Cold filaments in galaxy clusters: effects of heat conduction
We determine the critical size l_crit of a filament of cold (T~10^4 K) gas that is in radiative equilibrium with X-ray emitting gas at temperatures T_out~10^6 - 10^8 K. Filaments smaller than l_crit will be rapidly evaporated, while longer ones will induce the condensation of the ambient medium. At...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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2004
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| _version_ | 1797092288336232448 |
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| author | Nipoti, C Binney, J |
| author_facet | Nipoti, C Binney, J |
| author_sort | Nipoti, C |
| collection | OXFORD |
| description | We determine the critical size l_crit of a filament of cold (T~10^4 K) gas that is in radiative equilibrium with X-ray emitting gas at temperatures T_out~10^6 - 10^8 K. Filaments smaller than l_crit will be rapidly evaporated, while longer ones will induce the condensation of the ambient medium. At fixed pressure P, l_crit increases as T_out^(11/4), while at fixed T_out it scales as 1/P. It scales as f^(1/2), where f is the factor by which the magnetic field depresses the thermal conductivity below Spitzer's benchmark value. For plausible values of f, l_crit is similar to the lengths of observed filaments. In a cluster such as Perseus, the value of l_crit increases by over an order of magnitude between the centre and a radius of 100 kpc. If the spectrum of seed filament lengths l is strongly falling with l, as is natural, then these results explain why filaments are only seen within a few kiloparsecs of the centres of clusters, and are not seen in clusters that have no cooling flow. We calculate the differential emission measure as a function of temperature for the interface between filaments and ambient gas of various temperatures. We discuss the implications of our results for the origin of the galaxy luminosity function. |
| first_indexed | 2024-03-07T03:44:01Z |
| format | Journal article |
| id | oxford-uuid:bed6dd6b-b321-4697-9ccb-4991d9d658ae |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:44:01Z |
| publishDate | 2004 |
| record_format | dspace |
| spelling | oxford-uuid:bed6dd6b-b321-4697-9ccb-4991d9d658ae2022-03-27T05:42:57ZCold filaments in galaxy clusters: effects of heat conductionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bed6dd6b-b321-4697-9ccb-4991d9d658aeEnglishSymplectic Elements at Oxford2004Nipoti, CBinney, JWe determine the critical size l_crit of a filament of cold (T~10^4 K) gas that is in radiative equilibrium with X-ray emitting gas at temperatures T_out~10^6 - 10^8 K. Filaments smaller than l_crit will be rapidly evaporated, while longer ones will induce the condensation of the ambient medium. At fixed pressure P, l_crit increases as T_out^(11/4), while at fixed T_out it scales as 1/P. It scales as f^(1/2), where f is the factor by which the magnetic field depresses the thermal conductivity below Spitzer's benchmark value. For plausible values of f, l_crit is similar to the lengths of observed filaments. In a cluster such as Perseus, the value of l_crit increases by over an order of magnitude between the centre and a radius of 100 kpc. If the spectrum of seed filament lengths l is strongly falling with l, as is natural, then these results explain why filaments are only seen within a few kiloparsecs of the centres of clusters, and are not seen in clusters that have no cooling flow. We calculate the differential emission measure as a function of temperature for the interface between filaments and ambient gas of various temperatures. We discuss the implications of our results for the origin of the galaxy luminosity function. |
| spellingShingle | Nipoti, C Binney, J Cold filaments in galaxy clusters: effects of heat conduction |
| title | Cold filaments in galaxy clusters: effects of heat conduction |
| title_full | Cold filaments in galaxy clusters: effects of heat conduction |
| title_fullStr | Cold filaments in galaxy clusters: effects of heat conduction |
| title_full_unstemmed | Cold filaments in galaxy clusters: effects of heat conduction |
| title_short | Cold filaments in galaxy clusters: effects of heat conduction |
| title_sort | cold filaments in galaxy clusters effects of heat conduction |
| work_keys_str_mv | AT nipotic coldfilamentsingalaxyclusterseffectsofheatconduction AT binneyj coldfilamentsingalaxyclusterseffectsofheatconduction |