Proper motion survey and kinematic analysis of the Rho Ophiuchi embedded cluster

Abstract

We aim at performing a kinematic census of young stellar objects (YSOs) in the Rho Ophiuchi F core and partially in the E core of the L1688 dark cloud. We run a proper motion program at the ESO New Technology Telescope (NTT) with the Son of ISAAC (SOFI) instrument over nine years in the near-infrared. We complemented these observations with various public image databases to enlarge the time base of observations and the field of investigation to 0.5 deg X 0.5 deg. We derived positions and proper motions for 2213 objects. From these, 607 proper motions were derived from SOFI observations with a ~1.8 mas/yr accuracy while the remaining objects were measured only from auxiliary data with a mean precision of about ~3 mas/yr. We performed a kinematic analysis of the most accurate proper motions derived in this work, which allowed us to separate cluster members from field stars and to derive the mean properties of the cluster. From the kinematic analysis we derived a list of 68 members and 14 candidate members, comprising 26 new objects with a high membership probability. These new members are generally fainter than the known ones. We measured a mean proper motion of (mu_RA*, mu_DEC)=(-8.2, -24.3)+/-0.8 mas/yr for the L1688 dark cloud. A supervised classification was applied to photometric data of members to allocate a spectral energy distribution (SED) classification to the unclassified members.} We kinematically confirmed that the 56 members that were known from previous studies of the Rho Ophiuchi F cluster and that were also part of our survey are members of the cluster, and we added 26 new members. We defined the evolutionary status of the unclassified members of the cluster. We showed that a large part (23) of these new members are probably brown dwarfs, which multiplies the number of known substellar objects in the cluster by a factor of 3.3.

16 pages, 13 figures, 3 tables in electronic form

References in corpus (16)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• Accretion in the Rho-Oph pre-main sequence stars
• A Submillimeter View of Circumstellar Dust Disks in $\rho$ Ophiuchus
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• Pre-main sequence spectroscopic binaries suitable for VLTI observations
• An accurate distance to 2M1207Ab
• Deep near-IR variability survey of pre-main-sequence stars in Rho Ophiuchi
• A Survey for Young Spectroscopic Binary K7-M4 Stars in Ophiuchus
• Near Infrared Spectroscopy of Young Brown Dwarfs in Upper Scorpius
• Gaia: Organisation and challenges for the data processing
• Trigonometric parallaxes of high velocity halo white dwarf candidates
• Messier 35 (NGC2168) DANCe I. Membership, proper motions and multi-wavelength photometry
• Characterization of the known T type dwarfs towards the Sigma Orionis cluster
• Testing Model Atmospheres for Young Very Low Mass Stars and Brown Dwarfs in the Infrared: Evidence for Significantly Underestimated Dust Opacities

Cited by in corpus (11)

• SPICY: The Spitzer/IRAC Candidate YSO Catalog for the Inner Galactic Midplane
• A rich population of free-floating planets in the Upper Scorpius young stellar association
• Unveiling the star formation history of the Upper Scorpius association through its kinematics
• The $\rho$ Oph region revisited with Gaia EDR3
• Low Mass Stars as Tracers of Star and Cluster Formation
• Gas and dust in the star-forming region rho Oph A: II. The gas in the PDR and in the dense cores
• Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars
• Revealing the dust grain polarization properties as a function of extinction and distance towards NGC 1893
• HP2 Survey V. Ophiuchus: Filament formation in a dispersing cloud complex
• Interplay between Young Stars and Molecular Clouds in the Ophiuchus Star-forming Complex
• A High-Mass Young Star-forming Core Escaping from Its Parental Filament