Mass-to-light ratio gradients in early-type galaxy haloes
Since the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterising the halo masses from both observational and theoretical results: \dML, the logarithmic radial gradient of the mass-to-light...
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ftcern:oai:cds.cern.ch:807018 2023-05-15T16:01:29+02:00 Mass-to-light ratio gradients in early-type galaxy haloes Napolitano, N R Capaccioli, M Romanowsky, A J Douglas, N G Merrifield, M R Kuijken, K Arnaboldi, M Gerhard, O Freeman, K C 2004-11-23 http://cds.cern.ch/record/807018 eng eng http://cds.cern.ch/record/807018 astro-ph/0411639 oai:cds.cern.ch:807018 Astrophysics and Astronomy 2004 ftcern 2018-07-28T07:03:34Z Since the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterising the halo masses from both observational and theoretical results: \dML, the logarithmic radial gradient of the mass-to-light ratio. Using halo density profiles from LCDM simulations, we derive predictions for this gradient for various galaxy luminosities and star formation efficiencies $\epsilon_{SF}$. As a pilot study, we assemble the available \dML\ data from kinematics in early-type galaxies - representing the first unbiassed study of halo masses in a wide range of early-type galaxy luminosities - and find a correlation between luminosity and \dML, such that the brightest galaxies appear the most dark-matter dominated. We find that the gradients in most of the brightest galaxies may fit in well with the LCDM predictions, but that there is also a population of fainter galaxies whose gradients are so low as to imply an unreasonably high star formation efficiency $\epsilon_{SF} > 1$. This difficulty is eased if dark haloes are not assumed to have the standard LCDM profiles, but lower central concentrations. Other/Unknown Material DML CERN Document Server (CDS) |
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CERN Document Server (CDS) |
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ftcern |
language |
English |
topic |
Astrophysics and Astronomy |
spellingShingle |
Astrophysics and Astronomy Napolitano, N R Capaccioli, M Romanowsky, A J Douglas, N G Merrifield, M R Kuijken, K Arnaboldi, M Gerhard, O Freeman, K C Mass-to-light ratio gradients in early-type galaxy haloes |
topic_facet |
Astrophysics and Astronomy |
description |
Since the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterising the halo masses from both observational and theoretical results: \dML, the logarithmic radial gradient of the mass-to-light ratio. Using halo density profiles from LCDM simulations, we derive predictions for this gradient for various galaxy luminosities and star formation efficiencies $\epsilon_{SF}$. As a pilot study, we assemble the available \dML\ data from kinematics in early-type galaxies - representing the first unbiassed study of halo masses in a wide range of early-type galaxy luminosities - and find a correlation between luminosity and \dML, such that the brightest galaxies appear the most dark-matter dominated. We find that the gradients in most of the brightest galaxies may fit in well with the LCDM predictions, but that there is also a population of fainter galaxies whose gradients are so low as to imply an unreasonably high star formation efficiency $\epsilon_{SF} > 1$. This difficulty is eased if dark haloes are not assumed to have the standard LCDM profiles, but lower central concentrations. |
author |
Napolitano, N R Capaccioli, M Romanowsky, A J Douglas, N G Merrifield, M R Kuijken, K Arnaboldi, M Gerhard, O Freeman, K C |
author_facet |
Napolitano, N R Capaccioli, M Romanowsky, A J Douglas, N G Merrifield, M R Kuijken, K Arnaboldi, M Gerhard, O Freeman, K C |
author_sort |
Napolitano, N R |
title |
Mass-to-light ratio gradients in early-type galaxy haloes |
title_short |
Mass-to-light ratio gradients in early-type galaxy haloes |
title_full |
Mass-to-light ratio gradients in early-type galaxy haloes |
title_fullStr |
Mass-to-light ratio gradients in early-type galaxy haloes |
title_full_unstemmed |
Mass-to-light ratio gradients in early-type galaxy haloes |
title_sort |
mass-to-light ratio gradients in early-type galaxy haloes |
publishDate |
2004 |
url |
http://cds.cern.ch/record/807018 |
genre |
DML |
genre_facet |
DML |
op_relation |
http://cds.cern.ch/record/807018 astro-ph/0411639 oai:cds.cern.ch:807018 |
_version_ |
1766397312163119104 |