BIPOLAR NEBULAE.

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References
1.- 2007, The S2N2 metallicity calibrator and the abundance gradient of M33. MNRAS, 381, 1719-1726 (WHT).2.- 2007, The metallicity gradient of M33: chemical abundances of HII regions. A&A, 470, 86

Se ha medido el gradiente de abundancia de Oxígeno en la galaxia M33 con muestras relativamente grandes de regiones HII y usando dos métodos diferentes: primero, mediante el calibrador S2N2 aplicado a 76 regiones HII, y segundo, mediante el método empírico, usando la temperatura electrónica medida a partir de las líneas de [OIII] en 14 regiones HII (más otras 15 de la literatura). Ambos métodos indican un gradiente de -0.06 (±0.01) dex/kpc.

Pie de imagen: Una parte de la galaxia M33 con varias regiones HII de las que se midieron en nuestro trabajo. La imagen es del INT con la Wide Field Camera y tres filtros: H-alfa, [OIII] 5007 A y Stromgren-Y

 

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