J/AJ/114/2402 Rotation curves of early-type galaxies (Courteau+, 1997)
Optical rotation curves and linewidths for Tully-Fisher applications.
Courteau S.
<Astron. J. 114, 2402 (1997)>
=1997AJ....114.2402C 1997AJ....114.2402C
ADC_Keywords: Galaxies, rotation ; Spectroscopy
Description:
Optical long-slit rotation curves have been studied for 304 northern
Sb-Sc galaxies from the Courteau-Faber (CF) sample designed for
Tully-Fischer (TF) applications; r-band photometry exists also for
each galaxy of the sample. The procedure of rotation curve (RC)
extraction and construction of optical profiles are analogous to 21cm
integrated linewidths.
More than 20% of the galaxies were observed twice or more, allowing
for a proper determination of systematic errors. Various measures of
maximum rotational velocity to be used as input in the TF relation are
tested on the basis of their repeatability, minimization of TF
scatter, and match with 21cm linewidths. The best measure of TF
velocity, V2.2 is given at the location of peak rotational velocity of
a pure exponential disk. An alternative measure to V2.2 which makes no
assumption about the luminosity profile or shape of the rotation curve
is Vhist, the 20% width of the velocity histogram, though the match
with 21cm linewidths is not good. The paper shows that optical TF
calibrations yield internal scatter comparable to, if not smaller
than, the best calibrations based on single-dish 21cm radio linewidths.
Tables 6 and 7 contain the values of the parameters fitting the
rotation curves of two samples of galaxies: the CF (Courteau-Faber)
sample (table6) and the MAT (Mathewson et al., 1992ApJS...81..413M 1992ApJS...81..413M)
sample (table7). Two fitting models were used: the ArcTan function
(Model 1) where the velocity varies as
v(r) = v(0) + K . arctan(R) (R being (r-r0)/rt)
and a multi-parameter function (Model 2) modelling the rotation curve
close to a solid-body close to the rotation center, and close to a
flat rotation at large distances (see section 5 of the paper).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 144 304 Spectroscopy parameters
table6.dat 68 438 *Fit Parameters for CF (Courteau & Faber) Galaxies
table7.dat 88 958 Fit Parameters for MAT (Mathewson et al.,
1992ApJS...81..413M 1992ApJS...81..413M) Galaxies
tables.tex 147 1804 LaTeX version of the tables
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Note on table6.dat: Courteau & Faber, 1998, in
"The Extragalactic Distance Scale", edited by
S. van den Bergh and C. Pritchet (ASP, San Fransisco), p. 366.
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See also:
J/ApJS/99/501 : Spiral galaxies rotation curves (Persic+ 1995)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Galaxy name (UGC or Zwicky)
12 I1 --- Nobs Total number of observations per galaxies
15- 16 I2 deg i Inclination
20- 24 I5 km/s czLG Radial velocity corrected for motion with
respect to the Local Group
28- 32 I5 km/s czCMB Radial velocity in frame of the
Cosmic Microwave Background
35- 39 F5.1 km/s W15 Velocity width measured from the flux-weighted
rotation profile at 15% of the total area
42- 46 F5.1 km/s W20 Velocity width measured from the flux-weighted
rotation profile at 20% of the total area
49- 53 F5.1 km/s Vmax Peak velocity from the fit with Model 2 (G2)
56- 60 F5.1 km/s V2.2 Velocity from Model 2 measured at rdisk=2.15h,
where h is the disk scale length from 1D
bulge-to-disk decompositions
63- 67 F5.1 km/s Vopt Velocity from Model 2 measured at r_opt=3.2h,
the optical radius defined as in PSS
(Persic et al. 1996MNRAS.281...27P 1996MNRAS.281...27P)
70- 74 F5.1 km/s Vhist Velocity difference between the 10th and 90th
(interpolated) percentile points in the
ranked distribution of velocities
76- 80 F5.2 --- logsm logarithmic slope measured from Model 3
(Universal Rotation Curve) between rdisk
and the last fitted velocity point
82- 86 F5.2 --- logsr logarithmic slope measured from the observed
rotation curve between rdisk and the last
measured velocity point
88- 92 F5.2 --- logs24 ?=0.0 logarithmic slope measured between 2
and 4 disk scale lengths (1)
95- 96 I2 --- o_logs24 number of points that entered the fit
99-102 F4.2 --- e_logs24 Typical error of the fit (determined by boostrap
technique)
105-110 F6.2 Mpc Dist Distance of the galaxy
113-117 F5.2 arcsec rmax Maximum spatial extent of either the approaching
or receding side of the galaxy spectrum
121-125 F5.2 kpc rkpc Same as rmax but in kpc
128-132 F5.2 mag rmag Corrected r-band total apparent magnitude (2)
135-140 F6.2 mag rMAG Corrected absolute r-band magnitude
144 I1 --- Ft [1/2] Freeman (1970ApJ...160..811F 1970ApJ...160..811F) luminosity
profile type of the galaxy
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Note (1): If logs24 could not be measured, because the rotation curve
of the galaxy does not extend beyond 4 disk scale lengths or if there
are less than 6 velocity points in the fit, logs24 is set to 0.
