The AMBRE project: The thick thin disk and thin thick disk of the Milky Way

被引：81

作者：

Hayden, M. R. ^{[1
]}

Recio-Blanco, A. ^{[1
]}

de laverny, P. ^{[1
]}

Mikolaitis, S. ^{[2
]}

Worley, C. C. ^{[3
]}

机构：

[1] Univ Nice Sophia Antipolis, Lab Lagrange, UMR 7293, CNRS,Observ Cote dAzur, BP 4229, F-06304 Nice 4, France

[2] Vilnius Univ, Inst Theoret Phys & Astron, Sauletekio Al 3, LT-10257 Vilnius, Lithuania

[3] Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England

来源：

ASTRONOMY & ASTROPHYSICS | 2017年 / 608卷

关键词：

Galaxy: disk; Galaxy: structure; Galaxy: evolution; Galaxy: abundances; Galaxy: stellar content; GALACTIC THICK; FAINT STARS; STELLAR; ABUNDANCES;

D O I：

10.1051/0004-6361/201731494

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We analyze 494 main sequence turnoff and subgiant stars from the AMBRE:HARPS survey. These stars have accurate astrometric information from Gaia DR1, providing reliable age estimates with relative uncertainties of +/- 1 or 2 Gyr and allowing precise orbital determinations. The sample is split based on chemistry into a low-[Mg/Fe] sequence, which are often identified as thin disk stellar populations, and high-[Mg/Fe] sequence, which are often associated with thick disk stellar populations. We find that the high[Mg/Fe] chemical sequence has extended star formation for several Gyr and is coeval with the oldest stars of the low-[Mg/Fe] chemical sequence: both the low-and high-[Mg/Fe] sequences were forming stars at the same time. We find that the high-[Mg/Fe] stellar populations are only vertically extended for the oldest, most-metal poor and highest [Mg/Fe] stars. When comparing vertical velocity dispersion for the low-and high-[Mg/Fe] sequences, the high-[Mg/Fe] sequence has lower vertical velocity dispersion than the low-[Mg/Fe] sequence for stars of similar age. This means that identifying either group as thin or thick disk based on chemistry is misleading. The stars belonging to the high-[Mg/Fe] sequence have perigalacticons that originate in the inner disk, while the perigalacticons of stars on the low-[Mg/Fe] sequence are generally around the solar neighborhood. From the orbital properties of the stars, the high-[Mg/Fe] and low-[Mg/Fe] sequences are most likely a reflection of the chemical enrichment history of the inner and outer disk populations, respectively; radial mixing causes both populations to be observed in situ at the solar position. Based on these results, we emphasize that it is important to be clear in defining what populations are being referenced when using the terms thin and thick disk, and that ideally the term thick disk should be reserved for purely geometric definitions to avoid confusion and be consistent with definitions in external galaxies.

引用

页数：5

共 40 条

[11] The AMBRE project: Parameterisation of FGK-type stars from the ESO:HARPS archived spectra [J].

De Pascale, M. ;

Worley, C. C. ;

de Laverny, P. ;

Recio-Blanco, A. ;

Hill, V. ;

Bijaoui, A. .

ASTRONOMY & ASTROPHYSICS, 2014, 570

[12]

Dotter A., 2008, APJS, V178

[13]

EDVARDSSON B, 1993, ASTRON ASTROPHYS, V275, P101

[14]

Fuhrmann K, 1998, ASTRON ASTROPHYS, V338, P161

[15] NEW LIGHT ON FAINT STARS .3. GALACTIC STRUCTURE TOWARDS THE SOUTH-POLE AND THE GALACTIC THICK DISK [J].

GILMORE, G ;

REID, N .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1983, 202 (03) :1025-1047

[16] Simulating from very deep to very shallow photometric surveys with the TRILEGAL code [J].

Girardi, L ;

Groenewegen, MAT ;

Hatziminaoglou, E ;

da Costa, L .

