Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0
We compare deep Magellan spectroscopy of 26 groups at 0.3 ≤ z ≤ 0.55, selected from the Canadian Network for Observational Cosmology 2 field survey, with a large sample of nearby groups from the 2PIGG catalogue. We find that the fraction of group galaxies with significant [O II]λ3727 emission (≥5 Å)...
| Автори: | , , , , , , , , , |
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| Формат: | Journal article |
| Мова: | English |
| Опубліковано: |
2005
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| _version_ | 1826263686851854336 |
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| author | Wilman, D Balogh, M Bower, R Mulchaey, J Oemler, A Carlberg, R Eke, V Lewis, I Morris, S Whitaker, R |
| author_facet | Wilman, D Balogh, M Bower, R Mulchaey, J Oemler, A Carlberg, R Eke, V Lewis, I Morris, S Whitaker, R |
| author_sort | Wilman, D |
| collection | OXFORD |
| description | We compare deep Magellan spectroscopy of 26 groups at 0.3 ≤ z ≤ 0.55, selected from the Canadian Network for Observational Cosmology 2 field survey, with a large sample of nearby groups from the 2PIGG catalogue. We find that the fraction of group galaxies with significant [O II]λ3727 emission (≥5 Å) increases strongly with redshift, from ∼29 per cent in 2dFGRS to ∼58 per cent in CNOC2, for all galaxies brighter than ∼M* + 1.75. This trend is parallel to the evolution of field galaxies, where the equivalent fraction of emission-line galaxies increases from ∼53 to ∼75 per cent. The fraction of emission-line galaxies in groups is lower than in the field, across the full redshift range, indicating that the history of star formation in groups is influenced by their environment. We show that the evolution required to explain the data is inconsistent with a quiescent model of galaxy evolution; instead, discrete events in which galaxies cease forming stars (truncation events) are required. We constrain the probability of truncation (P trunc) and find that a high value is required in a simple evolutionary scenario neglecting galaxy mergers (P trunc ≳ 0.3 Gyr -1). However, without assuming significant density evolution, P trunc is not required to be larger in groups than in the field, suggesting that the environmental dependence of star formation was embedded at redshifts z ≳ 0.45. © 2005 RAS. |
| first_indexed | 2024-03-06T19:55:46Z |
| format | Journal article |
| id | oxford-uuid:2586d475-6ca8-43b1-8153-19920643fbb4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:55:46Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:2586d475-6ca8-43b1-8153-19920643fbb42022-03-26T11:56:11ZGalaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2586d475-6ca8-43b1-8153-19920643fbb4EnglishSymplectic Elements at Oxford2005Wilman, DBalogh, MBower, RMulchaey, JOemler, ACarlberg, REke, VLewis, IMorris, SWhitaker, RWe compare deep Magellan spectroscopy of 26 groups at 0.3 ≤ z ≤ 0.55, selected from the Canadian Network for Observational Cosmology 2 field survey, with a large sample of nearby groups from the 2PIGG catalogue. We find that the fraction of group galaxies with significant [O II]λ3727 emission (≥5 Å) increases strongly with redshift, from ∼29 per cent in 2dFGRS to ∼58 per cent in CNOC2, for all galaxies brighter than ∼M* + 1.75. This trend is parallel to the evolution of field galaxies, where the equivalent fraction of emission-line galaxies increases from ∼53 to ∼75 per cent. The fraction of emission-line galaxies in groups is lower than in the field, across the full redshift range, indicating that the history of star formation in groups is influenced by their environment. We show that the evolution required to explain the data is inconsistent with a quiescent model of galaxy evolution; instead, discrete events in which galaxies cease forming stars (truncation events) are required. We constrain the probability of truncation (P trunc) and find that a high value is required in a simple evolutionary scenario neglecting galaxy mergers (P trunc ≳ 0.3 Gyr -1). However, without assuming significant density evolution, P trunc is not required to be larger in groups than in the field, suggesting that the environmental dependence of star formation was embedded at redshifts z ≳ 0.45. © 2005 RAS. |
| spellingShingle | Wilman, D Balogh, M Bower, R Mulchaey, J Oemler, A Carlberg, R Eke, V Lewis, I Morris, S Whitaker, R Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title | Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title_full | Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title_fullStr | Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title_full_unstemmed | Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title_short | Galaxy groups at 0.3 ≤ z ≤ 0.55 - II. Evolution to z ∼ 0 |
| title_sort | galaxy groups at 0 3 ≤ z ≤ 0 55 ii evolution to z ∼ 0 |
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