ADC/CDS Standard Document for Catalog:/journal_tables/ApJ/448/683/
ADC/CDS Standard Document for Catalog:| 1. Use the ADC Data Viewer Suite to visualize the data. |
|
| 2. Get the data files via anonymous FTP. (See Note.) |
|
J/ApJ/448/683 Hyades RASS observations (Stern+ 1995)
================================================================================
ROSAT all-sky survey observations of the Hyades cluster
Stern R.A., Schmitt J.H.M.M., Kahabka P.T.
<Astrophys. J. 448, 683 (1995)>
=1995ApJ...448..683S (SIMBAD/NED BibCode)
================================================================================
ADC_Keywords: Clusters, open ; Binaries, X-ray
Keywords: binaries: close - surveys - X-rays: stars -
open clusters and associations: individual (Hyades)
Mission_Name: ROSAT
Abstract:
We report the results of a complete X-ray survey of the Hyades cluster
region using the ROSAT All-Sky Survey (RASS). Our survey covers over
900deg^2^ of the sky. Over 185 optically identified Hyades were
detected down to a limiting X-ray luminosity of ~1-2x10^28^ergs/s
(0.1-1.8keV); among solar-like stars, i.e., main-sequence stars of
spectral type G, the RASS detection rate is ~90%. The presence of many
binary systems in the cluster is a key factor influencing the X-ray
luminosity function. Short-period (~ a few days or less) binaries are
anomalously X-ray bright, as might be expected; however, the X-ray
luminosity functions of K and possibly M binaries of all types are
significantly different from their single counterparts, confirming the
results of Pye et al. (1994MNRAS.266..798P) for a smaller K star
sample drawn from deep ROSAT pointings. Comparison with Einstein
Observatory studies of a subset of Hyades stars demonstrates a general
lack of significant
(> a factor of 2) long-term X-ray variability. This may be the result
of the dominance of a small-scale, turbulent dynamo in the younger
Hyades stars compared to the large-scale, cyclic dynamo observed in
the Sun.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1 104 440 Hyades survey
table2 82 4 Reid (1992, Cat. <J/MNRAS/257/257>) stars detected
in X-rays
table3 70 20 Non-members in optical catalog detected in X-rays
--------------------------------------------------------------------------------
See also:
IX/11 : The ROSAT Source Catalogue (Voges+ 1995)
Byte-by-byte Description of file: table1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Star Star name (1)
12- 13 I2 h RAh Optical right ascension (J2000)
15- 16 I2 min RAm Optical right ascension (J2000)
18- 21 F4.1 s RAs Optical right ascension (J2000)
23- 24 I2 deg DEd Optical declination (J2000)
26- 27 I2 arcmin DEm Optical declination (J2000)
29- 32 F4.1 arcsec DEs Optical declination (J2000)
34- 37 F4.1 arcsec X-Opos ? Difference in X-ray and optical positions
39- 43 F5.2 mag Vmag ? V magnitude
45- 46 I2 --- r_Vmag ? Reference for V magnitude (2)
48- 52 F5.2 mag B-V ? B-V colour index
54- 55 I2 --- r_B-V ? Reference for B-V index (2)
57- 60 F4.1 pc Dist ? Distance
62 A1 --- r_Dist [HS] Reference for distance (3)
65- 74 A10 --- Binarity Binarity codes (4)
76- 81 F6.1 --- M/L ? Maximum likelihood ratio for X-ray
source existence
83 A1 --- l_LX45 Limit flag on LX45
84- 88 F5.1 ZW LX45 X-ray luminosity based upon an assumed
45pc distance
90- 93 F4.1 ZW e_LX45 ? rms uncertainty on LX45
95 A1 --- l_LXd Limt flag on LXd
96-100 F5.1 ZW LXd ? X-ray luminosity using the distance
from Dist column
102-104 F3.1 ZW e_LXd ? rms uncertainty on LXd
--------------------------------------------------------------------------------
Note (1): For members with multiple designations, the name used is determined
by the following order of preference:
vB (van Bueren, 1952BAN....11..385V),
VA (van Altena, 1969AJ.....74....2V),
BD (Bonner Durchmusterung, Cat. <I/122>),
GH 7 or GH 8 (Giclas, Burnham, & Thomas, 1962LowOB...5..257G),
L (Pels et al., 1975A&A....43..423P),
LP (Luyten et al., 1981, see Cat. <I/130>),
H (Hanson 1975, Cat. <J/AJ/80/379>),
OS (Osvald, 1954AN....281..193O),
AK (Artyukhina & Khopolov
1975, Trans. Gos. Astron. Inst. Sternberg, 46 No. 2, 57
and 1976, Trans. Gos. Astron. Inst. Sternberg, 47 ,105)
HD, or other designation.
