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How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate? (2024)
Journal Article
Petley, J. W., Morabito, L. K., Rankine, A. L., Richards, G. T., Thomas, N. L., Alexander, D. M., …Kolwa, S. (2024). How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?. Monthly Notices of the Royal Astronomical Society, 529(3), 1995-2007. https://doi.org/10.1093/mnras/stae626

The origin of radio emission in different populations of radio-quiet quasars is relatively unknown, but recent work has uncovered various drivers of increased radio-detection fraction. In this work, we pull together three known factors: optical colou... Read More about How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?.

Nuclear regions as seen with LOFAR international baselines: A high-resolution study of the recurrent activity (2024)
Journal Article
Jurlin, N., Morganti, R., Sweijen, F., Morabito, L. K., Brienza, M., Barthel, P., & Miley, G. K. (2024). Nuclear regions as seen with LOFAR international baselines: A high-resolution study of the recurrent activity. Astronomy & Astrophysics, 682, Article A118. https://doi.org/10.1051/0004-6361/202245821

Context. Radio galaxies dominate the sky at radio wavelengths and represent an essential piece in the galaxy evolution puzzle. High-resolution studies focussed on statistical samples of radio galaxies are expected to shed light on the triggering mech... Read More about Nuclear regions as seen with LOFAR international baselines: A high-resolution study of the recurrent activity.

Exploring the radio loudness of SDSS quasars with spectral stacking (2024)
Journal Article
Arnaudova, M. I., Smith, D. J. B., Hardcastle, M. J., Das, S., Drake, A., Duncan, K., …Tasse, C. (2024). Exploring the radio loudness of SDSS quasars with spectral stacking. Monthly Notices of the Royal Astronomical Society, 528(3), 4547-4567. https://doi.org/10.1093/mnras/stae233

We use new 144 MHz observations over 5634 deg2 from the LOFAR (Low Frequency Array) Two-metre Sky Survey (LoTSS) to compile the largest sample of uniformly selected, spectroscopically confirmed quasars from the 14th data release of the Sloan Digital... Read More about Exploring the radio loudness of SDSS quasars with spectral stacking.

MIGHTEE: multi-wavelength counterparts in the COSMOS field (2023)
Journal Article
Whittam, I., Prescott, M., Hale, C., Jarvis, M. .., Heywood, I., An, F., …White, S. (2024). MIGHTEE: multi-wavelength counterparts in the COSMOS field. Monthly Notices of the Royal Astronomical Society, 527(2), 3231-3245. https://doi.org/10.1093/mnras/stad3307

In this paper we combine the Early Science radio continuum data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey, with optical and near-infrared data and release the cross-matched catalogues. The radio data used in... Read More about MIGHTEE: multi-wavelength counterparts in the COSMOS field.

Subarcsecond-resolution Imaging of M51 with the International LOFAR Telescope (2023)
Journal Article
Venkattu, D., Lundqvist, P., Torres, M. P., Morabito, L., Moldón, J., Conway, J., …Tasse, C. (2023). Subarcsecond-resolution Imaging of M51 with the International LOFAR Telescope. Astrophysical Journal, 953(2), Article 157. https://doi.org/10.3847/1538-4357/ace2c1

We present an International LOFAR Telescope (ILT) subarcsecond-resolution image of the nearby galaxy M51 with a beam size of 0farcs436 × 0farcs366 and rms of 46 μJy. We compare this image with a European VLBI Network study of M51 and discuss the supe... Read More about Subarcsecond-resolution Imaging of M51 with the International LOFAR Telescope.

A Quick Look at the 3 GHz Radio Sky. II. Hunting for DRAGNs in the VLA Sky Survey (2023)
Journal Article
Gordon, Y. A., Rudnick, L., Andernach, H., Morabito, L. K., O’Dea, C. P., Achong, K., …Vantyghem, A. N. (2023). A Quick Look at the 3 GHz Radio Sky. II. Hunting for DRAGNs in the VLA Sky Survey. Astrophysical Journal Supplement, 267(2), Article 37. https://doi.org/10.3847/1538-4365/acda30

Active galactic nuclei (AGNs) can often be identified in radio images as two lobes, sometimes connected to a core by a radio jet. This multicomponent morphology unfortunately creates difficulties for source finders, leading to components that are (a)... Read More about A Quick Look at the 3 GHz Radio Sky. II. Hunting for DRAGNs in the VLA Sky Survey.

