Browsing University of Hertfordshire by Author "Shimwell, T."

Now showing items 1-11 of 11

    • The bright end of the infrared luminosity functions and the abundance of hyperluminous infrared galaxies 

      Wang, L.; Gao, F.; Best, P. N.; Duncan, K.; Hardcastle, M. J.; Kondapally, R.; Malek, K.; McCheyne, I.; Sabater, J.; Shimwell, T.; Tasse, C.; Bonato, M.; Bondi, M.; Cochrane, R. K.; Farrah, D.; Gurkan, G.; Haskell, P.; Pearson, W. J.; Prandoni, I.; Rottgering, H. J. A.; Smith, D. J. B.; Vaccari, M.; Williams, W. L. (2021-04-07)
      We provide the most accurate estimate yet of the bright end of the infrared (IR) luminosity functions (LFs) and the abundance of hyperluminous IR galaxies (HLIRGs) with IR luminosities > 10^13 L_solar, thanks to the ...

    • The galaxy group NGC 507: newly detected AGN remnant plasma transported by sloshing 

      Brienza, M.; Lovisari, L.; Rajpurohit, K.; Bonafede, A.; Gastaldello, F.; Murgia, M.; Vazza, F.; Bonnassieux, E.; Botteon, A.; Brunetti, G.; Drabent, A.; Hardcastle, M. J.; Pasini, T.; Riseley, C. J.; Röttgering, H. J. A.; Shimwell, T.; Simionescu, A.; Weeren, R. J. van (2022-05-06)
      Jets from active galactic nuclei (AGN) are known to recurrently enrich their surrounding medium with mildly-relativistic particles and magnetic fields. Here, we present a detailed multi-frequency analysis of the nearby ...

    • The great Kite in the sky: a LOFAR observation of the radio source in Abell 2626 

      Ignesti, A.; Shimwell, T.; Brunetti, G.; Gitti, M.; Intema, H.; Weeren, R. J. van; Hardcastle, M. J.; Clarke, A. O.; Botteon, A.; Gennaro, G. Di; Brüggen, M.; Browne, I.; Mandal, S.; Röttgering, H. J. A.; Cuciti, V.; Gasperin, F. de; Cassano, R.; Scaife, Anna M.M. (2020-09-29)
      The radio source at the center of the galaxy cluster Abell 2626, also known as the Kite, stands out for its unique morphology composed of four, symmetric arcs. Previous studies have probed the properties of this source at ...

    • The LOFAR LBA Sky Survey I. survey description and preliminary data release 

      Gasperin, F. de; Williams, W. L.; Best, P.; Bruggen, M.; Brunetti, G.; Cuciti, V.; Dijkema, T. J.; Hardcastle, M. J.; Norden, M. J.; Offringa, A.; Shimwell, T.; Weeren, R. van; Bomans, D.; Bonafede, A.; Botteon, A.; Callingham, J. R.; Cassano, R.; Chyzy, K. T.; Emig, K. L.; Edler, H.; Haverkorn, M.; Heald, G.; Heesen, V.; Iacobelli, M.; Intema, H. T.; Kadler, M.; Malek, K.; Mevius, M.; Miley, G.; Mingo, B.; Morabito, L. K.; Sabater, J.; Morganti, R.; Orru, E.; Pizzo, R.; Prandoni, I.; Shulevski, A.; Tasse, C.; Vaccari, M.; Zarka, P.; Rottgering, H. (2021-02-17)
      Context. The LOw Frequency ARray (LOFAR)istheonlyradiotelescopethatispresentlycapableofhigh-sensitivity,high-resolution (i.e. < 1mJybeam−1 and < 1500) observations at ultra-low frequencies(< 100MHz). To utilise these ...

    • The LOFAR LBA Sky Survey II. First data release 

      Gasperin, F. de; Edler, H. W.; Williams, W. L.; Callingham, J. R.; Asabere, B.; Bruggen, M.; Brunetti, G.; Dijkema, T. J.; Hardcastle, M. J.; Iacobelli, M.; Offringa, A.; Norden, M. J.; Rottgering, H. J. A.; Shimwell, T.; Weeren, R. J. van; Tasse, C.; Bomans, D. J.; Bonafede, A.; Botteon, A.; Cassano, R.; Chyzy, K. T.; Cuciti, V.; Emig, K. L.; Kadler, M.; Miley, G.; Mingo, B.; Oei, M. S. S. L.; Prandoni, I.; Schwarz, D. J.; Zarka, P. (2023-05-26)
      Context. The Low Frequency Array (LOFAR) is the only existing radio interferometer able to observe at ultra-low frequencies (<100 MHz) with high resolution (<15") and high sensitivity (<1 mJy beam-1). To exploit these ...

