Gaia-ESO Survey: Global properties of clusters Trumpler 14 and 16 in the Carina nebula

We present the first extensive spectroscopic study of the global population in star clusters Trumpler~16, Trumpler~14 and Collinder~232 in the Carina Nebula, using data from the Gaia-ESO Survey, down to solar-mass stars. In addition to the standard homogeneous Survey data reduction, a special processing was applied here because of the bright nebulosity surrounding Carina stars. We find about four hundred good candidate members ranging from OB types down to slightly sub-solar masses. About one-hundred heavily-reddened early-type Carina members found here were previously unrecognized or poorly classified, including two candidate O stars and several candidate Herbig Ae/Be stars. Their large brightness makes them useful tracers of the obscured Carina population. The spectroscopically-derived temperatures for nearly 300 low-mass members allows the inference of individual extinction values, and the study of the relative placement of stars along the line of sight. We find a complex spatial structure, with definite clustering of low-mass members around the most massive stars, and spatially-variable extinction. By combining the new data with existing X-ray data we obtain a more complete picture of the three-dimensional spatial structure of the Carina clusters, and of their connection to bright and dark nebulosity, and UV sources. The identification of tens of background giants enables us also to determine the total optical depth of the Carina nebula along many sightlines. We are also able to put constraints on the star-formation history of the region, with Trumpler~14 stars found to be systematically younger than stars in other sub-clusters. We find a large percentage of fast-rotating stars among Carina solar-mass members, which provide new constraints on the rotational evolution of pre-main-sequence stars in this mass range.

[1]  Sergey E. Koposov,et al.  Gaia-ESO Survey: Gas dynamics in the Carina nebula through optical emission lines , 2016, Astronomy & Astrophysics.

[2]  S. Molinari,et al.  The Carina Nebula and Gum 31 molecular complex – I. Molecular gas distribution, column densities, and dust temperatures , 2015, 1511.07513.

[3]  Wen-Ping Chen,et al.  OPTICAL SPECTROSCOPY OF X-RAY-SELECTED YOUNG STARS IN THE CARINA NEBULA , 2015 .

[4]  T. Preibisch,et al.  The VISTA Carina Nebula Survey II. Spatial distribution of the infrared-excess-selected young stellar population , 2015, 1510.01631.

[5]  N. Walton,et al.  Classical T Tauri stars with VPHAS+ – I. H α and u-band accretion rates in the Lagoon Nebula M8 , 2015, 1507.06786.

[6]  N. Walborn,et al.  The little-studied cluster Berkeley 90 I. LS III +46 11: a very massive O3.5 If* + O3.5 If* binary , 2015, 1504.06977.

[7]  C. Babusiaux,et al.  Gaia-ESO Survey: Analysis of pre-main sequence stellar spectra , 2015, 1501.04450.

[8]  G. Micela,et al.  The Gaia-ESO Survey: Chromospheric emission, accretion properties, and rotation in γ Velorum and Chamaeleon I , 2014, 1412.4153.

[9]  A. Bragaglia,et al.  Gaia-ESO Survey: Empirical classification of VLT/Giraffe stellar spectra in the wavelength range 6440–6810 Å in the γ Velorum cluster, and calibration of spectral indices , 2014, 1405.1205.

[10]  R. Jeffries.  Using rotation, magnetic activity and lithium to estimate the ages of low mass stars , 2014, 1404.7156.

[11]  H. J. Farnhill,et al.  The VST Photometric Hα Survey of the Southern Galactic Plane and Bulge (VPHAS , 2014, 1402.7024.

[12]  C. Evans,et al.  The VLT-FLAMES Tarantula Survey XVI. The optical+NIR extinction laws in 30 Doradus and the photometric determination of the effective temperatures of OB stars , 2014, 1402.3062.

[13]  N. Morrell,et al.  THE GALACTIC O-STAR SPECTROSCOPIC SURVEY (GOSSS). II. BRIGHT SOUTHERN STARS , 2013, 1312.6222.

