Browsing Research publications by Author "Knapen, J. H."

Now showing items 1-9 of 9

    • The ages of circumnuclear starbursts from Near-IR spectroscopy: Bushfires or Mexican Wave 

      Ryder, S.D.; Knapen, J.; Alonso-Herrero, A.; Takamiya, M. (Astronomical Society of the Pacific, 2001)
      We have pbtained K-band spectra with CGS4 on UKIRT for circumnuclear star-forming regions in NGC 4321, NGC 2903 and NGC 7469. A comparison of the equivalent widths of Bry emission and CO absorption with starburst models ...

    • The curious activity in the nucleus of NGC 4151 : jet interaction causing variability? 

      Williams, D. R. A.; Baldi, R. D.; McHardy, I. M.; Beswick, R. J.; Panessa, F.; May, D.; Moldón, J.; Argo, M. K.; Bruni, G.; Dullo, B. T.; Knapen, J. H.; Brinks, E.; Fenech, D. M.; Mundell, C. G.; Muxlow, T. W. B.; Pahari, M.; Westcott, J. (2020-05-04)
      A key characteristic of many active galactic nuclei (AGNs) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ∼50 per cent increase in peak flux ...

    • LeMMINGs – I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores 

      Baldi, R. D.; Williams, D.R.A.; McHardy, I.M.; Beswick, R.J.; Argo, M. K.; Dullo, B. T.; Knapen, J. H.; Brinks, Elias; Muxlow, T. W. B.; Aalto, S.; Alberdi, A.; Bendo, G. J.; Corbel, S.; Evans, R.; Fenech, D.M.; Green, D. A.; Klöckner, H. R; Körding, E.; Kharb, P.; Maccarone, T. J.; Martí-Vidal, I.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Saikia, D. J.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Uttley, P.; Westcott, J. (2018-05-21)
      We present the first data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes ...

    • LeMMINGs. II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale 

      Baldi, R. D.; Williams, D. R. A.; McHardy, I. M.; Beswick, R. J.; Brinks, E.; Dullo, B. T.; Knapen, J. H.; Argo, M. K.; Aalto, S.; Alberdi, A.; Baan, W. A.; Bendo, G. J.; Corbel, S.; Fenech, D. M.; Gallagher, J. S.; Green, D. A.; Kennicutt, R. C.; Klöckner, H. -R.; Körding, E.; Maccarone, T. J.; Muxlow, T. W. B.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Romero-Cañizales, C.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Varenius, E.; Ward, M. J.; Yates, J. (2020-11-17)
      We present the second data release of high-resolution ($\leq0.2$ arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the LeMMINGs (Legacy e-MERLIN ...

    • LeMMINGs. III. The e-MERLIN Legacy Survey of the Palomar sample. Exploring the origin of nuclear radio emission in active and inactive galaxies through the [O III] -- radio connection 

      Baldi, R. D.; Williams, D. R. A.; Beswick, R. J.; McHardy, I.; Dullo, B. T.; Knapen, J. H.; Zanisi, L.; Argo, M. K.; Aalto, S.; Alberdi, A.; Baan, W. A.; Bendo, G. J.; Fenech, D. M.; Green, D. A.; Klöckner, H. -R.; Körding, E.; Maccarone, T. J.; Marcaide, J. M.; Mutie, I.; Panessa, F.; Pérez-Torres, M. A.; Romero-Cañizales, C.; Saikia, D. J.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Uttley, P.; Brinks, E.; Corbel, S.; Martí-Vidal, I.; Mundell, C. G.; Pahari, M.; Ward, M. J. (2021-12-01)
      What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O iii] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the ...

    • A possible signature of the influence of tidal perturbations in dwarf galaxy scaling relations 

      Watkins, A. E.; Salo, H.; Kaviraj, S.; Collins, C. A.; Knapen, J. H.; Venhola, A.; Román, J. (2023-03-02)
      Dwarf galaxies are excellent cosmological probes, because their shallow potential wells make them very sensitive to the key processes that drive galaxy evolution, including baryonic feedback, tidal interactions, and ram ...

    • Preparing for low surface brightness science with the Vera C. Rubin Observatory: Characterisation of tidal features from mock images 

      Martin, G.; Bazkiaei, A. E.; Spavone, M.; Iodice, E.; Mihos, J. C.; Montes, M.; Benavides, J. A.; Brough, S.; Carlin, J. L.; Collins, C. A.; Duc, P. A.; Gómez, F. A.; Galaz, G.; Hernández-Toledo, H. M.; Jackson, R. A.; Kaviraj, S.; Knapen, J. H.; Martínez-Lombilla, C.; McGee, S.; O'Ryan, D.; Prole, D. J.; Rich, R. M.; Román, J.; Shah, E. A.; Starkenburg, T. K.; Watkins, A. E.; Zaritsky, D.; Laigle, C.; Pichon, C.; Armus, L.; Bianconi, M.; Buitrago, F.; Busá, I.; Davis, F.; Demarco, R.; Desmons, A.; García, P.; Graham, A. W.; Holwerda, B.; Hon, D. S. -H.; Khalid, A.; Klehammer, J.; Klutse, D. Y.; Lazar, I.; Nair, P.; Noakes-Kettel, E. A.; Rutkowski, M.; Saha, K.; Sahu, N.; Sola, E.; Vázquez-Mata, J. A.; Vera-Casanova, A.; Yoon, I. (2022-06-01)
      Tidal features in the outskirts of galaxies yield unique information about their past interactions and are a key prediction of the hierarchical structure formation paradigm. The Vera C. Rubin Observatory is poised to deliver ...

    • Radio jets in NGC 4151 where eMERLIN meets HST 

      Williams, D. R. A.; McHardy, I. M.; Baldi, R. D.; Beswick, R. J.; Argo, M. K.; Dullo, B. T.; Knapen, J. H.; Brinks, E.; Fenech, D. M.; Mundell, C.G.; Muxlow, T.W.B.; Panessa, F.; Rampadarath, H.; Westcott, J. (2017-12-21)
      We present high-sensitivity eMERLIN radio images of the Seyfert galaxy NGC 4151 at 1.5 GHz. We compare the new eMERLIN images to those from archival MERLIN observations in 1993 to determine the change in jet morphology in ...

    • Strategies for optimal sky subtraction in the low surface brightness regime 

      Watkins, A. E.; Kaviraj, S.; Collins, C. C.; Knapen, J. H.; Kelvin, L. S.; Duc, P. -A.; Román, J.; Mihos, J. C. (2024-03-01)
      The low surface brightness (LSB) regime (μg  ≳  26 mag arcsec−2) comprises a vast, mostly unexplored discovery space, from dwarf galaxies to the diffuse interstellar medium. Accessing this regime requires precisely removing ...