    • The LOFAR Two Meter Sky Survey : Deep Fields Data Release 1, I -- Direction-dependent calibration and imaging 

      Tasse, C.; Shimwell, T.; Hardcastle, M. J.; O'Sullivan, S. P.; Weeren, R. van; Best, P. N.; Bester, L.; Hugo, B.; Smirnov, O.; Sabater, J.; Calistro-Rivera, G.; Gasperin, F. de; Morabito, L. K.; Röttgering, H.; Williams, W. L.; Bonato, M.; Bondi, M.; Botteon, A.; Brüggen, M.; Brunetti, G.; Chyży, K. T.; Garrett, M. A.; Gürkan, G.; Jarvis, M. J.; Kondapally, R.; Mandal, S.; Prandoni, I.; Repetti, A.; Retana-Montenegro, E.; Schwarz, D. J.; Shulevski, A.; Wiaux, Y. (2021-04-07)
      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 ...

    • The LOFAR Two-metre Sky Survey Deep Fields Data Release 1 V. Survey description, source classifications and host galaxy properties 

      Best, P. N.; Kondapally, R.; Williams, W. L.; Cochrane, R. K.; Duncan, K. J.; Hale, C. L.; Haskell, P.; Malek, K.; McCheyne, I.; Smith, D. J. B.; Wang, L.; Botteon, A.; Bonato, M.; Bondi, M.; Rivera, G. Calistro; Gao, F.; Gurkan, G.; Hardcastle, M. J.; Jarvis, M. J.; Mingo, B.; Miraghaei, H.; Morabito, L. K.; Nisbet, D.; Prandoni, I.; Rottgering, H. J. A.; Sabater, J.; Shimwell, T.; Tasse, C.; Weeren, R. van (2023-08-01)
      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 ...

    • The LOFAR – eFEDS survey: The incidence of radio and X-ray AGN and the disk–jet connection 

      Igo, Z.; Merloni, A.; Hoang, D.; Buchner, J.; Liu, T.; Salvato, M.; Arcodia, R.; Bellstedt, S.; Brüggen, M.; Croston, J. H.; Gasperin, F. de; Georgakakis, A.; Hardcastle, M. J.; Nandra, K.; Ni, Q.; Pasini, T.; Shimwell, T.; Wolf, J. (2024-06-30)
      Context. Radio jets are present in a diverse sample of AGN. However, the mechanisms of jet powering are not fully understood, and it remains unclear to what extent they obey mass-invariant scaling relations similar to those ...

    • Possible discovery of Calvera's supernova remnant 

      Arias, M.; Botteon, A.; Bassa, C. G.; Jagt, S. van der; Weeren, R. J. van; O'Sullivan, S. P.; Bosschaart, Q.; Dullaart, R. S.; Hardcastle, M. J.; Hessels, J. W. T.; Shimwell, T.; Slob, M. M.; Sturm, J. A.; Tasse, C.; Theijssen, N. C. M. A.; Vink, J. (2022-11-01)
      We report the discovery of a ring of low surface brightness radio emission around the Calvera pulsar, a high Galactic latitude, isolated neutron star, in the LOFAR Two-metre Sky Survey (LoTSS). It is centered at α = ...

    • Signatures from a merging galaxy cluster and its AGN population : LOFAR observations of Abell 1682 

      Clarke, A. O.; Scaife, Anna M.M.; Shimwell, T.; Weeren, R. J. van; Bonafede, A.; Heald, George; Brunetti, G.; Cantwell, T. M.; Gasperin, F. de; Brüggen, M.; Botteon, A.; Hoeft, M.; Horellou, C.; Cassano, R.; Harwood, J. J.; Röttgering, H. J. A. (2019-07-05)
      We present LOFAR data from 110-180 MHz of the merging galaxy cluster Abell 1682, alongside archival optical, radio, and X-ray data. Our images of 6 arcsec in resolution at low frequencies reveal new structures associated ...

    • Studying the late evolution of a radio-loud AGN in a galaxy group with LOFAR 

      Savini, F.; Bonafede, A.; Brüggen, M.; Wilber, A.; Harwood, J. J.; Murgia, M.; Shimwell, T.; Rafferty, D.; Shulevski, A.; Brienza, M.; Hardcastle, M. J.; Morganti, R.; Röttgering, H.; Clarke, A. O.; de Gasperin, F.; van Weeren, R.; Best, P. N.; Botteon, A.; Brunetti, G.; Cassano, R. (2018-03-11)
      Feedback by radio-loud active galactic nuclei (AGNs) in galaxy groups is not fully understood. Open questions include the duty cycle of theAGN, the spatial extent of the radio lobes, the effect they have on the intragroup ...