Feedback processes from active galactic nuclei (AGN) are thought to play a crucial role in regulating star formation in massive galaxies. Previous studies using Herschel have resulted in conflicting conclusions as to whether star formation is quenched, enhanced, or not affected by AGN feedback. We use new deep 850 µm observations from the SCUBA-2 Cosmology Legacy survey (S2CLS) to investigate star formation in a sample of X-ray selected AGN, probing galaxies up to L 0.5−7 keV = 10 46 erg s −1 . Here we present the results of our analysis on a sample of 1957 galaxies at 1 < z < 3, using both S2CLS and ancilliary data at seven additional wavelengths (24-500 µm) from Herschel and Spitzer. We perform a stacking analysis, binning our sample by redshift and X-ray luminosity. By fitting analytical spectral energy distributions (SEDs) to decompose contributions from cold and warm dust, we estimate star-formation rates for each 'average' source. We find that the average AGN in our sample resides in a star-forming host galaxy, with SFRs ranging from 80-600 M year −1 . Within each redshift bin, we see no trend of SFR with X-ray luminosity, instead finding a flat distribution of SFR across ∼3 orders of magnitude of AGN luminosity. By studying instantaneous X-ray luminosities and SFRs, we find no evidence that AGN activity affects star formation in host galaxies.

The Atacama Large Aperture Submillimeter Telescope (AtLAST) is a concept for a 50m class single-dish telescope that will provide high sensitivity, fast mapping of the (sub-)millimeter sky. Expected to be powered by renewable energy sources, and to be constructed in the Atacama desert in the 2030s, AtLAST's suite of up to six stateof-the-art instruments will take advantage of its large field of view and high throughput to deliver efficient continuum and spectroscopic observations of the faint, large-scale emission that eludes current facilities.The AtLAST design study project is currently supported by a Horizon 2020 grant aimed at studying the governance, telescope design, site selection, telescope operations, sustainable energy supply, and science drivers of the future AtLAST observatory. With quantified and specific science goals, we can begin to place technical specifications on the telescope and its instrumentation. As a first step in this process, we conducted a consultation on potential AtLAST science with the global (sub-)millimeter astrophysics community. The consultation involved nearly 100 scientists based in 22 countries, and the resulting 28 use cases indicate the breadth of transformational science that such a high-throughput facility could make possible: from exploring the prebiotic molecular chemistry of comets in our own Solar System, detecting the extended, diffuse cold gas in the circumgalactic medium of both our own and distant galaxies, to detailed measurements of the thermal, kinetic, and relativistic Sunyaev-Zeldovich effect and mapping of large-scale structure. Already these science cases define some core requirements for AtLAST's instrumentation: wide bandwidths, multichroic observations, high spectral resolution, fast mapping

Aims. We investigate the radio properties of a sample of 850 μm-selected sources from the SCUBA-2 Cosmology Legacy Survey (S2CLS) using new deep, low-frequency radio imaging of the Lockman Hole field from the Low Frequency Array. This sample consists of 53 sources, 41 of which are detected at >5σ at 150 MHz. Methods. Combining these data with additional observations at 324 MHz, 610 MHz, and 1.4 GHz from the Giant Metrewave Radio Telescope and the Jansky Very Large Array, we find a variety of radio spectral shapes and luminosities (L1.4 GHz ranging from ~4 × 1023−1 × 1025) within our sample despite their similarly bright submillimetre flux densities (>4 mJy). We characterise their spectral shapes in terms of multi-band radio spectral indices. Finding strong spectral flattening at low frequencies in ~20% of sources, we investigate the differences between sources with extremely flat low-frequency spectra and those with ‘normal’ radio spectral indices (α > −0.25). Results. As there are no other statistically significant differences between the two subgroups of our sample as split by the radio spectral index, we suggest that any differences are undetectable in galaxy-averaged properties that we can observe with our unresolved images, and likely relate to galaxy properties that we cannot resolve, on scales ≲1 kpc. We attribute the observed spectral flattening in the radio to free–free absorption, proposing that those sources with significant low-frequency spectral flattening have a clumpy distribution of star-forming gas. We estimate an average spatial extent of absorbing material of at most several hundred parsecs to produce the levels of absorption observed in the radio spectra. This estimate is consistent with the highest-resolution observations of submillimetre galaxies in the literature, which find examples of non-uniform dust distributions on scales of ~100 pc, with evidence for clumps and knots in the interstellar medium. Additionally, we find two bright (>6 mJy) S2CLS sources undetected at all other wavelengths. We speculate that these objects may be very high redshift sources, likely residing at z > 4.

The Atacama Large Aperture Submillimeter Telescope (AtLAST) is a concept for a 50m class single-dish telescope that will provide high sensitivity, fast mapping of the (sub-)millimeter sky. Expected to be powered by renewable energy sources, and to be constructed in the Atacama desert in the 2030s, AtLAST's suite of up to six stateof-the-art instruments will take advantage of its large field of view and high throughput to deliver efficient continuum and spectroscopic observations of the faint, large-scale emission that eludes current facilities.The AtLAST design study project is currently supported by a Horizon 2020 grant aimed at studying the governance, telescope design, site selection, telescope operations, sustainable energy supply, and science drivers of the future AtLAST observatory. With quantified and specific science goals, we can begin to place technical specifications on the telescope and its instrumentation. As a first step in this process, we conducted a consultation on potential AtLAST science with the global (sub-)millimeter astrophysics community. The consultation involved nearly 100 scientists based in 22 countries, and the resulting 28 use cases indicate the breadth of transformational science that such a high-throughput facility could make possible: from exploring the prebiotic molecular chemistry of comets in our own Solar System, detecting the extended, diffuse cold gas in the circumgalactic medium of both our own and distant galaxies, to detailed measurements of the thermal, kinetic, and relativistic Sunyaev-Zeldovich effect and mapping of large-scale structure. Already these science cases define some core requirements for AtLAST's instrumentation: wide bandwidths, multichroic observations, high spectral resolution, fast mapping