TY  - JOUR
KW  - stars
KW  -  AGB and post-AGB
KW  -  mass-loss
KW  -  supernovae
KW  -  dust
KW  -  extinction
KW  -  galaxies evolution
KW  -  galaxies
KW  -  the Magellanic Clouds
N1  - This article has been published in Monthly Notices of the Royal Astronomical Society © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
IS  - 3
EP  -  2536
TI  - The global gas and dust budget of the Small Magellanic Cloud
SN  - 0035-8711
AV  - public
JF  - Monthly Notices of the Royal Astronomical Society
A1  - Matsuura, M
A1  - Woods, PM
A1  - Owen, PJ
VL  - 429
SP  - 2527 
N2  - In order to understand the evolution of the interstellar medium (ISM) of a galaxy, we have analysed the gas and dust budget of the Small Magellanic Cloud (SMC).

Using the Spitzer Space Telescope, we measured the integrated gas mass-loss rate across asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the SMC, and obtained a rate of 1.4 × 10?3?M??yr?1. This is much smaller than the estimated gas ejection rate from Type II supernovae (SNe) (2?4 × 10?2?M??yr?1). The SMC underwent an increase in star formation rate in the last 12?Myr, and consequently the galaxy has a relatively high SN rate at present. Thus, SNe are more important gas sources than AGB stars in the SMC. The total gas input from stellar sources into the ISM is 2?4 × 10?2?M??yr?1. This is slightly smaller than the ISM gas consumed by star formation (?8 × 10?2?M??yr?1). Star formation in the SMC relies on a gas reservoir in the ISM, but eventually the star formation rate will decline in this galaxy, unless gas infalls into the ISM from an external source.

The dust injection rate from AGB and RSG candidates is 1 × 10?5?M??yr?1. Dust injection from SNe is in the range 0.2?11 × 10?4?M??yr?1, although the SN contribution is rather uncertain. Stellar sources could be important for ISM dust (3 × 105?M?) in the SMC, if the dust lifetime is about 1.4?Gyr.

We found that the presence of poly-aromatic hydrocarbons (PAHs) in the ISM cannot be explained entirely by carbon-rich AGB stars. Carbon-rich AGB stars could inject only 7 × 10?9?M??yr?1? of PAHs at most, which could contribute up to 100?M?? of PAHs in the lifetime of a PAH. The estimated PAH mass of 1800?M?? in the SMC cannot be explained. Additional PAH sources, or ISM reprocessing should be needed.
ID  - discovery1398691
UR  - http://dx.doi.org/10.1093/mnras/sts521
Y1  - 2012/12//
ER  -