CHEMICAL CARTOGRAPHY WITH APOGEE: METALLICITY DISTRIBUTION FUNCTIONS AND THE CHEMICAL STRUCTURE OF THE MILKY WAY DISK

Using a sample of 69,919 red giants from the SDSS-III/APOGEE Data Release 12, we measure the distribution of stars in the [/Fe] versus [Fe/H] plane and the metallicity distribution functions (MDFs) across an unprecedented volume of the Milky Way disk, with radius 3 < R < 15 kpc and height kpc. Stars in the inner disk (R < 5 kpc) lie along a single track in [/Fe] versus [Fe/H], starting with -enhanced, metal-poor stars and ending at [/Fe] ∼ 0 and [Fe/H] ∼ +0.4. At larger radii we find two distinct sequences in [/Fe] versus [Fe/H] space, with a roughly solar- sequence that spans a decade in metallicity and a high- sequence that merges with the low- sequence at super-solar [Fe/H]. The location of the high- sequence is nearly constant across the disk.

[1]  W. M. Wood-Vasey,et al.  SDSS-III: MASSIVE SPECTROSCOPIC SURVEYS OF THE DISTANT UNIVERSE, THE MILKY WAY, AND EXTRA-SOLAR PLANETARY SYSTEMS , 2011, 1101.1529.

[2]  Walter A. Siegmund,et al.  The 2.5 m Telescope of the Sloan Digital Sky Survey , 2006, astro-ph/0602326.

[3]  D. A. García-Hernández,et al.  TRACING CHEMICAL EVOLUTION OVER THE EXTENT OF THE MILKY WAY'S DISK WITH APOGEE RED CLUMP STARS , 2014, 1409.3566.

[4]  C. Prieto,et al.  CALIBRATIONS OF ATMOSPHERIC PARAMETERS OBTAINED FROM THE FIRST YEAR OF SDSS-III APOGEE OBSERVATIONS , 2013, 1308.6617.

[5]  James Binney,et al.  Stellar distances from spectroscopic observations: a new technique , 2010, 1004.4367.

[6]  F. Castelli,et al.  NEW H-BAND STELLAR SPECTRAL LIBRARIES FOR THE SDSS-III/APOGEE SURVEY , 2015, 1502.05237.

[7]  R. Indebetouw,et al.  The Spitzer/GLIMPSE Surveys: A New View of the Milky Way , 2009 .

[8]  C. Chiappini,et al.  Chemodynamical evolution of the Milky Way disk - I. The solar vicinity , 2012, 1208.1506.

[9]  M. Lehnert,et al.  The age structure of stellar populations in the solar vicinity Clues of a two-phase formation history of the Milky Way disk , 2013, 1305.4663.

[10]  The Galactic Thick Disk Stellar Abundances , 2000, astro-ph/0008075.

[11]  Annie C. Robin,et al.  ABUNDANCES, STELLAR PARAMETERS, AND SPECTRA FROM THE SDSS-III/APOGEE SURVEY , 2015, 1501.04110.

[12]  Martin G. Cohen,et al.  THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE): MISSION DESCRIPTION AND INITIAL ON-ORBIT PERFORMANCE , 2010, 1008.0031.

[13]  B. E. Patchett,et al.  Metal Abundances in Nearby Stars and the Chemical History of the Solar Neighbourhood , 1975 .

[14]  Thomas Bensby,et al.  Elemental abundance trends in the Galactic thin and thick disks as traced by nearby F and G dwarf stars , 2003 .

[15]  T. Beers,et al.  THE METALLICITY DISTRIBUTION FUNCTIONS OF SEGUE G AND K DWARFS: CONSTRAINTS FOR DISK CHEMICAL EVOLUTION AND FORMATION , 2011, 1112.2214.

[16]  J. Bird,et al.  Radial mixing in galactic discs: the effects of disc structure and satellite bombardment , 2011, 1104.0933.

[17]  R. Indebetouw,et al.  GLIMPSE. I. An SIRTF Legacy Project to Map the Inner Galaxy , 2003, astro-ph/0306274.

[18]  C. Chiappini,et al.  Abundance Gradients and the Formation of the Milky Way , 2001, astro-ph/0102134.

[19]  S. Ortolani,et al.  The metal content of bulge field stars from FLAMES-GIRAFFE spectra - I. Stellar parameters and iron abundances , 2008, 0805.1218.

[20]  USA,et al.  alpha-, r-, and s-process element trends in the Galactic thin and thick disks , 2004, astro-ph/0412132.

[21]  J. Navarro,et al.  THE EFFECT OF RADIAL MIGRATION ON GALACTIC DISKS , 2014, 1405.3317.

[22]  V. Adibekyan,et al.  Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program - Galactic stellar populations and planets , 2012, 1207.2388.

[23]  Scott W. Fleming,et al.  THE DATA REDUCTION PIPELINE FOR THE APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT , 2015, 1501.03742.

[24]  David W. Hogg,et al.  THE MILKY WAY'S CIRCULAR-VELOCITY CURVE BETWEEN 4 AND 14 kpc FROM APOGEE DATA , 2012, 1209.0759.

