Observable consequences of cold clouds as dark matter
Cold, dense clouds of gas have been proposed as baryonic candidates for the dark matter in Galactic haloes, and have also been invoked in the Galactic disc as an explanation for the excess faint sub-mm sources detected by SCUBA. Even if their dust-to-gas ratio is only a small percentage of that in c...
| मुख्य लेखकों: | , , |
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| स्वरूप: | Journal article |
| प्रकाशित: |
2002
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| _version_ | 1826292025721356288 |
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| author | Kerins, E Binney, J Silk, J |
| author_facet | Kerins, E Binney, J Silk, J |
| author_sort | Kerins, E |
| collection | OXFORD |
| description | Cold, dense clouds of gas have been proposed as baryonic candidates for the dark matter in Galactic haloes, and have also been invoked in the Galactic disc as an explanation for the excess faint sub-mm sources detected by SCUBA. Even if their dust-to-gas ratio is only a small percentage of that in conventional gas clouds, these dense systems would be opaque to visible radiation. This presents the possibility of detecting them by looking for occultations of background stars. We examine the possibility that the data sets of microlensing experiments searching for massive compact halo objects can also be used to search for occultation signatures by cold clouds. We compute the rate and timescale distribution of stellar transits by clouds in the Galactic disc and halo. We find that, for cloud parameters typically advocated by theoretical models, thousands of transit events should already exist within microlensing survey data sets. We examine the seasonal modulation in the rate caused by the Earth's orbital motion and find it provides an excellent probe of whether detected clouds are of disc or halo origin. |
| first_indexed | 2024-03-07T03:08:21Z |
| format | Journal article |
| id | oxford-uuid:b3568e69-4d09-413f-9ac3-8525e5d21e71 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:08:21Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:b3568e69-4d09-413f-9ac3-8525e5d21e712022-03-27T04:18:14ZObservable consequences of cold clouds as dark matterJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b3568e69-4d09-413f-9ac3-8525e5d21e71Symplectic Elements at Oxford2002Kerins, EBinney, JSilk, JCold, dense clouds of gas have been proposed as baryonic candidates for the dark matter in Galactic haloes, and have also been invoked in the Galactic disc as an explanation for the excess faint sub-mm sources detected by SCUBA. Even if their dust-to-gas ratio is only a small percentage of that in conventional gas clouds, these dense systems would be opaque to visible radiation. This presents the possibility of detecting them by looking for occultations of background stars. We examine the possibility that the data sets of microlensing experiments searching for massive compact halo objects can also be used to search for occultation signatures by cold clouds. We compute the rate and timescale distribution of stellar transits by clouds in the Galactic disc and halo. We find that, for cloud parameters typically advocated by theoretical models, thousands of transit events should already exist within microlensing survey data sets. We examine the seasonal modulation in the rate caused by the Earth's orbital motion and find it provides an excellent probe of whether detected clouds are of disc or halo origin. |
| spellingShingle | Kerins, E Binney, J Silk, J Observable consequences of cold clouds as dark matter |
| title | Observable consequences of cold clouds as dark matter |
| title_full | Observable consequences of cold clouds as dark matter |
| title_fullStr | Observable consequences of cold clouds as dark matter |
| title_full_unstemmed | Observable consequences of cold clouds as dark matter |
| title_short | Observable consequences of cold clouds as dark matter |
| title_sort | observable consequences of cold clouds as dark matter |
| work_keys_str_mv | AT kerinse observableconsequencesofcoldcloudsasdarkmatter AT binneyj observableconsequencesofcoldcloudsasdarkmatter AT silkj observableconsequencesofcoldcloudsasdarkmatter |