Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/732/108     Abundances of 92 giants in Plaut's window     (Johnson+, 2011)

Alpha enhancement and the metallicity distribution function of Plaut's window. Johnson C.I., Rich R.M., Fulbright J.P., Valenti E., McWilliam A. <Astrophys. J., 732, 108 (2011)> =2011ApJ...732..108J
ADC_Keywords: Abundances ; Stars, giant ; Milky Way ; Radial velocities Keywords: Galaxy: abundances - Galaxy: bulge - stars: abundances - stars: Population II Abstract: We present Fe, Si, and Ca abundances for 61 giants in Plaut's window (l=-1°, b=-8.5°) and Fe abundances for an additional 31 giants in a second, nearby field (l=0°, b=-8°) derived from high-resolution (R∼25000) spectra obtained with the Blanco 4m telescope and Hydra multifiber spectrograph. The median metallicity of red giant branch (RGB) stars in the Plaut's field is ∼0.4dex lower than those in Baade's window, and confirms the presence of an iron abundance gradient along the bulge minor axis. The full metallicity range of our (biased) RGB sample spans -1.5<[Fe/H]<+0.3, which is similar to that found in other bulge fields. We also derive a photometric metallicity distribution function for RGB stars in the (l=-1°, b=-8.5°) field and find very good agreement with the spectroscopic metallicity distribution. The radial velocity (RV) and dispersion data for the bulge RGB stars are in agreement with previous results of the Bulge Radial Velocity Assay survey, and we find evidence for a decreasing velocity dispersion with increasing [Fe/H]. The [α/Fe] enhancement in Plaut field stars is nearly identical to that observed in Baade's window, and suggests that an [α/Fe] gradient does not exist between b=-4° and -8°. Additionally, a subset of our sample (23 stars) appears to be foreground red clump stars that are very metal rich, exhibit small metallicity and RV dispersions, and are enhanced in α elements. While these stars likely belong to the Galactic inner disk population, they exhibit [α/Fe] ratios that are enhanced above the thin and thick disk. Description: The spectra for this project were obtained at CTIO using the Blanco 4m telescope and Hydra multifiber spectrograph. The observations covered two separate runs spanning 2006 May 27-28 and 2007 May 19-23, and targeted the approximate spectral regions of 6000-6250, 6150-6400, 6500-6800, and 7650-7950Å. A set of B, V, and I images for both bulge fields analyzed here spectroscopically were obtained at the Las Campanas Observatory in 2002 August. We used the optical imager mounted at the Swope 40 inch telescope. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 83 92 Program star parameters and results table2.dat 46 92 Random and systematic uncertainties
See also: VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/A+A/546/A57 : Structure and formation of the Bulge (Uttenthaler+, 2012) J/A+A/513/A35 : Abundances of Galactic red giants (Alves-Brito+, 2010) J/A+A/512/A41 : Abundances of microlensed stars in the Bulge (Bensby+, 2010) J/ApJ/691/1387 : Spectroscopy of the Galactic bar. I. (Rangwala+, 2009) J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE (Zoccali+, 2008) J/A+A/465/799 : Abundances of Galactic Bulge red giants (Lecureur+, 2007) J/AJ/134/1432 : Proper motions in Plaut's window (Vieira+, 2007) J/AJ/131/431 : Abundances of Galactic G dwarfs (Brewer+, 2006) J/ApJ/636/821 : Abundances of Baade's Window K giants (Fulbright+, 2006) J/MNRAS/367/1329 : Elemental abundances for 176 stars (Reddy+, 2006) J/A+A/433/185 : Abundance analysis of 102 F and G dwarfs (Bensby+, 2005) J/A+A/410/527 : Abundances in the Galactic disk (Bensby+, 2003) J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003) J/AJ/120/1841 : Abundances of Halo and Disk Stars (Fulbright 2000) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS 2MASS identification (HHMMSSss+DDMMSSs; J2000) 18- 23 F6.3 mag Vmag The V band magnitude (1m Swope Telescope) 25- 30 F6.3 mag Jmag 2MASS J band magnitude 32- 37 F6.3 mag Ksmag 2MASS Ks band magnitude 39- 42 I4 K Teff Effective temperature 44- 47 F4.2 [cm/s2] log(g) Log of the surface gravity 49- 53 F5.2 [Sun] [Fe/H] Metallicity 55- 58 F4.2 km/s Vt Turbulent velocity 60- 64 F5.2 [Sun] [Si/Fe] ? Log of the Si/Fe abundance ratio 66- 70 F5.2 [Sun] [Ca/Fe] ? Log of the Ca/Fe abundance ratio 72- 75 I4 km/s HRV Heliocentric radial velocity 77- 83 A7 --- Note The RGB/Field information (1)
Note (1): Note as follows: RGB = probable RGB member; Clump = probable red clump member; 1 = Field 1 (l=-1 degrees, b=-8.5 degrees); 2 = Field 2 (l=0 degrees, b=-8 degrees)
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 2MASS 2MASS identification (HHMMSSss+DDMMSSs; J2000) 18- 21 F4.2 [Sun] re.Fe Random uncertainty in log Fe number abundance 23- 26 F4.2 [Sun] sy.Fe Systematic uncertainty in log Fe number abundance 28- 31 F4.2 [Sun] re.Si ? Random uncertainty in log Si number abundance 33- 36 F4.2 [Sun] sy.Si ? Systematic uncertainty in log Si number abundance 38- 41 F4.2 [Sun] re.Ca ? Random uncertainty in log Ca number abundance 43- 46 F4.2 [Sun] sy.Ca ? Systematic uncertainty in log Ca number abundance
History: From electronic version of the journal Reference: Johnson et al. Paper II. 2012ApJ...749..175J Cat. J/ApJ/749/175
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 05-Nov-2012
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service