J/MNRAS/363/769 Dynamical modelling of 4 early-type galaxies (Samurovic+, 2005)
Dark matter in early-type galaxies:
dynamical modelling of IC 1459, IC 3370, NGC 3379 and NGC 4105.
Samurovic S., Danziger I.J.
<Mon. Not. R. Astron. Soc., 363, 769-800 (2005)>
=2005MNRAS.363..769S 2005MNRAS.363..769S
ADC_Keywords: Galaxies, spectra ; Velocity dispersion ; Morphology
Keywords: galaxies: elliptical and lenticular -
galaxies: kinematics and dynamics - galaxies: ISM - X-rays -
galaxies: structure - dark matter
Abstract:
We analyse long-slit spectra of four early-type galaxies which extend
from ∼1 to 3 effective radii: IC 1459; IC 3370; NGC 3379 and NGC 4105.
We have extracted the full line-of-sight velocity distribution (in the
case of NGC 3379 we also used data from the literature), which we
model using the two-integral approach. Using two-integral modelling,
we find no strong evidence for dark haloes, but the fits suggest that
three-integral modelling is necessary. We also find that the inferred
constant mass-to-light ratio in all the four cases is typical for
early-type galaxies. Finally, we also discuss the constraints on the
mass-to-light ratio, which can be obtained using X-ray haloes in the
case of IC 1459, NGC 3379 and NGC 4105, and compare the estimated
values with the predictions from the dynamical modelling.
Description:
IC 1459 : Photometric observations were made by one of us (IJD) during
1997 August 2830 using the European Southern Observatory (ESO) New
Technology Telescope (NTT) and ESO Multi-Mode Instrument (EMMI) in the
Red Medium Spectroscopy mode in the V band.
IC 3370 : We used frames kindly provided by O. Hainaut using ESO NTT
and EMMI in the RILD mode on 2002 July 34, in the B band.
NGC 3379 : The surface brightness was taken from the paper of
Capaccioli et al. (1990AJ.....99.1813C 1990AJ.....99.1813C)
NGC 4105 : Photometric data were extracted from frames obtained by the
courtesy of M. Carollo and K. Freeman (who used ESO 2.2-m telescope
with ESO Faint Object Spectrograph and Camera; EFOSC) using standard
iraf routines. The photometric profiles are given in the R band.
Objects:
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RA (2000) DE Designation(s) (Files)
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22 57 10.6 -36 27 44 IC 1459 = LEDA 70090 (tablea[12],tableb1)
12 27 37.2 -39 20 16 IC 3370 = LEDA 40887 (tablea3,tableb[234])
10 47 49.8 +12 34 55 NGC 3379 = LEDA 32256 (tablea4,tableb5)
12 06 40.6 -29 45 42 NGC 4105 = LEDA 38411 (tablea[56],tableb[67])
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 21 89 Photometric data of IC 1459 (Bmag)
tablea2.dat 55 40 Photometric data of IC 1459 (a4, PA)
tablea3.dat 70 49 Photometric data of IC 3370 (Bmag,a4, PA)
tablea4.dat 55 47 Photometric data of NGC 3379 (a4, PA)
tablea5.dat 21 87 Photometric data of NGC 4105 (Bmag)
tablea6.dat 55 35 Photometric data of NGC 4105 (a4, PA)
tableb1.dat 71 105 Kinematic data of IC 1459 (major axis)
tableb2.dat 71 30 Kinematic data of IC 3370 (major axis)
tableb3.dat 71 29 Kinematic data of IC 3370 (minor axis)
tableb4.dat 71 26 Kinematic data of IC 3370 (intermediate axis)
tableb5.dat 71 21 Kinematic data of NGC 3379 (major axis)
tableb6.dat 71 34 Kinematic data of NGC 4105 (major axis)
tableb7.dat 71 24 Kinematic data of NGC 4105 (minor axis)
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See also:
VII/242 : LEDA galaxies with DENIS measurements catalog (Paturel+, 2005)
VII/206 : General Photometry of Galaxies (Prugniel+ 1998)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
VII/238 : HYPERLEDA. II. Homogenized HI data (Paturel+, 2003)
Byte-by-byte Description of file: tablea1.dat tablea5.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 arcsec Rad Radius
9- 13 F5.2 mag Bmaj B magnitude along major axis
17- 21 F5.2 mag Bmin B magnitude along minor axis
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Byte-by-byte Description of file: tablea2.dat tablea4.dat tablea6.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 arcsec Rad Radius
9- 14 F6.4 --- Ell Ellipticity
17- 22 F6.4 --- e_Ell rms uncertainty on Ell
25- 31 F7.4 --- a4 a4 parameter (G1)
33- 38 F6.4 --- e_a4 rms uncertainty on a4
40- 47 F8.4 deg PA Position angle
49- 55 F7.4 deg e_PA rms uncertainty on PA
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 arcsec Rad Radius
9- 13 F5.2 mag Bmaj B magnitude along major axis
17- 21 F5.2 mag Bmin B magnitude along minor axis
25- 30 F6.4 --- Ell Ellipticity
33- 38 F6.4 --- e_Ell rms uncertainty on Ell
41- 47 F7.4 --- a4 a4 parameter (G1)
49- 54 F6.4 --- e_a4 rms uncertainty on a4
57- 63 F7.4 deg PA Position angle
65- 70 F6.4 deg e_PA rms uncertainty on PA
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Byte-by-byte Description of file: tableb?.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 arcsec Rad [-120/120] Radius
10- 17 F8.3 km/s Vel Velocity
19- 24 F6.3 km/s e_Vel rms uncertainty on Vel
27- 33 F7.3 km/s sigma Velocity dispersion
35- 41 F7.3 km/s e_sigma rms uncertainty on sigma
43- 48 F6.3 --- h3 Gauss-Hermite h3 parameter (1)
51- 55 F5.3 --- e_h3 rms uncertainty on h3
59- 64 F6.3 --- h4 Gauss-Hermite h4 parameter (2)
67- 71 F5.3 --- e_h4 rms uncertainty on h4
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Note (1): h3 measure asymmetric departures from the Gaussian.
Note (2): h4 measure symmetric departures from the Gaussian.
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Global notes:
Note (G1): a4 measures the fourth Fourier component of the intensity
variations along the best-fitting ellipse to an isophote. A positive
value of a4 indicates that the isophotes are discy, while a negative
value indicates that the isophotes are boxy.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-May-2006