... IRAF

IRAF is distributed by the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation.

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... bar

NGC 1530 rotates clockwise (Zurita et al. 2004).

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... GAIA

GAIA is a derivative of the Skycat catalogue and image display tool, developed as part of the VLT project at ESO. Skycat and GAIA are free software under the terms of the GNU copyright.

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... 0.25-0.35

A similar colour excess is required when the Cardelli et al. (1989) parametrization of the interstellar extinction is employed for $R_V\sim4$.

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... factor

The geometrical filling factor is defined to be the fraction of the total volume of the H  II region occupied by the clumps. It is determined by the clump size and the number density of clumps inside the H  II region (Giammanco et al. 2004).

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...=0.008

The Geneva stellar evolutionary tracks employed by Starburst99 are still on the scale of the old solar abundance (Vazquez & Leitherer 2005), in which $12 + \log$ (O/H)$_\odot$ = 8.9. On that scale, the metallicity of NGC 1530 is 0.5 $Z_\odot$-$Z_\odot$, which determines our selection of metallicity for the Starburst99 simulations.

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