GBT Multiwavelength Survey of the Galactic Center Region

TL;DR

This paper presents a detailed radio continuum survey of the Galactic Center region using the Green Bank Telescope at multiple wavelengths, providing catalogs, spectral analysis, and insights into thermal and nonthermal emission contributions.

Contribution

It offers the most sensitive and high-resolution single dish radio surveys of the central Galactic region, with comprehensive source catalogs and spectral index analysis.

Findings

Thermal flux fraction is 28% at 3.5 cm and 19% at 6 cm.

Total flux densities are 783 Jy at 3.5 cm and 1063 Jy at 6 cm.

Evidence of mixed thermal and nonthermal emission in star-forming regions.

Abstract

We describe the results of a radio continuum survey of the central 4x1deg with the 100 m Green Bank Telescope (GBT) at wavelengths of 3.5, 6, 20, and 90 cm. The 3.5 and 6 cm surveys are the most sensitive and highest resolution single dish surveys made of the central degrees of our Galaxy. We present catalogs of compact and extended sources in the central four degrees of our Galaxy, including detailed spectral index studies of all sources. The analysis covers star-forming regions such as Sgr B and Sgr C where we find evidence of a mixture of thermal and nonthermal emission. The analysis quantifies the relative contribution of thermal and nonthermal processes to the radio continuum flux density toward the GC region. In the central 4x1deg of the GC, the thermal and nonthermal flux fractions for all compact and diffuse sources are 28%/72% at 3.5 cm and 19%/81% at 6 cm. The total flux densities from these sources are 783+-52 Jy and 1063+-93 Jy at 3.5 and 6 cm, respectively, excluding the contribution of Galactic synchrotron emission.