J/A+A/459/391 Dynamics of NGC 4636 globular cluster system (Schuberth+, 2006)
Dynamics of the NGC 4636 globular cluster system.
An extremely dark matter dominated galaxy?
Schuberth Y., Richtler T., Dirsch B., Hilker M., Larsen S.S.,
Kissler-Patig M., Mebold U.
<Astron. Astrophys., 459, 391-406 (2006)>
=2006A&A...459..391S 2006A&A...459..391S
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Photometry ;
Radial velocities
Keywords: galaxies: elliptical and lenticular, cD -
galaxies: kinematics and dynamics - galaxies: individual: NGC 4636 -
galaxies: halos
Abstract:
We present the first dynamical study of the globular cluster system of
NGC 4636. It is the southernmost giant elliptical galaxy of the Virgo
cluster and is claimed to be extremely dark matter dominated,
according to X-ray observations. Globular clusters are used as
dynamical tracers to investigate, by stellar dynamical means, the dark
matter content of this galaxy. Several hundred medium resolution
spectra were acquired at the VLT with FORS 2/MXU. We obtained
velocities for 174 globular clusters in the radial range
0.90'<R<15.5', or 0.5-9Re in units of effective radius. Assuming a
distance of 15Mpc, the clusters are found at projected galactocentric
distances in the range 4 to 70kpc, the overwhelming majority within
30kpc. The measured line-of-sight velocity dispersions are compared to
Jeans-models.
Description:
The observations were carried out over four nights (May 7-10, 2002) at
the European Southern Observatory (ESO) Very Large Telescope (VLT)
facility on Cerro Paranal, Chile.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 66 174 Globular cluster data
tablea2.dat 66 175 Star data
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See also:
J/MNRAS/367/156 : C-T1 photometry in NGC 1374, 1379 and 1387 (Bassino+, 2006)
J/A+A/433/43 : NGC 4636 globular cluster system C-T1 phot. (Dirsch+, 2005)
J/A+A/443/413 : VIKs photometry of NGC 4365 globular clusters (Larsen+, 2005)
Byte-by-byte Description of file: tablea?.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- [SRD2006] Identification number, F.F NNN
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22 I1 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 30 F4.1 arcsec DEs Declination (J2000)
32- 38 F7.4 mag C-R ?=- C-R colour index (C filter at 391±110nm)
40- 44 F5.3 mag e_C-R ?=- rms uncertainty on C-R
46- 50 F5.2 mag Rmag ?=- R magnitude
52- 56 F5.3 mag e_Rmag ?=- rms uncertainty on Rmag
58- 62 I5 km/s Vel Radial Velocity
64- 66 I3 km/s e_Vel rms uncertainty on Vel
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-May-2007