A table of cross-referenced Hyades members provided by E. Weis
was used in selecting the primary designation.
Note (2): Optical photometry references are as follows:
(1)-(3) Weis & Hanson, 1988AJ.....96..148W
(4)-(6) Upgren et al., 1985AJ.....90.2039U
(7) Weis, 1983PASP...95...29W
(8)-(9) Weis & Upgren, 1982PASP...94..475W
(10) Stauffer, 1982AJ.....87..899S
(11) Weis et al., 1979PASP...91..766W
(12)-(13) Weis, 1992, unpublished photometry;
(14) Pels et al., 1975A&A....43..423P
(15) Eggen, 1969ApJ...157..287E
(16) Morel & Mangnenat, 1978, Cat. <II/7>
(17) Schwan, 1991A&A...243..386
(18) Reid, 1992, Cat. <J/MNRAS/257/257>
(19) Hanson, 1975, Cat. <J/AJ/80/379>
(20) Griffin et al., 1988AJ.....96..172G
Note (3): H: Hanson, 1975, Cat. <J/AJ/80/379>
S: Schwan, 1991A&A...243..386
Note (4): Binary notations:
GR: spectroscopic binary as noted in Griffin et al., 1988AJ.....96..172G
GP: photometric binary as noted in Griffin et al., 1988AJ.....96..172G
GV: visual binary as noted in Griffin et al., 1988AJ.....96..172G
B: spectroscopic binary listed in Batten et al., 1989, Cat. <V/64>
C: photometric binary from Carney, 1982AJ.....87.1527C
T: photometric binary as noted by Bettis, 1975 (reference not precised)
S: photometric binary as noted by Stauffer, 1982AJ.....87..899S
UW: photometric binary as noted by Upgren & Weis, 1977AJ.....82..978U
A: visual binary in ADS catalog
MD: definite speckle binary in Mason et al., 1993AJ....105..220M
MP: probable speckle binary in Mason et al., 1993AJ....105..220M
MS: suspected speckle binary in Mason et al., 1993AJ....105..220M
SP: spectroscopic binary or triple based on unpublished data
(Stauffer, private communication).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Star Star designation (Reid number,
Cat. <J/MNRAS/257/257>)
7 I1 h RAh Optical right ascension (J2000)
9- 10 I2 min RAm Optical right ascension (J2000)
12- 15 F4.1 s RAs Optical right ascension (J2000)
17- 18 I2 deg DEd Optical declination (J2000)
20- 21 I2 arcmin DEm Optical declination (J2000)
23- 26 F4.1 arcsec DEs Optical declination (J2000)
28- 32 F5.2 mag Vmag ? V magnitude
34- 37 F4.2 mag B-V ? B-V colour index
39- 42 F4.1 --- M/L ? Maximum likelihood ratio for X-ray
source existence
44- 48 F5.3 ct/s PSPC PSPC count
50- 54 F5.3 ct/s e_PSPC rms uncertainty on PSPC
56- 59 F4.1 arcsec X-Opos ? Difference in X-ray and optical positions
61- 83 A23 --- Note Notes
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Star Star name
12- 13 I2 h RAh Optical right ascension (J2000)
15- 16 I2 min RAm Optical right ascension (J2000)
18- 21 F4.1 s RAs Optical right ascension (J2000)
23- 24 I2 deg DEd Optical declination (J2000)
26- 27 I2 arcmin DEm Optical declination (J2000)
29- 32 F4.1 arcsec DEs Optical declination (J2000)
34- 38 F5.2 mag Vmag ? V magnitude
40- 43 F4.2 mag B-V ? B-V colour index
45- 46 A2 --- Binarity Binarity codes (1)
48- 53 F6.1 --- M/L ? Maximum likelihood ratio for X-ray
source existence
55- 59 F5.3 ct/s PSPC PSPC count
61- 65 F5.3 ct/s e_PSPC rms uncertainty on PSPC
67- 70 F4.1 arcsec X-Opos ? Difference in X-ray and optical positions
--------------------------------------------------------------------------------
Note (1): Binary notations:
GR: spectroscopic binary as noted in Griffin et al., 1988AJ.....96..172G
UW: photometric binary as noted by Upgren & Weis, 1977AJ.....82..978U
--------------------------------------------------------------------------------
History: Prepared via OCR at CDS.
================================================================================
(End) James Marcout, Patricia Bauer [CDS] 08-Apr-1997