J/MNRAS/452/2208 NGC 4473 globular clusters (Alabi+, 2015)
The SLUGGS survey: globular cluster kinematics in a 'double sigma' galaxy -
NGC 4473.
Alabi A.B., Foster C., Forbes D.A., Romanowsky A.J., Pastorello N.,
Brodie J.P., Spitler L.R., Strader J., Usher C.
<Mon. Not. R. Astron. Soc., 452, 2208-2219 (2015)>
=2015MNRAS.452.2208A 2015MNRAS.452.2208A (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Radial velocities ;
Photometry
Keywords: galaxies: evolution - galaxies: kinematics and dynamics -
galaxies: star - clusters: general
Abstract:
NGC 4473 is a so-called double sigma (2σ) galaxy, i.e. a galaxy
with rare, double peaks in its 2D stellar velocity dispersion. Here,
we present the globular cluster (GC) kinematics in NGC 4473 out to
∼10Re (effective radii) using data from combined Hubble Space
Telescope/Advanced Camera for Surveys and Subaru/Suprime-Cam imaging
and Keck/Deep Imaging Multi-Object Spectrograph. We find that the
2σ nature of NGC 4473 persists up to 3Re, though it becomes
misaligned to the photometric major axis. We also observe a
significant offset between the stellar and GC rotation amplitudes.
This offset can be understood as a co-addition of counter-rotating
stars producing little net stellar rotation. We identify a sharp
radial transition in the GC kinematics at ∼4Re suggesting a well
defined kinematically distinct halo. In the inner region (<4Re), the
blue GCs rotate along the photometric major axis, but in an opposite
direction to the galaxy stars and red GCs. In the outer region
(>4Re), the red GCs rotate in an opposite direction compared to the
inner region red GCs, along the photometric major axis, while the blue
GCs rotate along an axis intermediate between the major and minor
photometric axes. We also find a kinematically distinct population of
very red GCs in the inner region with elevated rotation amplitude and
velocity dispersion. The multiple kinematic components in NGC 4473
highlight the complex formation and evolutionary history of this
2σ galaxy, as well as a distinct transition between the inner
and outer components.
Description:
NGC 4473 was observed with Suprime-Cam on the Subaru telescope on the
night of 2010 November 4. The total exposure times were 688, 270 and
450 s with average seeing of 0.65, 0.65 and 0.67 arcsec in the g, r
and i bands, respectively.
We used the Deep Imaging Multi-Object Spectrograph (DEIMOS) on the
Keck II telescope to obtain spectra for objects that are probable GCs
from our photometric catalogue. The spectroscopic observations were
taken on the nights of 2011 March 30, 2012 February 19 and 2012
February 20.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 106 Spectroscopically confirmed globular clusters
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See also:
J/MNRAS/426/1475 : CaT in 903 globular clusters (Usher+, 2012)
J/MNRAS/428/389 : SLUGGS globular clusters in early-type galaxies (Pota+ 2013)
J/MNRAS/436/1172 : Globular Clusters of NGC 4278 in SLUGGS (Usher+, 2013)
J/AJ/148/32 : Globular cluster candidates in NGC 3115 (Jennings+, 2014)
J/MNRAS/450/1962 : M60 SLUGGS and Gemini/GMOS combined study (Pota+, 2015)
J/MNRAS/451/2625 : SLUGGS Globular Cluster CaT and [Z/H] (Pastorello+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- ID Globular cluster identification (NGC4473-GCNNN)
15- 23 F9.5 deg RAdeg Rigth ascension (J2000.0)
25- 32 F8.5 deg DEdeg Declination (J2000.0)
34- 37 I4 km/s HRV Measured heliocentric radial velocity
39- 40 I2 km/s e_HRV rms uncertainty on HRV
42- 47 F6.3 mag gmag Subaru g magnitude, corrected for Galactic
extinction
49- 53 F5.3 mag e_gmag rms uncertainty on gmag
55- 60 F6.3 mag rmag Subaru r magnitude, corrected for Galactic
extinction
62- 66 F5.3 mag e_rmag rms uncertainty on rmag
68- 73 F6.3 mag imag Subaru i magnitude, corrected for Galactic
extinction
75- 79 F5.3 mag e_imag rms uncertainty on imag
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Feb-2016