VLBI imaging of high-redshift galaxies and protoclusters at low radio frequencies with the International LOFAR Telescope (2023)
Journal Article
Cordun, C. M., Timmerman, R., Miley, G. K., van Weeren, R. J., Sweijen, F., Morabito, L. K., & Röttgering, H. J. A. (2023). VLBI imaging of high-redshift galaxies and protoclusters at low radio frequencies with the International LOFAR Telescope. Astronomy & Astrophysics, 676, Article A29. https://doi.org/10.1051/0004-6361/202346320

It is generally known that luminous, ultra-steep spectrum radio sources are preferentially associated with massive galaxies at high redshifts. In this paper, we describe a pilot project directed at such objects to demonstrate the feasibility and impo... Read More about VLBI imaging of high-redshift galaxies and protoclusters at low radio frequencies with the International LOFAR Telescope.

The LOFAR Two-metre Sky Survey: Deep Fields Data Release 1. V. Survey description, source classifications and host galaxy properties (2023)
Journal Article
Best, P., Kondapally, R., Williams, W., Cochrane, R., Duncan, K., Hale, C., …van Weeren, R. (2023). The LOFAR Two-metre Sky Survey: Deep Fields Data Release 1. V. Survey description, source classifications and host galaxy properties. Monthly Notices of the Royal Astronomical Society, 523(2), 1729–1755. https://doi.org/10.1093/mnras/stad1308

Source classifications, stellar masses and star formation rates are presented for ≈80,000 radio sources from the first data release of the Low Frequency Array Two-metre Sky Survey (LoTSS) Deep Fields, which represents the widest deep radio survey eve... Read More about The LOFAR Two-metre Sky Survey: Deep Fields Data Release 1. V. Survey description, source classifications and host galaxy properties.

Identifying Active Galactic Nuclei at z ∼ 3 from the HETDEX Survey Using Machine Learning (2023)
Journal Article
Tardugno Poleo, V., Finkelstein, S. L., Leung, G., Mentuch Cooper, E., Gebhardt, K., Farrow, D. J., …Liu, C. (2023). Identifying Active Galactic Nuclei at z ∼ 3 from the HETDEX Survey Using Machine Learning. Astronomical Journal, 165(4), Article 153. https://doi.org/10.3847/1538-3881/acba92

We used data from the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) to study the incidence of AGN in continuum-selected galaxies at z ∼ 3. From optical and infrared imaging in the 24 deg2 Spitzer HETDEX Exploratory Large Area survey, we cons... Read More about Identifying Active Galactic Nuclei at z ∼ 3 from the HETDEX Survey Using Machine Learning.

Piercing the dusty veil of hyper-luminous infrared galaxies: Sub-arcsecond 144 MHz ILT observations of HLIRGs in the Lockman Hole (2023)
Journal Article
Sweijen, F., Lyu, Y., Wang, L., Gao, F., Röttgering, H., van Weeren, R., …Bondi, M. (2023). Piercing the dusty veil of hyper-luminous infrared galaxies: Sub-arcsecond 144 MHz ILT observations of HLIRGs in the Lockman Hole. Astronomy & Astrophysics, 671, Article A85. https://doi.org/10.1051/0004-6361/202244378

Context. Hyper-luminous infrared galaxies (HLIRGs) are among the most extreme systems in the Universe. With infrared (IR) luminosities of LIR > 1013 L⊙ they can have IR-derived star formation rates (SFRs) exceeding 103 M⊙ yr−1. Theoretical models hav... Read More about Piercing the dusty veil of hyper-luminous infrared galaxies: Sub-arcsecond 144 MHz ILT observations of HLIRGs in the Lockman Hole.

V-LoTSS: The circularly polarised LOFAR Two-metre Sky Survey (2023)
Journal Article
Callingham, J., Shimwell, T., Vedantham, H., Bassa, C., O’Sullivan, S., Yiu, T., …Zheng, J. (2023). V-LoTSS: The circularly polarised LOFAR Two-metre Sky Survey. Astronomy & Astrophysics, 670, Article A124. https://doi.org/10.1051/0004-6361/202245567

We present the detection of 68 sources from the most sensitive radio survey in circular polarisation conducted to date. We used the second data release of the 144 MHz LOFAR Two-metre Sky Survey to produce circularly polarised maps with a median noise... Read More about V-LoTSS: The circularly polarised LOFAR Two-metre Sky Survey.

