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

¹ INAF–Osservatorio Astronomico di Palermo G. S. Vaiana, Piazza del Parlamento 1, 90134 Palermo, Italy
e-mail: damiani@astropa.inaf.it
² INAF–Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania, Italy
³ Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG, UK
⁴ INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
⁵ Centro de Astrobiología (CSIC-INTA), ESAC campus, Camino bajo del castillo s/n, 28 692 Villanueva de la Cañada, Madrid, Spain
⁶ Armagh Observatory, College Hill, Armagh BT61 9DG, UK
⁷ School of Mathematics & Physics, Queen’s University Belfast, Belfast BT61 7NN, UK
⁸ Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
⁹ Dipartimento di Fisica e Chimica, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
¹⁰ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
¹¹ GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
¹² Moscow MV Lomonosov State University, Sternberg Astronomical Institute, Moscow 119992, Russia
¹³ Dipartimento di Fisica e Astronomia, Sezione Astrofisica, Università di Catania, via S. Sofia 78, 95123 Catania, Italy
¹⁴ Instituto de Física y Astronomiía, Universidad de Valparaiíso, Chile
¹⁵ European Southern Observatory, Alonso de Cordova 3107 Vitacura, Santiago de Chile, Chile
¹⁶ Instituto de Astrofísica de Andalucía-CSIC, Apdo. 3004, 18080 Granada, Spain
¹⁷ INAF–Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
¹⁸ Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
¹⁹ Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK
²⁰ Departamento de Ciencias Fisicas, Universidad Andres Bello, Republica 220, Santiago, Chile
²¹ INAF–Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy

Received: 27 May 2016
Accepted: 14 February 2017

Abstract

Aims. 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.

Methods. In addition to the standard homogeneous survey data reduction, a special processing was applied here because of the bright nebulosity surrounding Carina stars.

Results. We find about 400 good candidate members ranging from OB types down to slightly subsolar masses. About 100 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 enables the inference of individual extinction values and the study of the relative placement of stars along the line of sight.

Conclusions. 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 also enables us 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 subclusters. 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.