Skip to main content
Log in

Hot Atmospheres, Cold Gas, AGN Feedback and the Evolution of Early Type Galaxies: A Topical Perspective

  • Published:
Space Science Reviews Aims and scope Submit manuscript

Abstract

Most galaxies comparable to or larger than the mass of the Milky Way host hot, X-ray emitting atmospheres, and many such galaxies are radio sources. Hot atmospheres and radio jets and lobes are the ingredients of radio-mechanical active galactic nucleus (AGN) feedback. While a consensus has emerged that such feedback suppresses cooling of hot cluster atmospheres, less attention has been paid to massive galaxies where similar mechanisms are at play. Observation indicates that the atmospheres of elliptical and S0 galaxies were accreted externally during the process of galaxy assembly and augmented significantly by stellar mass loss. Their atmospheres have entropy and cooling time profiles that are remarkably similar to those of central cluster galaxies. About half display filamentary or disky nebulae of cool and cold gas, much of which has likely cooled from the hot atmospheres. We review the observational and theoretical perspectives on thermal instabilities in galactic atmospheres and the evidence that AGN heating is able to roughly balance the atmospheric cooling. Such heating and cooling may be regulating star formation in all massive spheroids at late times.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14

Similar content being viewed by others

Notes

  1. It matters only when one needs to estimate the thermal energy inside the bubble, which for a given volume and pressure depends on the adiabatic index of the gas.

References

Download references

Acknowledgements

NW was supported by the Lendület LP2016-11 grant awarded by the Hungarian Academy of Sciences. BRM thanks the Natural Sciences and Engineering Research Council of Canada and the Canadian Space Agency for financial support.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to N. Werner.

Additional information

Clusters of Galaxies: Physics and Cosmology

Edited by Andrei Bykov, Jelle Kaastra, Marcus Brüggen, Maxim Markevitch, Maurizio Falanga and Frederik Bernard Stefan Paerels

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Werner, N., McNamara, B.R., Churazov, E. et al. Hot Atmospheres, Cold Gas, AGN Feedback and the Evolution of Early Type Galaxies: A Topical Perspective. Space Sci Rev 215, 5 (2019). https://doi.org/10.1007/s11214-018-0571-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11214-018-0571-9

Keywords

Navigation