A low-frequency sub-arcsecond view of powerful radio galaxies in rich-cluster environments: 3C 34 and 3C 320 (2023)
Journal Article
Mahatma, V., Basu, A., Hardcastle, M., Morabito, L., & van Weeren, R. (2023). A low-frequency sub-arcsecond view of powerful radio galaxies in rich-cluster environments: 3C 34 and 3C 320. Monthly Notices of the Royal Astronomical Society, 520(3), 4427-4442. https://doi.org/10.1093/mnras/stad395

Models of radio galaxy physics have been primarily based on high frequency (≥1 GHz) observations of their jets, hotspots, and lobes. Without highly resolved low-frequency observations, which provide information on older plasma, our understanding of t... Read More about A low-frequency sub-arcsecond view of powerful radio galaxies in rich-cluster environments: 3C 34 and 3C 320.

Measuring cavity powers of active galactic nuclei in clusters using a hybrid X-ray–radio method. A new window on feedback opened by subarcsecond LOFAR-VLBI observations (2022)
Journal Article
Timmerman, R., van Weeren, R., Botteon, A., Röttgering, H., McNamara, B., Sweijen, F., …Morabito, L. (2022). Measuring cavity powers of active galactic nuclei in clusters using a hybrid X-ray–radio method. A new window on feedback opened by subarcsecond LOFAR-VLBI observations. Astronomy & Astrophysics, 668, Article A65. https://doi.org/10.1051/0004-6361/202243936

Measurements of the quantity of radio-mode feedback injected by an active galactic nucleus into the cluster environment have mostly relied on X-ray observations, which reveal cavities in the intracluster medium excavated by the radio lobes. However,... Read More about Measuring cavity powers of active galactic nuclei in clusters using a hybrid X-ray–radio method. A new window on feedback opened by subarcsecond LOFAR-VLBI observations.

MIGHTEE: deep 1.4 GHz source counts and the sky temperature contribution of star-forming galaxies and active galactic nuclei (2022)
Journal Article
Hale, C., Whittam, I., Jarvis, M., Best, P., Thomas, N., Heywood, I., …Taylor, A. (2023). MIGHTEE: deep 1.4 GHz source counts and the sky temperature contribution of star-forming galaxies and active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 520(2), 2668 - 2691. https://doi.org/10.1093/mnras/stac3320

We present deep 1.4 GHz source counts from ∼5 deg2 of the continuum Early Science data release of the MeerKAT International Gigahertz Tiered Extragalactic Exploration survey down to S1.4GHz ∼15 μ Jy. Using observations over two extragalactic fields (... Read More about MIGHTEE: deep 1.4 GHz source counts and the sky temperature contribution of star-forming galaxies and active galactic nuclei.

A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems (2022)
Journal Article
Andonie, C., Alexander, D. M., Rosario, D., Laloux, B., Georgakakis, A., Morabito, L. K., …Shankar, F. (2022). A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems. Monthly Notices of the Royal Astronomical Society, 517(2), 2577-2598. https://doi.org/10.1093/mnras/stac2800

To understand the active galactic nuclei (AGNs) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive mul... Read More about A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems.

MIGHTEE: the nature of the radio-loud AGN population (2022)
Journal Article
Whittam, I., Jarvis, M., Hale, C., Prescott, M., Morabito, L., Heywood, I., …Vaccari, M. (2022). MIGHTEE: the nature of the radio-loud AGN population. Monthly Notices of the Royal Astronomical Society, 516(1), 245-263. https://doi.org/10.1093/mnras/stac2140

We study the nature of the faint radio source population detected in the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science data in the COSMOS field, focusing on the properties of the radio-loud active galactic nuclei... Read More about MIGHTEE: the nature of the radio-loud AGN population.

Identifying active galactic nuclei via brightness temperature with sub-arcsecond international LOFAR Telescope observations (2022)
Journal Article
Morabito, L. K., Sweijen, F., Radcliffe, J., Best, P., Kondapally, R., Bondi, M., …Rivera, G. C. (2022). Identifying active galactic nuclei via brightness temperature with sub-arcsecond international LOFAR Telescope observations. Monthly Notices of the Royal Astronomical Society, 515(4), 5758-5774. https://doi.org/10.1093/mnras/stac2129

Identifying active galactic nuclei (AGNs) and isolating their contribution to a galaxy’s energy budget is crucial for studying the co-evolution of AGNs and their host galaxies. Brightness temperature (Tb) measurements from high-resolution radio obser... Read More about Identifying active galactic nuclei via brightness temperature with sub-arcsecond international LOFAR Telescope observations.

