NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-24 T18:19:37 PDT
Help | Comment | NED Home

For refcode 1998ApJ...496..145L:
Retrieve 44 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1998ApJ...496..145L Dust-to-Gas Ratio and Metal Abundance in Dwarf Galaxies U. LISENFELD AND A. FERRARA Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy Received 1997 May 6; accepted 1997 October 30 ABSTRACT We have compared the metallicity (represented by oxygen abundance), X_o_, and the dust-to-gas ratio, D, in a sample of dwarf galaxies. For dwarf irregulars (dIrrs) we find a good correlation between the two quantities, with a power-law index of 0.52 +/- 0.25. Blue compact dwarf (BCD) galaxies do not show such a good correlation; in addition, both the dust-to-gas ratio and the metallicity tend to be higher than for dIrrs. We have then developed a simple but physical analytical model for the above relation. Comparing the model results with the data, we conclude that (i) for low values of D, the D-X_o_ relation is quasi-linear, whereas for higher values, the curve strongly deviates from the linear behavior, implying that the commonly used power-law approximation is very poor; (ii) the deviation from the linear behavior depends critically on the parameter {chi}, the "differential" mass outflow rate from the galaxy in units of the star formation rate, {psi}; (iii) the shape of the D-X_o_ curve does not depend on {psi}, but only on {chi}, however, the specific location of a given galaxy on the curve does depend on {psi}; and (iv) the BCD metallicity segregation is the result of a higher {psi}, together with a significant differential mass outflow. Thus, the lack of correlation can be produced by largely different star formation rates and values of {chi} in these objects. Subject headings: dust, extinction-galaxies: abundances-galaxies: evolution-galaxies: irregular
Retrieve 44 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home