Seeing the forest and the trees: a radio investigation of the ULIRG Mrk 273

Galaxy mergers have been observed to trigger nuclear activity by feeding gas to the central supermassive black hole. One such class of objects are Ultra Luminous InfraRed Galaxies (ULIRGs), which are mostly late stage major mergers of gas-rich galaxies. Recently, large-scale (∼100 kpc) radio continuum emission has been detected in a select number of ULIRGs, all of which also harbour powerful Active Galactic Nuclei (AGN). This hints at the presence of large-scale radio emission being evidence for nuclear activity. Exploring the origin of this radio emission and its link to nuclear activity requires high sensitivity multi-frequency data. We present such an analysis of the ULIRG Mrk 273. Using the International LOFAR telescope (ILT), we detected spectacular large-scale arcs in this system. This detection includes, for the first time, a giant ∼190 kpc arc in the north. We propose these arcs are fuelled by a low power radio AGN triggered by the merger. We also identified a bright ∼45 kpc radio ridge, which is likely related to the ionised gas nebula in that region. We combined this with high sensitivity data from APERture Tile In Focus (Apertif) and archival data from the Very Large Array (VLA) to explore the spectral properties. The ILT simultaneously allowed us to probe the nucleus at a resolution of ∼0.3″, where we detected three components, and, for the first time, diffuse emission around these components. Combining this with archival high frequency VLA images of the nucleus allowed us to detect absorption in one component, and a steep spectrum radio AGN in another. We then extrapolate from this case study to the importance of investigating the presence of radio emission in more ULIRGs and what it can tell us about the link between mergers and the presence of radio activity

Chromatic periodic activity down to 120 MHz in a Fast Radio Burst

Fast radio bursts (FRBs) are extragalactic astrophysical transients whose brightness requires emitters that are highly energetic, yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected between 300 MHz and 8 GHz, but lower-frequency emission has remained elusive. A subset of FRBs is known to repeat, and one of those sources, FRB 20180916B, does so with a 16.3 day activity period. Using simultaneous Apertif and LOFAR data, we show that FRB 20180916B emits down to 120 MHz, and that its activity window is both narrower and earlier at higher frequencies. Binary wind interaction models predict a narrower periodic activity window at lower frequencies, which is the opposite of our observations. Our detections establish that low-frequency FRB emission can escape the local medium. For bursts of the same fluence, FRB 20180916B is more active below 200 MHz than at 1.4 GHz. Combining our results with previous upper-limits on the all-sky FRB rate at 150 MHz, we find that there are 3-450 FRBs/sky/day above 50 Jy ms at 90% confidence. We are able to rule out the scenario in which companion winds cause FRB periodicity. We also demonstrate that some FRBs live in clean environments that do not absorb or scatter low-frequency radiation.Comment: 50 pages, 14 figures, 3 tables, submitte

ONNX model trained on weather prediction dataset

Neural Network model in ONNX format trained on the Weather Prediction dataset, specifically the weather_prediction_dataset_light.csv version of the data. The model predicts the season based on the weather at the De Bilt weather station during a single month. The model training is described in a repository related to the Deep Insight and Neural Network Analysis (DIANNA) project

PowerSensor3

PowerSensor is a low-cost, custom-built device that measures the instantaneous power consumption of GPUs and other devices at a high time resolution

PowerSensor3

<h2>What's Changed</h2> <ul> <li>Fix typo in docs by @loostrum in https://github.com/nlesc-recruit/PowerSensor3/pull/147</li> <li>Update psconfig usage by @loostrum in https://github.com/nlesc-recruit/PowerSensor3/pull/142</li> <li>Bump actions/checkout from 3 to 4 by @dependabot in https://github.com/nlesc-recruit/PowerSensor3/pull/143</li> <li>Print sensor pair numbers in psconfig output. by @loostrum in https://github.com/nlesc-recruit/PowerSensor3/pull/148</li> <li>Pin documentation build depdencies to versions at time of last successful run (Jul 2023) by @loostrum in https://github.com/nlesc-recruit/PowerSensor3/pull/151</li> <li>Add option to invert polarity of sensor by @loostrum in https://github.com/nlesc-recruit/PowerSensor3/pull/150</li> </ul> <p><strong>Full Changelog</strong>: https://github.com/nlesc-recruit/PowerSensor3/compare/v1.3.2...v1.3.3</p>If you use this software, please cite it using the metadata from this file

