A Survey for New Stars and Brown Dwarfs in the Ophiuchus Star-forming Complex

Abstract

We have performed a survey for new members of the Ophiuchus cloud complex using high-precision astrometry from the second data release of Gaia, proper motions measured with multi-epoch images from the Spitzer Space Telescope, and color-magnitude diagrams constructed with photometry from various sources. Through spectroscopy of candidates selected with those data, we have identified 155 new young stars. Based on available measurements of kinematics, we classify 102, 47, and six of those stars as members of Ophiuchus, Upper Sco, and other populations in Sco-Cen, respectively. We have also assessed the membership of all other stars in the vicinity of Ophiuchus that have spectroscopic evidence of youth from previous studies, arriving at a catalog of 373 adopted members of the cloud complex. For those adopted members, we have compiled mid-IR photometry from Spitzer and the Wide-field Infrared Survey Explorer} and have used mid-IR colors to identify and classify circumstellar disks. We find that 210 of the members show evidence of disks, including 48 disks that are in advanced stages of evolution. Finally, we have estimated the relative median ages of the populations near the Ophiuchus clouds and the surrounding Upper Sco association using absolute K-band magnitudes (M_K) based on Gaia} parallaxes. If we adopt an age 10 Myr for Upper Sco, then the relative values of M_K imply median ages of ~2 Myr for L1689 and embedded stars in L1688, 3-4 Myr for low-extinction stars near L1688, and ~6 Myr for the group containing rho Oph.

8 Pages, 10 figures, accepted in AJ, machine readable tables available at https://www.dropbox.com/sh/kxmumhgdpsfbevd/AACDjnB5FdmjmU4hzc08BxaIa?dl=0

References in corpus (24)

• 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
• An Optical Spectroscopic Study of T Tauri Stars. I. Photospheric Properties
• Accretion in the Rho-Oph pre-main sequence stars
• The COMPLETE Survey of Star-Forming Regions: Phase I Data
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• The Gould's Belt Distances Survey (GOBELINS) I. Trigonometric parallax distances and depth of the Ophiuchus complex
• A Large-Area Search for Low Mass Objects in Upper Scorpius I: The Photometric Campaign and New Brown Dwarfs
• A Large-Area Search for Low-Mass Objects in Upper Scorpius II: Age and Mass Distributions
• Spatially extended PAHs in circumstellar disks around T Tauri and Herbig Ae stars
• A Survey for New Members of the Taurus Star-Forming Region with the Sloan Digital Sky Survey
• New Pre-main-Sequence Stars in the Upper Scorpius Subgroup of Sco-Cen
• The Nature of Transition Circumstellar Disks II. Southern Molecular Clouds
• A continuum of accretion burst behavior in young stars observed by K2
• X-Shooter study of accretion in $\rho$-Ophiucus: very low-mass stars and brown dwarfs
• Dust properties inside molecular clouds from coreshine modeling and observations
• A Survey for Young Spectroscopic Binary K7-M4 Stars in Ophiuchus
• An initial overview of the extent and structure of recent star formation within the Serpens Molecular Cloud using Gaia Data Release 2
• A Survey For Planetary-mass Brown Dwarfs in the Taurus and Perseus Star-forming Regions
• A census of $\rho$ Oph candidate members from Gaia DR2
• YSOVAR: Mid-IR variability in the star forming region Lynds 1688
• More Rapidly Rotating PMS M Dwarfs with Light Curves Suggestive of Orbiting Clouds of Material
• Accretion in rho-Ophiuchi brown dwarfs: infrared hydrogen line ratios
• A survey for planetary-mass brown dwarfs in the Chamaeleon I star-forming region

Cited by in corpus (28)

• Refining the Census of the Upper Scorpius Association with Gaia
• The protoplanetary disk population in the rho-Ophiuchi region L1688 and the time evolution of Class II YSOs
• Bridging the gap between protoplanetary and debris disks: separate evolution of millimeter and micrometer-sized dust
• KMOS study of the mass accretion rate from Class I to Class II in NGC 1333
• The $\rho$ Oph region revisited with Gaia EDR3
• A Gaia Survey for Young Stars Associated with the Lupus Clouds
• A Census of Stars and Disks in Corona Australis
• Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. II. Advanced modeling of interstellar 26Al, 53Mn, 60Fe, and 244Pu influxes as traces of past supernovae in the solar neighborhood
• Substructure, supernovae, and a time-resolved star formation history for Upper Scorpius
• A wide planetary-mass companion to a young low-mass brown dwarf in Ophiuchus
• A Mid-Infrared Study of Directly-Imaged Planetary-Mass Companions using Archival Spitzer/IRAC Images
• One-third of Sun-like stars are born with misaligned planet-forming disks
• The IGRINS YSO Survey III: Stellar parameters of pre-main sequence stars in Ophiuchus and Upper Scorpius
• Disks around young planetary-mass objects: Ultradeep Spitzer imaging of NGC1333
• Spectroscopic substellar initial mass function of NGC 2244
• A millimeter-multiwavelength continuum study of VLA 1623 West
• Subaru Hyper Suprime-Cam Survey of Cygnus OB2 Complex -- I: Introduction, Photometry and Source Catalog
• Optical and Near-Infrared Excesses are Correlated in T Tauri Stars
• Spectral characterization of young LT dwarfs
• Giant planets population around B stars from the first part of the BEAST survey
• Mapping and characterizing magnetic fields in the Rho Ophiuchus-A molecular cloud with SOFIA/HAWC$+$
• The Ophiuchus DIsk Survey Employing ALMA (ODISEA): A Unified Evolutionary Sequence of Planet-Driven Substructures Explaining the Diversity of Disk Morphologies
• The grazing angle icy protoplanetary disk PDS 453
• Interplay between Young Stars and Molecular Clouds in the Ophiuchus Star-forming Complex
• Planet-forming disks and their environment across regions and time from the full NIR census
• Discovery of a brown dwarf with quasi-spherical mass-loss
• The accretion luminosity of Class I protostars
• Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU) II: Two Young Bound Companions to Ophiuchus Stars