Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE

Julie A. Krugler; T. C. Beers; Y. S. Lee; T. Sivarani; B. Marsteller; R. Wilhelm; C. Allende Prieto; A. Frebel; J. E. Norris; J. Johnson; I. Ivans; B. Yanny; C. Rockosi; H. Morrison; H. J. Newberg; J. Knapp

doi:10.1063/1.2905525

Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE

Julie A. Krugler, T. C. Beers, Y. S. Lee, T. Sivarani, B. Marsteller, R. Wilhelm, C. Allende Prieto, A. Frebel, J. E. Norris, J. Johnson, I. Ivans, B. Yanny, C. Rockosi, H. Morrison, H. J. Newberg, J. Knapp

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

Abstract

There are several hundred thousand R=2000 stellar spectra reported in the final public release of the Sloan Digital Sky Survey (SDSS-I) and the continuing project SEGUE (Sloan Extension for Galactic Exploration and Understanding), which has completed roughly half of its scheduled set of observations to date. The stars in this sample were targeted for a wide variety of reasons, and hence do not represent a sample from which an unbiased metallicity distribution function (MDF) of stars in the halo or thick-disk populations may be drawn. However, there exist over 6500 stars with estimated metallicities [Fe/H]<-2.0 and effective temperatures in the range 4500K<T_eff<7000K among this sample, based on application of the SDSS/SEGUE spectroscopic parameter analysis pipeline. We have continued to refine estimates of the stellar parameters for these stars, using an automated synthetic spectrum approach, autoMOOG. This technique produces estimates of [Fe/H] as well as [C/Fe] (or upper limits on these quantities) based on MOOG syntheses of the region of spectrum around the CaII K line and the CH G band, respectively. This sample represents, by a factor of more than three, the largest database of very metal-poor stars yet assembled. A least 1000 of these stars have g<16.5, and hence are amenable to high-resolution spectroscopic studies with presently available large-aperture telescopes.

Original language	English
Title of host publication	First Stars III
Pages	151-153
Number of pages	3
DOIs	https://doi.org/10.1063/1.2905525
Publication status	Published - 2008
Event	First Stars III - Santa Fe, NM, United States Duration: 15 Jul 2007 → 20 Jul 2007

Publication series

Name	AIP Conference Proceedings
Volume	990
ISSN (Print)	0094-243X
ISSN (Electronic)	1551-7616

Conference

Conference	First Stars III
Country/Territory	United States
City	Santa Fe, NM
Period	15/07/07 → 20/07/07

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10.1063/1.2905525

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Krugler, J. A., Beers, T. C., Lee, Y. S., Sivarani, T., Marsteller, B., Wilhelm, R., Prieto, C. A., Frebel, A., Norris, J. E., Johnson, J., Ivans, I., Yanny, B., Rockosi, C., Morrison, H., Newberg, H. J., & Knapp, J. (2008). Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE. In First Stars III (pp. 151-153). (AIP Conference Proceedings; Vol. 990). https://doi.org/10.1063/1.2905525

@inproceedings{c4e52de1b70c4a94b8e7b9e35a48b384,

title = "Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE",

abstract = "There are several hundred thousand R=2000 stellar spectra reported in the final public release of the Sloan Digital Sky Survey (SDSS-I) and the continuing project SEGUE (Sloan Extension for Galactic Exploration and Understanding), which has completed roughly half of its scheduled set of observations to date. The stars in this sample were targeted for a wide variety of reasons, and hence do not represent a sample from which an unbiased metallicity distribution function (MDF) of stars in the halo or thick-disk populations may be drawn. However, there exist over 6500 stars with estimated metallicities [Fe/H]<-2.0 and effective temperatures in the range 4500K<Teff<7000K among this sample, based on application of the SDSS/SEGUE spectroscopic parameter analysis pipeline. We have continued to refine estimates of the stellar parameters for these stars, using an automated synthetic spectrum approach, autoMOOG. This technique produces estimates of [Fe/H] as well as [C/Fe] (or upper limits on these quantities) based on MOOG syntheses of the region of spectrum around the CaII K line and the CH G band, respectively. This sample represents, by a factor of more than three, the largest database of very metal-poor stars yet assembled. A least 1000 of these stars have g<16.5, and hence are amenable to high-resolution spectroscopic studies with presently available large-aperture telescopes.",

keywords = "Galactic halo, Metal-poor stars, Milky Way, Wide-angle spectroscopic surveys",

