J/A+A/359/227 Lindroos binary systems X-ray emission (Huelamo+, 2000)
X-ray emission from Lindroos binary systems.
Huelamo N., Neuhaeuser R., Stelzer B., Supper R., Zinnecker H.
<Astron. Astrophys. 359, 227 (2000)>
=2000A&A...359..227H 2000A&A...359..227H
ADC_Keywords: Binaries, X-ray ; Magnitudes
Keywords: stars: binaries: visual - stars: early-type -
stars: pre-main sequence - stars: individual: HR 4796 - X-rays: stars
Abstract:
We present a study of the X-ray emission from binary systems extracted
from the Lindroos catalogue (Lindroos, 1986A&A...156..223L 1986A&A...156..223L) based on
the ROSAT All-Sky survey as well as ROSAT PSPC and HRI pointings. The
studied sample consists of visual binary systems comprised of
early-type primaries and late-type secondaries. The ages of the
systems were determined by Lindroos (1985, Cat. II/127) from
uvbyβ photometry of the primaries. These ages range between 33
and 135Myr, so if the late-type secondaries are physically bound to
the early-type primaries, they could be Post-T Tauri stars (PTTS). We
have found strong X-ray emission from several secondaries. This fact
together with their optical and IR data, make them bona fide PTTS
candidates. We have also detected X-ray emission from several
early-type primaries and, in particular, from most of the late-B type
stars. Because their HRI hardness ratios are similar to those from
resolved late-type stars, the presence of an unresolved late-type
companion seems to be the cause of this emission.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 90 50 Stellar Data of the binary sample
table2.dat 99 37 RASS observations: Detections and upper limits
table3.dat 112 5 PSPC pointed observations
table4.dat 112 46 HRI observations
table5.dat 43 51 X-ray luminosities
table6.dat 37 10 HRI soft-band rate and UV-rate for detected
early-type stars
table7.dat 67 20 Stellar properties of the post-TTau (PTTS) candidates
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See also:
B/cb : Cataclysmic Binaries, LMXBs, and related objects (Ritter+, 2008)
II/127 : Visual Double Stars with Early-Type Primaries. IV (Lindroos 1985)
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000)
IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD (Cat. III/135) number
8- 10 A3 --- m_HD (A+BCX ) Multiplicity index on HD
12- 23 A12 --- SpType MK spectral type (1)
25- 26 I2 h RAh Optical right ascension (J2000) (2)
28- 29 I2 min RAm Optical right ascension (J2000) (2)
31- 35 F5.2 s RAs Optical right ascension (J2000) (2)
37 A1 --- DE- Optical declination sign (J2000) (2)
38- 39 I2 deg DEd Optical declination (J2000) (2)
41- 42 I2 arcmin DEm Optical declination (J2000) (2)
44- 48 F5.2 arcsec DEs Optical declination (J2000) (2)
50- 54 F5.1 arcsec Sep Separation angle (1)
56- 61 F6.1 pc Dist Distance (3)
62 A1 --- u_Dist Uncertainty flag on Dist
63 A1 --- r_Dist [+] +: data from Lindroos, 1986A&A...156..223L 1986A&A...156..223L
64- 68 F5.1 pc e_Dist ? rms uncertainty on Dist
69 A1 --- ueDist Uncertainty flag on e_Dist
71- 74 F4.2 mag VmagA V magnitude of the primary
75 A1 --- n_VmagA [*] Note on VmagA (4)
77- 81 F5.2 mag VmagB ? V magnitude of the secondary
82 A1 --- n_VmagB [*7] Note on VmagB (4), (7)
84- 87 F4.2 mag AV ? Absorption in V band
89- 90 A2 --- Class Classification (6)
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Note (1): Taken from Pallavicini et al. (1992A&A...261..245P 1992A&A...261..245P)
Note (2): Coordinates of the primary star
Note (3): Deduced from Hipparcos parallax of the primary star, except
those marked with + taken from Lindroos, 1986A&A...156..223L 1986A&A...156..223L
Note (4): Adopted from Pallavicini et al. (1992A&A...261..245P 1992A&A...261..245P) except
those marked with an asterisk obtained from the SIMBAD database
Note (6): Classification taken by Pallavicini et al. (1992A&A...261..245P 1992A&A...261..245P)
