A spectroscopic census in young stellar regions: the Sigma Orionis cluster

Abstract

We present a spectroscopic survey of the stellar population of the Sigma Orionis cluster. We have obtained spectral types for 340 stars. Spectroscopic data for spectral typing come from several spectrographs with similar spectroscopic coverage and resolution. More than a half of stars of our sample are members confirmed by the presence of lithium in absorption, strong H$\alpha$ in emission or weak gravity-sensitive features. In addition, we have obtained high resolution (R~34000) spectra in the H$\alpha$ region for 169 stars in the region. Radial velocities were calculated from this data set. The radial velocity distribution for members of the cluster is in agreement with previous work. Analysis of the profile of the H$\alpha$ line and infrared observations reveals two binary systems or fast rotators that mimic the H$\alpha$ width expected in stars with accretion disks. On the other hand there are stars with optically thick disks and narrow H$\alpha$ profile not expected in stars with accretion disks. This contribution constitutes the largest homogeneous spectroscopic data set of the Sigma Orionis cluster to date.

56 pages, 14 figures. Accepted in The Astrophysical Journal

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Cited by in corpus (22)

• Close companions around young stars
• OB associations and their origins
• Orbits, Distance, and Stellar Masses of the Massive Triple Star Sigma Orionis
• PENELLOPE: the ESO data legacy program to complement the Hubble UV Legacy Library of Young Stars (ULLYSES) I. Survey presentation and accretion properties of Orion OB1 and $\sigma$-Orionis
• Determining the recurrence timescale of long-lasting YSO outbursts
• Stellar Rotation of T Tauri stars in the Orion Star-Forming Complex
• An Improved HR Diagram for the Orion Trapezium Cluster
• A Herschel view of protoplanetary disks in the $\sigma$ Ori cluster
• The Evolution Of The Inner Regions of Protoplanetary Disks
• A Census of the Low Accretors. I: The Catalog
• Testing external photoevaporation in the $\sigma$-Orionis cluster with spectroscopy and disk mass measurements
• Determining Dust Properties in Protoplanetary Disks: SED-derived Masses and Settling With ALMA
• Synthetic RGB photometry of bright stars: definition of the standard photometric system and UCM library of spectrophotometric spectra
• SDSS-V Local Volume Mapper (LVM): A Glimpse into Orion
• A novel survey for young substellar objects with the W-band filter VI: Spectroscopic census of sub-stellar members and the IMF of $\sigma$ Orionis cluster
• Very low-luminosity Class I/Flat outflow sources in sigma Orionis
• A New Look at Disk Winds and External Photoevaporation in the $\sigma$-Orionis Cluster
• Understanding the angular momentum evolution of T Tauri and Herbig Ae/Be stars
• NGTS clusters survey $-$ V: Rotation in the Orion Star-forming Complex
• The NEMESIS Catalogue of Young Stellar Objects for the Orion Star Formation Complex. I. General description of data curation
• An Incipient Debris Disk in the Chamaeleon I Cloud
• Dynamical masses of young stellar objects with the VLBA: DYNAMO-VLBA: Radio binary stars in Orion