Sigma Orionis IRS1 A and B: A Binary Containing a Proplyd

Abstract

We report optical and infrared imaging spectroscopy observations of the young binary object Sigma Orionis IRS1 A/B. The brighter component (Sigma Ori IRS1 A) of this binary system has M1 spectral type and a mass in the range of 0.3 to 0.8 solar masses. The fainter component (Sigma Ori IRS1 B) has a unique morphology and spectrum. The unresolved stellar object is surrounded by an extended envelope that is slightly offset from the position of this star. The envelope's spectrum shows strong emission lines of H and HeI but no shock-excited emission from molecular hydrogen or from [FeII]. The embedded stellar object Sigma Ori IRS1 B has an absorption spectrum characteristic of a late M photosphere, but with an additional approximately equal amount of dust continuum flux veiling the absorption lines. Sigma Ori IRS1 B is probably a young brown dwarf embedded in a proplyd that is being photo-evaporated by the UV flux of the nearby multiple O and B star system Sigma Ori.

The paper has been accepted for publicaiton by The Astrophysical Journal Letters. It has 11 pages of text and 5 figures

References in corpus (7)

• Main-Seqence Fitting Distance to the sigma Ori Cluster
• The brightest stars of the sigma Orionis cluster
• High-Resolution Chandra X-ray Imaging and Spectroscopy of the Sigma Orionis Cluster
• A deep look into the cores of young clusters I. sigma-Orionis
• New constraints on the membership of the T dwarf S Ori 70 in the sigma Orionis cluster
• Discovery of an old photoevaporating disk in sigma Orionis
• A near-infrared/optical/X-ray survey in the centre of sigma Orionis

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• A Herschel view of protoplanetary disks in the $\sigma$ Ori cluster
• A third massive star component in the σ Orionis AB system
• The Launch Region of the SVS 13 Outflow and Jet
• Search and characterization of T-type planetary mass candidates in the sigma Orionis cluster
• The origin of free-floating planets
• HRC-I/Chandra X-ray observations towards sigma Orionis
• Dusty OB stars in the Small Magellanic Cloud - II: Extragalactic Disks or Examples of the Pleiades Phenomenon?
• A search for pre- and proto-brown dwarfs in the dark cloud Barnard 30 with ALMA
• Stars and brown dwarfs in the sigma Orionis cluster. III. OSIRIS/GTC low-resolution spectroscopy of variable sources
• Wide sigma Orionis binaries resolved by UKIDSS