Explore the vast range of titles available.

Modern interferometers routinely provide radio-astronomical images down to subarcsecond resolution. However, interferometers filter out spatial scales larger than those sampled by the shortest baselines, which affects the measurement of both spatial and spectral features. Complementary single-dish data are vital for recovering the true flux distribution of spatially resolved astronomical sources with such extended emission. In this work, we provide an overview of the prominent available methods to combine single-dish and interferometric observations. We test each of these methods in the framework of the CASA data analysis software package on both synthetic continuum and observed spectral data sets. We develop a set of new assessment tools that are generally applicable to all radio-astronomical cases of data combination. Applying these new assessment diagnostics, we evaluate the methods’ performance and demonstrate the significant improvement of the combined results in comparison to purely interferometric reductions. We provide combination and assessment scripts as add-on material. Our results highlight the advantage of using data combination to ensure high-quality science images of spatially resolved objects.

We present a new package for joint deconvolution of ALMA 12 m, 7 m, and Total Power (TP) data, dubbed \"Total Power Map to Visibilities (Tp2vis)\". It converts a TP (single-dish) map into visibilities on the Casa platform, which can be input into deconvolvers (e.g., Clean) along with 12 m and 7 m visibilities. The Tp2vis procedure is based primarily on the one discussed in Koda et al. A manual is presented in the Github repository (https://github.com/tp2vis/distribute). Combining data from the different ALMA arrays is a driver for a number of science topics, namely those that probe size scales of extended and compact structures simultaneously (e.g., protostar outflows and environment, AGB stars and planetary nebulae, molecular clouds and cores, and molecular clouds in galaxies). We test Tp2vis using model images, one with a single Gaussian and another that mimics the internal structures of giant molecular clouds. The result shows that the better uv coverage with Tp2vis visibilities clearly helps the deconvolution process and reproduces the model image within errors of only 5% over two orders of magnitude in flux. In the Appendix, we describe how the model image is generated.

We present a new package for joint deconvolution of ALMA 12 m, 7 m, and Total Power (TP) data, dubbed “Total Power Map to Visibilities (TP2VIS)”. It converts a TP (single-dish) map into visibilities on the CASA platform, which can be input into deconvolvers (e.g., CLEAN) along with 12 m and 7 m visibilities. The TP2VIS procedure is based primarily on the one discussed in Koda et al. A manual is presented in the GITHUB repository (https://github.com/tp2vis/distribute). Combining data from the different ALMA arrays is a driver for a number of science topics, namely those that probe size scales of extended and compact structures simultaneously (e.g., protostar outflows and environment, AGB stars and planetary nebulae, molecular clouds and cores, and molecular clouds in galaxies). We test TP2VIS using model images, one with a single Gaussian and another that mimics the internal structures of giant molecular clouds. The result shows that the better uv coverage with TP2VIS visibilities clearly helps the deconvolution process and reproduces the model image within errors of only 5% over two orders of magnitude in flux. In the Appendix, we describe how the model image is generated.

Modern interferometers routinely provide radio-astronomical images down to subarcsecond resolution. However, interferometers filter out spatial scales larger than those sampled by the shortest baselines, which affects the measurement of both spatial and spectral features. Complementary single-dish data are vital for recovering the true flux distribution of spatially resolved astronomical sources with such extended emission. In this work, we provide an overview of the prominent available methods to combine single-dish and interferometric observations. We test each of these methods in the framework of the CASA data analysis software package on both synthetic continuum and observed spectral data sets. We develop a set of new assessment tools that are generally applicable to all radio-astronomical cases of data combination. Applying these new assessment diagnostics, we evaluate the methods’ performance and demonstrate the significant improvement of the combined results in comparison to purely interferometric reductions. We provide combination and assessment scripts as add-on material. Our results highlight the advantage of using data combination to ensure high-quality science images of spatially resolved objects.

