Abstract
THERE is a growing consensus that the emergence of quasars at high redshifts is related to the onset of galaxy formation1, suggesting that the detection of concentrations of gas accompanying such quasars should provide clues about the early history of galaxies. Quasar companions have been recently identified at redshifts up to z ≈ 3 (refs 2–4). Here we report observations of Lyman-α emission (a tracer of ionized hydrogen) from the companion to a quasar at z = 4.7, corresponding to a time when the Universe was less than ten per cent of its present age. We argue that most of the emission arises in a gaseous nebula that has been photoionized by the quasar, but an additional component of continuum light—perhaps quasar light scattered from dust in the companion body, or emission from young stars within the nebula—appears necessary to explain the observations. These observations may be indicative of the first stages in the assembly of galaxy-sized structures.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to the full article PDF.
USD 39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Haehnelt, M. & Rees, M. J. Mon. Not. R. astr. Soc. 263, 168–178 (1993).
Djorgovski, S., Spinrad, H., McCarthy, P. & Strauss, M. A. Astrophys. J. 299, L1–L5 (1985).
Steidel, C. C., Sargent, W. L. W. & Dickinson, M. Astr. J. 101, 1187–1195 (1991).
Møller, P. & Warren, S. J. Astr. Astrophys. 270, 43–52 (1993).
Irwin, M. J., McMahon, R. G. & Hazard, C. in The Space Distribution of Quasars (ed. Crampton, D.) 21, 117–126 (ASP Conf. Ser., San Francisco, 1991).
Pahre, M. A. & Djorgovski, S. G. Astrophys. J. 449, L1–L4 (1995).
Wampler, E. J. et al. Astr. Astrophys. (in the press).
Giallongo, E. et al. Astrophys. J. 425, L1–L4 (1994).
Bacon, R. et al. Astr. Astrophys. Suppl. Ser. 113, 347–357 (1995).
Ferruit, P. & Pécontal, E. Astr. Astrophys. 288, 65–76 (1994).
Bacon, R., Emsellem, E., Monnet, G. & Neito, J. L. Astr. Astrophys. 281, 691–712 (1994).
Lu, L., Sargent, W. L. W., Womble, D. S. & Barlow, T. A. Astrophys. J. Lett. (in the press).
Wolfe, A. M. Astrophys. J. 402, 411–419 (1993).
Pettini, M., Hunstead, R. W., King, D. L. & Smith, L. J. in QSO Absorption Lines (ed. Meylan, G.) 55–58 (ESO, Garching, 1995).
Lowenthal, J. D. et al. Astrophys. J. 451, 484–497 (1995).
Charlot, S. & Fall, S. M. Astrophys. J. 415, 580–588 (1993).
Valls-Gabaud, D. Astrophys. J. 419, 7–11 (1993).
Fontana, A., Cristiani, S., D'Odorico, S., Giallongo, E. & Savaglio, S. Mon. Not. R. astr. Soc. (in the press).
Djorgovski, S. G. in Science with VLT (eds Walsh, J. R. & Danziger, J.) 351–360 (ESO, Garching, 1995).
Hu, E. M., McMahon, R. G. & Egami, E. Astrophys, J. Lett. (in the press).
Hu, E. M., Songaila, A., Cowie, L. L. & Stockton, A. Astrophys. J. 368, 28–39 (1991).
Thompson, D., Djorgovski, S. & Trauger, J. Astr. J. 110, 963–981 (1995).
Pritchet, C. J. Publs astr. Soc. Pacif. 106, 1052–1067 (1994).
McMahon, R. G., Omont, A., Bergeron, J., Kreysa, E. & Haslam, C. G. T. Mon. Not. R. astr. Soc. 267, L9–L12 (1994).
Isaak, K. G., McMahon, R. G., Hills, R. E. & Withington, S. Mon. Not. R. astr. Soc. 269, L28–L32 (1994).
McCarthy, P. J. A. Rev. Astr. Astrophys. 31, 639–688 (1993).
Ferland, G. J. Int. Rep. (Dept of Physics & Astronomy, Univ. Kentucky, Lexington, 1993).
Madau, P. Astrophys J. 441, 18–27 (1995).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Petitjean, P., Pécontal, E., Valls-Gabaud, D. et al. A companion to a quasar at redshift z = 4.7. Nature 380, 411–413 (1996). https://doi.org/10.1038/380411a0
Received:
Accepted:
Issue date:
DOI: https://doi.org/10.1038/380411a0
This article is cited by
-
Detection of molecular gas in the quasar BR1202 – 0725 at redshift z = 4.69
Nature (1996)
-
A 3.5-Gyr-old galaxy at redshift 1.55
Nature (1996)
-
Molecular gas and dust around a radio-quiet quasar at redshift 4.69
Nature (1996)
-
Detection of Lyman-α-emitting galaxies at redshift 4.55
Nature (1996)
