Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample

Michael A. Strauss; David H. Weinberg; Robert H. Lupton; Vijay K. Narayanan; James Annis; Mariangela Bernardi; Michael Blanton; Scott Burles; A. J. Connolly; Julianne Dalcanton; Mamoru Doi; Daniel Eisenstein; Joshua A. Frieman; Masataka Fukugita; James E. Gunn; Željko Ivezić; Stephen Kent; Rita S.J. Kim; G. R. Knapp; Richard G. Kron; Jeffrey A. Munn; Heidi Jo Newberg; R. C. Nichol; Sadanori Okamura; Thomas R. Quinn; Michael W. Richmond; David J. Schlegel; Kazuhiro Shimasaku; Mark SubbaRao; Alexander S. Szalay; Dan Vanden Berk; Michael S. Vogeley; Brian Yanny; Naoki Yasuda; Donald G. York; Idit Zehavi

doi:10.1086/342343

Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample

Michael A. Strauss, David H. Weinberg, Robert H. Lupton, Vijay K. Narayanan, James Annis, Mariangela Bernardi, Michael Blanton, Scott Burles, A. J. Connolly, Julianne Dalcanton, Mamoru Doi, Daniel Eisenstein, Joshua A. Frieman, Masataka Fukugita, James E. Gunn, Željko Ivezić, Stephen Kent, Rita S.J. Kim, G. R. Knapp, Richard G. KronJeffrey A. Munn, Heidi Jo Newberg, R. C. Nichol, Sadanori Okamura, Thomas R. Quinn, Michael W. Richmond, David J. Schlegel, Kazuhiro Shimasaku, Mark SubbaRao, Alexander S. Szalay, Dan Vanden Berk, Michael S. Vogeley, Brian Yanny, Naoki Yasuda, Donald G. York, Idit Zehavi

Research output: Contribution to journal › Review article › peer-review

Abstract

We describe the algorithm that selects the main sample of galaxies for spectroscopy in the Sloan Digital Sky Survey (SDSS) from the photometric data obtained by the imaging survey. Galaxy photometric properties are measured using the Petrosian magnitude system, which measures flux in apertures determined by the shape of the surface brightness profile. The metric aperture used is essentially independent of cosmological surface brightness dimming, foreground extinction, sky brightness, and the galaxy central surface brightness. The main galaxy sample consists of galaxies with r-band Petrosian magnitudes r ≤ 17.77 and r-band Petrosian half-light surface brightnesses μ₅₀ ≤ 24.5 mag arcsec^-2. These cuts select about 90 galaxy targets per square degree, with a median redshift of 0.104. We carry out a number of tests to show that (1) our star-galaxy separation criterion is effective at eliminating nearly all stellar contamination while removing almost no genuine galaxies, (2) the fraction of galaxies eliminated by our surface brightness cut is very small (∼0.1%), (3) the completeness of the sample is high, exceeding 99%, and (4) the reproducibility of target selection based on repeated imaging scans is consistent with the expected random photometric errors. The main cause of incompleteness is blending with saturated stars, which becomes more significant for brighter, larger galaxies. The SDSS spectra are of high enough signal-to-noise ratio (S/N > 4 per pixel) that essentially all targeted galaxies (99.9%) yield a reliable redshift (i.e., with statistical error less than 30 km s^-1). About 6% of galaxies that satisfy the selection criteria are not observed because they have a companion closer than the 55″ minimum separation of spectroscopic fibers, but these galaxies can be accounted for in statistical analyses of clustering or galaxy properties. The uniformity and completeness of the galaxy sample make it ideal for studies of large-scale structure and the characteristics of the galaxy population in the local universe.

Original language	English (US)
Pages (from-to)	1810-1824
Number of pages	15
Journal	Astronomical Journal
Volume	124
Issue number	3 1761
DOIs	https://doi.org/10.1086/342343
State	Published - Sep 2002

Keywords

Galaxies: distances and redshifts
Galaxies: photometry
Surveys

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1086/342343

Cite this

Strauss, M. A., Weinberg, D. H., Lupton, R. H., Narayanan, V. K., Annis, J., Bernardi, M., Blanton, M., Burles, S., Connolly, A. J., Dalcanton, J., Doi, M., Eisenstein, D., Frieman, J. A., Fukugita, M., Gunn, J. E., Ivezić, Ž., Kent, S., Kim, R. S. J., Knapp, G. R., ... Zehavi, I. (2002). Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample. Astronomical Journal, 124(3 1761), 1810-1824. https://doi.org/10.1086/342343

Strauss, MA, Weinberg, DH, Lupton, RH, Narayanan, VK, Annis, J, Bernardi, M, Blanton, M, Burles, S, Connolly, AJ, Dalcanton, J, Doi, M, Eisenstein, D, Frieman, JA, Fukugita, M, Gunn, JE, Ivezić, Ž, Kent, S, Kim, RSJ, Knapp, GR, Kron, RG, Munn, JA, Newberg, HJ, Nichol, RC, Okamura, S, Quinn, TR, Richmond, MW, Schlegel, DJ, Shimasaku, K, SubbaRao, M, Szalay, AS, Berk, DV, Vogeley, MS, Yanny, B, Yasuda, N, York, DG & Zehavi, I 2002, 'Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample', Astronomical Journal, vol. 124, no. 3 1761, pp. 1810-1824. https://doi.org/10.1086/342343

