THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?

Acquaviva, Viviana; Vargas, Carlos; Gawiser, Eric; Guaita, Lucia

doi:10.1088/2041-8205/751/2/L26

Title: THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?

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Abstract

Ly{alpha} emitting (LAE) galaxies are thought to be progenitors of present-day L* galaxies. Clustering analyses have suggested that LAEs at z {approx} 3 might evolve into LAEs at z {approx} 2, but it is unclear whether the physical nature of these galaxies is compatible with this hypothesis. Several groups have investigated the properties of LAEs using spectral energy distribution (SED) fitting, but direct comparison of their results is complicated by inconsistencies in the treatment of the data and in the assumptions made in modeling the stellar populations, which are degenerate with the effects of galaxy evolution. By using the same data analysis pipeline and SED fitting software on two stacked samples of LAEs at z = 3.1 and z = 2.1, and by eliminating several systematic uncertainties that might cause a discrepancy, we determine that the physical properties of these two samples of galaxies are dramatically different. LAEs at z = 3.1 are found to be old (age {approx}1 Gyr) and metal-poor (Z < 0.2 Z{sub Sun }), while LAEs at z = 2.1 appear to be young (age {approx}50 Myr) and metal-rich (Z > Z{sub Sun }). The difference in the observed stellar ages makes it very unlikely thatmore »« less

Authors:

Acquaviva, Viviana; Vargas, Carlos; Gawiser, Eric ^[1]; Guaita, Lucia ^[2]

Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States)
Institutionen foer Astronomi, Stockholms Universitet, SE-106 91 Stockholm (Sweden)

Publication Date:: Fri Jun 01 00:00:00 EDT 2012

OSTI Identifier:: 22047798

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal Letters

Additional Journal Information:: Journal Volume: 751; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; COMPARATIVE EVALUATIONS; COMPUTER CODES; COMPUTERIZED SIMULATION; DATA ANALYSIS; ENERGY SPECTRA; GALACTIC EVOLUTION; GALAXIES; GALAXY CLUSTERS; LYMAN LINES; METALS; PHYSICAL PROPERTIES; RED SHIFT

Citation Formats


                    Acquaviva, Viviana, Vargas, Carlos, Gawiser, Eric, and Guaita, Lucia. THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?.  United States: N. p., 2012. 
        Web.  doi:10.1088/2041-8205/751/2/L26.

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                    Acquaviva, Viviana, Vargas, Carlos, Gawiser, Eric, & Guaita, Lucia. THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?.  United States.  https://doi.org/10.1088/2041-8205/751/2/L26

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                    Acquaviva, Viviana, Vargas, Carlos, Gawiser, Eric, and Guaita, Lucia. 2012.  
        "THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?".  United States.  https://doi.org/10.1088/2041-8205/751/2/L26.

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@article{osti_22047798,

  title        = {THE CURIOUS CASE OF Ly{alpha} EMITTERS: GROWING YOUNGER FROM z {approx} 3 to z {approx} 2?},

  author       = {Acquaviva, Viviana and Vargas, Carlos and Gawiser, Eric and Guaita, Lucia},

  abstractNote = {Ly{alpha} emitting (LAE) galaxies are thought to be progenitors of present-day L* galaxies. Clustering analyses have suggested that LAEs at z {approx} 3 might evolve into LAEs at z {approx} 2, but it is unclear whether the physical nature of these galaxies is compatible with this hypothesis. Several groups have investigated the properties of LAEs using spectral energy distribution (SED) fitting, but direct comparison of their results is complicated by inconsistencies in the treatment of the data and in the assumptions made in modeling the stellar populations, which are degenerate with the effects of galaxy evolution. By using the same data analysis pipeline and SED fitting software on two stacked samples of LAEs at z = 3.1 and z = 2.1, and by eliminating several systematic uncertainties that might cause a discrepancy, we determine that the physical properties of these two samples of galaxies are dramatically different. LAEs at z = 3.1 are found to be old (age {approx}1 Gyr) and metal-poor (Z < 0.2 Z{sub Sun }), while LAEs at z = 2.1 appear to be young (age {approx}50 Myr) and metal-rich (Z > Z{sub Sun }). The difference in the observed stellar ages makes it very unlikely that z 3.1 LAEs evolve directly into z = 2.1 LAEs. Larger samples of galaxies, studies of individual objects, and spectroscopic measurements of metallicity at these redshifts are needed to confirm this picture, which is difficult to reconcile with the effects of 1 Gyr of cosmological evolution.},

  doi          = {10.1088/2041-8205/751/2/L26},

  url          = {https://www.osti.gov/biblio/22047798},
  journal      = {Astrophysical Journal Letters},

  issn         = {2041-8205},

  number       = 2,

  volume       = 751,

  place        = {United States},

  year         = {Fri Jun 01 00:00:00 EDT 2012},

  month        = {Fri Jun 01 00:00:00 EDT 2012}

}

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https://doi.org/10.1088/2041-8205/751/2/L26

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