Think outside the color box: Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog

Jo Bovy, Joseph F. Hennawi, David W. Hogg, Adam D. Myers, Jessica A. Kirkpatrick, David J. Schlegel, Nicholas P. Ross, Erin S. Sheldon, Ian D. McGreer, Donald P. Schneider, Benjamin A. Weaver

    Research output: Contribution to journalArticle

    Abstract

    We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 ≲ z ≲ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 ≤ z ≤ 3.5), and high-redshift (z>3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45mag in the 14,555deg2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available.

    Original languageEnglish (US)
    Article number141
    JournalAstrophysical Journal
    Volume729
    Issue number2
    DOIs
    StatePublished - Mar 10 2011

    Fingerprint

    quasars
    targeting
    catalogs
    boxes
    color
    deconvolution
    point source
    oscillation
    point sources
    baryons
    contamination
    method
    stars
    oscillations
    estimates

    Keywords

    • catalogs
    • galaxies: distances and redshifts
    • methods: statistical
    • quasars: general
    • stars: general
    • stars: statistics

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Bovy, J., Hennawi, J. F., Hogg, D. W., Myers, A. D., Kirkpatrick, J. A., Schlegel, D. J., ... Weaver, B. A. (2011). Think outside the color box: Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog. Astrophysical Journal, 729(2), [141]. https://doi.org/10.1088/0004-637X/729/2/141

    Think outside the color box : Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog. / Bovy, Jo; Hennawi, Joseph F.; Hogg, David W.; Myers, Adam D.; Kirkpatrick, Jessica A.; Schlegel, David J.; Ross, Nicholas P.; Sheldon, Erin S.; McGreer, Ian D.; Schneider, Donald P.; Weaver, Benjamin A.

    In: Astrophysical Journal, Vol. 729, No. 2, 141, 10.03.2011.

    Research output: Contribution to journalArticle

    Bovy, J, Hennawi, JF, Hogg, DW, Myers, AD, Kirkpatrick, JA, Schlegel, DJ, Ross, NP, Sheldon, ES, McGreer, ID, Schneider, DP & Weaver, BA 2011, 'Think outside the color box: Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog', Astrophysical Journal, vol. 729, no. 2, 141. https://doi.org/10.1088/0004-637X/729/2/141
    Bovy, Jo ; Hennawi, Joseph F. ; Hogg, David W. ; Myers, Adam D. ; Kirkpatrick, Jessica A. ; Schlegel, David J. ; Ross, Nicholas P. ; Sheldon, Erin S. ; McGreer, Ian D. ; Schneider, Donald P. ; Weaver, Benjamin A. / Think outside the color box : Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog. In: Astrophysical Journal. 2011 ; Vol. 729, No. 2.
    @article{f9c92d333b1043ccb74db3588d641fb5,
    title = "Think outside the color box: Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog",
    abstract = "We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 ≲ z ≲ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 ≤ z ≤ 3.5), and high-redshift (z>3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45mag in the 14,555deg2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available.",
    keywords = "catalogs, galaxies: distances and redshifts, methods: statistical, quasars: general, stars: general, stars: statistics",
    author = "Jo Bovy and Hennawi, {Joseph F.} and Hogg, {David W.} and Myers, {Adam D.} and Kirkpatrick, {Jessica A.} and Schlegel, {David J.} and Ross, {Nicholas P.} and Sheldon, {Erin S.} and McGreer, {Ian D.} and Schneider, {Donald P.} and Weaver, {Benjamin A.}",
    year = "2011",
    month = "3",
    day = "10",
    doi = "10.1088/0004-637X/729/2/141",
    language = "English (US)",
    volume = "729",
    journal = "Astrophysical Journal",
    issn = "0004-637X",
    publisher = "IOP Publishing Ltd.",
    number = "2",

    }

    TY - JOUR

    T1 - Think outside the color box

    T2 - Probabilistic target selection and the SDSS-XDQSO quasar targeting catalog

    AU - Bovy, Jo

    AU - Hennawi, Joseph F.

    AU - Hogg, David W.

    AU - Myers, Adam D.

    AU - Kirkpatrick, Jessica A.

    AU - Schlegel, David J.

    AU - Ross, Nicholas P.

    AU - Sheldon, Erin S.

    AU - McGreer, Ian D.

    AU - Schneider, Donald P.

    AU - Weaver, Benjamin A.

    PY - 2011/3/10

    Y1 - 2011/3/10

    N2 - We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 ≲ z ≲ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 ≤ z ≤ 3.5), and high-redshift (z>3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45mag in the 14,555deg2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available.

    AB - We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 ≲ z ≲ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 ≤ z ≤ 3.5), and high-redshift (z>3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45mag in the 14,555deg2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available.

    KW - catalogs

    KW - galaxies: distances and redshifts

    KW - methods: statistical

    KW - quasars: general

    KW - stars: general

    KW - stars: statistics

    UR - http://www.scopus.com/inward/record.url?scp=79952158782&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=79952158782&partnerID=8YFLogxK

    U2 - 10.1088/0004-637X/729/2/141

    DO - 10.1088/0004-637X/729/2/141

    M3 - Article

    AN - SCOPUS:79952158782

    VL - 729

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 2

    M1 - 141

    ER -