[14]  T. Zwitter,et al.  PROPERTIES OF DIFFUSE INTERSTELLAR BANDS AT DIFFERENT PHYSICAL CONDITIONS OF THE INTERSTELLAR MEDIUM , 2013, 1306.5788.

[15]  Sergio Ortolani,et al.  The Gaia-ESO Public Spectroscopic Survey , 2012 .

[16]  M. Bessell,et al.  DISTANCE AND THE INITIAL MASS FUNCTION OF YOUNG OPEN CLUSTERS IN THE η CARINA NEBULA: Tr 14 AND Tr 16 , 2012, 1201.0623.

[17]  N. Mowlavi,et al.  Grids of stellar models with rotation - I. Models from 0.8 to 120 M⊙ at solar metallicity (Z = 0.014) , 2011, 1110.5049.

[18]  Antonino Francesco Lanza,et al.  Modelling the rotational evolution of solar-like stars: the rotational coupling time-scale , 2011, 1105.3125.

[19]  S. Majewski,et al.  A PAN-CARINA YOUNG STELLAR OBJECT CATALOG: INTERMEDIATE-MASS YOUNG STELLAR OBJECTS IN THE CARINA NEBULA IDENTIFIED VIA MID-INFRARED EXCESS EMISSION , 2011, 1103.2060.

[20]  E. Feigelson,et al.  THE CHANDRA CARINA COMPLEX PROJECT VIEW OF TRUMPLER 16 , 2011, 1103.1126.

[21]  E. Feigelson,et al.  X-RAY STAR CLUSTERS IN THE CARINA COMPLEX , 2011, 1103.0802.

[22]  S. Majewski,et al.  CANDIDATE X-RAY-EMITTING OB STARS IN THE CARINA NEBULA IDENTIFIED VIA INFRARED SPECTRAL ENERGY DISTRIBUTIONS , 2011, 1102.5366.

[23]  E. Feigelson,et al.  A CATALOG OF CHANDRA X-RAY SOURCES IN THE CARINA NEBULA , 2011, 1102.5121.

[24]  Patrick S. Broos,et al.  A NAIVE BAYES SOURCE CLASSIFIER FOR X-RAY SOURCES , 2011, 1102.5120.

[25]  Keivan G. Stassun,et al.  AN INTRODUCTION TO THE CHANDRA CARINA COMPLEX PROJECT , 2011, 1102.4779.

[26]  Accretion‐induced luminosity spreads in young clusters: evidence from stellar rotation , 2011, 1102.3836.

[27]  M. Garcia,et al.  The IACOB spectroscopic database of galactic OB stars , 2010, Proceedings of the International Astronomical Union.

[28]  K. Stassun,et al.  Spitzer Space Telescope observations of the Carina Nebula: The steady march of feedback-driven star formation , 2010, 1004.2263.

[29]  N. Morrell,et al.  SPECTROSCOPIC SURVEY OF GALACTIC O AND WN STARS. OWN SURVEY: NEW BINARIES AND TRAPEZIUM-LIKE SYSTEMS , 2010 .

[30]  J. F. Albacete-Colombo,et al.  An X-ray survey of low-mass stars in Trumpler 16 with Chandra , 2008, 0807.4456.

[31]  G.Rauw,et al.  UvA-DARE ( Digital Academic Repository ) XMM-Newton X-ray study of early type stars in the Carina OB 1 association , 2007 .

[32]  K. Brooks,et al.  A census of the Carina Nebula – II. Energy budget and global properties of the nebulosity , 2007, 0705.3053.

[33]  M. Tamura,et al.  An X-Ray and Near-Infrared Study of Young Stars in the Carina Nebula , 2007 .

[34]  S. P. Littlefair,et al.  Empirical isochrones and relative ages for young stars, and the radiative–convective gap , 2006, astro-ph/0612090.

[35]  N. Huélamo,et al.  The young star cluster NGC 2362 : low-mass population and initial mass function from a Chandra X-ray observation , 2006 .

[36]  S. Sciortino,et al.  The rich young cluster NGC 6530: a combined X-ray-optical-infrared study , 2006 .

