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Star Formation in Cooling Flows (Invited Paper)

Published online by Cambridge University Press:  25 April 2016

P. E. J. Nulsen ,
R. M. Johnstone  and
A. C. Fabian
P. E. J. Nulsen
Affiliation:
Mount Stromlo and Siding Spring Observatories, Australian National University
R. M. Johnstone
Affiliation:
Institute of Astronomy, Madingley Road, Cambridge CB3 OHA, England
A. C. Fabian
Affiliation:
Institute of Astronomy, Madingley Road, Cambridge CB3 OHA, England
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Abstract

X-ray data show that substantial quantities of hot gas are cooling near the centres of many clusters and groups of galaxies. The existence of such cooling flows has been challenged because of the lack of evidence for star formation from the cooled gas. Spectra of cooling flow galaxies show filling in of the continuum shortward of the break at 4000 Å relative to normal elliptical galaxies. This is consistent with some continuing star formation. Extended regions of line emission are commonly associated with cooling flows. If the initial-mass-function of the newly formed stars which affect the 4000 Å break is like that which applies in the solar neighbourhood, then these stars can also power the line emission. The strength of the 4000 Å break is shown to correlate with the Hβ flux in the manner expected when this is the case. This allows us to esimate the star formation rate from the line luminosity.

The rate of star formation required to account for the line emission still falls well short of the rate at which gas is inferred to be cooling. It is argued that, nevertheless, the cooling gas is probably forming into stars. The overall initial-mass-function must be different from that which applies in the solar neighbourhood, but this should not be surprising given the different ambient conditions in a cooling flow.

Type
Theoretical
Information
Publications of the Astronomical Society of Australia , Volume 7 , Issue 2 , 1987 , pp. 132 - 135
Copyright
Copyright © Astronomical Society of Australia 1987

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References

Bertschinger, E., and Meiksin, A., 1986, Astrophys. J. Lett., 306, L1.CrossRefGoogle Scholar
Binette, L., Dipita, M.A., and Tuohy, I. R., 1985, Astrophys. J., 297, 476.CrossRefGoogle Scholar
Bruzual, G. A., 1981, PhD Thesis, University of California, Berkeley.Google Scholar
Bruzual, G. A., 1983, Astrophys. J., 273, 105.CrossRefGoogle Scholar
Canizares, C. R., Clark, G. W., Jernigan, J. G., and Markert, T. H., 1982, Astrophys. J., 262, 33.CrossRefGoogle Scholar
Cowie, L. L., Fabian, A.C., and Nulsen, P. E. J., 1980, Mon. Not. R. Astron. Soc., 191, 399.CrossRefGoogle Scholar
Cowie, L. L., Hu, E. M., Jenkins, E.B., and York, D. G., 1983, Astrophys. J., 272, 29.CrossRefGoogle Scholar
Fabian, A.C., Arnaud, K. A., Nulsen, P. E. J., Watson, M. G., McHardy, I., Smith, A., Cooke, B., Elvis, M., and Mushotzky, R. F., 1985, Mon. Not. R. Astron. Soc., 216, 923.CrossRefGoogle Scholar
Fabian, A.C., Ku, W.H.-M., Malin, D. F., Mushotzky, R. F., Nulsen, P. E. J., and Stewart, G.C., 1981, Mon. Not. R. Astron. Soc., 196, 35p.CrossRefGoogle Scholar
Fabian, A.C., and Nulsen, P. E. J., 1977, Mon. Not. R. Ästron. Soc., 180, 479.CrossRefGoogle Scholar
Fabian, A.C., Nulsen, P. E. J. and Canizares, C. R., 1982, Mon. Not. R. Astron. Soc., 201, 933.CrossRefGoogle Scholar
Fabian, A.C., Nulsen, P. E. J., and Canizares, C. R., 1984, Nature, 310, 733.CrossRefGoogle Scholar
Heckman, T. M., 1981, Astrophys. J. Lett., 250, L59.CrossRefGoogle Scholar
Henriksen, M. J., and Mushotzky, R. F., 1985, Astrophys. J., 292, 441.CrossRefGoogle Scholar
Hu, E. M., Cowie, L. L., and Wang, Z., 1985, Astrophys. J. Suppl. Ser., 59, 447.CrossRefGoogle Scholar
Johnstone, R. M., Fabian, A.C., and Nulsen, P. E. J., 1987, Mon. Not. R. Astron. Soc., in Press.Google Scholar
Kennicutt, R.C., 1983, Astrophys. J., 272, 54.CrossRefGoogle Scholar
Kent, S. M., and Sargent, W. L. W., 1979, Astrophys. J., 230, 667.CrossRefGoogle Scholar
Kurucz, R. L., 1979, Astrophys. J. Suppl. Ser., 40, 1.CrossRefGoogle Scholar
Larson, R.B., 1986, Mon. Not. R. Astron. Soc., 218, 409.CrossRefGoogle Scholar
Lea, S. M., Mushotzky, R. and Holt, S. S., 1982, Astrophys. J., 262, 24.CrossRefGoogle Scholar
Lynds, R., 1970, Astrophys. J. Lett., 159, L151.CrossRefGoogle Scholar
Mathews, W. G., and Bregman, J. N., 1978, Astrophys. J., 244, 308.CrossRefGoogle Scholar
Nulsen, P. E. J., 1986, Mon. Not. R. Astrong. Soc., 221, 377.CrossRefGoogle Scholar
Rubin, V.C., Ford, W. K., Peterson, C. J., and Oort, J. H., 1977, Astrophys. J., 211, 693.CrossRefGoogle Scholar
Sarazin, C. L., 1986, Rev. Mod. Phys., 58, 1.CrossRefGoogle Scholar
Sarzin, C. L., and O’Connell, R. W., 1983, Astrophys. J., 268, 552.CrossRefGoogle Scholar
Spitzer, L. and Tomasko, M. G., 1968, Astrophys. J., 152, 971.CrossRefGoogle Scholar
Stewart, G.C., Canizares, C. R., Fabian, A.C., and Nulsen, P. E.J., 1984a, Astrophys. J., 278, 536.CrossRefGoogle Scholar
Stewart, G.C., Fabian, A.C., Jones, C., and Forman, W., 1984b, Astrophys. J., 285, 1.CrossRefGoogle Scholar
Thomas, P. A., Fabian, A.C., and Nulsen, P. E.J., 1987, Mon. Not. R. Astron. Soc., in press.Google Scholar