A Hubble Space Telescope/NICMOS view of the prototypical giant H ii region NGC604 in M33

Barbá, Rodolfo H.; Maíz Apellániz, Jesús; Pérez, Enrique; Rubio, Mónica; Bolatto, Alberto; Fariña, Cecilia; Bosch, Guillermo; Walborn, Nolan R.
Astrophysics and Space Science, Volume 324, Issue 2-4, pp. 309-313


We present the first high-spatial-resolution near-infrared (NIR) imaging of NGC604, obtained with the NICMOS camera onboard the Hubble Space Telescope (HST). These NICMOS broad-band images reveal new NIR point sources, clusters, and diffuse structures. We find an excellent spatial correlation between the 8.4 GHz radio continuum and the 2.2 μm nebular emission. Moreover, massive young stellar object candidates appear aligned with these radio peaks, reinforcing the idea that those areas are star-forming regions. Three different scaled OB associations are recognized in the NICMOS images. The brightest NIR sources in our images have properties that suggest that they are red supergiant stars, of which one was previously known. This preliminary analysis of the NICMOS images shows the complexity of the stellar content of the NGC604 nebula.