Discovery of eight new extremely metal-poor galaxies in the sloan digital sky survey

Alexei Y. Kniazev; Eva K. Grebel; Lei Hao; Michael A. Strauss; Jonathan Brinkmann; Masataka Fukugita

doi:10.1086/378259

Discovery of eight new extremely metal-poor galaxies in the sloan digital sky survey

Alexei Y. Kniazev, Eva K. Grebel, Lei Hao, Michael A. Strauss, Jonathan Brinkmann, Masataka Fukugita

Research output: Contribution to journal › Article › peer-review

70 Scopus citations

Abstract

We report the discovery of eight new extremely metal-poor galaxies [XMPGs; 12 + log (O/H) < 7.65] and the recovery of four previously known or suspected XMPGs (I Zw 18, HS 0822+3542, HS 0837+4717, and All 16+517) using Sloan Digital Sky Survey (SDSS) spectroscopy. These new objects were identified after an analysis of 250,000 galaxy spectra within an area of ∼3000 deg ² on the sky. Our oxygen abundance determinations have an accuracy of ≤0.1 dex and are based on the temperature-sensitive [O III] λ4363 line and on the direct calculation of the electron temperature. We briefly discuss a new method of oxygen abundance determinations using the [O II] λλ 7319, 7330 lines that is particularly useful for SDSS emission-line spectra with redshifts ≤0.024 since the [O II ] λ 3727 emission line falls outside of the SDSS wavelength range. We detect XMPGs with redshifts ranging from 0.0005 to 0.0443 and M_g luminosities from -12.4 to -18.6 mag. Our eight new XMPGs increase the number of known metal-deficient galaxies by approximately one-quarter. The estimated surface density of XMPGs is 0.004 deg^-2 for r ≤ 17.77 mag.

Original language	English (US)
Pages (from-to)	L73-L76
Journal	Astrophysical Journal
Volume	593
Issue number	2 II
DOIs	https://doi.org/10.1086/378259
State	Published - Aug 20 2003
Externally published	Yes

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Keywords

Galaxies: abundances
Galaxies: dwarf
Galaxies: evolution

Access to Document

10.1086/378259

Cite this

@article{4e8bfda1b3a144b985faf9b5f23432e8,

title = "Discovery of eight new extremely metal-poor galaxies in the sloan digital sky survey",

abstract = "We report the discovery of eight new extremely metal-poor galaxies [XMPGs; 12 + log (O/H) < 7.65] and the recovery of four previously known or suspected XMPGs (I Zw 18, HS 0822+3542, HS 0837+4717, and All 16+517) using Sloan Digital Sky Survey (SDSS) spectroscopy. These new objects were identified after an analysis of 250,000 galaxy spectra within an area of ∼3000 deg 2 on the sky. Our oxygen abundance determinations have an accuracy of ≤0.1 dex and are based on the temperature-sensitive [O III] λ4363 line and on the direct calculation of the electron temperature. We briefly discuss a new method of oxygen abundance determinations using the [O II] λλ 7319, 7330 lines that is particularly useful for SDSS emission-line spectra with redshifts ≤0.024 since the [O II ] λ 3727 emission line falls outside of the SDSS wavelength range. We detect XMPGs with redshifts ranging from 0.0005 to 0.0443 and Mg luminosities from -12.4 to -18.6 mag. Our eight new XMPGs increase the number of known metal-deficient galaxies by approximately one-quarter. The estimated surface density of XMPGs is 0.004 deg-2 for r ≤ 17.77 mag.",

keywords = "Galaxies: abundances, Galaxies: dwarf, Galaxies: evolution",

author = "Kniazev, {Alexei Y.} and Grebel, {Eva K.} and Lei Hao and Strauss, {Michael A.} and Jonathan Brinkmann and Masataka Fukugita",

note = "Funding Information: L. H. and M. A. S. acknowledge the support of NSF grant AST 00-71079. Funding for the creation and distribution of the SDSS Archive has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Aeronautics and Space Administration, the National Science Foundation, the US Department of Energy, the Japanese Monbukagakusho, and the Max Planck Society. The SDSS7 is managed by the Astrophysical Research Consortium (ARC) for the Participating Institutions. The Participating Institutions are the University of Chicago, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, the University of Pittsburgh, Princeton University, the US Naval Observatory, and the University of Washington. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.",

year = "2003",

month = aug,

day = "20",

doi = "10.1086/378259",

language = "English (US)",

volume = "593",

pages = "L73--L76",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "2 II",

}

TY - JOUR

T1 - Discovery of eight new extremely metal-poor galaxies in the sloan digital sky survey

AU - Kniazev, Alexei Y.

