Proper Motions of the Radio Source Orion MR, Formerly Known as Orion n, and New Sources with Large Proper Motions in Orion BN/KL

Abstract

The infrared source known as Orion n was detected in 1980 with observations made with the 3.8-m United Kingdom Infrared Telescope. About two decades later, sensitive observations made with the Very Large Array revealed the presence of a mJy double radio source apparently coincident in position with the infrared source n. The radio source was assumed to be the counterpart of the infrared source. However, over the years it has been concluded that the radio source shows large proper motions to the south while the infrared source n is stationary. Here we reanalyze the proper motions of the radio source adding both older and newer VLA observations than previously used. We confirm the proper motions of the radio source that at present no longer coincides positionally with the infrared source. The solution to this problem is, most probably, that the infrared source n and the radio source are not the same object: the infrared source is a stationary object in the region while the radio counterpart is moving as a result of the explosion that took place in this region some 500 years ago and that expelled large amounts of molecular gas as well as several compact sources. Considering the paper where it was first reported, we refer to this double radio source as Orion MR. In addition, we use these new observations to fully confirm the large proper motions of the sources IRc23 and Zapata 11. Together with sources BN, I, Orion MR, and x, there are at least six compact sources that recede from a point in common in Orion BN/KL. However, IRc23 is peculiar in that its ejection age appears to be only $\sim$300 years. The relatively large number of sources rules out as a possible mechanism the classic three-body scenario since then only two escaping bodies are expected: a tight binary plus the third star involved in the encounter.

14 pages, 7 figures, to appear in The Astrophysical Journal

References in corpus (7)

• The Gould's Belt Distances Survey (GOBELINS) II. Distances and structure towards the Orion Molecular Clouds
• The ALMA View of the OMC1 Explosion in Orion
• Radio Measurements of the stellar proper motions in the core of the Orion Nebula Cluster
• The Proper Motions of the Double Radio Source n in the Orion BN/KL Region
• New Evidence for the Dynamical Decay of a Multiple System in the Orion Kleinmann-Low Nebula
• Hubble Space Telescope NICMOS Polarization Measurements of OMC-1
• The complexity of Orion: an ALMA view III. The explosion impact

Cited by in corpus (8)

• Magnetic Fields in Massive Star-Forming Regions (MagMaR) I. Linear Polarized Imaging of the UCHII Region G5.89-0.39
• Confirming the Explosive Outflow in G5.89 with ALMA
• A gravitational and dynamical framework of star formation: The Orion Nebula
• A VLBA Survey of radio stars in the Orion Nebula Cluster: II. Astrometry
• Evidence for dense gas heated by the explosion in Orion KL
• Possible Explosive Dispersal Outflow in IRAS 16076-5134 revealed with ALMA
• From downtown to the outskirts: a radio survey of the Orion Nebula Cluster
• An ionized outflow in Orion-KL source I?