ASTRONOMY & ASTROPHYSICS, 2005, 436 (03) :895-915

[17]

GUIGLION G, 2015, A A, V583

[18] The Gaia-ESO Survey: Churning through the Milky Way [J].

Hayden, M. R. ;

Recio-Blanco, A. ;

de Laverny, P. ;

Mikolaitis, S. ;

Guiglion, G. ;

Hill, V. ;

Gilmore, G. ;

Randich, S. ;

Bayo, A. ;

Bensby, T. ;

Bergemann, M. ;

Bragaglia, A. ;

Casey, A. ;

Costado, M. ;

Feltzing, S. ;

Franciosini, E. ;

Hourihane, A. ;

Jofre, P. ;

Koposov, S. ;

Kordopatis, G. ;

Lanzafame, A. ;

Lardo, C. ;

Lewis, J. ;

Lind, K. ;

Magrini, L. ;

Monaco, L. ;

Morbidelli, L. ;

Pancino, E. ;

Sacco, G. ;

Stonkute, E. ;

Worley, C. C. ;

Zwitter, T. .

ASTRONOMY & ASTROPHYSICS, 2018, 609

[19] CHEMICAL CARTOGRAPHY WITH APOGEE: METALLICITY DISTRIBUTION FUNCTIONS AND THE CHEMICAL STRUCTURE OF THE MILKY WAY DISK [J].

Hayden, Michael R. ;

Bovy, Jo ;

Holtzman, Jon A. ;

Nidever, David L. ;

Bird, Jonathan C. ;

Weinberg, David H. ;

Andrews, Brett H. ;

Majewski, Steven R. ;

Allende Prieto, Carlos ;

Anders, Friedrich ;

Beers, Timothy C. ;

Bizyaev, Dmitry ;

Chiappini, Cristina ;

Cunha, Katia ;

Frinchaboy, Peter ;

Garcia-Hernandez, D. A. ;

Garcia Perez, Ana E. ;

Girardi, Leo ;

Harding, Paul ;

Hearty, Fred R. ;

Johnson, Jennifer A. ;

Meszaros, Szabolcs ;

Minchev, Ivan ;

O'Connell, Robert ;

Pan, Kaike ;

Robin, Annie C. ;

Schiavon, Ricardo P. ;

Schneider, Donald P. ;

Schultheis, Mathias ;

Shetrone, Matthew ;

Skrutskie, Michael ;

Steinmetz, Matthias ;

Smith, Verne ;

Wilson, John C. ;

Zamora, Olga ;

Zasowski, Gail .

ASTROPHYSICAL JOURNAL, 2015, 808 (02)

[20] CHEMICAL CARTOGRAPHY WITH APOGEE: LARGE-SCALE MEAN METALLICITY MAPS OF THE MILKY WAY DISK [J].

Hayden, Michael R. ;

Holtzman, Jon A. ;

Bovy, Jo ;

Majewski, Steven R. ;

Johnson, Jennifer A. ;

Allende Prieto, Carlos ;

Beers, Timothy C. ;

Cunha, Katia ;

Frinchaboy, Peter M. ;

Perez, Ana E. Garcia ;

Girardi, Leo ;

Hearty, Fred R. ;

Lee, Young Sun ;

Nidever, David ;

Schiavon, Ricardo P. ;

Schlesinger, Katharine J. ;

Schneider, Donald P. ;

Schultheis, Mathias ;

Shetrone, Matthew ;

Smith, Verne V. ;

Zasowski, Gail ;

Bizyaev, Dmitry ;

Feuillet, Diane ;

Hasselquist, Sten ;

Kinemuchi, Karen ;

Malanushenko, Elena ;

Malanushenko, Viktor ;

O'Connell, Robert ;

Pan, Kaike ;

Stassun, Keivan .

ASTRONOMICAL JOURNAL, 2014, 147 (05)

← 1 2 3 4 →