dianna

What's Changed 386 dashboard selection method for xai method by @laurasootes in https://github.com/dianna-ai/dianna/pull/416 Pin prospector version to avoid pyroma install error by @loostrum in https://github.com/dianna-ai/dianna/pull/424 update test instructions by @cwmeijer in https://github.com/dianna-ai/dianna/pull/425 378 update button for execution by @geek-yang in https://github.com/dianna-ai/dianna/pull/396 Fixed error message with method selection and removed unnecessary run… by @cpranav93 in https://github.com/dianna-ai/dianna/pull/431 make label a required argument (Fixes #131) by @cwmeijer in https://github.com/dianna-ai/dianna/pull/426 Unpin prospector by @egpbos in https://github.com/dianna-ai/dianna/pull/442 429 implement recent dashboard layout changes to text tab by @laurasootes in https://github.com/dianna-ai/dianna/pull/438 refactor rise and fix linter issues (refs 447) by @cwmeijer in https://github.com/dianna-ai/dianna/pull/450 New Contributors @cpranav93 made their first contribution in https://github.com/dianna-ai/dianna/pull/431 Full Changelog: https://github.com/dianna-ai/dianna/compare/v0.6.0...v0.7.0</p

dianna

What's Changed Make input text lowercase before tokenizing by @loostrum in https://github.com/dianna-ai/dianna/pull/463 Add visualization for timeseries by @stefsmeets in https://github.com/dianna-ai/dianna/pull/491 Cache python install in github actions by @stefsmeets in https://github.com/dianna-ai/dianna/pull/482 400 implement label file upload support by @cpranav93 in https://github.com/dianna-ai/dianna/pull/451 Combine special characters into single token by @loostrum in https://github.com/dianna-ai/dianna/pull/462 467 write a short readme on how to start the dashboard by @laurasootes in https://github.com/dianna-ai/dianna/pull/497 Added label file upload for text by @cpranav93 in https://github.com/dianna-ai/dianna/pull/495 Add notebook requirement by @stefsmeets in https://github.com/dianna-ai/dianna/pull/499 Refactor dashboard by @stefsmeets in https://github.com/dianna-ai/dianna/pull/502 Make paths independent in notebooks by @stefsmeets in https://github.com/dianna-ai/dianna/pull/509 Add button to show/hide parameters by @stefsmeets in https://github.com/dianna-ai/dianna/pull/504 create label file for ResNet model by @laurasootes in https://github.com/dianna-ai/dianna/pull/513 Add license by @WillemSpek in https://github.com/dianna-ai/dianna/pull/516 Downgrade dash by @WillemSpek in https://github.com/dianna-ai/dianna/pull/530 517 dashboard robust path by @WillemSpek in https://github.com/dianna-ai/dianna/pull/518 add time step masking (refs #477) by @cwmeijer in https://github.com/dianna-ai/dianna/pull/494 Add pre-commit for linting/auto-formatting by @stefsmeets in https://github.com/dianna-ai/dianna/pull/508 435 long text does not fit in dashboard explanation image by @laurasootes in https://github.com/dianna-ai/dianna/pull/526 529 update readmes and roadmap by @elboyran in https://github.com/dianna-ai/dianna/pull/532 Run CI only on PRs ready for review by @stefsmeets in https://github.com/dianna-ai/dianna/pull/533 478 rise for time series by @cwmeijer in https://github.com/dianna-ai/dianna/pull/506 539 polish notebook rise timeseries by @geek-yang in https://github.com/dianna-ai/dianna/pull/540 New Contributors @stefsmeets made their first contribution in https://github.com/dianna-ai/dianna/pull/491 @WillemSpek made their first contribution in https://github.com/dianna-ai/dianna/pull/516 Full Changelog: https://github.com/dianna-ai/dianna/compare/v0.7.0...v0.8.0</p

LOFAR discovery and wide-band characterisation of an ultra-steep spectrum AGN radio remnant associated with Abell 1318

We present the discovery of a very extended (550 kpc) and low-surface-brightness (3.3 µJy arcsec−2 at 144 MHz) radio emission region in Abell 1318. These properties are consistent with its characterisation as an active galactic nucleus (AGN) remnant radio plasma, based on its morphology and radio spectral properties. We performed a broad-band (54–1400 MHz) radio spectral index and curvature analysis using LOFAR, uGMRT, and WSRT-APERTIF data. We also derived the radiative age of the detected emission, estimating a maximum age of 250 Myr. The morphology of the source is remarkably intriguing, with two larger, oval-shaped components and a thinner, elongated, and filamentary structure in between, plausibly reminiscent of two aged lobes and a jet. Based on archival Swift as well as SDSS data we performed an X-ray and optical characterisation of the system, whose virial mass was estimated to be ∼7.4 × 1013 M. This places A1318 in the galaxy group regime. Interestingly, the radio source does not have a clear optical counterpart embedded in it, thus, we propose that it is most likely an unusual AGN remnant of previous episode(s) of activity of the AGN hosted by the brightest group galaxy (∼2.6 × 1012 M), which is located at a projected distance of ∼170 kpc in the current epoch. This relatively high offset may be a result of IGrM sloshing sourced by a minor merger. The filamentary morphology of the source may suggest that the remnant plasma has been perturbed by the system dynamics, however, only future deeper X-ray observations will be able to address this question.</p