author = "Krugler, {Julie A.} and Beers, {T. C.} and Lee, {Y. S.} and T. Sivarani and B. Marsteller and R. Wilhelm and Prieto, {C. Allende} and A. Frebel and Norris, {J. E.} and J. Johnson and I. Ivans and B. Yanny and C. Rockosi and H. Morrison and Newberg, {H. J.} and J. Knapp",

year = "2008",

doi = "10.1063/1.2905525",

language = "English",

isbn = "9780735405097",

series = "AIP Conference Proceedings",

pages = "151--153",

booktitle = "First Stars III",

note = "First Stars III ; Conference date: 15-07-2007 Through 20-07-2007",

}

Krugler, JA, Beers, TC, Lee, YS, Sivarani, T, Marsteller, B, Wilhelm, R, Prieto, CA, Frebel, A, Norris, JE, Johnson, J, Ivans, I, Yanny, B, Rockosi, C, Morrison, H, Newberg, HJ & Knapp, J 2008, Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE. in First Stars III. AIP Conference Proceedings, vol. 990, pp. 151-153, First Stars III, Santa Fe, NM, United States, 15/07/07. https://doi.org/10.1063/1.2905525

TY - GEN

T1 - Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE

AU - Krugler, Julie A.

AU - Beers, T. C.

AU - Lee, Y. S.

AU - Sivarani, T.

AU - Marsteller, B.

AU - Wilhelm, R.

AU - Prieto, C. Allende

AU - Frebel, A.

AU - Norris, J. E.

AU - Johnson, J.

AU - Ivans, I.

AU - Yanny, B.

AU - Rockosi, C.

AU - Morrison, H.

AU - Newberg, H. J.

AU - Knapp, J.

PY - 2008

Y1 - 2008

N2 - There are several hundred thousand R=2000 stellar spectra reported in the final public release of the Sloan Digital Sky Survey (SDSS-I) and the continuing project SEGUE (Sloan Extension for Galactic Exploration and Understanding), which has completed roughly half of its scheduled set of observations to date. The stars in this sample were targeted for a wide variety of reasons, and hence do not represent a sample from which an unbiased metallicity distribution function (MDF) of stars in the halo or thick-disk populations may be drawn. However, there exist over 6500 stars with estimated metallicities [Fe/H]<-2.0 and effective temperatures in the range 4500K<Teff<7000K among this sample, based on application of the SDSS/SEGUE spectroscopic parameter analysis pipeline. We have continued to refine estimates of the stellar parameters for these stars, using an automated synthetic spectrum approach, autoMOOG. This technique produces estimates of [Fe/H] as well as [C/Fe] (or upper limits on these quantities) based on MOOG syntheses of the region of spectrum around the CaII K line and the CH G band, respectively. This sample represents, by a factor of more than three, the largest database of very metal-poor stars yet assembled. A least 1000 of these stars have g<16.5, and hence are amenable to high-resolution spectroscopic studies with presently available large-aperture telescopes.

AB - There are several hundred thousand R=2000 stellar spectra reported in the final public release of the Sloan Digital Sky Survey (SDSS-I) and the continuing project SEGUE (Sloan Extension for Galactic Exploration and Understanding), which has completed roughly half of its scheduled set of observations to date. The stars in this sample were targeted for a wide variety of reasons, and hence do not represent a sample from which an unbiased metallicity distribution function (MDF) of stars in the halo or thick-disk populations may be drawn. However, there exist over 6500 stars with estimated metallicities [Fe/H]<-2.0 and effective temperatures in the range 4500K<Teff<7000K among this sample, based on application of the SDSS/SEGUE spectroscopic parameter analysis pipeline. We have continued to refine estimates of the stellar parameters for these stars, using an automated synthetic spectrum approach, autoMOOG. This technique produces estimates of [Fe/H] as well as [C/Fe] (or upper limits on these quantities) based on MOOG syntheses of the region of spectrum around the CaII K line and the CH G band, respectively. This sample represents, by a factor of more than three, the largest database of very metal-poor stars yet assembled. A least 1000 of these stars have g<16.5, and hence are amenable to high-resolution spectroscopic studies with presently available large-aperture telescopes.

KW - Galactic halo

KW - Metal-poor stars

KW - Milky Way

KW - Wide-angle spectroscopic surveys

UR - http://www.scopus.com/inward/record.url?scp=42449141891&partnerID=8YFLogxK

U2 - 10.1063/1.2905525

DO - 10.1063/1.2905525

M3 - Conference contribution

SN - 9780735405097

T3 - AIP Conference Proceedings

SP - 151

EP - 153

BT - First Stars III

T2 - First Stars III

Y2 - 15 July 2007 through 20 July 2007

ER -

Revised parameter estimates for the most metal-poor candidates in SDSS-I and SEGUE

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