[25]  R. Larson.  Models for the Formation of Disc Galaxies , 1976 .

[26]  V. Adibekyan,et al.  A new α-enhanced super-solar metallicity population , 2011, 1111.4936.

[27]  D. Schneider,et al.  Spectro-photometric distances to stars: a general-purpose Bayesian approach , 2015, 1501.05500.

[28]  E. Athanassoula,et al.  Evolution of the Milky Way with radial motions of stars and gas - I. The solar neighbourhood and the thin and thick disks , 2014, 1412.0585.

[29]  L. Casagrande,et al.  New constraints on the chemical evolution of the solar neighbourhood and galactic disc(s) - improved astrophysical parameters for the Geneva-Copenhagen Survey , 2011, 1103.4651.

[30]  J. Sellwood,et al.  Radial migration in galactic thick discs , 2012, 1202.1418.

[31]  E. Hatziminaoglou,et al.  Star counts in the Galaxy - Simulating from very deep to very shallow photometric surveys with the TRILEGAL code , 2005, astro-ph/0504047.

[32]  U. Munari,et al.  The radial velocity experiment (RAVE): First data release , 2006 .

[33]  J. Brinkmann,et al.  Chemodynamics of the Milky Way - I. The first year of APOGEE data , 2013, 1311.4549.

[34]  C. Chiappini,et al.  Chemodynamical evolution of the Milky Way disk II: Variations with Galactic radius and height above the disk plane , 2014, 1401.5796.

[35]  A. Helmi,et al.  Galactic kinematics and dynamics from radial velocity experiment stars , 2014 .

[36]  M. Martig,et al.  ON THE FORMATION OF GALACTIC THICK DISKS , 2015, 1502.06606.

[37]  David W. Hogg,et al.  THE MILKY WAY HAS NO DISTINCT THICK DISK , 2011, 1111.6585.

[38]  J. Bird,et al.  INSIDE OUT AND UPSIDE DOWN: TRACING THE ASSEMBLY OF A SIMULATED DISK GALAXY USING MONO-AGE STELLAR POPULATIONS , 2013, 1301.0620.

[39]  D. A. García-Hernández,et al.  THE TENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY: FIRST SPECTROSCOPIC DATA FROM THE SDSS-III APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT , 2013, 1307.7735.

[40]  H. Rix,et al.  THE SPATIAL STRUCTURE OF MONO-ABUNDANCE SUB-POPULATIONS OF THE MILKY WAY DISK , 2011, 1111.1724.

[41]  James Binney,et al.  Chemical evolution with radial mixing , 2008, 0809.3006.

[42]  Gerard Gilmore,et al.  New light on faint stars – III. Galactic structure towards the South Pole and the Galactic thick disc , 1983 .

[43]  C. Allende Prieto,et al.  TARGET SELECTION FOR THE APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT (APOGEE) , 2013 .

[44]  J. Binney.  Radial mixing in galactic discs , 2002, astro-ph/0203510.

[45]  Lars Koesterke,et al.  THE APOGEE RED-CLUMP CATALOG: PRECISE DISTANCES, VELOCITIES, AND HIGH-RESOLUTION ELEMENTAL ABUNDANCES OVER A LARGE AREA OF THE MILKY WAY'S DISK , 2014, 1405.1032.

[46]  Walter Dehnen,et al.  Simple Distribution Functions for Stellar Disks , 1999, astro-ph/9906082.

[47]  Ž. Ivezić,et al.  THE GENESIS OF THE MILKY WAY'S THICK DISK VIA STELLAR MIGRATION , 2010, 1009.5997.

[48]  M. Bershady,et al.  SparsePak: A Formatted Fiber Field Unit for the WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration , 2004, astro-ph/0403456.

[49]  D. Minniti,et al.  Reddening and metallicity maps of the Milky Way bulge from VVV and 2MASS - III. The first global photometric metallicity map of the Galactic bulge , 2013, 1302.0243.

[50]  Walter J. Maciel,et al.  The metallicity distribution of G dwarfs in the solar neighbourhood , 1996 .

[51]  C. Chiappini,et al.  Stellar diffusion in barred spiral galaxies , 2011, 1108.5631.

[52]  M. Schmidt.  The Rate of Star Formation. II. The Rate of Formation of Stars of Different Mass. , 1963 .

[53]  C. Prieto,et al.  OXYGEN ABUNDANCES IN NEARBY FGK STARS AND THE GALACTIC CHEMICAL EVOLUTION OF THE LOCAL DISK AND HALO , 2013, 1301.1582.

[54]  A UNIVERSAL, LOCAL STAR FORMATION LAW IN GALACTIC CLOUDS, NEARBY GALAXIES, HIGH-REDSHIFT DISKS, AND STARBURSTS , 2011, 1109.4150.

[55]  David W. Hogg,et al.  THE VERTICAL MOTIONS OF MONO-ABUNDANCE SUB-POPULATIONS IN THE MILKY WAY DISK , 2012, 1202.2819.

[56]  B. Yanny,et al.  A Spectroscopic Study of the Ancient Milky Way: F- and G-Type Stars in the Third Data Release of the Sloan Digital Sky Survey , 2005, astro-ph/0509812.

