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Baade's window and APOGEE : Metallicities, ages, and chemical abundances

Schultheis, M.; Rojas-Arriagada, A.; García Pérez, A. E.; Jönsson, H. LU ; Hayden, M.; Nandakumar, G. LU ; Cunha, K.; Allende Prieto, C.; Holtzman, J. A. LU and Beers, T. C., et al. (2017) In Astronomy and Astrophysics 600.
Abstract

Context. Baade's window (BW) is one of the most observed Galactic bulge fields in terms of chemical abundances. Owing to its low and homogeneous interstellar absorption it is considered the perfect calibration field for Galactic bulge studies. Aims. In the era of large spectroscopic surveys, calibration fields such as BW are necessary for cross calibrating the stellar parameters and individual abundances of the APOGEE survey. Methods. We use the APOGEE BW stars to derive the metallicity distribution function (MDF) and individual abundances for α-and iron-peak elements of the APOGEE ASPCAP pipeline (DR13), as well as the age distribution for stars in BW. Results. We determine the MDF of APOGEE stars in BW and find a remarkable agreement... (More)

Context. Baade's window (BW) is one of the most observed Galactic bulge fields in terms of chemical abundances. Owing to its low and homogeneous interstellar absorption it is considered the perfect calibration field for Galactic bulge studies. Aims. In the era of large spectroscopic surveys, calibration fields such as BW are necessary for cross calibrating the stellar parameters and individual abundances of the APOGEE survey. Methods. We use the APOGEE BW stars to derive the metallicity distribution function (MDF) and individual abundances for α-and iron-peak elements of the APOGEE ASPCAP pipeline (DR13), as well as the age distribution for stars in BW. Results. We determine the MDF of APOGEE stars in BW and find a remarkable agreement with that of the Gaia-ESO survey (GES). Both exhibit a clear bimodal distribution. We also find that the Mg-metallicity planes of the two surveys agree well, except for the metal-rich part ([Fe/H] > 0.1), where APOGEE finds systematically higher Mg abundances with respect to the GES. The ages based on the [C/N] ratio reveal a bimodal age distribution, with a major old population at ~ 10 Gyr, with a decreasing tail towards younger stars. A comparison of stellar parameters determined by APOGEE and those determined by other sources reveals detectable systematic offsets, in particular for spectroscopic surface gravity estimates. In general, we find a good agreement between individual abundances of O, Na, Mg, Al, Si, K, Ca, Cr, Mn, Co, and Ni from APOGEE with that of literature values. Conclusions. We have shown that in general APOGEE data show a good agreement in terms of MDF and individual chemical abundances with respect to literature works. Using the [C/N] ratio we found a significant fraction of young stars in BW.

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published
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keywords
Galaxy: bulge, Galaxy: stellar content, Infrared: stars, Stars: abundances, Stars: fundamental parameters
in
Astronomy and Astrophysics
volume
600
publisher
EDP Sciences
external identifiers
  • scopus:85016164325
ISSN
0004-6361
DOI
10.1051/0004-6361/201630154
language
English
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no
id
64070f02-9007-4f4e-b176-060534280041
date added to LUP
2019-05-06 11:46:56
date last changed
2019-08-14 04:35:58
@article{64070f02-9007-4f4e-b176-060534280041,
  abstract     = {<p>Context. Baade's window (BW) is one of the most observed Galactic bulge fields in terms of chemical abundances. Owing to its low and homogeneous interstellar absorption it is considered the perfect calibration field for Galactic bulge studies. Aims. In the era of large spectroscopic surveys, calibration fields such as BW are necessary for cross calibrating the stellar parameters and individual abundances of the APOGEE survey. Methods. We use the APOGEE BW stars to derive the metallicity distribution function (MDF) and individual abundances for α-and iron-peak elements of the APOGEE ASPCAP pipeline (DR13), as well as the age distribution for stars in BW. Results. We determine the MDF of APOGEE stars in BW and find a remarkable agreement with that of the Gaia-ESO survey (GES). Both exhibit a clear bimodal distribution. We also find that the Mg-metallicity planes of the two surveys agree well, except for the metal-rich part ([Fe/H] &gt; 0.1), where APOGEE finds systematically higher Mg abundances with respect to the GES. The ages based on the [C/N] ratio reveal a bimodal age distribution, with a major old population at ~ 10 Gyr, with a decreasing tail towards younger stars. A comparison of stellar parameters determined by APOGEE and those determined by other sources reveals detectable systematic offsets, in particular for spectroscopic surface gravity estimates. In general, we find a good agreement between individual abundances of O, Na, Mg, Al, Si, K, Ca, Cr, Mn, Co, and Ni from APOGEE with that of literature values. Conclusions. We have shown that in general APOGEE data show a good agreement in terms of MDF and individual chemical abundances with respect to literature works. Using the [C/N] ratio we found a significant fraction of young stars in BW.</p>},
  articleno    = {A14},
  author       = {Schultheis, M. and Rojas-Arriagada, A. and García Pérez, A. E. and Jönsson, H. and Hayden, M. and Nandakumar, G. and Cunha, K. and Allende Prieto, C. and Holtzman, J. A. and Beers, T. C. and Bizyaev, D. and Brinkmann, J. and Carrera, R. and Cohen, R. E. and Geisler, D. and Hearty, F. R. and Fernandez-Tricado, J. G. and Maraston, C. and Minnitti, D. and Nitschelm, C. and Roman-Lopes, A. and Schneider, D. P. and Tang, B. and Villanova, S. and Zasowski, G. and Majewski, S. R.},
  issn         = {0004-6361},
  keyword      = {Galaxy: bulge,Galaxy: stellar content,Infrared: stars,Stars: abundances,Stars: fundamental parameters},
  language     = {eng},
  month        = {04},
  publisher    = {EDP Sciences},
  series       = {Astronomy and Astrophysics},
  title        = {Baade's window and APOGEE : Metallicities, ages, and chemical abundances},
  url          = {http://dx.doi.org/10.1051/0004-6361/201630154},
  volume       = {600},
  year         = {2017},
}