Seeing the forest and the trees: a radio investigation of the ULIRG Mrk 273 (2022)
Journal Article
Kukreti, P., Morganti, R., Bondi, M., Oosterloo, T., Tadhunter, C., Morabito, L. K., …Ziemke, J. (2022). Seeing the forest and the trees: a radio investigation of the ULIRG Mrk 273. Astronomy & Astrophysics, 664, Article A25. https://doi.org/10.1051/0004-6361/202243174

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 galaxi... Read More about Seeing the forest and the trees: a radio investigation of the ULIRG Mrk 273.

Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars (2022)
Journal Article
Petley, J., Morabito, L., Alexander, D., Rankine, A., Fawcett, V., Rosario, D., …Drabent, A. (2022). Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars. Monthly Notices of the Royal Astronomical Society, 515(4), 5159-5174. https://doi.org/10.1093/mnras/stac2067

Broad Absorption Line Quasars (BALQSOs) show strong signatures of powerful outflows, with the potential to alter the cosmic history of their host galaxies. These signatures are only seen in ∼10% of optically selected quasars, although the fraction si... Read More about Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars.

Subarcsecond view on the high-redshift blazar GB 1508+5714 by the International LOFAR Telescope (2022)
Journal Article
Kappes, A., Burd, P., Kadler, M., Ghisellini, G., Perucho, M., Brüggen, M., …Moldon, J. (2022). Subarcsecond view on the high-redshift blazar GB 1508+5714 by the International LOFAR Telescope. Astronomy & Astrophysics, 663, Article A44. https://doi.org/10.1051/0004-6361/202141720

Context. Studies of the most distant active galactic nuclei (AGNs) allow us to test our current understanding of the physics present in radio-jetted AGNs across a range of environments, and probe their interactions with these environments. The decrea... Read More about Subarcsecond view on the high-redshift blazar GB 1508+5714 by the International LOFAR Telescope.

Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter (2022)
Journal Article
Fawcett, V., Alexander, D., Rosario, D., Klindt, L., Lusso, E., Morabito, L., & Calistro Rivera, G. (2022). Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter. Monthly Notices of the Royal Astronomical Society, 513(1), 1254-1274. https://doi.org/10.1093/mnras/stac945

We have recently found fundamental differences in the radio properties of red quasars when compared to typical blue quasars. In this paper, we use data from the X-shooter spectrograph on the Very Large Telescope, providing spectral coverage from ∼300... Read More about Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter.

The LOFAR Two-metre Sky Survey (2022)
Journal Article
Shimwell, T., Hardcastle, M., Tasse, C., Best, P., Röttgering, H., Williams, W., …Zheng, J. (2022). The LOFAR Two-metre Sky Survey. Astronomy & Astrophysics, 659, Article A1. https://doi.org/10.1051/0004-6361/202142484

In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120–168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44◦300 and 1h00m +28◦000 an... Read More about The LOFAR Two-metre Sky Survey.

Deep sub-arcsecond wide-field imaging of the Lockman Hole field at 144 MHz (2022)
Journal Article
Sweijen, F., van Weeren, R., Röttgering, H., Morabito, L., Jackson, N., Offringa, A., …Thomson, A. (2022). Deep sub-arcsecond wide-field imaging of the Lockman Hole field at 144 MHz. Nature Astronomy, 6(3), 350-356. https://doi.org/10.1038/s41550-021-01573-z

Recent observations of the radio sky show that the vast majority of sources detected at 144 MHz are unresolved at the typical resolution of a few arcseconds1, demonstrating the need for sub-arcsecond-resolution surveys to make detailed studies. At lo... Read More about Deep sub-arcsecond wide-field imaging of the Lockman Hole field at 144 MHz.

Sub-arcsecond imaging with the International LOFAR Telescope (2022)
Journal Article
Jackson, N., Badole, S., Morgan, J., Chhetri, R., Prūsis, K., Nikolajevs, A., …Zucca, P. (2022). Sub-arcsecond imaging with the International LOFAR Telescope. Astronomy & Astrophysics, 658, Article A2. https://doi.org/10.1051/0004-6361/202140649

The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 MHz. However, it is technicall... Read More about Sub-arcsecond imaging with the International LOFAR Telescope.

