Dust in the early Universe: evidence for non-stellar dust production or observational errors?
2011 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 414, no 1, 781-791 p.Article in journal (Refereed) Published
Observations have revealed unexpectedly large amounts of dust in high-redshift galaxies and its origin is still much debated. Valiante et al. suggested the net stellar dust production of the quasar host galaxy SDSS J1148+5251 may be sufficient to explain the large dust mass detected in this galaxy, albeit under some very special assumptions (e.g. 'closed-box' evolution and a rather high gas mass). Here it is shown that since accretion of essentially pristine material may lower the efficiency of dust formation significantly, and the observationally derived dust-to-gas ratios for these high-redshift galaxies are remarkably high, stellar dust production is likely insufficient. A model including metallicity-dependent, non-stellar dust formation ('secondary dust') is presented. The required contribution from this non-stellar dust component appears too large, however. If all observational constraints are to be met, the resultant dust-to-metals ratio is close to unity, which means that almost all interstellar metals exist in the form of dust. This is a very unlikely situation and suggests the large dust-to-gas ratios at high redshifts may be due to observational uncertainties and/or incorrect calibration of conversion factors for gas and dust tracers.
Place, publisher, year, edition, pages
2011. Vol. 414, no 1, 781-791 p.
AGB and post-AGB, supernovae, dust, extinction, evolution, high-redshift, quasars, SDSS J1148+5251, starburst
IdentifiersURN: urn:nbn:se:uu:diva-156227DOI: 10.1111/j.1365-2966.2011.18447.xISI: 000292141600083OAI: oai:DiVA.org:uu-156227DiVA: diva2:431479