We present multiple‐field imaging simulations that explore the issue of large‐scale flux recovery using five current and future millimeter‐wavelength interferometers. The simulations show that nonlinear deconvolutions routinely applied to interferometric maps interpolate and extrapolate to unsampled spatial frequencies and thereby reconstruct much larger scale structures than an analytical treatment of the flux recovery issue would suggest. We show that the fraction of flux recovered for a given observation is a function of the signal‐to‐noise ratio (S/N) of the map; however, even for S/Ns as low as 3, a deconvolved map reconstructs more flux than an un‐deconvolved map. Both the noise‐free and the noise‐added simulations demonstrate that in order to make accurate maps of even moderately large (≳20 \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $\\arcsec$\\end{document} ) sources at millimeter wavelengths, it is generally necessary to include single‐dish (“total‐power”) or very short spacing data. We demonstrate that for high‐S/N data, how well an individual telescope recovers large‐scale structure for a mosaiced observation is more closely related to the minimum distance between its dishes, \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $S_{\\mathrm{min}\\,}-D$ \\end{document} , than to the minimum center‐to‐center distance, \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $S_{\\mathrm{min}\\,}$ \\end{document} . For a source that is large in one dimension but small in another (e.g., an elliptical Gaussian), the simulations show that the flux recovery is more closely determined by the small dimension than by the long dimension. This may help with the real imaging of spiral galaxies, where the rotation tends to confine the emission in any given channel map to a relatively small region in one dimension. These simulations were motivated by our work with mosaics from the Berkeley‐Illinois‐Maryland Association Survey of Nearby Galaxies (BIMA SONG), but the results apply generally to millimeter‐wavelength interferometric images.

Beck et al present new measurements of interstellar magnetic fields in the bar region of the galaxy NGC1097. The direction of gas flow in the galaxy is inferred.

We present a new package for joint deconvolution of ALMA 12m, 7m, and Total Power (TP) data, dubbed ``Total Power Map to Visibilities (TP2VIS)\". It converts a TP (single-dish) map into visibilities on the CASA platform, which can be input into deconvolvers (e.g., CLEAN) along with 12m and 7m visibilities. A manual is presented in the Github repository (https://github.com/tp2vis/distribute). Combining data from the different ALMA arrays is a driver for a number of science topics, namely those that probe size scales of extended and compact structures simultaneously. We test TP2VIS using model images, one with a single Gaussian and another that mimics the internal structures of giant molecular clouds. The result shows that the better uv coverage with TP2VIS visibilities helps the deconvolution process and reproduces the model image within errors of only 5% over two orders of magnitude in flux.

New measurements of polarized radio emission from a barred spiral galaxy have allowed researchers to determine the galactic magnetic field, and to link it to interstellar gas flow in the bar region. Their results suggest that magnetic stress may be an efficient way of fuelling the supermassive black hole thought to exist in the active galactic nucleus of many galaxies.

Modern interferometers routinely provide radio-astronomical images down to subarcsecond resolution. However, interferometers filter out spatial scales larger than those sampled by the shortest baselines, which affects the measurement of both spatial and spectral features. Complementary single-dish data are vital for recovering the true flux distribution of spatially resolved astronomical sources with such extended emission. In this work, we provide an overview of the prominent available methods to combine single-dish and interferometric observations. We test each of these methods in the framework of the CASA data analysis software package on both synthetic continuum and observed spectral data sets. We develop a set of new assessment tools that are generally applicable to all radio-astronomical cases of data combination. Applying these new assessment diagnostics, we evaluate the methods' performance and demonstrate the significant improvement of the combined results in comparison to purely interferometric reductions. We provide combination and assessment scripts as add-on material. Our results highlight the advantage of using data combination to ensure high-quality science images of spatially resolved objects.

This BoF is a continuation of the ADASS FADS tradition of yore, which aims tostimulate discussion (or at least awareness) about the non-technical aspects of our trade.This year, as we expected, it proved to be difficult to have a real discussion by means of Zoom. But the Metis polls and the DisCord log show that we have nevertheless beensuccesful in getting people to (begin to) think about the wayUsers, Developers andManagers work together, inside and between our MultiVerse of Bubbles. Next year wewill try to focus this discussion by means of a Proxy demonstrator. We feel that there isa world to be won.