J/ApJ/315/687 X-Ray emission from solar-type stars: F and G (Maggio+, 1987)
Einstein Observatory survey of X-ray emission from solar-type stars: the late F
and G dwarf stars.
Maggio A., Sciortino S., Vaiana G.S., Majer P., Bookbinder J., Golub L.,
Harnden F.R.Jr, Rosner R.
<Astrophys. J. 315, 687 (1987)>
=1987ApJ...315..687M 1987ApJ...315..687M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Stars, F-type ; Stars, G-type ; X-ray sources
Mission_Name: Einstein
Keywords: CaII emission - stars: evolution stars: X-Rays
Abstract:
Results of a volume-limited X-ray survey of stars of luminosity
classes IV and V in the spectral range F7-G9 observed with the
Einstein Observatory are presented. Using survival analysis
techniques, the stellar X-ray luminosity function in the 0.15-4.0
keV energy band for both single and multiple sources. It is shown
that the difference in X-ray luminosity between these two classes
of sources is consistent with the superposition of individual
components in multiple-component systems, whose X-ray properties
are similar to those of the single-component sources. The X-ray
emission of the stars in our sample is well correlated with their
chromospheric CA II H-K line emission and with their projected
equatorial rotational velocity. Comparison of the X-ray
luminosity function constructed for the sample of the dG stars of
the local population with the corresponding functions derived
elsewhere for the Hyades, the Pleiades, and the Orion Ic open
cluster confirms that the level of X-ray emission decreases with
stellar age.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
gstars_1.dat 137 62 EO Survey of Solar-type Stars: Optical Properties
gstars_2.dat 27 61 EO Survey of Solar-type Stars: X-ray Fluxes
gstars_3.dat 42 62 EO Survey of Solar-type Stars: X-ray Luminosities
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See also:
J/ApJ/348/253 : Einstein Survey of Late-type Giant and Supergiant Stars
J/ApJ/325/798 : Einstein Survey of Hyades-cluster Region
J/ApJ/348/557 : Einstein Survey of the Pleiades Cluster
J/ApJ/351/492 : X-ray Emission in the Ursa Major Stream
Byte-by-byte Description of file: gstars_1.dat
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Bytes Format Units Label Explanations
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2- 9 A8 --- Name Star-name (1)
11- 18 A8 --- HD ? HD/DM (Henry Draper Catalog) number (1)
20- 23 I4 --- HR HR (Bright Star Catalog) number (1)
25- 34 A10 --- Oname Other Name (1)
36- 46 A11 --- Sp Spectral class (2)
48- 51 F4.2 mag Mabs Absolute visual magnitude (2)
53- 56 F4.2 mag B-V B-V color index (2)
58- 62 F5.2 pc Dist Distance (2)
64-118 A55 --- Rem Remarks (3)
120-121 I2 h RAh Right Ascension (B1950) (hour)
123-124 I2 min RAm Right Ascension (B1950) (min)
126-127 I2 s RAs Right Ascension (B1950) (sec)
129 A1 --- DE- Declination sign (B1950)
130-131 I2 deg DEd Declination (B1950) (deg)
133-134 I2 arcmin DEm Declination (B1950) (arcmin)
136-137 I2 arcsec DEs Declination (B1950) (arcsec)
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Note (1): These columns contain the name of the star, its HD (Henry Draper
Catalog (Cat.III/135) number, its HR (Bright Star Catalog
(See V/50)) number, and its other name, if any.
Note (2): These columns contain basic optical information about the stars
in this survey. The spectral class, listed in the "Sp" column, is
from Hoffleit and Jaschek 1982 (See Cat. V/50). The absolute
visual magnitude is given in the "Mabs" column; the B-V color
index is given in the "B-V" column; and the distance, in parsecs,
is given in the "Dist" column.
Note (3): This column contains remarks, mostly from Hoffleit and Jaschek
(1982) (See Cat. V/50:
SB1 and SB2 -- indicate spectroscopic binaries with single- or
double-lined spectra (respectively)
suffix "O" -- signifies that an orbit has been determined
Cp -- indicates companion
CPM -- common proper motion
RV -- radial velocity
A,B,C -- indicate first, second, and third brightest members
(respectively) in multiple systems
Sun -- Not directly observed; for inferences of solar
X-ray emission from Einstein observations of the
sunlit Earth, see Schmitt, Harnden, and Fink
(1987ApJ...322.1023S 1987ApJ...322.1023S)
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Byte-by-byte Description of file: gstars_2.dat
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Bytes Format Units Label Explanations
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2- 9 A8 --- Name Star name (1)
11 A1 --- mult [SM] Multiplicity flag (1)
13-17 I5 --- Seqno IPC sequence number (2)
19 A1 --- f_fx [01] "1" if X-ray flux is an upper limit (3)
21-25 F5.2 10-16W/m2 fx X-ray flux in the 0.16-4.0 keV band (3)
27 A1 --- Remark Numeric reference to remarks from the
published table (4)
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Note (1): The "Name" column gives the star name. For the star's HD (Bright
Star Catalog (See V/50)) or HR (Henry Draper Catalog
(Cat.III/135) numbers, or its other name, see the table
gstars_1.dat. The "mult" column contains a multiplicity flag. We
consider a source (or upper limit) to be multiple (M), for
purposes of determining X-ray fluxes, if there is at least one
other optical source within a 2' radius of the optical
counterpart of the IPC source and as long as there is no
additional X-ray information from HRI exposures which resolves
the sources. Otherwise, the source is considered single (S).