Origin of the ring structures in Hercules A. Sub-arcsecond 144 MHz to 7 GHz observations (2022)
Journal Article
Timmerman, R., van Weeren, R., Callingham, J., Cotton, W., Perley, R., Morabito, L., …Brunetti, G. (2022). Origin of the ring structures in Hercules A. Sub-arcsecond 144 MHz to 7 GHz observations. Astronomy & Astrophysics, 658, Article A5. https://doi.org/10.1051/0004-6361/202140880

The prominent radio source Hercules A features complex structures in its radio lobes. Although it is one of the most comprehensively studied sources in the radio sky, the origin of the ring structures in the Hercules A radio lobes remains an open que... Read More about Origin of the ring structures in Hercules A. Sub-arcsecond 144 MHz to 7 GHz observations.

Pushing sub-arcsecond resolution imaging down to 30 MHz with the trans-European International LOFAR Telescope (2022)
Journal Article
Groeneveld, C., van Weeren, R., Miley, G., Morabito, L., de Gasperin, F., Callingham, J., …Röttgering, H. (2022). Pushing sub-arcsecond resolution imaging down to 30 MHz with the trans-European International LOFAR Telescope. Astronomy & Astrophysics, 658, Article A9. https://doi.org/10.1051/0004-6361/202141352

Relatively little information is available about the Universe at ultra-low radio frequencies (ULF; i.e., below 50 MHz), although the ULF spectral window contains a wealth of unique diagnostics for studying galactic and extragalactic phenomena. Subarc... Read More about Pushing sub-arcsecond resolution imaging down to 30 MHz with the trans-European International LOFAR Telescope.

The resolved jet of 3C 273 at 150 MHz: Sub-arcsecond imaging with the LOFAR international baselines (2022)
Journal Article
Harwood, J., Mooney, S., Morabito, L., Quinn, J., Sweijen, F., Groeneveld, C., …Moldon, J. (2022). The resolved jet of 3C 273 at 150 MHz: Sub-arcsecond imaging with the LOFAR international baselines. Astronomy & Astrophysics, 658, Article A8. https://doi.org/10.1051/0004-6361/202141579

Context. Since its discovery in 1963, 3C 273 has become one of the most widely studied quasars with investigations spanning the electromagnetic spectrum. While much has therefore been discovered about this historically notable source, its low-frequen... Read More about The resolved jet of 3C 273 at 150 MHz: Sub-arcsecond imaging with the LOFAR international baselines.

High-resolution international LOFAR observations of 4C 43.15. Spectral ages and injection indices in a high-z radio galaxy (2022)
Journal Article
Sweijen, F., Morabito, L., Harwood, J., van Weeren, R., Röttgering, H., Callingham, J., …Moldon, J. (2022). High-resolution international LOFAR observations of 4C 43.15. Spectral ages and injection indices in a high-z radio galaxy. Astronomy & Astrophysics, 658, Article A3. https://doi.org/10.1051/0004-6361/202039871

It has long been known that radio sources with the steepest spectra are preferentially associated with the most distant galaxies, the α − z relation, but the reason for this relation is an open question. The spatial distribution of spectra in high-z... Read More about High-resolution international LOFAR observations of 4C 43.15. Spectral ages and injection indices in a high-z radio galaxy.

Unmasking the history of 3C 293 with LOFAR sub‐arcsecond imaging (2021)
Conference Proceeding
Kukreti, P., Morganti, R., Shimwell, T. W., Morabito, L. K., Beswick, R. J., Brienza, M., …Gasperin, F. D. (2021). Unmasking the history of 3C 293 with LOFAR sub‐arcsecond imaging. . https://doi.org/10.1002/asna.20210107

Active galactic nuclei show episodic activity, which can be evident in galaxies that exhibit restarted radio jets. These restarted jets can interact with their environment, leaving signatures in the radio spectral energy distribution. Tracing these s... Read More about Unmasking the history of 3C 293 with LOFAR sub‐arcsecond imaging.

Spectral analysis of spatially resolved 3C295 (sub-arcsecond resolution) with the International LOFAR Telescope (2021)
Journal Article
Bonnassieux, E., Sweijen, F., Brienza, M., Rajpurohit, K., Riseley, C., Bonafede, A., …van Weeren, R. (2022). Spectral analysis of spatially resolved 3C295 (sub-arcsecond resolution) with the International LOFAR Telescope. Astronomy & Astrophysics, 658, Article A10. https://doi.org/10.1051/0004-6361/202141731

3C295 is a bright, compact steep spectrum source with a well-studied integrated radio spectral energy distribution (SED) from 132 MHz to 15 GHz. However, spatially resolved spectral studies have been limited due to a lack of high resolution images at... Read More about Spectral analysis of spatially resolved 3C295 (sub-arcsecond resolution) with the International LOFAR Telescope.

