Associated Universities, Inc.

To reproduce observed galaxy properties, cosmological simulations require that massive galaxies experience feedback from active galactic nuclei, which regulates star formation within those galaxies. However, the energetics and timescales of these feedback processes are poorly constrained. We combined optical, infrared, submillimeter, and radio observations of the active galaxy VV 340a, which is hosting a low-power jet launched from a supermassive black hole at its center. We found that the jet undergoes precession, with a period of (8.2 ± 5.5) × 105 years, and drives an outflow of gas at a rate of 19.4 ± 7.9 solar masses per year. The jet shocks the gas, producing highly ionized plasma that extends several kiloparsecs from the nucleus. The outflow ejects sufficient gas from the galaxy to influence its star-formation rate.

We report the bulk soil electrical conductivity and relative permittivity at a site in the Canadian High Arctic (79.37980 degrees N, 90.99885 degrees W). The soil parameters are determined using impedance measurements of a dipole antenna mounted horizontally 52 cm above the surface. The antenna is part of the Mapper of the IGM Spin Temperature (MIST) radio cosmology experiment. The measurements were conducted on July 17-28, 2022, every 111 minutes, and in the frequency range 25-125 MHz. To estimate the soil parameters, we compare the impedance measurements with models produced from numerical electromagnetic simulations of the antenna, considering single- and two-layer soil models. Our best-fit soil model corresponds to a two-layer model in which the electrical parameters are consistent with unfrozen soil at the top and frozen soil underneath. The best-fit parameters further agree with measurements done at other Arctic sites with more traditional techniques, such as capacitively-coupled resistivity, electrical resistivity tomography, and ground-penetrating radar.

Advanced Data Products (ADPs) are increasingly central to enhancing the efficiency and scientific output of radio observatories. Designed to bridge the gap between raw observational data and science-ready results, ADPs reduce processing overhead, improve reproducibility, and enable a wider range of researchers to engage with complex datasets. Their benefits include accelerated research, interoperability across archives, and reduced duplication of computational effort, with direct implications for sustainability. This paper summarizes the outcomes of the ADP2024 workshop, which reviewed current practices at major facilities including ALMA, SKAO, LOFAR, VLA, and ESO. We highlight lessons learned from ongoing initiatives. Critical issues identified include standardization, provenance tracking, quality assurance, and long-term maintenance. We conclude that ADPs represent a key step toward sustainable, accessible, and scientifically optimized data ecosystems in radio astronomy.

We present JWST MIRI MRS, NIRSpec, NIRCam, and MIRI imaging observations of 3C 305, a radio galaxy with a compact jet that is confined within the galaxy. We use the H2 0-0 S(1)-S(7) lines, several mid-IR fine-structure lines, and PAH emission in the MIRI MRS spectrum to conduct a multiphase study of the radio jet's impact on the interstellar medium. Multiple tracers, including H2/PAH 11.3 um and [Fe II] 5.34 um, provide evidence for shocks at the jet termination locations. Two Gaussian components are required to reproduce the warm H2 kinematics adequately, with one representing the bulk low-velocity component and the other corresponding to an outflow. The ionized gas reaches higher outflow velocities than the H2 gas, and the sharp increase in velocity at the jet hotspots points to jet-driven outflows. We fit the H2 excitation diagram with a power-law temperature distribution and find that the hotspots exhibit flatter slopes, indicating a larger warm/hot gas mass fraction at these locations. Our MAPPINGS line-ratio analysis indicates that most of the mid-IR ionized gas can be fit by a shock-plus-precursor model. We find that strong radiative losses dominated by line cooling, together with moderate kinetic power in the molecular and ionized gas outflows, can account for the estimated jet power, indicating high jet coupling efficiency in 3C 305. Together with other studies of multiphase gas, our results show that jets can efficiently shock-heat and accelerate the gas they encounter, driving massive, kiloparsec-scale, multiphase outflows.

We report on the H I content of an isolated, compact group of six dwarf galaxies at a distance of 145 Mpc. The distribution and kinematics of the H ​​​​​​ I , including multiple gaseous bridges, indicate the group is a gravitationally bound system. The H I maps further reveal two newly discovered dwarf satellites easily identified by their gas but only barely visible in optical images. The four dwarf group members previously identified in the Sloan Digital Sky Survey have 9.06 < log( M _* / M _⊙ ) < 9.43 and 9.42 < log( M _H _I / M _⊙ ) < 9.73. The two newly discovered dwarf satellites have log( M _* / M _⊙ ) = 6.10 with log(M _H _I / M _⊙ ) = 8.71 and log( M _* / M _⊙ ) = 7.07 with log( M _H _I / M _⊙ ) = 9.18. New Gemini optical spectra link the H I detections and their optical counterparts. The group’s 3D velocity dispersion (188 km s ^−1 ), mass-to-light ratio ( M / L _B ∼ 44), dynamical-to-baryonic mass ratio ( M _dyn / M _bar ∼ 21), size (69 kpc), and gas fraction (0.56) are all consistent with the compact dwarf groups in the TNG50 simulation. The group has a top-heavy satellite mass function that is inconsistent with predictions for LMC-sized hosts and may instead be two or more groups coming together. A Voronoi tessellation reveals the group resides in a tendril outside the intersection of two filaments. These intermediate-density environments within the large-scale structure provide the conditions needed for groups of star-forming, gas-rich dwarf galaxies to form and eventually merge. Our results further show that it is possible to uncover fainter dwarf satellites around dwarf galaxy hosts via H I maps.