J/ApJ/821/L25 Bulge RR Lyrae Radial Velocity Assay (BRAVA-RR) (Kunder+, 2016)
Before the bar: kinematic detection of a spheroidal metal-poor bulge component.
Kunder A., Rich R.M., Koch A., Storm J., Nataf D.M., De Propris R.,
Walker A.R., Bono G., Johnson C.I., Shen J., Li Z.-Y.
<Astrophys. J., 821, L25-L25 (2016)>
=2016ApJ...821L..25K 2016ApJ...821L..25K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Radial velocities ; Photometry, VRI ; Milky Way
Keywords: Galaxy: bulge; Galaxy: evolution; Galaxy: formation; Galaxy: halo;
Galaxy: kinematics and dynamics; Galaxy: structure
Abstract:
We present 947 radial velocities of RR Lyrae variable stars in four
fields located toward the Galactic bulge, observed within the data
from the ongoing Bulge RR Lyrae Radial Velocity Assay (BRAVA-RR). We
show that these RR Lyrae stars (RRLs) exhibit hot kinematics and null
or negligible rotation and are therefore members of a separate
population from the bar/pseudobulge that currently dominates the mass
and luminosity of the inner Galaxy. Our RRLs predate these structures
and have metallicities, kinematics, and spatial distribution that are
consistent with a "classical" bulge, although we cannot yet completely
rule out the possibility that they are the metal-poor tail of a more
metal-rich ([Fe/H]~-1dex) halo-bulge population.
Description:
Observations were performed using the AAOmega multi-fiber spectrograph
on the Anglo-Australian Telescope (AAT) on 2013 May, 2013 June, 2014
June, and 2015 August, in dual beam mode centered on 8600Å, with
the 580 V and 1700D gratings to probe the Calcium Triplet (NOAO
PropID: 2014A-0143; PI: A. Kunder and NOAO PropID: 2015B-071; PI: A.
Kunder). This covers the wavelength regime of about 8300-8800Å at a
resolution of R∼10000. Exposure times were between one to two hours,
and in general, there are between 2 and 5 epochs for each RRL.
The 2013 observations were carried out in conjunction with a bulge
survey designed for detached red giant eclipsing binary twins (AAT:
2013A-05; PI: D. Nataf). Extra fibers were available and resourcefully
allocated to 95 bulge RRLs, and these RRLs have up to 15 epochs of
observations.
The OGLE-III catalog of RRLs (Pietrukowicz et al. 2012ApJ...750..169P 2012ApJ...750..169P)
was used to select the targets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 74 947 Radial velocities of BRAVA-RR stars
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See also:
III/176 : RR Lyrae Metallicities (Layden 1994)
J/A+A/587/A124 : Metal-poor stars towards the Galactic bulge (Koch+, 2016)
J/MNRAS/453/2022 : Double-mode radial-non-radial RR Lyrae stars (Netzel+, 2015)
J/MNRAS/441/715 : Mid-infrared study of RR Lyrae stars (Gavrilchenko+, 2014)
J/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2014)
J/A+A/562/A66 : GIRAFFE Inner Bulge Survey (GIBS). I. (Zoccali+, 2014)
J/AJ/144/114 : Radial velocities of 6 field RR Lyrae (Sesar+, 2012)
J/AJ/143/57 : RVs from the spectroscopic survey BRAVA (II) (Kunder+, 2012)
J/AcA/61/1 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2011)
J/ApJ/733/L47 : Galaxy bulge types within 11Mpc (Fisher+, 2011)
J/ApJ/732/108 : Abundances of 92 giants in Plaut's window (Johnson+, 2011)
J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE spectra (Zoccali+, 2008)
J/AJ/136/2441 : Metallicity of RR0 Lyrae in the galactic bulge (Kunder+, 2008)
J/AJ/135/631 : Reddenings for the MACHO bulge RR0 Lyrae stars (Kunder+, 2008)
J/ApJ/651/197 : OGLE fundamental-mode RR Lyrae in Bulge (Collinge+, 2006)
J/MNRAS/348/1439 : OGLE II Galactic center proper motions (Sumi+, 2004)
J/AJ/119/2866 : Proper motions of metal-poor stars (Beers+, 2000)
J/AcA/48/113 : OGLE RR Lyrae VI photometry (Udalski, 1998)
J/AJ/108/1016 : Kinematics of local RR lyrae stars. I. (Layden, 1994)
J/ApJS/61/667 : Kinematics of Galactic old population (Norris 1986)
http://ogle.astrouw.edu.pl/ : OGLE home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I05 --- OGLE [6032/35208] OGLE identifier (1)
7- 8 I2 h RAh [17/18] OGLE Hour of Right Ascension (J2000)
10- 11 I2 min RAm OGLE Minute of Right Ascension (J2000)
13- 17 F5.2 s RAs OGLE Second of Right Ascension (J2000)
19 A1 --- DE- [-] Sign of the OGLE Declination (J2000)
20- 21 I2 deg DEd [27/35] OGLE Degree of Declination (J2000)
23- 24 I2 arcmin DEm OGLE Arcminute of Declination (J2000)
26- 29 F4.1 arcsec DEs OGLE Arcsecond of Declination (J2000)
31- 34 I4 km/s HRV [-508/434] Time averaged heliocentric
radial velocity
35 A1 --- u_HRV [:] Uncertainty flag on HRV
37- 38 I2 --- o_HRV [1/17] Number of epochs used for HRV
40- 49 F10.8 d Period [0.3/1] OGLE period
51- 56 F6.3 mag Vmag [15.2/]?=99.999 OGLE V band magnitude
58- 63 F6.3 mag Imag [14.4/17.7] OGLE I band magnitude
65- 68 F4.2 mag Iamp [0.08/0.9] OGLE I-band amplitude
70- 74 F5.2 [-] [Fe/H] [-2.4/78.7] Photometric metallicity (2)
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Note (1): in Simbad; see Soszynski+, 2014, J/AcA/64/177
Note (2): From the OGLE I band light curve.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Jul-2016