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The ISM and Stellar Distributions Near Sgr A*
Author(s) -
Scoville Nick,
Stolovy Susan R.,
Christopher Micol
Publication year - 2003
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200385089
Subject(s) - physics , astrophysics , extinction (optical mineralogy) , stars , brightness , radius , astronomy , surface brightness , galaxy , optics , computer security , computer science
HST‐NICMOS imaging in the 1.87 μ mP α line and 1.90 μ m continuum and OVRO interferometry of the 3mm HCN line provide maps of the ionized and molecular gas at 0.2 and 3″ resolution, respectively. Comparison of the observed P α emission with the 6‐cm radio continuum yields a map of the foreground extinction. High apparent extinction is seen along the periphery of the ionized disk and is well‐correlated with the molecular torus. The median extinction is A V = 31.1 mag. This extinction distribution is then used to correct the observed P α emission map to yield an ‘extinction‐corrected’ image of the ionized gas at 0.2″ resolution. The stellar distribution near Sgr A* is also analyzed from the 1.9 μ m continuum image – indicating a drop in the surface brightness distribution of star light within 1″ radius of SgrA*. This could be the result of stellar collisions which deplete giant stars within this radius or indicate the presence of a secondary lower mass black hole.