[57]  J. Brinkmann,et al.  THE VERTICAL METALLICITY GRADIENT OF THE MILKY WAY DISK: TRANSITIONS IN [α/Fe] POPULATIONS , 2014, 1405.6724.

[58]  Steven R. Majewski,et al.  LIFTING THE DUSTY VEIL WITH NEAR- AND MID-INFRARED PHOTOMETRY. I. DESCRIPTION AND APPLICATIONS OF THE RAYLEIGH–JEANS COLOR EXCESS METHOD , 2011, 1106.2542.

[59]  M. Martig,et al.  THE THICK DISKS OF SPIRAL GALAXIES AS RELICS FROM GAS-RICH, TURBULENT, CLUMPY DISKS AT HIGH REDSHIFT , 2009, 0910.3677.

[60]  J. Audouze.  Nucleosynthesis and Chemical Evolution of Galaxies , 1983 .

[61]  Hilo,et al.  THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III , 2015, 1501.00963.

[62]  Hans-Walter Rix,et al.  The Milky Way’s stellar disk , 2013, 1301.3168.

[63]  T. Beers,et al.  CHEMICAL CARTOGRAPHY WITH APOGEE: LARGE-SCALE MEAN METALLICITY MAPS OF THE MILKY WAY DISK , 2013, 1311.4569.

[64]  Ž. Ivezić,et al.  FORMATION AND EVOLUTION OF THE DISK SYSTEM OF THE MILKY WAY: [α/Fe] RATIOS AND KINEMATICS OF THE SEGUE G-DWARF SAMPLE , 2011, 1104.3114.

[65]  R. Larson.  Early star formation and the evolution of the stellar initial mass function in galaxies , 1998, astro-ph/9808145.

[66]  M. Lehnert,et al.  Reconstructing the star formation history of the Milky Way disc(s) from chemical abundances , 2014, 1410.3829.

[67]  The Geneva-Copenhagen survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk , 2007, 0707.1891.

[68]  D. O. Astronomy,et al.  Exploring the Milky Way stellar disk - A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood , 2013, 1309.2631.

[69]  Bangalore,et al.  Elemental abundance survey of the Galactic thick disc , 2005, astro-ph/0512505.

[70]  Naohito Nakasato,et al.  CHEMODYNAMICAL SIMULATIONS OF THE MILKY WAY GALAXY , 2008, Proceedings of the International Astronomical Union.

[71]  Judy Y. Cheng,et al.  A SHORT SCALE LENGTH FOR THE α-ENHANCED THICK DISK OF THE MILKY WAY: EVIDENCE FROM LOW-LATITUDE SEGUE DATA , 2012, 1204.5179.

[72]  F. Combes,et al.  Quantifying stellar radial migration in an N-body simulation: blurring, churning, and the outer regions of galaxy discs , 2015, 1501.00664.

[73]  C. Chiappini,et al.  The Chemical Evolution of the Galaxy: The Two-Infall Model , 1996, astro-ph/9609199.

[74]  J. Mel'endez,et al.  A FIRST CONSTRAINT ON THE THICK DISK SCALE LENGTH: DIFFERENTIAL RADIAL ABUNDANCES IN K GIANTS AT GALACTOCENTRIC RADII 4, 8, AND 12 kpc , 2011, 1106.1914.

[75]  U. Munari,et al.  Distance determination for RAVE stars using stellar models - III. The nature of the RAVE survey and Milky Way chemistry , 2011 .

[76]  L. Girardi,et al.  Population effects on the red giant clump absolute magnitude, and distance determinations to nearby galaxies , 2001 .

[77]  S. van den Bergh,et al.  The frequency of stars with different metal abundances. , 1962 .

[78]  Judy Y. Cheng,et al.  METALLICITY GRADIENTS IN THE MILKY WAY DISK AS OBSERVED BY THE SEGUE SURVEY , 2011, 1110.5933.

[79]  Sergey E. Koposov,et al.  The Gaia-ESO Survey : radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk , 2014, 1401.4437.

[80]  M. Skrutskie,et al.  The Two Micron All Sky Survey (2MASS) , 2006 .

[81]  Mamoru Doi,et al.  The Milky Way Tomography with SDSS. II. Stellar Metallicity , 2008, 0804.3850.

[82]  G. Stinson,et al.  Riding the Spiral Waves: Implications of Stellar Migration for the Properties of Galactic Disks , 2008, 0808.0206.

[83]  Heidi Jo Newberg,et al.  SEGUE: A SPECTROSCOPIC SURVEY OF 240,000 STARS WITH g = 14–20 , 2009, 0902.1781.

[84]  B. Gibson,et al.  Chemical gradients in the Milky Way from the RAVE data , 2013, 1309.4279.

[85]  G. Lewis,et al.  ARGOS - III. Stellar populations in the Galactic bulge of the Milky Way , 2012, 1212.1540.

[86]  Sergey E. Koposov,et al.  The Gaia-ESO Survey: the Galactic thick to thin disc transition , 2014, 1403.7568.

[87]  R. Ibata,et al.  ARGOS – II. The Galactic bulge survey , 2012, 1212.1541.