J/AJ/106/1839 Metal-rich halo A stars (Rodgers+ 1993)
Early-type stars in orthogonal halo fields.
II. Identification of metal-rich A stars in the halo
Rodgers A.W., Roberts W.H.
<Astron. J. 106, 1839 (1993)>
=1993AJ....106.1839R 1993AJ....106.1839R
ADC_Keywords: Stars, early-type ; Radial velocities ; Equivalent widths
Abstract:
The results of spectrophotometry of the Ca II K and Balmer lines and
radial velocity measurements for stars earlier than type F0, with
10<V<15.5 in fields at (l;b)=(90deg, 270deg; -45deg) are reported.
Slit spectroscopy of 320 stars shows that in this magnitude range
there are ∼80 stars with [Fe/H]>-0.5. The metal-rich population has
a vertical scale height of ∼600pc and a space density at the Sun
equal to 1/225 of the young thin disk A star population. The
metal-rich A stars have Vrot=210±60km/s with decreasing
angular momentum as a function of distance from the Galactic plane.
The line-of-sight velocity dispersion is 40±3km/s indicating an
anomalous relation between structure and kinematics. There is strong
evidence that these stars are identical in properties to the
metal-rich extended populations found by Perry [1969AJ.....74..139P 1969AJ.....74..139P]
at the NGP and Rodgers [1971ApJ...165..581R 1971ApJ...165..581R] at the SGP.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 43 332 Spectrophotometry and radial velocities of
stars classified as of type earlier than F0 in
the fields (l;b)=(90 deg, 270 deg; -45 deg)
from the catalog of Paper I
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See also:
J/AJ/106/591 : OP Survey of Halo early-type stars (Rodgers+ 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Object identifier
11- 14 F4.1 0.1nm EWK Equivalent width of Ca II K
16- 20 F5.1 0.1nm EWHd Equivalent width of Ca II Hdelta
22- 26 I5 km/s RV *Radial velocity rel. to Local Std. of Rest
28- 35 F8.3 deg GLON Galactic longitude
37- 43 F7.3 deg GLAT Galactic latitude
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Note on RV: The following corrections were adopted:
for l=90 deg; b=-45 deg, Vlsr=Vhelio+6km/s
for l=270 deg; b=-45 deg, Vlsr=Vhelio-16km/s
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Referneces:
Rodgers A.W. & Roberts W.H., Paper III. =1993AJ....106.2294R 1993AJ....106.2294R
Origin: AAS CD-ROM series, Volume 6, 1996 Lee Brotzman [ADS] 19-Feb-1996
(End) [CDS] 05-Sep-1996