XMM-Newton investigations of the Lambda Orionis star-forming region (XILO). I. The young cluster Collinder 69

Abstract

This is the first paper of a series devoted to the Lambda Orionis star-forming region, from the X-ray perspective, which will provide a comprehensive view of this complex region. In this paper we focus in uncovering the population of the central, young cluster Collinder 69 (C69), and in particular those diskless members not identified by previous near- and mid-infrared surveys, and to establish the X-ray luminosity function for the association. We have combined two exposures taken with the XMM-Newton satellite with an exhaustive data set of optical, near- and mid-infrared photometry to assess the membership of the X-ray sources based on color-color and color-magnitude diagrams, as well as other properties, such as effective temperatures, masses and bolometric luminosities. We detected a total of 164 X-ray sources, of which 66 are probable and possible cluster members. A total of 16 are newly identified probable members. The two XMM-Newton pointings east and west of the cluster center have allowed us to verify the heterogeneous spatial distribution of young stars, probably related to the large scale structure of the region. The disk fraction of the X-ray detected cluster sample is very low, close to 10%, in remarkable contrast to the low-mass stellar and substellar population (mostly undetected in X-rays) where the disk fraction reaches about 50%. The X-ray luminosity function of C69 provides support for an age of several Myr when compared with other well known young associations. With our improved cluster census we confirm previous reports on the untypically low disk fraction compared to other clusters of several Myr age. The different disk fractions of X-ray detected (essentially solar-like) and undetected (mostly low-mass stars and brown dwarfs) members can be understood as a consequence of a mass-dependence of the time-scale for disk evolution.

arXiv comment38 pages, 16 figures

References in corpus (35)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
• The XMM-Newton Optical/UV Monitor Telescope
• Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• The Origin of T Tauri X-ray Emission: New Insights from the Chandra Orion Ultradeep Project
• Observations of IC348: The Disk Population at 2-3 Million Years
• Chandra Orion Ultradeep Project: Observations and Source Lists
• Optical and Infrared Properties of the 2 Ms Chandra Deep Field-North X-ray Sources
• The GOODS-MUSIC sample: a multicolour catalog of near-IR selected galaxies in the GOODS-South field
• Point Source Extraction with MOPEX
• An empirical criterion to classify T Tauri stars and substellar analogs using low-resolution optical spectroscopy
• X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
• Membership of the Orion Nebula Population from the Chandra Orion Ultradeep Project
• The HELLAS2XMM survey: I. The X-ray data and the Log(N)-Log(S)
• A Survey for New Members of Taurus with the Spitzer Space Telescope
• Evolution of brown dwarf disks: A Spitzer survey in Upper Scorpius
• FLAMES spectroscopy of low-mass stars in the young clusters sigma Ori and lambda Ori
• A Photometric Study of the Young Stellar Population Throughout the lambda Orionis Star-Forming Region
• Properties of dusty tori in AGN: I. The Case of SWIRE/SDSS Quasars
• ACIS-I observations of NGC2264. Membership and X-ray properties of PMS stars
• An IRAS High Resolution Image Restoration (HIRES) Atlas of All Interacting Galaxies in the IRAS Revised Bright Galaxy Sample
• The substellar population of the young cluster lambda Orionis
• SPITZER: Accretion in Low Mass Stars and Brown Dwarfs in the Lambda Orionis Cluster
• XMM-Newton and the Pleiades -- I: Bright coronal sources and the X-ray emission from intermediate-type stars
• Accretion and Outflow in the Substellar Domain: Magellan Spectroscopy of LS-RCrA 1
• Further X-ray detections of Herbig stars
• Spitzer Observations of the Lambda Orionis cluster I: the frequency of young debris disks at 5 Myr
• Late B-type stars and their candidate companions resolved with Chandra
• The X-ray activity-rotation relation of T Tauri stars in Taurus-Auriga
• Spectroscopic identifications of Spitzer sources in the SWIRE/XMM-NEWTON/ELAIS-S1 field: a large fraction of Active Galactic Nuclei with high F(24micron)/F(R) ratio
• A brown dwarf companion to the intermediate-mass star HR6037
• A deep look into the core of young clusters. II. lambda-Orionis
• A mid-infrared study of very low mass stars and brown dwarfs in Upper Scorpius

Cited by in corpus (15)

• Pre-main-sequence isochrones -- II. Revising star and planet formation timescales
• Spectroscopy of Very Low Mass Stars and Brown Dwarfs in the Lambda Orionis Star Forming Region. I. Enlarging the census down to the planetary mass domain in Collinder 69
• Spectroscopy of Very Low Mass Stars and Brown Dwarfs in the Lambda Orionis Star Forming Region
• The ultracool dwarf DENIS-P J104814.7-395606. Chromospheres and coronae at the low-mass end of the main-sequence
• The APOGEE-2 Survey of the Orion Star Forming Complex: I. Target Selection and Validation with early observations
• The Gaia-ESO Survey: Constraining evolutionary models and ages for young low mass stars with measurements of lithium depletion and rotation
• A Significant Population of Candidate New Members of the Rho Ophiuchi Cluster
• Linking ice and gas in the Lambda Orionis Barnard 35A cloud
• XMM-Newton observations of the young open cluster around lambda Orionis
• Star formation history of Canis Major OB1 - II. A bimodal X-ray population revealed by XMM-Newton
• A comprehensive study of NGC 2023 with XMM-Newton and Spitzer
• Early phases in the stellar and substellar formation and evolution: Infrared and submillimeter data in the Barnard 30 dark cloud
• The NEMESIS Catalogue of Young Stellar Objects for the Orion Star Formation Complex. I. General description of data curation
• HH 175: A Giant HH Flow Emanating From A Multiple Protostar
• The dispersal of protoplanetary discs -- III: Influence of stellar mass on disc photoevaporation