Browsing Research publications by Author "Knapen, J."

Now showing items 1-20 of 99

    • Adaptive optics imaging and TAURUS 2-D spectroscopy of galaxy cores 

      Knapen, J. (2001)
      Many barred galaxies show enhanced star formation activity in ring-like regions around their centres, at typical radii of 1–2 kpc. We show how kinematic (WHT TAURUS Fabry-Pérot velocity mapping) and imaging (CFHT near ...

    • Age dating a starburst: Gemini/CIRPASS observations of the core of M 83 

      Ryder, S.D.; Knapen, J.; Mazzuca, L.M.; Sharp, R.G.; Parry, I.R. (Astronomical Society of the Pacific, 2004)
      The circumnuclear starburst in NGC 5236 (M 83) has been studied photometrically by Harris et al. (2001) using HST/WFPC2 images in the broad-band near-UV and optical, as well as narrow-band H® and H¯ to derive colors and ...

    • Age-dating a star-burst with GEMINI/CIRPASS observations of the core of M83 

      Sharp, R.G.; Parry, I.R.; Ryder, S.D.; Knapen, J.; Mazzuca, L.M. (2004)
      We present preliminary results from a set of near-IR integral field spectroscopic observations of the central, star-burst, regions of the barred spiral galaxy M83, obtained with CIRPASS on Gemini-S. We present maps in the ...

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

      Ryder, S.D.; Knapen, J.; Alonso-Herrero, A.; Takamiya, M. (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 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 ...

    • Arm and Interarm star formation in spiral galaxies 

      Stedman, S.; Knapen, J. (2001)
      We present an outline of our study of the effects of star formation on the different components of the interstellar medium in the discs of spiral galaxies, both globally and as a function of arm and interarm environment. ...

    • Atomic hydrogen in the spiral galaxy NGC 3631 

      Knapen, J. (1997)
      New high resolution, high sensitivity WSRT Hi synthesis observations of the spiral galaxy NGC 3631 are presented. In the total atomic hydrogen map, the spiral arms are well distinguished from the interarm regions, while ...

    • Bar evolution over the last 8 billion years: A constant fraction of strong bars in th GEMS Survey 

      Jogee, S.; Barazza, F.D.; Rix, H-W.; Shlosman, I.; Barden, M.; Wolf, C.; Davies, J.; Heyer, I.; Beckwith, S.; Bell, E.F.; Caldwell, J.A.R.; Conselice, J.; Dahlen, T.; Haussler, B.; Heymans, C.; Jahnke, K.; Knapen, J.; Laine, S.; Lubell, G.M.; Mobasher, B.; McIntosh, D.; Meisenheimar, K.; Peng, C.Y.; Sanchez, S.F.; Somerville, R.S.; Wisotzki, L. (2004-11)
      One-third of present-day spirals host optically visible strong bars that drive their dynamical evolution. However, the fundamental question of how bars evolve over cosmological times has yet to be resolved, and even the ...

    • Bar-Driven Disk Evolution: Grand Design Nuclear Spirals 

      Jogee, S.; Shlosman, I.; Laine, S.; Englmaier, P.; Knapen, J.; Scoville, N.Z.; Wilson, C.D. (Astronomical Society of the Pacific, 2003)
      Our study of the grand-design spiral galaxy NGC 5248 reveals that the feature previously thought to be an inclined disk is in fact an extended bar or semi-major axis 7.1 kpc, embedded within a fainter outer disk which is ...

    • Barred galaxies : Stars and Bars 

      Knapen, J. (2005)
      Bars are prominent features that occur in most disc galaxies and have important dynamical effects on their hosts. This paper describes some of the known properties of bars, illustrating the discussion with images that show ...

    • Bars and Seyferts 

      Knapen, J.; Laine, S.; Shlosman, I.; Peletier, R.F. (Astronomical Society of the Pacific, 2003)
      We describe the results of two studies recently undertaken, aimed at quantifying the properties of single and nested stellar bars in well-matched samples of Seyfert and non-Seyfert galaxies. We find that Seyfert host ...

    • Bars and the symmetry of star formation patterns in the discs of spiral galaxies 

      Rozas, M.; Knapen, J.; Beckman, J.E. (1998)
      We present a test for the degree of symmetry in the distribution of the Hα brightness along the arms of a sample of spiral galaxies. The test consists of deriving the cross-correlation function of the Hα brightness as a ...

    • The Central Kiloparsec of Starbursts and Active Galactic Nuclei: The La Palma Connection 

      Knapen, J.; Beckman, J.E.; Shlosman, I.; Mahoney, T.J.; Terence, J. (2002-03)

    • Circumnuclear kinematics in NGC 5248: the origin of nuclear spiral arms 

      Laine, S.; Knapen, J.; Perez-Ramirez, D.; Englmaier, P.; Matthias, M. (2001-07)

    • Circumnuclear Regions and their Barred Host Galaxies 

      Perez-Ramirez, D.; Knapen, J.; Laine, S. (2001)
      In this paper we present first results from an observational study of the connection between the global parameters of barred galaxies and the appearance of structures, such as dust lanes and star-forming rings in their ...

    • Circumnuclear regions in barred spiral galaxies - I. Near-infrared imaging 

      Perez-Ramirez, D.; Knapen, J.; Peletier, R.F.; Laine, S.; Doyon, R.; Nadeau, D. (2000-09)

    • Circumnuclear regions in barred spiral galaxies - II. Relations to host galaxies 

      Knapen, J.; Perez-Ramirez, D.; Laine, S. (2002-12)

    • Circumnuclear Star Formation in M100 

      Ryder, S.D.; Knapen, J. (2001)
      Near-infrared (JHK) images of the nucleus of the barred spiral galaxy M100 (NGC 4321) have been obtained using a high-bandwidth tip-tilt secondary and fast guider system on the 3.8 m United Kingdom Infrared Telescope ...

    • Circumnuclear Star-forming Regions in barred Galaxies 

      Knapen, J.; Laine, S.; Relano, M. (1999)
      We present high-resolution Hα velocity fields and rotation curves of the circum nuclear star-forming regions of five barred galaxies. Two of the five objects show substantially smaller initial rises than the three others; ...

    • The Circumnuclear Starburst in M83 

      Ryder, S.D.; Sharp, R.G.; Knapen, J.; Mazzuca, L.M.; Parry, I.R. (American Institute of Physics (AIP), 2005)
      We present results from near-infrared integral-field spectroscopy of the circumnuclear starburst in M83, using the CIRPASS instrument on Gemini South. The combination of Pa, CO (6,3), and [Fe II] equivalent width measurements ...