2006/10/24 by Vincent L. Fish, Laura K. Zschaechner, Loránt O. Sjouwerman +4 · 6 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Atomic physics #Excited state #Galaxies: Formation, Evolution, Phenomena #Maser #Physics #Star (game theory) #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/510382
published in The Astrophysical Journal 653(1), L45-L48 (IOP Publishing) · 4 pages, to appear in ApJL
arxiv created 2006/10/24 · openalex publication_date 2006/11/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Recent observational and theoretical advances have called into question traditional OH maser pumping models in evolved (OH/IR) stars. The detection of excited-state OH lines would provide additional constraints to discriminate among these theoretical models. In this Letter, we report on VLA observations of the 4750 and 4765 MHz lines of OH toward 45 sources, mostly evolved stars. We detect 4765 MHz emission in the star-forming regions Mon R2 and LDN 1084, but we do not detect excited-state emission in any evolved stars. The flux density and velocity of the 4765 MHz detection in Mon R2 suggest that a new flaring event has begun.