J/AJ/113/950 Kinematic Profiles of S0 Galaxies (Fisher 1997)
Kinematic Profiles of S0 Galaxies
Fisher D.
<Astron. J. 113, 950 (1997)>
=1997AJ....113..950F 1997AJ....113..950F (SIMBAD/NED BibCode)
ADC_Keywords: Radial velocities ; Velocity dispersion
Abstract:
Stellar rotation curves, velocity dispersion profiles, and line of
sight velocity distributions (LOSVD) as derived from absorption-lines
are presented for the major axes of 18 S0 and two elliptical galaxies.
Ionized gas rotation curves and dispersions were measured from the
[OIII] 5007A emission line in the 9 S0 galaxies displaying this
feature. Minor-axis results are given for 14 of the S0 galaxies and
one of the ellipticals. A wide range of behaviors are observed in the
rotation and velocity dispersion profiles. These variations could be
the result of the superposition of stars and gas belonging to the
disks and bulges as well as the possible influences of bars, nuclear
disks, and warps. Deviations from a Gaussian LOSVD are found along the
major axes of all the galaxies in our sample. As parametrised by the
Gauss-Hermite series of orthogonal functions, asymmetric deviations
are always found in the inner regions of the S0 galaxies such that the
prograde wing of the LOSVD is steeper than the retrograde wing. This
is similar to the behavior observed in elliptical galaxies. However,
at larger radii these asymmetries can change their sign. We find that
in 9 of the 18 S0 galaxies a high-speed tail to the LOSVD develops
along the major-axis beyond the central regions. In 3 of these 9
objects the LOSVD asymmetries display a second change of sign with
radius such that a low-speed tail is again present and persists to our
last measured values. No correlations were found between the sizes of
the stellar velocity dispersion gradients and either central velocity
dispersion, absolute magnitude, disk-to-bulge ratio, Mg2 or Fe line
strength gradients. For the objects in our sample with edge-on
orientations a comparison between the minor-axis 'bulge' velocity
dispersion gradients and those found in elliptical galaxies indicates
that the S0 bulges display, on average, logarithmic gradients
approximately 4 times steeper than those found in normal luminous
ellipticals. A number of galaxies show particularly interesting
features. For the LINER S0 galaxy NGC 3998 we find that the velocity
dispersion profiles of both the stars and gas rise sharply towards the
center reaching nuclear values of sigma∼320km/s. Nuclear disks of
rapidly rotating gas are found in NGC 4350 and NGC 4762. A nuclear
stellar disk is apparent in the edge-on galaxy NGC 4111 and an
extended disk of counterrotating gas is observed in the barred S0
NGC 3941.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2 64 1281 Stellar radial velocities and velocity dispersions
table3 64 425 Stellar Gauss-Hermite h3 and h4 terms
table4 61 594 [OIII] 5007A radial velocities & velocity dispersions
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 8 A8 --- NGC NGC number
10- 12 I3 deg PA Position angle of observations
14- 19 A6 --- Oslit Offset of the slit with respect to the nucleus
21- 25 A5 --- Axis Axis (Major or Minor)
27- 32 F6.2 arcsec Radius Radius measure from center of galaxy
34- 40 F7.2 km/s RV []? Radial velocity
42- 48 F7.2 km/s e_RV []? Error in RV
50- 56 F7.2 km/s Sigma []? Velocity dispersion
58- 64 F7.2 km/s e_Sigma []? Error in Sigma
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Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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1- 8 A8 --- NGC NGC number
10- 12 I3 deg PA Position angle of observations
14- 19 A6 --- Oslit Offset of the slit with respect to the nucleus
21- 25 A5 --- Axis Axis (Major or Minor)
27- 32 F6.2 arcsec Radius Radius measure from center of galaxy
35- 40 F6.3 --- h3 *Gaussian-Hermite h_3 parameter
43- 48 F6.3 --- e_h3 Error in h3
51- 56 F6.3 --- h4 *Gaussian-Hermite h_4 parameter
59- 64 F6.3 --- e_h4 Error in h4
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Note to h3, h4:
The velocity distribution is parametrised by the Gauss-Hermite series
of orthogonal functions yielding two measures of the deviations of
the line profile from a Gaussian: a parameter h_3 which measures
asymmetric deviations, and a parameter h_4 measuring symmetric
deviations.
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Byte-by-byte Description of file: table4
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Bytes Format Units Label Explanations
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1- 8 A8 --- NGC NGC number
10- 12 I3 deg PA Position angle of observations
14- 19 A6 --- Oslit Offset of the slit with respect to the nucleus
21- 25 A5 --- Axis Axis (Major or Minor)
27- 31 F5.1 arcsec Radius Radius measure from center of galaxy
35- 40 F6.1 km/s RV Radial velocity
43- 47 F5.1 km/s e_RV Error in RV
50- 54 F5.1 km/s Sigma []?=-99. Velocity dispersion
57- 61 F5.1 km/s e_Sigma []?=0. Error in Sigma
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Origin: AAS CD-ROM series, volume 7, 1996 Lee Brotzman [ADS] 12-Nov-1996
(End) Patricia Bauer [CDS] 11-Feb-1997