J/ApJ/830/126 The Carina project. X. Radial velocities (Fabrizio+, 2016)
The Carina project.
X. On the kinematics of old and intermediate-age stellar populations.
Fabrizio M., Bono G., Nonino M., Lokas E.L., Ferraro I., Iannicola G.,
Buonanno R., Cassisi S., Coppola G., Dall'Ora M., Gilmozzi R., Marconi M.,
Monelli M., Romaniello M., Stetson P.B., Thevenin F., Walker A.R.
<Astrophys. J., 830, 126-126 (2016)>
=2016ApJ...830..126F 2016ApJ...830..126F (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Radial velocities ; Photometry, UBVRI ;
Stars, horizontal branch ; Stars, giant
Keywords: galaxies: dwarf; galaxies: individual: Carina;
galaxies: kinematics and dynamics; galaxies: stellar content
Abstract:
We present new radial velocity (RV) measurements of old (horizontal
branch) and intermediate-age (red clump) stellar tracers in the Carina
dwarf spheroidal. They are based on more than 2200 low-resolution
spectra collected with VIMOS at Very Large Telescope (VLT). The
targets are faint (20≲V≲21.5mag), but the accuracy at the faintest
limit is ≤9km/s. These data were complemented with RV measurements
either based on spectra collected with FORS2 and FLAMES/GIRAFFE at VLT
or available in the literature. We ended up with a sample of 2748
stars and among them, 1389 are candidate Carina stars. We found that
the intermediate-age stellar component shows a well-defined rotational
pattern around the minor axis. The western and the eastern side of the
galaxy differ by +5 and -4km/s when compared with the main RV peak.
The old stellar component is characterized by a larger RV dispersion
and does not show evidence of the RV pattern. We compared the observed
RV distribution with N-body simulations for a former disky dwarf
galaxy orbiting a giant Milky Way-like galaxy. We rotated the
simulated galaxy by 60° with respect to the major axis, we kept
the observer on the orbital plane of the dwarf and extracted a sample
of stars similar to the observed one. Observed and predicted
Vrot/σ ratios across the central regions are in remarkable
agreement. This evidence indicates that Carina was a disky dwarf
galaxy that experienced several strong tidal interactions with the
Milky Way. Owing to these interactions, Carina transformed from a
disky to a prolate spheroid and the rotational velocity transformed
into random motions.
Description:
To constrain the Carina kinematical structure, we adopted data
collected at four spectrographs mounted at the Very Large Telescope
(VLT) of the European Southern Observatory (ESO). The spectral
resolution of data ranges from 600 to 40000, allowing us to obtain
accurate RVs up to the horizontal branch (HB) magnitude level
(V∼21.5mag).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 88 2748 Radial velocities of spectroscopic targets
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See also:
J/ApJ/814/71 : Carina project IX: UBVI of Carina variables (Coppola+, 2015)
J/A+A/580/A18 : Carina Project VIII. α-element abund. (Fabrizio+, 2015)
J/A+A/572/A10 : (BV) photometry in Carina dSph (de Boer+, 2014)
J/A+A/538/A100 : Abundances red giants in Carina dSph (Lemasle+, 2012)
J/ApJ/751/102 : Equivalent widths of 9 RGB in Carina dSph (Venn+, 2012)
J/PASP/124/519 : Iron abundances of red giants in Carina gal. (Fabrizio+, 2012)
J/AJ/137/3100 : Radial velocities of 4 dSph galaxies (Walker+, 2009)
J/AJ/135/1580 : Element abundances in ten red giants of Car dSph (Koch+, 2008)
J/ApJ/649/201 : Velocities & Washington photom. in Carina dSph (Munoz+, 2006)
J/AJ/130/2677 : Stars in the Carina dSph galaxy field (Majewski+, 2005)
J/AJ/126/197 : Carina project. I. Bright variable stars (Dall'Ora+, 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- Name [3145/162379] Star Name (1)
9- 16 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 25 F8.4 deg DEdeg Declination in decimal degrees (J2000)
27- 32 F6.3 mag Vmag [13.8/24.6] Literature V magnitude (1)
34- 38 F5.3 mag e_Vmag Uncertainty in Vmag (1)
40- 45 F6.3 mag Bmag [14.5/25]? Literature B magnitude (1)
47- 51 F5.3 mag e_Bmag ? Uncertainty in Bmag (1)
53- 58 F6.3 mag Imag [12.9/24]? Literature I magnitude (1)
60- 64 F5.3 mag e_Imag ? Uncertainty in Imag (1)
66- 71 F6.1 km/s RVel [-364/457] Mean Radial Velocity
73- 76 F4.1 km/s e_RVel [0/37] Uncertainty in RVel
78- 86 A9 --- Spec Adopted Spectrograph(s) (2)
88- 88 I1 --- Pop [0/4]? Stellar population flag (3)
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Note (1): Star names and photometry adopted from Bono+ 2010PASP..122..651B 2010PASP..122..651B;
Stetson+ 2011Msngr.144...32S 2011Msngr.144...32S
Note (2): Adopted spectrographs as follows:
1 = UVES (Ultraviolet and Visual Echelle Spectrographs;
high spectral resolution R∼40000);
2 = Gir-HR (FLAMES/GIRAFFE high resolution, R∼20000);
3 = Gir-LR (FLAMES/GIRAFFE medium resolution, R∼6500);
4 = FORS2 (FOcal Reducer/low dispersion Spectrograph 2;
medium-resolution (R∼2500))
5 = VIMOS (VIsible MultiObject Spectrograph;
low-resolution (R∼600))
6 = MMFS (Michigan/MIKE fiber system; collected RV measurements from
Walker+ (2007ApJ...667L..53W 2007ApJ...667L..53W); R∼20000-25000).
See section 2 for further details.
Note (3): Stellar population flags as follows:
0 = Field candidates;
1 = Old red giant branch (RGB) candidates;
2 = Intermediate RGB candidates;
3 = Horizontal Branch;
4 = Red Clump.
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History:
From electronic version of the journal
References:
Dall'ora et al. Paper I. 2003AJ....126..197D 2003AJ....126..197D Cat. J/AJ/126/197
Monelli et al. Paper II. 2003AJ....126..218M 2003AJ....126..218M
Fabrizio et al. Paper IV. 2011PASP..123..384F 2011PASP..123..384F
Fabrizio et al. Paper V. 2012PASP..124..519F 2012PASP..124..519F Cat. J/PASP/124/519
Coppola et al. Paper VI. 2013ApJ...775....6C 2013ApJ...775....6C
Monelli et al. Paper VII. 2014ApJ...796...90M 2014ApJ...796...90M
Fabrizio et al. Paper VIII. 2015A&A...580A..18F 2015A&A...580A..18F Cat. J/A+A/580/A18
Coppola et al. Paper IX. 2015ApJ...814...71C 2015ApJ...814...71C Cat. J/ApJ/814/71
Fabrizio et al. Paper X. 2016ApJ...830..126F 2016ApJ...830..126F This catalog
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Jan-2017