Browsing University of Hertfordshire by Title

Now showing items 21133-21152 of 24120

    • 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 ...

    • Studying the spatially resolved Schmidt-Kennicutt law in interacting galaxies : The case of Arp 158 

      Boquien, M.; Lisenfeld, U.; Duc, P. -A.; Braine, J.; Bournaud, F.; Brinks, E.; Charmandaris, V. (2011-09)
      Context. Recent studies have shown that star formation in mergers does not seem to follow the same Schmidt-Kennicutt relation as in spiral disks, presenting a higher star formation rate (SFR) for a given gas column density. ...

    • Studying the YMC population of M83: how long clusters remain embedded, their interaction with the ISM and implications for GC formation theories 

      Hollyhead, K.; Bastian, N.; Adamo, A.; Silva-Villa, E.; Ryon, J.~E.; Gazak, Z.; Dale, James (2015-05-01)
      The study of young massive clusters can provide key information for the formation of globular clusters, as they are often considered analogues. A currently unanswered question in this field is how long these massive clusters ...

    • Sub-arcsecond imaging with the International LOFAR Telescope : I. Foundational calibration strategy and pipeline 

      Morabito, L. K.; Jackson, N. J.; Mooney, S.; Sweijen, F.; Badole, S.; Kukreti, P.; Venkattu, D.; Groeneveld, C.; Kappes, A.; Bonnassieux, E.; Drabent, A.; Iacobelli, M.; Croston, J. H.; Best, P. N.; Bondi, M.; Callingham, J. R.; Conway, J. E.; Deller, A. T.; Hardcastle, M. J.; McKean, J. P.; Miley, G. K.; Moldon, J.; Röttgering, H. J. A.; Tasse, C.; Shimwell, T. W.; Weeren, R. J. van; Anderson, J. M.; Asgekar, A.; Avruch, I. M.; Bemmel, I. M. van; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Butcher, H. R.; Ciardi, B.; Corstanje, A.; Coolen, A.; Damstra, S.; Gasperin, F. de; Duscha, S.; Eislöffel, J.; Engels, D.; Falcke, H.; Garrett, M. A.; Griessmeier, J.; Gunst, A. W.; Haarlem, M. P. van; Hoeft, M.; Horst, A. J. van der; Jütte, E.; Kadler, M.; Koopmans, L. V. E.; Krankowski, A.; Mann, G.; Nelles, A.; Oonk, J. B. R.; Orru, E.; Paas, H.; Pandey, V. N.; Pizzo, R. F.; Pandey-Pommier, M.; Reich, W.; Rothkaehl, H.; Ruiter, M.; Schwarz, D. J.; Shulevski, A.; Soida, M.; Tagger, M.; Vocks, C.; Wijers, R. A. M. J.; Wijnholds, S. J.; Wucknitz, O.; Zarka, P.; Zucca, P. (2022-02-28)
      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 ...

    • Sub-arcsecond imaging with the International LOFAR Telescope. II. Completion of the LOFAR Long-Baseline Calibrator Survey 

      Jackson, Neal; Badole, Shruti; Chhetri, Rajan; Prusis, Kaspars; Nikolajevs, Atvars; Morabito, Leah; Brentjens, Michiel; Sweijen, Frits; Iacobelli, Marco; Orrù, Emanuela; Sluman, J.; Blaauw, R.; Mulder, H.; Dijk, P. van; Mooney, Sean; Deller, Adam; Moldon, Javier; Callingham, J. R.; Harwood, Jeremy; Hardcastle, Martin; Heald, George; Drabent, Alexander; McKean, J. P.; Asgekar, A.; Avruch, I. M.; Bentum, M. J.; Bonafede, A.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Coolen, A.; Corstanje, A.; Damstra, S.; Duscha, S.; Eislöffel, J.; Falcke, H.; Garrett, M.; Gasperin, F. de; Griessmeier, J. -M.; Gunst, A. W.; Haarlem, M. P. van; Hoeft, M.; Horst, A. J. van der; Jütte, E.; Koopmans, L. V. E.; Krankowski, A.; Maat, P.; Mann, G.; Miley, G. K.; Nelles, A.; Norden, M.; Paas, M.; Pandey, V. N.; Pandey-Pommier, M.; Pizzo, R. F.; Reich, W.; Rothkaehl, H.; Rowlinson, A.; Ruiter, M.; Shulevski, A.; Schwarz, D. J.; Smirnov, O.; Tagger, M.; Vocks, C.; Weeren, R. J. van; Wijers, R.; Wucknitz, O.; Zarka, P.; Zensus, J. A.; Zucca, P. (2022-02-01)
      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, ...

    • Sub-Band Based Text-Dependent Speaker Verification 

      Sivakumaran, P.; Ariyaeeinia, A.; Loomes, M.J. (2003)
      This paper addresses various issues involved in sub-band based text-dependent speaker verification. The first part of the discussions is concerned with the classification methods. An important issue addressed in this part ...

    • Sub-millimeter detected z 2 radio-quiet QSOs : Accurate redshifts, black hole masses, and inflow/outflow velocities 

      Orellana, G.; Nagar, N.M.; Isaak, K.G.; Priddey, Robert Stephen; Maiolino, R.; McMahon, R.G.; Marconi, A.; Oliva, E. (2011)
      Context : We present near-IR spectroscopy of a sample of luminous (M B - 27.5; Lbol > 1014 L· ), sub-millimeter-detected, dusty (Md ∼ 109 M · ), radio-quiet quasi-stellar objects (QSOs) at z ∼ 2. Aims : A primary aim is ...

