info:eu-repo/semantics/article
The long bar as seen by the VVV Survey. II. Star counts
Fecha
2013-11Registro en:
Amôres, E. B.; López-Corredoira, M.; González-Fernández, C.; Moitinho, A; Minniti, D.; et al.; The long bar as seen by the VVV Survey. II. Star counts; Edp Sciences S A; Astronomy And Astrophysics; 599; 11-2013; 11-24
0004-6361
Autor
Amôres, E. B.
López-Corredoira, M.
González-Fernández, C.
Moitinho, A
Minniti, D.
Gurovich, Sebastian
Resumen
Context. There is still some debate about the presence and the morphological properties of the long bar in the inner Galaxy. Aims: We investigate the morphological properties of the long Galactic bar using the VVV survey extending star counts at least 3 mag deeper than 2MASS. Our study covers the relatively unexplored negative longitudes of the Galactic bar. We obtain a detailed description of the spatial distribution of star counts towards the long Galactic bar as well as to measure its parameters. Methods: We performed star counts towards -20° < ℓ < 0, |b|≤ 2° using VVV, 2MASS, and GLIMPSE data. We applied an average interstellar extinction correction. We also adjusted latitudinal profiles to obtain the centroid variation and bar thickness. Results: We probe the structure of long Galactic bar, as well as its far edge at ℓ ≈ -14°. The differences between counts with and without extinction correction allow us to produce a crude extinction map showing regions with high extinction, mainly beyond the end of long Galactic bar. The latitudinal profiles show evidence of the centroid vertical variation with Galactic longitude reaching a minimum at ℓ ≈ -13.8°. The bar has an inclination angle α = 43° ± 5° with respect to the line Sun-Galactic center. In addition, we have determined the bar parameters, such as thickness, length, and stellar distribution.