Astrophysical: Nebulae

  • Publication
    On the determination of temperatures of ionizing stars in H II regions
    Following earlier work by Shields and Searle and by Mathis, the authors define a radiation softness parameter η = (O+/O++)(S++/S+), which they recommend as a...
  • News
    Possible evidence of planet formation found in the Orion Nebula
    International research led by scientists at the Instituto de Astrofísica de Canarias (IAC) has shown the existence of solid sulphur compounds in HH514, a jet of...
  • Publication
    Radio and infrared structures of type I post-main sequence nebulae
    High-resolution VLA radio mapping at 1.46, 4.84, and 15.0 GHz is presented together with NIR J,H,K,L, and M mapping and photometry of a broad range of type I...
  • Publication
    Radio mapping of type I post-main-sequence nebulae
    Type I post-main-sequence nebulae appear to be characterised by a range of unusual, and in certain cases extreme physical characteristics, including high...
  • Publication
    Spatially resolved spectroscopy of WR ring nebulae. I - NGC 2359 and RCW 78
    We report detailed spatially resolved spectroscopy of the WR nebulae NGC 2359 and RCW 78 surrounding the WN 5 HD 56925 and WN 8 HD 117688 stars. The aim of this...
  • Publication
    Spatially resolved spectroscopy of WR ring nebulae. II - M1-67
    Detailed, high spatial resolution spectroscopy of the WR ring nebula M1-67 surrounding the WN 8 star WR 124 is presented. Abundances for 4 positions in M1-67...
  • Publication
    Spectroscopic study of gas outflows in the bipolar nebula S106
    High resolution bidimensional optical spectroscopy in H-alpha line, N II forbidden line at 6548 and 6583 A, and S II forbidden line at 6717 and 6713 A, of the...
  • Publication
    Spectroscopy of ring nebulae around Wolf-Rayet stars in M33
    We present high and low resolution spectroscopic observations for a sample of seven ring nebulae around Wolf-Rayet (WR) stars in M33: MC 27, MC 44, MC 46, MC 51...
  • Publication
    The Abundance Gradient in NGC 3344
    The steep abundance gradient found by McCall, Shields, and Rybski (1981) in the Sbc galaxy NGC 3344 is confirmed by a measurement of the electron temperature in...