with respect to the presence of the Lithium absorption line and CaII
(H and K) chromospheric lines in the spectrum of the secondary:
CP (certainly physical);
PP (probably physical);
LO (likely optical)
Note (7): Unknown visual magnitude for the secondary star.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD (Cat. III/135) number
8- 9 I2 h RAh ? X-ray right ascension (J2000)
11- 12 I2 min RAm ? X-ray right ascension (J2000)
14- 18 F5.2 s RAs ? X-ray right ascension (J2000)
20 A1 --- DE- X-ray declination sign (J2000)
21- 22 I2 deg DEd ? X-ray declination sign (J2000)
24- 25 I2 arcmin DEm ? X-ray declination sign (J2000)
27- 31 F5.2 arcsec DEs ? X-ray declination sign (J2000)
32- 36 F5.1 arcsec DeltaA ? Displacement between the detected X-ray
source and the optical position of the
primary component (1)
37 A1 --- --- [/]
38- 42 F5.2 arcsec DeltaB ? Displacement between the detected X-ray
source and the optical position of the
secondary component (1)
43 A1 --- l_Count Limit flag on Count
44- 49 F6.2 ct Count Count of the primary component or
of the both is upper limit (2)
50 A1 --- --- [/]
51- 54 F4.1 ct e_Count ? rms uncertainty on Counts
57- 60 F4.2 ct Bcnt ? Counts of the secondary component
63- 68 F6.1 s ExpTime Exposition time
70 A1 --- l_HR1 Limit flag on HR1
71- 75 F5.2 --- HR1 ? Hardness ratio 1 (G1)
77- 80 F4.2 --- e_HR1 ? rms uncertainty on HR1
82 A1 --- l_HR2 Limit flag on HR2
83- 87 F5.2 --- HR2 ? Hardness ratio 2 (G1)
89- 92 F4.2 --- e_HR2 ? rms uncertainty on HR2
94- 99 F6.1 --- ML ? Maximum likelihood
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Note (1): Given the low spatial resolution of the PSPC, we cannot resolve
the two components of the binary system. As a consequence, the
displacement δ between the detected X-ray source and the
optical positions of the two components of the system are given.
Note (2): In the case of non-detection, upper limits are computed at
the positions of both components, A and B, respectively.
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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- 6 I6 --- HD HD (Cat. III/135) number
8 I1 --- n_HD [1/2]? Individual note (1)
10- 15 I6 --- ROR ROSAT Observation request number
16 A1 --- m_ROR Multiplicity index on ROR
18- 19 I2 h RAh ? X-ray right ascension (J2000)
21- 22 I2 min RAm ? X-ray right ascension (J2000)
24- 28 F5.2 s RAs ? X-ray right ascension (J2000)
30 A1 --- DE- X-ray declination sign (J2000)
31- 32 I2 deg DEd ? X-ray declination sign (J2000)
34- 35 I2 arcmin DEm ? X-ray declination sign (J2000)
37- 41 F5.2 arcsec DEs ? X-ray declination sign (J2000)
42- 45 F4.1 arcsec DeltaA ? Displacement between the detected X-ray
source and the optical position of the
primary component
46 A1 --- --- [/]
47- 50 F4.1 arcsec DeltaB ? Displacement between the detected X-ray
source and the optical position of the
secondary component
52- 56 F5.2 arcmin Offaxis ? Offaxis
58 A1 --- l_Count Limit flag on Count
59- 64 F6.1 ct Count Count of the primary component or
of the both is upper limit (2)
65 A1 --- --- [/]
66- 69 F4.1 ct e_Count ? rms uncertainty on Counts
71- 75 F5.2 ct Bcnt ? Counts of the secondary component
77- 83 F7.1 s ExpTime Exposition time
85- 89 F5.2 --- HR1 ? Hardness ratio 1 (G1)
91- 94 F4.2 --- e_HR1 ? rms uncertainty on HR1
96- 99 F4.2 --- HR2 ? Hardness ratio 2 (G1)
101-104 F4.2 --- e_HR2 ? rms uncertainty on HR2
106-112 F7.1 --- ML ? Maximum likelihood
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Note (1): Individual notes as follows:
1 = The source is very close to the support structure of the
telescope, so we are not sure about the reliability of the
upper limit
2 = This source has two PSPC observations: 201271p and 201271 p-1.
There are no detections in the individual observations, so we
have added up both files to improve the S/N ratio.
