Abstract
The broad range of optical–infrared colours of radio QSOs,1 < B-K < 6, has been cited as evidence for several mag of dust extinction (Webster et al.. If such large extinctions are typical, the implications for our understanding of the space density of optically selected QSOs are profound. We have previously found that the host galaxies of several of the reddest B3 QSOs are readily detectable in K-band images. This suggests contamination of the K apparent magnitudes by starlight, i.e. the redness in B-Kmay be due to excess light in K, rather than to dust extinction of the B light. We have now imaged the B3 QSOs inUBVR, and we use the range of observed optical and optical–IR colours to place an upper limit on the amount of dust extinction present, rest-frame A V < 1.5 mag.
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References
Baker, J.C.: 1997, Mon. Not. R. Astron. Soc. 286, 23.
Benn, C.R., Vigotti, M., Carballo, R., González-Serrano, J.I. and Sánchez, S.F.: 1998, Mon. Not. R. Astron. Soc. 295, 451.
Calzetti, D., Kinney, A.L. and Storchi-Bergmann, T.: 1994, Astrophys J. 429, 582.
Carballo, R., González-Serrano, J.I., Benn, C.R., Sánchez, S.F. and Vigotti, M.: 1999, Mon. Not. R. Astron. Soc. 306, 137.
Carballo, R., Sánchez, S.F., González-Serrano, J.I., Benn, C.R. and Vigotti, M.: 1998, Astron. J. 115, 1234.
Fall, S.M. and Pei, Y.C.: 1993, Astrophys J. 402, 479.
Ficarra, A., Grueff, G. and Tomassetti, G.: 1985, Astron. Astrophys. Suppl. 59, 255.
Omont, A., McMahon, R.G., Cox, P., Kreysa, E., Bergeron, J., Pajot, F. and Storrie-Lombardi, L.J.: 1996, Astron. Astrophys. 315, 1.
Ostriker, J.P. and Heisler, J.: 1984, Astrophys J. 278, 1.
Vigotti, M., Grueff, G., Perley, R., Clark, B.G. and Bridle, A.H.: 1989, Astron. J. 98, 419.
Vigotti, M., Vettolani, G.V., Merighi, R., Lahulla, J.F. and Pedani,M.: 1997, Astron. Astrophys. Suppl. 123, 219.
Webster, R.L., Francis, P.J., Peterson, B.A., Drinkwater, M.J. and Masci, F.J.: 1995, Nature 375, 469.
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Benn, C., Vigotti, M., Carballo, R. et al. Limits on Dust Extinction in B3 QSOS. Astrophysics and Space Science 276, 1037–1040 (2001). https://doi.org/10.1023/A:1017513421922
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DOI: https://doi.org/10.1023/A:1017513421922