Bibcode
DOI
Silich, S.; Tenorio-Tagle, G.; Muñoz-Tuñón, C.; Cairos, L. M.
Bibliographical reference
The Astronomical Journal, Volume 123, Issue 5, pp. 2438-2448.
Advertised on:
5
2002
Citations
21
Refereed citations
17
Description
Here we attempt to infer the recent history of star formation in the BCD
galaxy VII Zw 403, based on an analysis that accounts for the dynamics
of the remnant generated either by an instantaneous burst or by a
continuous star formation event. The models are restricted by the size
of the diffuse X-ray-emitting region, the Hα luminosity from the
star-forming region, and the superbubble diffuse X-ray luminosity. We
have reobserved VII Zw 403 with a better sensitivity corresponding to
the threshold Hα flux 8.15×10-17 ergs
cm-2 s-1. The total Hα luminosity derived
from our data is much larger than reported before and presents a variety
of ionized filaments and incomplete shells superimposed on the diffuse
Hα emission. This result has a profound impact on the predicted
properties of the starburst-blown superbubble. Numerical calculations
based on the Hubble Space Telescope Hα data predict two different
scenarios of star formation able to match simultaneously all observed
parameters. These are an instantaneous burst of star formation with a
total mass of 5×105 Msolar and a
star-forming event with a constant star formation rate
SFR=4×10-3 Msolar yr-1, which
lasts for 35 Myr. The numerical calculations based on the energy input
rate derived from our observations predict a short episode of star
formation lasting less than 10 Myr with a total star cluster mass of
~(1-3)×106 Msolar. However, the five main
star-forming knots are sufficiently distant to form a coherent shell in
a short timescale and still keep their energies blocked within local,
spatially separated bubbles. The X-ray luminosities of these are here
shown to be consistent with the ROSAT PSPC diffuse X-ray emission.