Note (2): In the case of non-detection, upper limits are computed at the
positions of both components, A and B, respectively.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD ? HD (Cat. III/135) number)
8- 10 A3 --- n_HD Note on HD (1)
13- 18 I6 --- ROR ROSAT Observation request number
19- 23 A5 --- m_ROR Multiplicity index on ROR
25- 26 A2 --- n_Comp Note on elongation (2)
27- 32 A6 --- Comp Composant designation
34- 35 I2 h RAh ? X-ray right ascension (J2000)
37- 38 I2 min RAm ? X-ray right ascension (J2000)
40- 44 F5.2 s RAs ? X-ray right ascension (J2000)
46 A1 --- DE- X-ray declination sign (J2000)
47- 48 I2 deg DEd ? X-ray declination (J2000)
50- 51 I2 arcmin DEm ? X-ray declination (J2000)
53- 56 F4.1 arcsec DEs ? X-ray declination (J2000)
58- 61 F4.1 arcsec DeltaA ? Displacement between the detected X-ray
source and the optical position of the
binary system or of the primary component
if DeltaB exist (3)
62 A1 --- --- [/]
63- 65 F3.1 arcsec DeltaB ? Displacement between the detected X-ray
source and the optical position of the
secondary component (3)
67- 71 F5.2 arcmin OffAxis ? Displacement of the sources with respect to
the axis of the telescope
73 A1 --- l_Count Limit flag on Count
74- 80 F7.2 ct Count Total counts in the broad band
82- 85 F4.1 ct e_Count ? rms uncertainty on Counts
87- 93 F7.1 s ExpTime Exposition time (4)
95 A1 --- l_HR Limit flag in HR
96-100 F5.2 --- HR ? Hardness ratio
102-105 F4.2 --- e_HR ? rms uncertainty on HR
107-112 F6.1 --- ML ? Maximum of likelihood coefficient
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Note (1): Notes as follows:
1 = If both components are detected, coordinates of both X-ray
sources are given. The displacement of the secondary with
respect to the detected X-ray source is computed comparing with
its optical coordinates.
2 = The two stars of the system are not completely resolved so each
star is contributing to the count rate of the companion.
3 = The undetected component is so close to the X-ray source that no
reliable upper limit can be computed.
4 = HD74146 has another observation, 200186h, but with very low
exposure time (texp=357.5s).
s = stars previously studied by Schmitt et al. (1993ApJ...402L..13S 1993ApJ...402L..13S).
Note (2): Elongation information as follows:
e = for elongated sources;
* = The elongated shape is due to attitude problems in the
processed data
Note (3): When we cannot resolve the two components of the binary system,
the displacement δ between the detected X-ray source and the
optical positions of the two components of the system are given.
Note (4): For ROR 201685h B, the printed value is "4535.3.8", modified
in 45353.8 in the present table.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD (Cat. III/135) number
8- 10 A3 --- Comp Component designation
12 A1 --- l_logNH Limit flag on logNH
13- 17 F5.2 [cm-2] logNH Computed hydrogen column density
19 I1 --- r_logNH ? Source of logNH (1)
21 A1 --- Obs [HRP] Type of observations (2)
23 A1 --- l_logLX Limit flag on logLX
24- 28 F5.2 [10-7W] logLX X-ray luminosity (3)
31- 35 F5.2 [10-7W] e_logLX ? rms uncertainty on logLX
36 A1 --- n_logLX [*] *: Mean X-ray luminosity computed from
several observations
38 A1 --- l_logLX2 Limit flag on logLX2
39- 43 F5.2 [10-7W] logLX2 ? X-ray luminosity of the secondary
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Note (1): Source of logNH as follows:
1 = Adopted from Berghofer et al. (1996, Cat. J/A+AS/118/481)
2 = Adopted from Fruscione et al. (1994, Cat. J/ApJS/94/127)
Note (2): Type of observation as follows:
R = RASS (ROSAT All-Sky Survey, Cat. IX/10)
P = PSPC (Position-Sensitive Proportional Counter, Cat. IX/30)
H = HRI (High Resolution Imager, Cat. IX/28)
Note (3): If the binary system is observed and resolved by the HRI, we
provide the fluxes and luminosities for both members of the pair.
