Bibcode
Chan, S. J.; Beckman, J. E.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 553, id.A54, 11 pp.
Advertised on:
5
2013
Revista
Número de citas
2
Número de citas referidas
0
Descripción
Aims: We systematically study the relations between the Hα
luminosity and the near-IR luminosity and temperature of a set of
selected HII regions in the disc of M100.
Methods: By using the technique of cross-reference between the optical
Hα image (the catalogue of HII regions in M100)
and the Spitzer IRAC images, we locate the selected HII regions in the
IRAC image frames. By using the chi-squared non-linear fitting
technique, we estimate the IRAC-3-band colour temperature
Tcol(IRAC) of selected HII regions, and calculate their
near-IR luminosities. Results: The spectral fits allow us to
separate the PAH emission in the 3.6 μm band from the thermal dust
emission that dominates the other three bands, thereby assigning values
for the colour temperature of the dust. These values lie in the range
250 K to 350 K. There is a well defined linear relation between the
Hα luminosity and the derived IRAC luminosity for the HII regions,
but no apparent relation between the latter and the colour temperature.
While the range in Hα luminosity is almost two orders of
magnitude, the range in temperature is less than a factor two. We also
find that the colour temperature is independent of galactocentric
radius, in contrast to previous findings for electron temperatures in
HII regions. These results could be understood in scenarios where the OB
association pushes the surrounding dust and gas out to radii that are
larger for higher luminosity regions or, alternatively, where the dust
we are measuring consists of tiny stochastically heated grains.
Proyectos relacionados
![Poster Almeria Astronomy week Poster Almeria Astronomy week](/sites/default/files/styles/crop_square_2_2_to_320px/public/images/project/Webp.net-resizeimage.jpg?h=827748b7&itok=98Jq9KJn)
Estudios Cinemáticos, Estructurales y de Composición, de los Medios Interestelares e Intergalácticos
El objetivo básico del proyecto es investigar la evolución de las galaxias mediante el entendimiento de la interacción del medio interestelar y las estrellas. La técnica principal que utilizamos es la cinemática bidimensional de galaxias enteras observada por nuestro instrumento GHaFaS, un interferometro Fabry Perot en el telescopio William
Prof.
John E. Beckman