The first stars of the Rho Ophiuchi Dark Cloud. XMM-Newton view of Rho Oph and its neighbors

Abstract

Star formation in molecular clouds can be triggered by the dynamical action of winds from massive stars. Furthermore, X-ray and UV fluxes from massive stars can influence the life time of surrounding circumstellar disks. We present the results of a 53 ks XMM-Newton observation centered on the Rho Ophiuchi A+B binary system. Rho Ophiiuchi lies in the center of a ring of dust, likely formed by the action of its winds. This region is different from the dense core of the cloud (L1688 Core F) where star formation is at work. X-rays are detected from Rho Ophiuchi as well as a group of surrounding X-ray sources. We detected 89 X-ray sources, 47 of them have at least one counterpart in 2MASS + All-WISE catalogs. Based on IR and X-ray properties, we can distinguish between young stellar objects (YSOs) belonging to the cloud and background objects. Among the cloud members, we detect 3 debris disk objects and 22 disk-less / Class III young stars. We show that these stars have ages in $5-10$ Myr, and are significantly older than the YSOs in L1688. We speculate that they are the result of an early burst of star formation in the cloud. An X-ray energy of $\ge 5\times 10^{44}$ ergs has been injected into the surrounding medium during the past $5$ Myr, we discuss the effects of such energy budget in relation to the cloud properties and dynamics.

17 pages, 9 figures, 7 tables. Accepted for publication to Astronomy & Astrophysics

References in corpus (11)

• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• A Classification Scheme for Young Stellar Objects Using the WIDE-FIELD INFRARED SURVEY EXPLORER AllWISE Catalog: Revealing Low-Density Star Formation in the Outer Galaxy
• X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
• A Combined Spitzer and Chandra Survey of Young Stellar Objects in the Serpens Cloud Core
• Diagnostics of stellar flares from X-ray observations: from the decay to the rise phase
• The X-ray soft excess in classical T Tauri stars
• A survey of stellar X-ray flares from the XMM-Newton serendipitous source catalogue: Hipparcos-Tycho cool stars
• The Spatial Structure of Young Stellar Clusters. III. Physical Properties and Evolutionary States
• Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey
• Results from Droxo. I. The variability of fluorescent Fe 6.4 keV emission in the young star Elias 29: High-energy electrons in the star's accretion tubes?

Cited by in corpus (13)

• The stellar population of Sco OB2 revealed by Gaia DR2 data
• The Magnetic Early B-type Stars IV: Breakout or Leakage? H$\alpha$ emission as a diagnostic of plasma transport in centrifugal magnetospheres
• A WISE Survey of Circumstellar disks in the Upper Scorpius Association
• A scaling relationship for non-thermal radio emission from ordered magnetospheres: from the top of the Main Sequence to planets
• A Survey for New Stars and Brown Dwarfs in the Ophiuchus Star-forming Complex
• Unveiling the star formation history of the Upper Scorpius association through its kinematics
• The $\rho$ Oph region revisited with Gaia EDR3
• Evidence for radio and X-ray auroral emissions from the magnetic B-type star rho Oph A
• Substructure, supernovae, and a time-resolved star formation history for Upper Scorpius
• The auroral radio emission of the magnetic B-type star rho OphC
• The early B-type star Rho Oph A is an X-ray lighthouse
• Detection of magnetic field in the B2 star $\rho$ Oph A with ESO FORS2
• Detection of a centrifugal magnetosphere in one of the most massive stars in the $\rho$ Oph star-forming cloud