Bibcode
Elmegreen, B. G.; Herrera, Cinthya; Rubio, Monica; Elmegreen, Debra Meloy; Sánchez Almeida, J.; Muñoz-Tuñón, C.; Olmo-García, A.
Referencia bibliográfica
The Astrophysical Journal Letters, Volume 859, Issue 2, article id. L22, 6 pp. (2018).
Fecha de publicación:
6
2018
Número de citas
7
Número de citas referidas
5
Descripción
A giant star-forming region in a metal-poor dwarf galaxy has been
observed in optical lines with the 10 m Gran Telescopio Canarias (GTC)
and in the emission line of CO(1–0) with the Northern Extended
Millimeter Array (NOEMA) mm-wave interferometer. The metallicity was
determined to be 12+{log}({{O}}/{{H}})=7.83+/- 0.09, from which we
estimate a conversion factor of α CO ∼ 100 M
⊙ pc‑2(K km
s‑1)‑1 and a molecular cloud mass of
∼2.9 × 107 M ⊙. This is an enormous
concentration of molecular mass at one end of a small galaxy, suggesting
a recent accretion. The molecular cloud properties seem normal: the
surface density, 120 M ⊙ pc‑2, is
comparable to that of a standard giant molecular cloud; the
cloud’s virial ratio of ∼1.8 is in the star formation range;
and the gas consumption time, 0.5 Gyr, at the present star formation
rate is typical for molecular regions. The low metallicity implies that
the cloud has an average visual extinction of only 0.8 mag, which is
close to the threshold for molecule formation. With such an extinction
threshold, molecular clouds in metal-poor regions should have high
surface densities and high internal pressures. If high pressure is
associated with the formation of massive clusters, then metal-poor
galaxies such as dwarfs in the early universe could have been the hosts
of metal-poor globular clusters.
Proyectos relacionados
Grupo de Estudios de Formación Estelar GEFE
El proyecto interno GEFE está enmarcado en el proyecto coordinado, ESTALLIDOS, financiado por el plan nacional desde el año 2001. El ultimo proyecto aprobado es ESTALLIDOS 6.0 (AYA2016- 79724-C4-2-P). En el proyecto GEFE trabajamos en base al caso científico del proyecto ESTALLIDOS 6.0. Los estallidos de formación estelar (Starbursts o SB) son
Casiana
Muñoz Tuñón