Now showing items 1-11 of 11

    • Deep NIR photometry of HI galaxies in the Zone of Avoidance 

      Williams, Wendy L.; Kraan-Korteweg, Renée C.; Woudt, Patrick A. (2014-09-01)
      Current studies of the peculiar velocity flow field in the Local Universe are limited by either the lack of detection or accurate photometry for galaxies at low Galactic latitudes. The contribution to the dynamics of the ...
    • The discovery of a radio galaxy of at least 5 Mpc 

      Oei, Martijn S. S. L.; Weeren, Reinout J. van; Hardcastle, Martin J.; Botteon, Andrea; Shimwell, Tim W.; Dabhade, Pratik; Gast, Aivin R. D. J. G. I. B.; Röttgering, Huub J. A.; Brüggen, Marcus; Tasse, Cyril; Williams, Wendy L.; Shulevski, Aleksandar (2022-04-01)
      Context. Giant radio galaxies (GRGs, or colloquially giants) are the Universes largest structures generated by individual galaxies. They comprise synchrotron-radiating active galactic nucleus ejecta and attain cosmological ...
    • Finding Rare Quasars: VLA Snapshot Continuum Survey of FRI Quasar Candidates Selected from the LOFAR Two-Metre Sky Survey (LoTSS) 

      Gürkan, Gülay; Croston, Judith; Hardcastle, Martin J.; Mahatma, Vijay; Mingo, Beatriz; Williams, Wendy L. (2021-12-22)
      The radiative and jet power in active galactic nuclei is generated by accretion of material on to supermassive galactic-centre black holes. For quasars, where the radiative power is by definition very high, objects with ...
    • LOFAR/H-ATLAS: The low-frequency radio luminosity - star-formation rate relation 

      Gurkan, Gulay; Hardcastle, Martin J.; Smith, Daniel; Best, Philip N.; Bourne, Nathan; Calistro-Rivera, Gabriela; Heald, George; Jarvis, Matt J.; Prandoni, Isabella; Rottgering, Huub J. A.; Sabater, Jose; Shimwell, Tim; Tasse, Cyril; Williams, Wendy L. (2018-04-11)
      Radio emission is a key indicator of star-formation activity in galaxies, but the radio luminosity-star formation relation has to date been studied almost exclusively at frequencies of 1.4 GHz or above. At lower radio ...
    • A machine-learning classifier for LOFAR radio galaxy cross-matching techniques 

      Alegre, Lara; Sabater, Jose; Best, Philip; Mostert, Rafaël I.~J.; Williams, Wendy L.; Gürkan, Gülay; Hardcastle, Martin J.; Kondapally, Rohit; Shimwell, Tim W.; Smith, Daniel J.~B. (2022-08-30)
      New-generation radio telescopes like LOFAR are conducting extensive sky surveys, detecting millions of sources. To maximize the scientific value of these surveys, radio source components must be properly associated into ...
    • Megahertz peaked-spectrum sources in the Boötes field I - a route towards finding high-redshift AGN? 

      Coppejans, Rocco; Cseh, David; Williams, Wendy L.; Velzen, Sjoert van; Falcke, Heino (2015-06-21)
      We present a 324.5MHz image of the NOAO Bo\"otes field that was made using Very Large Array (VLA) P-band observations. The image has a resolution of 5.6x5.1arcsec, a radius of $2.05^\circ$ and a central noise of ~0.2mJy\beam. ...
    • NIR Tully-Fisher in the Zone of Avoidance. - II. 21 cm HI-line spectra of southern ZOA galaxies 

      Said, Khaled; Kraan-Korteweg, Renée C.; Staveley-Smith, Lister; Williams, Wendy L.; Jarrett, T. H.; Springob, Christopher M. (2016-02-10)
      High-accuracy H I profiles and linewidths are presented for inclined ((b/a) o < 0.5) spiral galaxies in the southern Zone of Avoidance (ZOA). These galaxies define a sample for use in the determinations of peculiar velocities ...
    • Photometric redshifts for the next generation of deep radio continuum surveys - I. Template fitting 

      Duncan, Kenneth J.; Brown, Michael J. I.; Williams, Wendy L.; Best, Philip N.; Buat, Veronique; Burgarella, Denis; Jarvis, Matt J.; Malek, Katarzyna; Oliver, S. J.; Rottgering, Huub J. A.; Smith, Daniel J. B. (2018-01-11)
      We present a study of photometric redshift performance for galaxies and active galactic nuclei detected in deep radio continuum surveys. Using two multiwavelength data sets, over the NOAO Deep Wide Field Survey Boötes and ...
    • Radio source-component association for the LOFAR Two-metre Sky Survey with region-based convolutional neural networks 

      Mostert, Rafaël I. J.; Duncan, Kenneth J.; Alegre, Lara; Röttgering, Huub J. A.; Williams, Wendy L.; Best, Philip N.; Hardcastle, Martin J.; Morganti, Raffaella (2022-12-01)
      Radio loud active galactic nuclei (RLAGNs) are often morphologically complex objects that can consist of multiple, spatially separated, components. Astronomers often rely on visual inspection to resolve radio component ...
    • What are the megahertz peaked-spectrum sources? 

      Coppejans, Rocco; Cseh, David; Velzen, Sjoert van; Falcke, Heino; Intema, Huib T.; Paragi, Zsolt; Muller, Cornelia; Williams, Wendy L.; Frey, Sandor; Gurvits, Leonid I.; Kording, Elmar G. (2016-07-01)
      Megahertz peaked-spectrum (MPS) sources have spectra that peak at frequencies below 1 GHz in the observer's frame and are believed to be radio-loud active galactic nuclei (AGN). We recently presented a new method to search ...
    • The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation 

      WEAVE consortium; Jin, Shoko; Trager, Scott C.; Dalton, Gavin B.; Aguerri, J. Alfonso L.; Drew, J. E.; Falcón-Barroso, Jesús; Gänsicke, Boris T.; Hill, Vanessa; Iovino, Angela; Pieri, Matthew M.; Poggianti, Bianca M.; Smith, D. J. B.; Vallenari, Antonella; Abrams, Don Carlos; Aguado, David S.; Antoja, Teresa; Aragón-Salamanca, Alfonso; Ascasibar, Yago; Babusiaux, Carine; Balcells, Marc; Barrena, R.; Battaglia, Giuseppina; Belokurov, Vasily; Bensby, Thomas; Bonifacio, Piercarlo; Bragaglia, Angela; Carrasco, Esperanza; Carrera, Ricardo; Cornwell, Daniel J.; Domínguez-Palmero, Lilian; Duncan, Kenneth J.; Famaey, Benoit; Fariña, Cecilia; Gonzalez, Oscar A.; Guest, Steve; Hatch, Nina A.; Hess, Kelley M.; Hoskin, Matthew J.; Irwin, Mike; Knapen, Johan H.; Monguió, Maria; Raddi, Roberto; Drake, Alyssa; Gledhill, T. M.; Hardcastle, Martin J.; Harris, Amy; Jarvis, Matt J.; Read, Shaun C.; Williams, Wendy L.; Wright, Nicholas J. (2023-03-11)
      WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, ...