Note (2): This column contains the Einstein sequence number, a two to five
digit number which uniquely identifies the observation. The
numbers were assigned sequentially at the time of proposal
submission.
Note (3): The first column is flagged with a "1" if the given X-ray flux is
an upper limit; if the column is marked with a "0", the star was
detected in the broad band and the X-ray flux is determined from
the measured count rate. The X-ray flux is given in the "fx"
column in the 0.15-4.0 keV band in units of 10-13 erg/cm2/s
(or 10-16 W/m2).
Present in the published table but omitted here is the fourth
column which gave X-ray fluxes from multiple IPC exposures of the
same star or from single IPC exposures for which an HRI exposure
is also available. Here we give only a single, "adopted" flux for
each star (which appeared in the fifth column of the published
table).
Note (4): This column gives a numeric reference to remarks in the published
table. The following are used:
1 77% of X-ray emission can be attributed to 34B (dM0) on the
basis of HRI observation (Harris and Johnson, 1985ApJ...294..649H 1985ApJ...294..649H)
2 Mean value adopted
3 Upper limit due to source confusion
4 70% of x-ray emission can be attributed to W559B (K0V) on the
basis of HRI observation (Golub, et al. 1982ApJ...253..242G 1982ApJ...253..242G)
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Byte-by-byte Description of file: gstars_3.dat
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Bytes Format Units Label Explanations
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2- 9 A8 --- Name Star name (1)
11 A1 --- f_lx Flag on lx (2)
13-17 F5.2 [10-7W] Lx log of X-ray luminosity from 0.15 - 4.0 keV (2)
19 A1 --- l_Age [ >] limit flag on age (3)
20-22 F3.1 Gyr Age ? yrs Age in Giga-years (3)
24 A1 --- r_Age Reference for age (3)
26-29 F4.1 km/s Vsini Rotational velocity (4)
31-33 F3.1 km/s e_Vsini Error on rotational velocity (4)
35 A1 --- r_Vsini Reference for rotational velocity (4)
37-40 F4.1 km/s Veq Equatorial velocity (5)
42 A1 --- r_Veq Reference for Equatorial velocity (5)
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Note (1): This column gives the star name. For the star's HD (Bright Star
Catalog) or HR (Henry Draper Catalog) number, or an alternative
name, see the table gstars_1.dat.
Note (2): The first column is flagged with a "1" if the given X-ray
luminosity is an upper limit; if the column is marked with a "0",
the star was detected in the broad band and the X-ray luminosity
is determined from the measured count rate. The log of the X-ray
luminosity is given in the "lx" column in ergs/s in the 0.15-4.0
keV passband. Because individual distances are known only to
within an error of 20% or less, we estimate an overall error of
0.25 in the logarithm of the X-ray luminosity.
Note (3): The "Age" column gives the age of the star, in billions of years.
The reference for the age is given in the "r_Age" column. The
following references were used (note: column is 0 if no reference
is made):
1 Soderblom, 1982ApJ...263..239S 1982ApJ...263..239S
3 Baliunas, et al. 1983ApJ...275..752B 1983ApJ...275..752B
Note (4): The rotational velocity and its error and reference are given in
these columns. The rotational velocity and error are in units of
km/s and the following references were used (note: column is 0 if
no reference is made):
1 Soderblom, 1982ApJ...263..239S 1982ApJ...263..239S
5 Smith, 1979PASP...91..737S 1979PASP...91..737S
6 Kraft, R.P. 1967ApJ...150..551K 1967ApJ...150..551K
Note (5): The "Veq" column gives equatorial velocity, inferred from
measured periods (in km/s). The reference is given in the
"r_Veq" column. The following references were used (note:
column is 0 if no reference is made):
2 Duncan, 1981ApJ...248..651D 1981ApJ...248..651D
4 Noyes, et al. 1984ApJ...279..763N 1984ApJ...279..763N
7 Hallam and Wolff, 1981ApJ...248L..73H 1981ApJ...248L..73H
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History:
Prepared from the tables available at the "ADS Catalogue Service"
(CfA, Harvard-Smithsonian Center for Astrophysics, Cambrigde MA)
References:
Hoffleit, D. and Jaschek, C. 1982, The Bright Star Catalogue (New Haven:
Yale University). (See the fifth edition V/50)
(End) Patricio Ortiz [CDS] 31-Mar-1999