[37]  J. M. Apellániz.  A uniform set of optical/NIR photometric zero points to be used with CHORIZOS , 2006, astro-ph/0609430.

[38]  L. Hartmann,et al.  A Correlation between Pre-Main-Sequence Stellar Rotation Rates and IRAC Excesses in Orion , 2006, astro-ph/0604104.

[39]  N. Smith,et al.  The Structure of the Homunculus. I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of η Carinae , 2006, astro-ph/0602464.

[40]  N. Morrell,et al.  Optical spectroscopy of X-Mega targets in the Carina nebula – VI. FO 15: a new O-type double-lined eclipsing binary , 2006, astro-ph/0601100.

[41]  J. Maíz Apellániz.  Accepted for publication in the Astronomical Journal A recalibration of optical photometry: , 2005 .

[42]  E. Feigelson,et al.  The Origin of T Tauri X-Ray Emission: New Insights from the Chandra Orion Ultradeep Project , 2005, astro-ph/0506526.

[43]  J. Ma'iz-Apell'aniz.  A Cross‐Calibration between Tycho‐2 Photometry and Hubble Space Telescope Spectrophotometry , 2005, astro-ph/0504085.

[44]  J. M. Apellániz.  A cross-calibration between Tycho-2 photometry and HST spectrophotometry , 2005 .

[45]  J. Máız-Apellániz.  CHORIZOS: A χ2 Code for Parameterized Modeling and Characterization of Photometry and Spectrophotometry , 2004, astro-ph/0408361.

[46]  G. Carraro,et al.  The star cluster Collinder 232 in the Carina complex and its relation to Trumpler 14/16 , , 2004, astro-ph/0401144.

[47]  The Angular Momentum Evolution of 0.1-10 M☉ Stars from the Birth Line to the Main Sequence , 2003, astro-ph/0310280.

[48]  J. Máız-Apellániz.  CHORIZOS : a CHi-square cOde for parameteRized modelIng and characteriZation of phOtometry and Spectrophotometry , 2004 .

[49]  C. Ledoux,et al.  The UVES Paranal Observatory Project: A Library of High- Resolution Spectra of Stars across the Hertzsprung-Russell Diagram , 2003 .

[50]  Lisa H. Wei,et al.  A Galactic O Star Catalog , 2003, astro-ph/0311196.

[51]  M. Roth,et al.  Imaging study of NGC 3372, the Carina nebula – I. UBVRIJHK photometry of Tr 14, Tr 15, Tr 16 and Car I , 2003 .

[52]  C. Lada,et al.  Embedded Clusters in Molecular Clouds , 2003, astro-ph/0301540.

[53]  S. Sciortino,et al.  Chandra X-Ray Observation of the Orion Nebula Cluster. II. Relationship between X-Ray Activity Indicators and Stellar Parameters , 2002, astro-ph/0208475.

[54]  Ivan Hubeny,et al.  A Grid of Non-LTE Line-blanketed Model Atmospheres of O-Type Stars , 2002, astro-ph/0210157.

[55]  Coryn A. L. Bailer-Jones,et al.  Stellar rotation and variability in the Orion Nebula Cluster , 2002 .

[56]  G. Walker,et al.  The Star Formation History of Trumpler 14 and Trumpler 16 , 2001 .

[57]  Keivan G. Stassun,et al.  The Rotation Period Distribution of Pre-Main-Sequence Stars in and around the Orion Nebula , 1999 .

[58]  T. Sigut.  Non-LTE Calculations for the C II Doublet System , 1996 .

[59]  L. Hartmann,et al.  Pre-Main-Sequence Evolution in the Taurus-Auriga Molecular Cloud , 1995 .

[60]  R. Mathieu.  Pre-Main-Sequence Binary Stars , 1994 .

[61]  N. Morrison,et al.  Non-LTE, line-blanketed model atmospheres for late O- and early B-type stars , 1992 .

[62]  R. G. Smith.  An infrared study of the stellar population in the direction of the Carina nebula: NGC 3372 , 1987 .

[63]  N. Walborn.  CHARACTERISTICS OF THE ETA CARINAE COMPLEX. , 1973 .