2000AJ....119..207L -
Astron. J., 119, 207-240 (2000/January-0)
A wide-field 90 centimeter VLA image of the Galactic Center region.
LAROSA T.N., KASSIM N.E., LAZIO T.J.W. and HYMAN S.D.
Abstract (from CDS):
We present a wide-field, high dynamic range, high-resolution, long-wavelength (λ=90 cm) VLA image of the Galactic center region. The image is centered on Sgr A, covers an area of 4°x5° with an angular resolution of 43", and has a rms sensitivity of ~5 mJy.beam–1. The image was constructed from archival (1989 and 1991) VLA data of Pedlar et al. and (ref???)Anantharamaiah et al. using new three-dimensional image restoration techniques. These three-dimensional imaging techniques resolve the problem of non-coplanar baselines encountered at long wavelengths and yield distortion-free imaging of far-field sources with improved sensitivity. At λ=90 cm the VLA is sensitive to both thermal and nonthermal emission and the resulting image gives an unprecedented contextual perspective of the large-scale radio structure in this unique and complicated region. We have catalogued over a hundred sources from this image and present for each source its 90 cm flux density, position, and size. For many of the small- diameter sources, we also derive the 20/90 cm spectral index. The spectral index as a function of length along several of the isolated nonthermal filaments has been estimated and found to be constant. We have found six new small-diameter sources, as well as several extended regions of emission, which are clearly distinct sources that have not been previously identified at higher frequencies. These data are presented as a first epoch of VLA observations that can be used to search for source variability in conjunction with a second epoch of observations that were recently initiated.
Abstract Copyright:
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Journal keyword(s):
Galaxy: Center - Radio Continuum
Nomenclature:
Table 1: NTF GLLL.ll+B.bb N=6 added. Table 2: [LKL2000] NN (Nos 1-78) = [LKL2000] GLLL.ll+B.bb N=78.
Errata:
Erratum vol. 119, p. 3145 (2000)
Simbad objects:
114
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