmag Counterpart V magnitude
179-183 F5.2 mag B-V Counterpart B-V colour index
185-189 F5.2 mag V-R ? Counterpart V-R colour index
191-194 F4.2 mag V-I ? Counterpart V-I colour index
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Note (1): HR1 = (CR[ch52-201]-CR[ch11-41])/CR[ch11-240] where
CD[cha-b] being the count-rate in the channels "a" to "b"
Note (2): 1: the binarity/multiplicity obtained by the photometry was confirmed
by the high-resolution spectra
2: the binarity was determined for the high-resolution spectra
3: the binarity is a visual one
4: the binarity information was only obtained through the literature
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- RXJ Source name
17- 18 I2 --- Ntot Total number of lines for the RXJ object
20- 21 I2 --- Nline Running line number in range [1,Ntot]
23- 80 A58 --- Note Text of the note
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History: Prepared via OCR at CDS
An error was detected in the original publication and corrected.
For RXJ 1413.7-0050, the position of the Counterpart (HD 124425) is
14 13 40.6 -00 50 40 instead of 14 13 40.6 -00 05 40
(End) Patricia Bauer [CDS] 31-Jul-1998