    • The sub-stellar birth rate from UKIDSS 

      Day-Jones, A. C.; Marocco, F.; Pinfield, D.J.; Zhang, Z. H.; Burningham, B.; Deacon, Niall; Ruiz, M. T.; Gallardo, J.; Jones, H.R.A.; Lucas, P.W.; Jenkins, J. S.; Gomes, J.; Folkes, S. L.; Clarke, J. R. A. (2013-04)
      We present a new sample of mid-L to mid-T dwarfs with effective temperatures of 11001700 K selected from the UKIDSS Large Area Survey (LAS) and confirmed with infrared spectra from X-shooter/Very Large Telescope. This ...

    • Subacromial impingement syndrome : A musculoskeletal condition or a clinical illusion? 

      Lewis, Jeremy (2011-10)
      Background: Subacromial impingement syndrome is considered by many to be the most common of the musculoskeletal conditions affecting the shoulder. It is based on a hypothesis that acromial irritation leads to external ...

    • Subacromial impingement syndrome : Has evolution failed us? 

      Lewis, J.; Green, A.; Yizhat, Z.; Pennington, D. (2001)
      Evolution has endowed the human shoulder girdle with a unique range of movement, that when combined with elbow movement enables the hand to perform a myriad functions. Although the human shoulder girdle is capable of large ...

    • A Subarcsecond Resolution Near infrared Study of Seyfert and “Normal” Galaxies. I. Imaging Data 

      Peletier, R.F.; Knapen, J.; Shlosman, I.; Perez-Ramirez, D.; Nadeau, D.; Doyon, R.; Rodriguez Espinosa, J.M.; Garcia Perez, A.M. (1999-12)
      We present new high-resolution near-infrared observations in the J, H, and K bands, obtained to study the properties of Seyfert host galaxies. The data set consists of images in the three bands of practically the entire ...

    • A Subarcsecond Resolution Near-infrared Study of Seyfert and Normal Galaxies II. Morphology 

      Knapen, J.; Shlosman, I.; Peletier, R.F. (2000-01)

    • Subarcsecond view on the high-redshift blazar GB 1508+5714 by the International LOFAR Telescope 

      Kappes, A.; Burd, P. R.; Kadler, M.; Ghisellini, G.; Bonnassieux, E.; Perucho, M.; Brüggen, Marcus; Cheung, C. C.; Ciardi, B.; Gallo, E.; Haardt, F.; Morabito, Leah K.; Sbarrato, T.; Drabent, A.; Harwood, J.; Jackson, N. J.; Moldon, Javier (2022-07-12)
      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 ...

    • Subaru IR Echelle Spectroscopy of Herbig-Haro Driving Sources. I. H2 and [Fe II] Emission 

      Takami, M.; Chrysostomou, A.; Ray, T.P.; Davis, C.J.; Dent, W.R.; Bailey, J.; Tamura, M.; Terada, H.; Pyo, T.S. (2006)

    • A Subaru/High Dispersion Spectrograph Study of Lead (Pb) Abundances in Eight s-Process Element-rich, Metal-poor Stars 

      Aoki, W.; Ryan, Sean G.; Norris, J.E.; Beers, T.C.; Ando, H.; Tsangarides, S. (2002-12)

    • Subcellular location and expression of tobacco Necrosis necrovirus p7a protein 

      Drouzas, A.D.; Offei, S.K.; Coutts, Robert H.A. (1996-06)
      A putative movement protein (p7a) of tobacco necrosis Necrovirus, strain D (TNV-D), produced in Escherichia coli using an expression vector, was used to raise an antiserum. Immunoblot analysis using this antiserum showed ...

    • Subclasses of Type Ia Supernovae as the origin of [α/Fe] ratios in dwarf spheroidal galaxies 

      Kobayashi, Chiaki; Nomoto, Ken'ichi; Hachisu, Izumi (2015-04-23)
      Recent extensive observations of Type Ia Supernovae (SNe Ia) have revealed the existence of a diversity of SNe Ia, including SNe Iax. We introduce two possible channels in the single degenerate scenario: 1) double detonations ...

    • The Subdwarf B + White Dwarf Binary KPD 1930+2752, a Supernova Type Ia Progenitor Candidate 

      Geier, S.; Nesslinger, S.; Heber, U.; Przybilla, N.; Napiwotzki, R.; Kudritzki, R-P. (Astronomical Society of the Pacific, 2007)
      The nature of the progenitors of type Ia supernovae is still under controversial debate. KPD 1930+2752 is one of the best SN Ia progenitor can- didates known today. The object is a double degenerate system consisting of a ...

    • Subdwarf B and O stars : which evolutionary pathways? 

      Napiwotzki, R. (2009)
      Hot subdwarf stars (spectral types subdwarf B and O) are long lived stars producing a large amount of UV radiation. This makes them excellent candidates to explain the UV radiation observed in old populations. However, the ...

    • Subdwarf B Binaries from the SPY Project 

      Karl, C.; Heber, U.; Napiwotzki, R. (Astronomical Society of the Pacific, 2005)
      In the course of our search for double degenerate binaries as potential progenitors of type Ia supernovae with the ESO VLT (ESO - SN Ia progenitor survey - SPY), several sdB binaries were discovered. We report on the ...