J/AJ/113/321 Stellar Kinematics toward (l=8.4, b=-6) (Tiede+ 1997)
A New Survey of Stellar Kinematics in the Central Milky Way
Tiede G.P., Terndrup D.M.
<Astron. J. 113, 321 (1997)>
=1997AJ....113..321T 1997AJ....113..321T
ADC_Keywords: Spectroscopy ; Abundances ; Radial velocities ; Photometry ;
Stars, distances
Abstract:
We present the results of a photometric and spectroscopic study of 189
stars in a field at (l,b)=(8.4deg,-6.0deg). We measure radial
velocities and selected indices of line strength from the spectra and
derive reddening, metallicity, photometric parallaxes, and azimuthal
rotation velocities and dispersion. We find an average reddening and
extinction to the field of E(V-I)=0.43±0.09 and A_V=1.07±0.22. We
use distances derived from photometric parallaxes and find that the
distribution of stars along this line of sight is not strongly peaked
at the tangent point. In an attempt to understand the apparent
decrease in line-of-sight velocity dispersion with increasing
metallicity, we divide our sample into metal-rich and metal-poor
groups. Though we lack enough stars to statistically analyze each
group, we find the average distances of the metal-rich and metal-poor
groups to be, =3.1kpc and =7.0kpc. Excluding stars in our sample
which are likely to be in the foreground disk, we calculate a
rotational velocity for the bulge of Vrot=97±9km/s,
σphi=71±11km/s. Combining this result with studies at other
(l,b), we find a rotation rate for the bulge of 10.6±0.6km/s/deg or
77±5km/s/kpc. We conclude that when attempting to understand the
properties of stars along lines of sight into the bulge it is
important to consider the line-of-sight distribution of the stars,
especially when more than a few degrees from the galactic center.
(Copyright) 1997 American Astronomical Society.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 189 Astrometry, photometry, radial velocity, and
distance modulus
table1.tex 104 211 AASTeX version of table1.dat
table3.dat 47 189 Transformed indices and calculated [Fe/H]
table3.tex 80 208 AASTeX version of table3.dat
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Star Star number
4- 6 I3 h RAh Right ascension, epoch B1950
7 A1 --- --- Always ':'
8- 9 I2 min RAm Right ascension, epoch B1950
10 A1 --- --- Always ':'
11- 15 F5.2 s RAs Right ascension, epoch B1950
17 A1 --- DE- Declination sign
18- 19 I2 deg DEd Declination, epoch B1950
20 A1 --- --- Always ':'
21- 22 I2 arcmin DEm Declination, epoch B1950
23 A1 --- --- Always ':'
24- 28 F5.2 arcsec DEs Declination, epoch B1950
30- 36 F7.3 mag Vmag V magnitude
38- 42 F5.3 mag e_Vmag Error in Vmag
44- 49 F6.3 mag V-I V-I color
51- 55 F5.3 mag e_V-I Error in V-I
57- 62 F6.1 km/s HRV ? Heliocentric radial velocity
64- 68 F5.1 km/s e_HRV ? Error in HRV
70- 75 F6.2 mag DMod ? Distance modulus, (m-M)0
77- 80 F4.2 mag e_DMod ? Error in DMod
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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- 3 I3 --- Star Star number
5- 9 F5.2 mag Fe5270 Fe5270 index (1)
11- 14 F4.2 mag e_Fe5270 Error in Fe5270
16- 20 F5.2 mag Fe5335 Fe5335 index (1)
22- 25 F4.2 mag e_Fe5335 Error in Fe5335
27- 31 F5.2 mag Hbeta ? Hbeta index
33- 36 F4.2 mag e_Hbeta ? Error in Hbeta
38- 42 F5.2 [Sun] [Fe/H] ? Metallicity [Fe/H]
44- 47 F4.2 [Sun] e_[Fe/H] ? Error in [Fe/H]
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Note (1):
Central bandpass Continuum bandpass
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Fe 5270 5248.00-5286.75 5235.50-5249.25
5288.00-5319.25
Fe 5335 5314.75-5353.50 5307.25-5317.25
5356.00-5364.75
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Origin: AAS CD-ROM series, Volume 8, 1997 Lee Brotzman [ADS] 04-Apr-1997
(End) [CDS] 03-Jul-1997