High-resolution imaging with the International LOFAR Telescope: Observations of the gravitational lenses MG 0751+2716 and CLASS B1600+434 (2021)
Journal Article
Badole, S., Venkattu, D., Jackson, N., Wallace, S., Dhandha, J., Hartley, P., …McKean, J. (2022). High-resolution imaging with the International LOFAR Telescope: Observations of the gravitational lenses MG 0751+2716 and CLASS B1600+434. Astronomy & Astrophysics, 658, Article A7. https://doi.org/10.1051/0004-6361/202141227

We present Low-Frequency Array (LOFAR) telescope observations of the radio-loud gravitational lens systems MG 0751+2716 and CLASS B1600+434. These observations produce images at 300 milliarcseconds (mas) resolution at 150 MHz. In the case of MG 0751+... Read More about High-resolution imaging with the International LOFAR Telescope: Observations of the gravitational lenses MG 0751+2716 and CLASS B1600+434.

Unmasking the history of 3C 293 with LOFAR sub-arcsecond imaging (2021)
Journal Article
Kukreti, P., Morganti, R., Shimwell, T., Morabito, L., Beswick, R., Brienza, M., …de Gasperin, F. (2022). Unmasking the history of 3C 293 with LOFAR sub-arcsecond imaging. Astronomy & Astrophysics, 658, Article A6. https://doi.org/10.1051/0004-6361/202140814

Active galactic nuclei (AGNs) show episodic activity, which can be evident in galaxies that exhibit restarted radio jets. These restarted jets can interact with their environment, leaving signatures on the radio spectral energy distribution. Tracing... Read More about Unmasking the history of 3C 293 with LOFAR sub-arcsecond imaging.

The radio loudness of SDSS quasars from the LOFAR Two-metre Sky Survey: ubiquitous jet activity and constraints on star formation (2021)
Journal Article
Macfarlane, C., Best, P., Sabater, J., Gürkan, G., Jarvis, M., Röttgering, H., …Retana-Montenegro, E. (2021). The radio loudness of SDSS quasars from the LOFAR Two-metre Sky Survey: ubiquitous jet activity and constraints on star formation. Monthly Notices of the Royal Astronomical Society, 506(4), 5888-5907. https://doi.org/10.1093/mnras/stab1998

Fundamental differences in the radio properties of red and blue quasars: kiloparsec-scale structures revealed by e-MERLIN (2021)
Journal Article
Rosario, D., Alexander, D., Moldon, J., Klindt, L., Thomson, A., Morabito, L., …Harrison, C. (2021). Fundamental differences in the radio properties of red and blue quasars: kiloparsec-scale structures revealed by e-MERLIN. Monthly Notices of the Royal Astronomical Society, 505(4), 5283-5300. https://doi.org/10.1093/mnras/stab1653

Red quasi-stellar objects (QSOs) are a subset of the quasar population with colours consistent with reddening due to intervening dust. Recent work has demonstrated that red QSOs show special radio properties that fundamentally distinguish them from n... Read More about Fundamental differences in the radio properties of red and blue quasars: kiloparsec-scale structures revealed by e-MERLIN.

Sub-arcsecond imaging with the International LOFAR Telescope II. Completion of the LOFAR Long-Baseline Calibrator Survey (2021)
Journal Article
Jackson, N., Badole, S., Morgan, J., Chhetri, R., Prūsis, K., Nikolajevs, A., …Zucca, P. (2022). Sub-arcsecond imaging with the International LOFAR Telescope II. Completion of the LOFAR Long-Baseline Calibrator Survey. Astronomy & Astrophysics, 658, Article A2. https://doi.org/10.1051/0004-6361/202140756

The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper, we present the complete survey, building on the preliminar... Read More about Sub-arcsecond imaging with the International LOFAR Telescope II. Completion of the LOFAR Long-Baseline Calibrator Survey.

