High angular resolution spectroscopic and polarimetric imaging of the galactic center in the near-infrared

Abstract

view Abstract Citations (111) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High Angular Resolution Spectroscopic and Polarimetric Imaging of the Galactic Center in the Near-Infrared Eckart, A. ; Genzel, R. ; Hofmann, R. ; Sams, B. J. ; Tacconi-Garman, L. E. Abstract We present improved 0.15 sec resolution K-band (2.2 micrometers) maps of the central 0.5 pc of the Galaxy as well as, for the first time, 0.2 sec J-band (1.25 micrometers) images, 0.2 sec K-band polarimetry, and 0.4 sec images in the 2.058 micrometer He 1 emission and 2.29 micrometers CO band head absorption features. The new K-band maps reach K magnitudes of about 16 and resolve the previously found object at the position of the radio source Sgr A*(R) into a small cluster of compact sources. With one exception, their polarizations are similar to other sources in its vicinity and thus are probably caused by antisotropic foreground dust extinction in the Galactic plane. The Sgr A*(IR) complex does not exhibit any significant flux density variations at 2.2 micrometers on timescales of minutes or years. We therefore interpret Sgr A*(IR) as a small local clustering of luminous stars (MK approximately equal to -3) near/at the position of the compact radio source. The central IRS 16 complex and the bright source IRS 13 are dominated by bright luminous He 1 stars and confirm the cluster of about a dozen He 1 stars found by Krabbe et al. (1991). There are also a dozen sources with K less than or equal to 12.5 exhibiting CO band head absorption within a radius of 10 sec of Sgr A*(IR). The drop in CO band head strength found by Sellgren et al. (1990) thus is most likely not caused by the disappearance of CO sources but by the additional presence of the bright early-type stars. Publication: The Astrophysical Journal Pub Date: May 1995 DOI: 10.1086/187880 Bibcode: 1995ApJ...445L..23E Keywords: Astronomical Maps; Astronomical Polarimetry; Astronomical Spectroscopy; Galactic Nuclei; Infrared Astronomy; Infrared Imagery; Near Infrared Radiation; Radio Sources (Astronomy); Stellar Luminosity; Extremely High Frequencies; Galactic Radiation; High Resolution; Narrowband; Polarized Radiation; Star Clusters; Astrophysics; GALAXY: CENTER; GALAXIES: NUCLEI; INFRARED: STARS full text sources ADS | data products SIMBAD (14)