Galaxy Evolution in a Pilot Survey up to z=1 and CDM Halos
We study spectral evolution of galaxies in a magnitude limited sample of 550 galaxies from z=1 down to z=0.3 on a pencil beam of ≈10′×10′. We concentrate on the large apparent cosmological structures along the line of sight, and we bin our individual galaxy spectra to obtain representative high S/N...
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| Format: | Article |
| Language: | English |
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Wiley
2011-01-01
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| Series: | Advances in Astronomy |
| Online Access: | http://dx.doi.org/10.1155/2011/508381 |
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| author | E. Giraud J. Melnick Q.-S. Gu H. Quintana F. Selman I. Toledo P. Zelaya |
| author_facet | E. Giraud J. Melnick Q.-S. Gu H. Quintana F. Selman I. Toledo P. Zelaya |
| author_sort | E. Giraud |
| collection | DOAJ |
| description | We study spectral evolution of galaxies in a magnitude limited sample of 550
galaxies from z=1 down to z=0.3 on a pencil beam of
≈10′×10′.
We concentrate on the large apparent cosmological structures along the line of
sight, and we bin our individual galaxy spectra to obtain representative high
S/N spectra based upon these structures. We divide the resulting average
spectra in three groups to facilitate the analysis:galaxies with pure
absorption line spectra, galaxies with emission lines and blue continua, and
galaxies with emission lines and red continua.
We revisit the question of downsizing in emission-line galaxies between
z=0.9 and z=0.45 in our pencil-beam and find the following results:
strong star formation in emission line galaxies, aging in emission line
galaxies, and aging in absorption systems, are shifting from bright to faint
systems as cosmological time increases. Each redshift bin is repopulated in
new starbursts.
Therefore at redshifts z⩽1 galaxy formation is downsizing both in
luminosity and number density. Our observations indicate that at z⩽1
star formation and hierarchical structure formation of CDM halos are not in
phase. |
| format | Article |
| id | doaj-art-d6f2a36a4ddc4e0bad72cc062577690f |
| institution | Kabale University |
| issn | 1687-7969 1687-7977 |
| language | English |
| publishDate | 2011-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Astronomy |
| spelling | doaj-art-d6f2a36a4ddc4e0bad72cc062577690f2025-02-03T01:26:27ZengWileyAdvances in Astronomy1687-79691687-79772011-01-01201110.1155/2011/508381508381Galaxy Evolution in a Pilot Survey up to z=1 and CDM HalosE. Giraud0J. Melnick1Q.-S. Gu2H. Quintana3F. Selman4I. Toledo5P. Zelaya6Laboratory of Theoretical Physics and Astroparticles, Montpellier University, 34095 Montpellier, FranceEuropean Southern Observatory, Alonso de Córdova, Santiago, 3107, ChileDepartment of Astronomy, Nanjing University, Nanjing 210093, ChinaDepartment of Astronomy and Astrophysics, P. Universidad Catolica de Chile, Casilla, Santiago, 306, ChileEuropean Southern Observatory, Alonso de Córdova, Santiago, 3107, ChileDepartment of Astronomy and Astrophysics, P. Universidad Catolica de Chile, Casilla, Santiago, 306, ChileDepartment of Astronomy and Astrophysics, P. Universidad Catolica de Chile, Casilla, Santiago, 306, ChileWe study spectral evolution of galaxies in a magnitude limited sample of 550 galaxies from z=1 down to z=0.3 on a pencil beam of ≈10′×10′. We concentrate on the large apparent cosmological structures along the line of sight, and we bin our individual galaxy spectra to obtain representative high S/N spectra based upon these structures. We divide the resulting average spectra in three groups to facilitate the analysis:galaxies with pure absorption line spectra, galaxies with emission lines and blue continua, and galaxies with emission lines and red continua. We revisit the question of downsizing in emission-line galaxies between z=0.9 and z=0.45 in our pencil-beam and find the following results: strong star formation in emission line galaxies, aging in emission line galaxies, and aging in absorption systems, are shifting from bright to faint systems as cosmological time increases. Each redshift bin is repopulated in new starbursts. Therefore at redshifts z⩽1 galaxy formation is downsizing both in luminosity and number density. Our observations indicate that at z⩽1 star formation and hierarchical structure formation of CDM halos are not in phase.http://dx.doi.org/10.1155/2011/508381 |
| spellingShingle | E. Giraud J. Melnick Q.-S. Gu H. Quintana F. Selman I. Toledo P. Zelaya Galaxy Evolution in a Pilot Survey up to z=1 and CDM Halos Advances in Astronomy |
| title | Galaxy Evolution in a Pilot Survey up to z=1
and CDM Halos |
| title_full | Galaxy Evolution in a Pilot Survey up to z=1
and CDM Halos |
| title_fullStr | Galaxy Evolution in a Pilot Survey up to z=1
and CDM Halos |
| title_full_unstemmed | Galaxy Evolution in a Pilot Survey up to z=1
and CDM Halos |
| title_short | Galaxy Evolution in a Pilot Survey up to z=1
and CDM Halos |
| title_sort | galaxy evolution in a pilot survey up to z 1 and cdm halos |
| url | http://dx.doi.org/10.1155/2011/508381 |
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