J/A+A/408/873 Gas and stellar kinematics in spirals (Corsini+, 2003)
Minor-axis velocity gradients in spirals and the case of inner polar disks
Corsini E.M., Pizzella A., Coccato L., Bertola F.
<Astron. Astrophys. 408, 873 (2003)>
=2003A&A...408..873C 2003A&A...408..873C
ADC_Keywords: Galaxies, optical ; Spectroscopy
Keywords: galaxies: kinematics and dynamics ; galaxies: spiral ;
galaxies: structure
Abstract:
We measured the ionized-gas and stellar kinematics along the major and
minor axis of a sample of 10 early-type spirals. Much to our surprise
we found a remarkable gas velocity gradient along the minor axis of 8
of them. According to the kinematic features observed in their
ionized-gas velocity fields, we divide our sample galaxies in three
classes of objects. (i) NGC 4984, NGC 7213, and NGC 7377 show an
overall velocity curve along the minor axis without zero-velocity
points, out to the last measured radius, which is interpreted as due
to the warped structure of the gaseous disk. (ii) NGC 3885, NGC 4224,
and NGC 4586 are characterized by a velocity gradient along both major
and minor axis, although non-zero velocities along the minor axis are
confined to the central regions. Such gas kinematics have been
explained as being due to non-circular motions induced by a triaxial
potential. (iii) NGC 2855 and NGC 7049 show a change of slope of the
velocity gradient measured along the major axis (which is shallower in
the center and steeper away from the nucleus), as well as non-zero gas
velocities in the central regions of the minor axis. This has been
attributed to the presence of a kinematically-decoupled gaseous
component in orthogonal rotation with respect to the galaxy disk,
namely an inner polar disk. The case and origin of inner polar disks
are discussed and the list of their host galaxies is presented.
Description:
Table 3 (table3.dat) gives spatially resolved ionized-gas kinematic
parameters (v, sigma) for the sample galaxies as well as Table 4
(table4.dat) gives spatially resolved stellar kinematic parameters
(v, sigma) for the sample galaxies.
Objects:
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RA (2000) DE Designation(s)
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04 41 36.5 -01 48 34 NGC1638 = UGC 3133
11 46 46.5 -27 55 22 NGC3885 = IRAS 11442-2738
12 16 33.8 +07 27 45 NGC4224 = IRAS 12140+0744
12 17 09.9 +07 11 28 NGC4235 = IRAS F12146+0728
12 38 28.4 +04 19 08 NGC4586 = IRAS F12359+0435
13 08 57.3 -15 30 59 NGC4984 = IRAS F13063-1515
21 19 00.3 -48 33 43 NGC7049 = IRAS 21156-4846
22 09 16.2 -47 10 00 NGC7213 = IRAS 22061-4724
22 47 47.4 -22 18 41 NGC7377 = IRAS 22451-2234
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 39 892 Ionized-gas kinematics for the sample galaxies
table4.dat 38 316 Stellar kinematics for the sample galaxies
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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 - 7 A7 --- Name Name of the galaxy
10 - 12 I3 deg PA Position angle of the slit (G1)
15 - 19 F5.1 arcsec r Distance from galaxy center
22 - 25 I4 km/s vg(r) Line-of-sight gas mean velocity
28 - 29 I2 km/s e_vg(r) Error of vg(r)
32 - 34 I3 km/s sigmag Line-of-sight gas velocity dispersion
37 - 39 I3 km/s e_sigmag Error of sigmag(r)
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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 - 7 A7 --- Name Name of the galaxy
10 - 12 I3 deg PA Position angle of the slit (G1)
15 - 19 F5.1 arcsec r Distance from galaxy center
22 - 25 I4 km/s v*(r) Line-of-sight star mean velocity
28 - 29 I2 km/s e_v*(r) Error of v_*(r)
32 - 34 I3 km/s sigma* Line-of-sight star velocity dispersion
37 - 38 I2 km/s e_sigma* Error of sigma_*(r)
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Global notes:
Note (G1): Position angle of the slit measured from North to East in the
range [0,180]
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Acknowledgements: Enrico Maria Corsini
(End) Enrico Maria Corsini [Univesita di Padova, Italy] 25-Jun-2003