The multiwavelength properties of red QSOs -- Evidence for dusty winds as the origin of QSO reddening (2021)
Journal Article
Calistro Rivera, G., Alexander, D., Rosario, D., Harrison, C., Stalevski, M., Rakshit, S., …Kondapally, R. (2021). The multiwavelength properties of red QSOs -- Evidence for dusty winds as the origin of QSO reddening. Astronomy & Astrophysics, 649, Article A102. https://doi.org/10.1051/0004-6361/202040214

Fundamental differences in the radio properties of red quasars (QSOs), as compared to blue QSOs, have been recently discovered, positioning them as a potential key population in the evolution of galaxies and black holes across cosmic time. To elucida... Read More about The multiwavelength properties of red QSOs -- Evidence for dusty winds as the origin of QSO reddening.

The LOFAR LBA Sky Survey: I. Survey description and preliminary data release (2021)
Journal Article
de Gasperin, F., Williams, W., Best, P., Brüggen, M., Brunetti, G., Cuciti, V., …Röttgering, H. (2021). The LOFAR LBA Sky Survey: I. Survey description and preliminary data release. Astronomy & Astrophysics, 648, Article A104. https://doi.org/10.1051/0004-6361/202140316

Context. The LOw Frequency ARray (LOFAR) is the only radio telescope that is presently capable of high-sensitivity, high-resolution (i.e. < 1 mJy beam−1 and < 15″) observations at ultra-low frequencies (< 100 MHz). To utilise these capabilities, the... Read More about The LOFAR LBA Sky Survey: I. Survey description and preliminary data release.

The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging (2021)
Journal Article
Tasse, C., Shimwell, T., Hardcastle, M., O'Sullivan, S., van Weeren, R., Best, P., …Wiaux, Y. (2021). The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging. Astronomy & Astrophysics, 648, Article A1. https://doi.org/10.1051/0004-6361/202038804

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large-scale and compact emission. It is, however, very challenging to synthesize thermal noise limited maps... Read More about The LOFAR Two Meter Sky Survey: Deep Fields, I -- Direction-dependent calibration and imaging.

The LOFAR Two-metre Sky Survey Deep Fields -- Data Release 1: IV. Photometric redshifts and stellar masses (2021)
Journal Article
Duncan, K., Kondapally, R., Brown, M., Bonato, M., Best, P., Röttgering, H., …Wołowska, A. (2021). The LOFAR Two-metre Sky Survey Deep Fields -- Data Release 1: IV. Photometric redshifts and stellar masses. Astronomy & Astrophysics, 648, Article A4. https://doi.org/10.1051/0004-6361/202038809

The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey split across multiple tiers over the northern sky. The first LoTSS Deep Fields data release consists of deep radio continuum imaging at 15... Read More about The LOFAR Two-metre Sky Survey Deep Fields -- Data Release 1: IV. Photometric redshifts and stellar masses.

Placing LOFAR-detected quasars in C iv emission space: implications for winds, jets and star formation (2021)
Journal Article
Rankine, A. L., Matthews, J. H., Hewett, P. C., Banerji, M., Morabito, L. K., & Richards, G. T. (2021). Placing LOFAR-detected quasars in C iv emission space: implications for winds, jets and star formation. Monthly Notices of the Royal Astronomical Society, 502(3), 4154-4169. https://doi.org/10.1093/mnras/stab302

We present an investigation of the low-frequency radio and ultraviolet properties of a sample of ≃10 500 quasars from the Sloan Digital Sky Survey Data Release 14, observed as part of the first data release of the Low-Frequency-Array Two-metre Sky Su... Read More about Placing LOFAR-detected quasars in C iv emission space: implications for winds, jets and star formation.

Extended X-ray emission around FR II radio galaxies: hotspots, lobes and galaxy clusters (2021)
Journal Article
Jimenez-Gallardo, A., Massaro, F., Paggi, A., D'Abrusco, R., Prieto, M. A., Peña-Herazo, H. A., …Morabito, L. K. (2021). Extended X-ray emission around FR II radio galaxies: hotspots, lobes and galaxy clusters. Astrophysical Journal Supplement, 252(2), Article 31. https://doi.org/10.3847/1538-4365/abcecd

We present a systematic analysis of the extended X-ray emission discovered around 35 FR II radio galaxies from the revised Third Cambridge catalog (3CR) Chandra Snapshot Survey with redshifts between 0.05 to 0.9. We aimed to (i) test for the presence... Read More about Extended X-ray emission around FR II radio galaxies: hotspots, lobes and galaxy clusters.

Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline (2021)
Journal Article
Morabito, L., Jackson, N., Mooney, S., Sweijen, F., Badole, S., Kukreti, P., …Zucca, P. (2021). Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline. Astronomy & Astrophysics, 658, Article A1. https://doi.org/10.1051/0004-6361/202140649

The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2000 km, LOFAR has the unique capability of achieving sub-arcsecond resolution at frequencies below 200 MHz. However, it is technicall... Read More about Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline.