AU - Grebel, Eva K.

AU - Hao, Lei

AU - Strauss, Michael A.

AU - Brinkmann, Jonathan

AU - Fukugita, Masataka

N1 - Funding Information: L. H. and M. A. S. acknowledge the support of NSF grant AST 00-71079. Funding for the creation and distribution of the SDSS Archive has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Aeronautics and Space Administration, the National Science Foundation, the US Department of Energy, the Japanese Monbukagakusho, and the Max Planck Society. The SDSS7 is managed by the Astrophysical Research Consortium (ARC) for the Participating Institutions. The Participating Institutions are the University of Chicago, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, Los Alamos National Laboratory, the Max-Planck-Institute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, the University of Pittsburgh, Princeton University, the US Naval Observatory, and the University of Washington. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

PY - 2003/8/20

Y1 - 2003/8/20

N2 - We report the discovery of eight new extremely metal-poor galaxies [XMPGs; 12 + log (O/H) < 7.65] and the recovery of four previously known or suspected XMPGs (I Zw 18, HS 0822+3542, HS 0837+4717, and All 16+517) using Sloan Digital Sky Survey (SDSS) spectroscopy. These new objects were identified after an analysis of 250,000 galaxy spectra within an area of ∼3000 deg 2 on the sky. Our oxygen abundance determinations have an accuracy of ≤0.1 dex and are based on the temperature-sensitive [O III] λ4363 line and on the direct calculation of the electron temperature. We briefly discuss a new method of oxygen abundance determinations using the [O II] λλ 7319, 7330 lines that is particularly useful for SDSS emission-line spectra with redshifts ≤0.024 since the [O II ] λ 3727 emission line falls outside of the SDSS wavelength range. We detect XMPGs with redshifts ranging from 0.0005 to 0.0443 and Mg luminosities from -12.4 to -18.6 mag. Our eight new XMPGs increase the number of known metal-deficient galaxies by approximately one-quarter. The estimated surface density of XMPGs is 0.004 deg-2 for r ≤ 17.77 mag.

AB - We report the discovery of eight new extremely metal-poor galaxies [XMPGs; 12 + log (O/H) < 7.65] and the recovery of four previously known or suspected XMPGs (I Zw 18, HS 0822+3542, HS 0837+4717, and All 16+517) using Sloan Digital Sky Survey (SDSS) spectroscopy. These new objects were identified after an analysis of 250,000 galaxy spectra within an area of ∼3000 deg 2 on the sky. Our oxygen abundance determinations have an accuracy of ≤0.1 dex and are based on the temperature-sensitive [O III] λ4363 line and on the direct calculation of the electron temperature. We briefly discuss a new method of oxygen abundance determinations using the [O II] λλ 7319, 7330 lines that is particularly useful for SDSS emission-line spectra with redshifts ≤0.024 since the [O II ] λ 3727 emission line falls outside of the SDSS wavelength range. We detect XMPGs with redshifts ranging from 0.0005 to 0.0443 and Mg luminosities from -12.4 to -18.6 mag. Our eight new XMPGs increase the number of known metal-deficient galaxies by approximately one-quarter. The estimated surface density of XMPGs is 0.004 deg-2 for r ≤ 17.77 mag.

KW - Galaxies: abundances

KW - Galaxies: dwarf

KW - Galaxies: evolution

UR - http://www.scopus.com/inward/record.url?scp=0242428196&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0242428196&partnerID=8YFLogxK

U2 - 10.1086/378259

DO - 10.1086/378259

M3 - Article

AN - SCOPUS:0242428196

VL - 593

SP - L73-L76

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 II

ER -

Discovery of eight new extremely metal-poor galaxies in the sloan digital sky survey

Abstract

All Science Journal Classification (ASJC) codes

Keywords

Access to Document

Other files and links

Fingerprint

Cite this