AzTEC survey of the central molecular zone: data reduction, analysis, and preliminary results
Yuping Tang, Q. Daniel Wang, G. W. Wilson, M. H. Heyer, Robert Gutermuth, P. Schloerb, Min S. Yun, John Bally, Laurent Loinard, Sergiy Silich, M. Chávez, Daryl Haggard, Alfredo Montaña, David Sánchez-Argüelles, M. Zeballos, Jorge A. Zavala, J. León-Tavares
Abstract
ABSTRACT We present a large-scale survey of the central molecular zone (CMZ) of our Galaxy, as well as a monitoring program of Sgr A*, with the AzTEC/Large Millimeter Telescope in the 1.1 mm continuum. Our 1.1 mm map covers the main body of the CMZ over a field of 1.6 × 1.1 deg2 with an angular resolution of 10.5 arcsec and a depth of 15 mJy beam−1. To account for the intensity loss due to the background removal process, we combine this map with lower resolution CSO/Bolocam and Planck/HFI data to produce an effective full intensity 1.1 mm continuum map. With this map and existing Herschel surveys, we have carried out a comprehensive analysis of the spectral energy distribution of dust in the CMZ. A key component of this analysis is the implementation of a model-based deconvolution approach, incorporating the Point Spread Functions (PSFs) of the different instruments, and hence recovering a significant amount of spatial information on angular scales larger than 10.5 arcsec. The monitoring of Sgr A* was carried out as part of a worldwide, multiwavelength campaign when the so-called G2 object was undergoing the pericentre passage around the massive black hole. Our preliminary results include (1) high-resolution maps of column density, temperature and dust spectral index across the CMZ; (2) a 1.1 mm light curve of Sgr A* showing an outburst of $140{{\ \rm per\ cent}}$ maximum amplitude on 2014 May 9th May, 2014 but otherwise only stochastic variations of $10{{\ \rm per\ cent}}$ and no systematic long-term change, consistent with other observations.