MIGHTEE: Are giant radio galaxies more common than we thought? (2020)
Journal Article
Delhaize, J., Heywood, I., Prescott, M., Jarvis, M., Delvecchio, I., Whittam, I., …Vaccari, M. (2021). MIGHTEE: Are giant radio galaxies more common than we thought?. Monthly Notices of the Royal Astronomical Society, 501(3), 3833-3845. https://doi.org/10.1093/mnras/staa3837

We report the discovery of two new giant radio galaxies (GRGs) using the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) survey. Both GRGs were found within a ∼1 deg2 region inside the COSMOS field. They have redshifts of z = 0.1... Read More about MIGHTEE: Are giant radio galaxies more common than we thought?.

Reaching small scales with low-frequency imaging: applications to the Dark Ages (2020)
Journal Article
Morabito, L., & Silk, J. (2021). Reaching small scales with low-frequency imaging: applications to the Dark Ages. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 379(2188), Article 20190571. https://doi.org/10.1098/rsta.2019.0571

The initial conditions for the density perturbations in the early Universe, which dictate the large-scale structure and distribution of galaxies we see today, are set during inflation. Measurements of primordial non-Gaussianity are crucial for distin... Read More about Reaching small scales with low-frequency imaging: applications to the Dark Ages.

Decoherence in LOFAR-VLBI beamforming (2020)
Journal Article
Bonnassieux, E., Edge, A., Morabito, L., & Bonafede, A. (2020). Decoherence in LOFAR-VLBI beamforming. Astronomy & Astrophysics, 637, Article A51. https://doi.org/10.1051/0004-6361/202037486

We show that the use of a superstation (a phased array created using multiple stations of an interferometric array) created in post-processing for LOFAR-VLBI observations introduces a direction-dependent loss of signal in the image. We show this effe... Read More about Decoherence in LOFAR-VLBI beamforming.

Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars (2020)
Journal Article
Fawcett, V., Alexander, D., Rosario, D., Klindt, L., Fotopoulou, S., Lusso, E., …Calistro Rivera, G. (2020). Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars. Monthly Notices of the Royal Astronomical Society, 494(4), 4802-4818. https://doi.org/10.1093/mnras/staa954

We have recently used the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey to show that red quasars have fundamentally different radio properties to typical blue quasars: a significant (factor ≈3) enhancement in the radio-detection... Read More about Fundamental differences in the radio properties of red and blue quasars: enhanced compact AGN emission in red quasars.

Fundamental differences in the radio properties of red and blue quasars: Insight from the LOFAR Two-metre Sky Survey (LoTSS) (2020)
Journal Article
Rosario, D., Fawcett, V., Klindt, L., Alexander, D., Morabito, L., Fotopoulou, S., …Rivera, G. C. (2020). Fundamental differences in the radio properties of red and blue quasars: Insight from the LOFAR Two-metre Sky Survey (LoTSS). Monthly Notices of the Royal Astronomical Society, 494(3), 3061-3079. https://doi.org/10.1093/mnras/staa866

Red quasi-stellar objects (QSOs) are a subset of the luminous end of the cosmic population of active galactic nuclei (AGN), most of which are reddened by intervening dust along the line-of-sight towards their central engines. In recent work from our... Read More about Fundamental differences in the radio properties of red and blue quasars: Insight from the LOFAR Two-metre Sky Survey (LoTSS).

The CALYMHA survey: Lyα luminosity function and global escape fraction of Lyα photons at z = 2.23 (2016)
Journal Article
Sobral, D., Matthee, J., Best, P., Stroe, A., Röttgering, H., Oteo, I., …Paulino-Afonso, A. (2017). The CALYMHA survey: Lyα luminosity function and global escape fraction of Lyα photons at z = 2.23. Monthly Notices of the Royal Astronomical Society, 466(1), 1242-1258. https://doi.org/10.1093/mnras/stw3090

We present the CAlibrating LYMan-α with Hα (CALYMHA) pilot survey and new results on Lyman α (Lyα) selected galaxies at z ∼ 2. We use a custom-built Lyα narrow-band filter at the Isaac Newton Telescope, designed to provide a matched volume coverage t... Read More about The CALYMHA survey: Lyα luminosity function and global escape fraction of Lyα photons at z = 2.23.