Persistent Link:
http://hdl.handle.net/10150/185621
Title:
Line emission from galaxies at high redshift.
Author:
Lowenthal, James Daniel.
Issue Date:
1991
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The results of a multi-faceted search for spectral line emission from galaxies at high redshift are presented. Deep two-dimensional spectra of four blank sky fields were taken at the Multiple Mirror Telescope (MMT) at wavelengths corresponding to redshifted Lyα emission in the range 2.7 < z < 4.7, and the resulting non-detections are used to place upper limits on the space density of randomly distributed Lyα emitters. Although the predictions of a conservative model of galaxy formation incorporating cold dark matter are not excluded in a statistical sense, the search would have detected star-forming dwarf galaxies comparable to the Magellanic Clouds at z = 3, given minimal extinction by dust. The Goddard Fabry-Perot Imager, a piezo-electrically controlled tunable narrow-band filter system with a stand-alone CCD system, was developed and tested, and used at the Kitt Peak National Observatory (KPNO) 4 m telescope to image the damped Lyα absorbing clouds towards three high-redshift QSOs in the light of redshifted Lyα. A companion galaxy to one of the damped systems was discovered and confirmed with followup spectroscopy, and its properties are presented and discussed; the companion exhibits strong Lyα and weak C IV λ1549 and He II λ1640 emission lines, and is apparently producing stars at a rate SFR ∼ 5 - 10M(⊙) yr⁻¹. The implications of the companion's proximity to the damped cloud are analyzed in view of the previous non-detections, and a lower limit to the spatial correlation function of the damped Lyα systems with galaxies is given. Spectroscopic limits on Lyα emission from seven damped systems, including some known to have low chemical and dust abundances, imply low levels of star formation, SFR ≲ 1 M(⊙) yr⁻¹, but extinction by dust in some cases may cause an underestimation of these rates. With near-infrared spectrographs at the MMT and the KPNO 4 m, eight damped Lyα systems were searched for spectral lines characteristic of star formation regions but redshifted from the optical into the near-infrared. A possible detection of (O II) λ3727 and Hβ from one system implies a star formation rate on the order of 100 M(⊙) yr⁻¹, though the remainder of the observations produced non-detections compatible with the Lyα emission limits. The implications for galaxy formation and evolution at high redshift are discussed.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Stars -- Evolution; Galaxies.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Astronomy; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Green, Richard

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleLine emission from galaxies at high redshift.en_US
dc.creatorLowenthal, James Daniel.en_US
dc.contributor.authorLowenthal, James Daniel.en_US
dc.date.issued1991en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe results of a multi-faceted search for spectral line emission from galaxies at high redshift are presented. Deep two-dimensional spectra of four blank sky fields were taken at the Multiple Mirror Telescope (MMT) at wavelengths corresponding to redshifted Lyα emission in the range 2.7 < z < 4.7, and the resulting non-detections are used to place upper limits on the space density of randomly distributed Lyα emitters. Although the predictions of a conservative model of galaxy formation incorporating cold dark matter are not excluded in a statistical sense, the search would have detected star-forming dwarf galaxies comparable to the Magellanic Clouds at z = 3, given minimal extinction by dust. The Goddard Fabry-Perot Imager, a piezo-electrically controlled tunable narrow-band filter system with a stand-alone CCD system, was developed and tested, and used at the Kitt Peak National Observatory (KPNO) 4 m telescope to image the damped Lyα absorbing clouds towards three high-redshift QSOs in the light of redshifted Lyα. A companion galaxy to one of the damped systems was discovered and confirmed with followup spectroscopy, and its properties are presented and discussed; the companion exhibits strong Lyα and weak C IV λ1549 and He II λ1640 emission lines, and is apparently producing stars at a rate SFR ∼ 5 - 10M(⊙) yr⁻¹. The implications of the companion's proximity to the damped cloud are analyzed in view of the previous non-detections, and a lower limit to the spatial correlation function of the damped Lyα systems with galaxies is given. Spectroscopic limits on Lyα emission from seven damped systems, including some known to have low chemical and dust abundances, imply low levels of star formation, SFR ≲ 1 M(⊙) yr⁻¹, but extinction by dust in some cases may cause an underestimation of these rates. With near-infrared spectrographs at the MMT and the KPNO 4 m, eight damped Lyα systems were searched for spectral lines characteristic of star formation regions but redshifted from the optical into the near-infrared. A possible detection of (O II) λ3727 and Hβ from one system implies a star formation rate on the order of 100 M(⊙) yr⁻¹, though the remainder of the observations produced non-detections compatible with the Lyα emission limits. The implications for galaxy formation and evolution at high redshift are discussed.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectStars -- Evolutionen_US
dc.subjectGalaxies.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAstronomyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGreen, Richarden_US
dc.contributor.committeememberHogan, Craigen_US
dc.contributor.committeememberRieke, Marciaen_US
dc.identifier.proquest9208021en_US
dc.identifier.oclc703612283en_US
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