ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691

A.S. Hirschauer; J.J. Salzer; E.D. Skillman; D. Berg; K.B.W. McQuinn; J.M. Cannon; A.J.R. Gordon; M.P. Haynes; R. Giovanelli; E.A.K. Adams; Steven Janowiecki; K.L. Rhode; R.W. Pogge; K.V. Croxall; E. Aver

doi:10.3847/0004-637X/822/2/108

ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691

A.S. Hirschauer, J.J. Salzer, E.D. Skillman, D. Berg, K.B.W. McQuinn, J.M. Cannon, A.J.R. Gordon, M.P. Haynes, R. Giovanelli, E.A.K. Adams, Steven Janowiecki, K.L. Rhode, R.W. Pogge, K.V. Croxall, E. Aver

International Centre for Radio Astronomy Research (ICRAR)

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

73 Citations (Scopus)

Abstract

© 2016. The American Astronomical Society. All rights reserved. We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part of the Survey of H I in Extremely Low-Mass Dwarfs project, which is a multi-wavelength study of galaxies with H I masses in the range of 106-107.2 M?, discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput KPNO Ohio State Multi-Object Spectrograph on the Mayall 4 m, as well as with the Blue Channel spectrograph on the MMT 6.5 m telescope. These observations enable the measurement of the temperature-sensitive [O III]?4363 line and hence the determination of a "direct" oxygen abundance for AGC 198691. We find this system to be an extremely metal-deficient (XMD) system with an oxygen abundance of 12+log(O/H) = 7.02 ± 0.03, making AGC 198691 the lowest-abundance star-forming galaxy known in the local universe. Two of the five lowest-abundance galaxies known have been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a paradigm shift in the search for extremely metal-poor galaxies.

Original language	English
Article number	108
Journal	The Astrophysical Journal
Volume	822
Issue number	2
DOIs	https://doi.org/10.3847/0004-637X/822/2/108
Publication status	Published - 10 May 2016

Access to Document

10.3847/0004-637X/822/2/108

Cite this

Hirschauer, A. S., Salzer, J. J., Skillman, E. D., Berg, D., McQuinn, K. B. W., Cannon, J. M., Gordon, A. J. R., Haynes, M. P., Giovanelli, R., Adams, E. A. K., Janowiecki, S., Rhode, K. L., Pogge, R. W., Croxall, K. V., & Aver, E. (2016). ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691. The Astrophysical Journal, 822(2), Article 108. https://doi.org/10.3847/0004-637X/822/2/108

@article{6ba9fc0361bf4181bccf5081db4cd56c,

title = "ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691",

abstract = "{\textcopyright} 2016. The American Astronomical Society. All rights reserved. We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part of the Survey of H I in Extremely Low-Mass Dwarfs project, which is a multi-wavelength study of galaxies with H I masses in the range of 106-107.2 M?, discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput KPNO Ohio State Multi-Object Spectrograph on the Mayall 4 m, as well as with the Blue Channel spectrograph on the MMT 6.5 m telescope. These observations enable the measurement of the temperature-sensitive [O III]?4363 line and hence the determination of a {"}direct{"} oxygen abundance for AGC 198691. We find this system to be an extremely metal-deficient (XMD) system with an oxygen abundance of 12+log(O/H) = 7.02 ± 0.03, making AGC 198691 the lowest-abundance star-forming galaxy known in the local universe. Two of the five lowest-abundance galaxies known have been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a paradigm shift in the search for extremely metal-poor galaxies.",

author = "A.S. Hirschauer and J.J. Salzer and E.D. Skillman and D. Berg and K.B.W. McQuinn and J.M. Cannon and A.J.R. Gordon and M.P. Haynes and R. Giovanelli and E.A.K. Adams and Steven Janowiecki and K.L. Rhode and R.W. Pogge and K.V. Croxall and E. Aver",

year = "2016",

month = may,

day = "10",

doi = "10.3847/0004-637X/822/2/108",

language = "English",

volume = "822",

journal = "The Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing",

number = "2",

}

TY - JOUR

T1 - ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691

AU - Hirschauer, A.S.

AU - Salzer, J.J.

AU - Skillman, E.D.

AU - Berg, D.

AU - McQuinn, K.B.W.

AU - Cannon, J.M.

AU - Gordon, A.J.R.

AU - Haynes, M.P.

AU - Giovanelli, R.

AU - Adams, E.A.K.

AU - Janowiecki, Steven

AU - Rhode, K.L.

AU - Pogge, R.W.

AU - Croxall, K.V.

AU - Aver, E.

PY - 2016/5/10

Y1 - 2016/5/10

N2 - © 2016. The American Astronomical Society. All rights reserved. We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part of the Survey of H I in Extremely Low-Mass Dwarfs project, which is a multi-wavelength study of galaxies with H I masses in the range of 106-107.2 M?, discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput KPNO Ohio State Multi-Object Spectrograph on the Mayall 4 m, as well as with the Blue Channel spectrograph on the MMT 6.5 m telescope. These observations enable the measurement of the temperature-sensitive [O III]?4363 line and hence the determination of a "direct" oxygen abundance for AGC 198691. We find this system to be an extremely metal-deficient (XMD) system with an oxygen abundance of 12+log(O/H) = 7.02 ± 0.03, making AGC 198691 the lowest-abundance star-forming galaxy known in the local universe. Two of the five lowest-abundance galaxies known have been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a paradigm shift in the search for extremely metal-poor galaxies.

AB - © 2016. The American Astronomical Society. All rights reserved. We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part of the Survey of H I in Extremely Low-Mass Dwarfs project, which is a multi-wavelength study of galaxies with H I masses in the range of 106-107.2 M?, discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput KPNO Ohio State Multi-Object Spectrograph on the Mayall 4 m, as well as with the Blue Channel spectrograph on the MMT 6.5 m telescope. These observations enable the measurement of the temperature-sensitive [O III]?4363 line and hence the determination of a "direct" oxygen abundance for AGC 198691. We find this system to be an extremely metal-deficient (XMD) system with an oxygen abundance of 12+log(O/H) = 7.02 ± 0.03, making AGC 198691 the lowest-abundance star-forming galaxy known in the local universe. Two of the five lowest-abundance galaxies known have been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a paradigm shift in the search for extremely metal-poor galaxies.

U2 - 10.3847/0004-637X/822/2/108

DO - 10.3847/0004-637X/822/2/108

M3 - Article

SN - 0004-637X

VL - 822

JO - The Astrophysical Journal

JF - The Astrophysical Journal

IS - 2

M1 - 108

ER -

ALFALFA DISCOVERY of the MOST METAL-POOR GAS-RICH GALAXY KNOWN: AGC 198691

Abstract

Access to Document

Fingerprint

Cite this