To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
In recent years, remarkably tight correlations have been observed between the properties of supermassive black holes (SMBHs) residing in galaxy cores and those of the host galaxies themselves (Magorrian et al. 1998; Gebhhardt et al. 2000; Häring and Rix 2004). A growing body of evidence seems to support the idea that feedback from active galactic nuclei (AGN) provides a natural link between these. While every galaxy can potentially host a SMBH, only a relatively small fraction of these are observed in an active state. AGN activity manifests itself through powerful outflows observable right across the electromagnetic spectrum.
The central black holes are powered by accretion of surrounding cold gas. The resultant outflows, in turn, affect the cold gas supply by heating and/or transporting this gas away from dense inner regions with short cooling times. It is for this reason that feedback from radio sources is particularly interesting. Despite only contributing around one per cent of the AGN bolometric luminosity, radio-loud AGNs can profoundly affect their surroundings through such mechanical feedback. One piece of observational evidence supporting this view comes from studies of X-ray clusters. In the absence of feedback, large amounts of cold gas are expected in dense cluster cores (due to short cooling times), however no such gas has been found. This well-known ‘cooling flow problem’ points to the need for a central, powerful heating source.
Email your librarian or administrator to recommend adding this to your organisation's collection.