If unresolved, we just can provide one X-ray luminosity associated
with the pair. In hese cases we have adopted a temperature of 1keV
to compute the ECF's although, in principle, both stars could be
contributing to the total emission. he last method has also been
applied to those systems with only RASS or PSPC pointed observations,
given that they are always unresolved. In the case of RASS or PSPC
non-detections, we have estimated two upper limit luminosities,
corresponding to the count rates computed at the optical positions
of the primary and the secondary star, respectively (see Table 2).
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD (Cat. III/135) number
7 A1 --- n_Umag Note on U-magnitudes (1)
9- 12 F4.2 mag Umag U magnitude (from HR catalogue V/50)
14- 18 F5.2 ct/ks Srate S-band count rate (2)
20- 24 F5.2 ct/ks UVrate UV count rate (2)
26- 32 F7.2 --- S/UV S to UV rates ratio
34- 37 F4.1 --- log(LX/Lbol) Bolometric to X-ray Luminosity ratio
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Note (1): *: No U-magnitudes available. We derived them from their spectral
types and their V-magnitudes, according to Kenyon & Hartmann (1995,
Cat. J/ApJS/101/117).
Note (2): The S-band rate and the UV rate have been both computed in
channels 1-8 of the detector.
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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- 6 I6 --- HD HD (Cat. III/135) number
8 A1 --- Comp Component designation
9 A1 --- u_Comp [?] Uncertainty flag on Comp
10 A1 --- n_HD [t] Note on HD (1)
12- 15 A4 --- SpType MK Spectral type
17 A1 --- l_logLX Limit flag on logLX
18- 22 F5.2 [10-7W] logLX X-ray luminosity
25 A1 --- l_EWLi Limit flag on EWLi
26- 30 F5.3 0.1nm EWLi Li I absorption line equivalent width
32- 36 F5.3 0.1nm e_EWLi ? rms uncertainty on EWLi
38 A1 --- n_EWLi [1-3] Note on EWLi (2)
40- 44 F5.3 Jy F12um ? 12µm flux density (3)
45 A1 --- u_F12um [?] ?: unknown value
47- 51 F5.3 Jy F100um ? 100µm flux density (3)
52 A1 --- u_F100um [?] ?: unknown value
54- 55 A2 --- f_RV [Ee :] Radial velocity comment (4)
57 A1 --- Xray [±] X-ray emission ? (5)
60 A1 --- LiI [±] Li I equivalent width ? (5)
63 A1 --- IR-ex [±?] Measured IR excess ? (5)
65- 67 A3 --- RV [±? ()] Measured radial velocity of pair ? (5)
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Note (1): The two sources marked with a t are located close to the Galactic
plane and this seems to be the reason of not being detected by IRAS
Note (2): Most of the Li I EW values have been adopted Pallavicini et al.
(1992A&A...261..245P 1992A&A...261..245P). These measurements were derived from
high-resolution spectra (resolution of 0.1Å), except those
with a note (1, 2 or 3):
1 = obtained from low-resolution spectra (resolution of 2Å)
2 = taken from Martin et al., 1992A&A...257..186M 1992A&A...257..186M
(disp. of 0.22Å/pix)
3 = adopted from Webb et al. (1999ApJ...512L..63W 1999ApJ...512L..63W);
Note (3): The IR data are taken from Ray et al. (1995ApJ...440L..89R 1995ApJ...440L..89R)
Note (4): If similar radial velocities have been measured for both members
of the pair it is indicated by an 'e' (if taken from Gahm, 1982,
Stockholm Obs. Rep. No.20 ) and by an 'E' (if taken from Martin et
al., 1992A&A...257..186M 1992A&A...257..186M). If the measurements are doubtful, it is
indicated by a ":" (see Gahm, 1982, Stockholm Obs. Rep. No.20, and
Martin et al., 1992A&A...257..186M 1992A&A...257..186M, for more details)
Note (5): We have summarized the data of the table in these columns using
the symbols +,- and ? for positive, negative and unknown properties
respectively. The (+) symbols indicate doubtful properties.
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Global notes:
Note (G1): Hardness ratio:
HR1=(H1+H2-S)/(H1+H2+S) and HR2=(H2-H1)/(H2+H1) where
S=0.1-0.4keV (Soft), H1=0.5-0.9keV (Hard1), H2=0.9-2.0keV (Hard2)
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History:
Prepared via OCR at CDS.
(End) James Marcout, Patricia Bauer [CDS] 24-Jan-2001