Note (2): r magnitude is from Paper I (Courteau, 1996ApJS..103..363C 1996ApJS..103..363C)
which here also includes a small K-correction term (cf. Willick et
al., 1997ApJS..109..333W 1997ApJS..109..333W, Cat. VII/198, Eq. A14)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Galaxy name (UGC or Zwicky)
10 A1 --- m_Name [abc] Galaxy name (UGC or Zwicky)
12- 19 A8 "DD/MM/YY" Date Observing date
21- 26 F6.1 km/s vc Multi-parameter Fit asymptotic velocity (G2)
28- 33 F6.1 kpc rt Multi-parameter Fit transition radius (G1)
35- 38 F4.1 --- Gamma Multi-parameter Fit Gamma value (G2)
40- 43 F4.1 --- Beta Multi-parameter Fit Beta value (G2)
45- 49 F5.1 --- Chi2 Multi-parameter Fit chi2nu value (G2)
51- 56 F6.1 km/s vcA Arctan Fit vc asymptotic velocity (G3)
58- 63 F6.1 kpc rtA Arctan Fit rc transition radius (G3)
65- 68 F4.1 --- Chi2A Arctan Fit chi2nu value (G3)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Galaxy Galaxy designation
14- 20 F7.1 km/s v0 Velocity center of rotation (G2)
22- 27 F6.2 kpc r0 Spatial center of the rotation (G2)
29- 35 F7.1 km/s vc Multi-parameter Fit asymptotic velocity (G2)
37- 42 F6.1 kpc rt Multi-parameter Fit transition radius (G1)
44- 47 F4.1 --- Gamma Multi-parameter Fit Gamma value (G2)
49- 52 F4.1 --- Beta Multi-parameter Fit Beta value (G2)
54- 59 F6.1 --- Chi2 Multi-parameter Fit chi2nu value (G2)
61- 68 F8.1 km/s vcA Arctan Fit vc asymptotic velocity (G3)
70- 76 F7.1 kpc rtA Arctan Fit rc transition radius (G3)
78- 82 F5.1 --- Chi2A Arctan Fit chi2nu value (G3)
84- 88 F5.1 ---- Dcz Difference in systematic velocity between the
multi-parameter fit and and the models by
Persic & Salucci (1995, Cat. J/ApJS/99/501)
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Global Notes:
Note (G1): rt is the transition radius between the rising and flat parts
of the rotation curve.
Note (G2): the multi-parameter function is:
v(r)=v0+vc([(1+x)beta]/[(1+xGamma)1/Gamma]), where
v0 is the velocity center of rotation,
x=rt/(r-r0) [r0 center of rotation, rt transition radius]
Note (G3): The ArcTan function model is
v(r)=v0+(2/π)vc.arctan(R)
where R=1/x=(r-r)/rt) [r0 center of rotation, rt transition radius]
Acknowledgements: Stephane Courteau
(End) Patricia Bauer [CDS] 26-May-1999