@article{3d9e7f15fb234fe499c7898fef6acc67,

title = "Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample",

abstract = "We describe the algorithm that selects the main sample of galaxies for spectroscopy in the Sloan Digital Sky Survey (SDSS) from the photometric data obtained by the imaging survey. Galaxy photometric properties are measured using the Petrosian magnitude system, which measures flux in apertures determined by the shape of the surface brightness profile. The metric aperture used is essentially independent of cosmological surface brightness dimming, foreground extinction, sky brightness, and the galaxy central surface brightness. The main galaxy sample consists of galaxies with r-band Petrosian magnitudes r ≤ 17.77 and r-band Petrosian half-light surface brightnesses μ50 ≤ 24.5 mag arcsec-2. These cuts select about 90 galaxy targets per square degree, with a median redshift of 0.104. We carry out a number of tests to show that (1) our star-galaxy separation criterion is effective at eliminating nearly all stellar contamination while removing almost no genuine galaxies, (2) the fraction of galaxies eliminated by our surface brightness cut is very small (∼0.1%), (3) the completeness of the sample is high, exceeding 99%, and (4) the reproducibility of target selection based on repeated imaging scans is consistent with the expected random photometric errors. The main cause of incompleteness is blending with saturated stars, which becomes more significant for brighter, larger galaxies. The SDSS spectra are of high enough signal-to-noise ratio (S/N > 4 per pixel) that essentially all targeted galaxies (99.9%) yield a reliable redshift (i.e., with statistical error less than 30 km s-1). About 6% of galaxies that satisfy the selection criteria are not observed because they have a companion closer than the 55″ minimum separation of spectroscopic fibers, but these galaxies can be accounted for in statistical analyses of clustering or galaxy properties. The uniformity and completeness of the galaxy sample make it ideal for studies of large-scale structure and the characteristics of the galaxy population in the local universe.",

keywords = "Galaxies: distances and redshifts, Galaxies: photometry, Surveys",

author = "Strauss, {Michael A.} and Weinberg, {David H.} and Lupton, {Robert H.} and Narayanan, {Vijay K.} and James Annis and Mariangela Bernardi and Michael Blanton and Scott Burles and Connolly, {A. J.} and Julianne Dalcanton and Mamoru Doi and Daniel Eisenstein and Frieman, {Joshua A.} and Masataka Fukugita and Gunn, {James E.} and {\v Z}eljko Ivezi{\'c} and Stephen Kent and Kim, {Rita S.J.} and Knapp, {G. R.} and Kron, {Richard G.} and Munn, {Jeffrey A.} and Newberg, {Heidi Jo} and Nichol, {R. C.} and Sadanori Okamura and Quinn, {Thomas R.} and Richmond, {Michael W.} and Schlegel, {David J.} and Kazuhiro Shimasaku and Mark SubbaRao and Szalay, {Alexander S.} and Berk, {Dan Vanden} and Vogeley, {Michael S.} and Brian Yanny and Naoki Yasuda and York, {Donald G.} and Idit Zehavi",

year = "2002",

month = sep,

doi = "10.1086/342343",

language = "English (US)",

volume = "124",

pages = "1810--1824",

journal = "Astronomical Journal",

issn = "0004-6256",

publisher = "IOP Publishing Ltd.",

number = "3 1761",

}

TY - JOUR

T1 - Spectroscopic target selection in the sloan digital sky survey

T2 - The main galaxy sample

AU - Strauss, Michael A.

AU - Weinberg, David H.

AU - Lupton, Robert H.

AU - Narayanan, Vijay K.

AU - Annis, James

AU - Bernardi, Mariangela

AU - Blanton, Michael

AU - Burles, Scott

AU - Connolly, A. J.

AU - Dalcanton, Julianne

AU - Doi, Mamoru

AU - Eisenstein, Daniel

AU - Frieman, Joshua A.

AU - Fukugita, Masataka

AU - Gunn, James E.

AU - Ivezić, Željko

AU - Kent, Stephen

AU - Kim, Rita S.J.

AU - Knapp, G. R.

AU - Kron, Richard G.

AU - Munn, Jeffrey A.

AU - Newberg, Heidi Jo

AU - Nichol, R. C.

AU - Okamura, Sadanori

AU - Quinn, Thomas R.

AU - Richmond, Michael W.

AU - Schlegel, David J.

AU - Shimasaku, Kazuhiro

AU - SubbaRao, Mark

AU - Szalay, Alexander S.

AU - Berk, Dan Vanden

AU - Vogeley, Michael S.

AU - Yanny, Brian

AU - Yasuda, Naoki

AU - York, Donald G.

AU - Zehavi, Idit

PY - 2002/9

Y1 - 2002/9

N2 - We describe the algorithm that selects the main sample of galaxies for spectroscopy in the Sloan Digital Sky Survey (SDSS) from the photometric data obtained by the imaging survey. Galaxy photometric properties are measured using the Petrosian magnitude system, which measures flux in apertures determined by the shape of the surface brightness profile. The metric aperture used is essentially independent of cosmological surface brightness dimming, foreground extinction, sky brightness, and the galaxy central surface brightness. The main galaxy sample consists of galaxies with r-band Petrosian magnitudes r ≤ 17.77 and r-band Petrosian half-light surface brightnesses μ50 ≤ 24.5 mag arcsec-2. These cuts select about 90 galaxy targets per square degree, with a median redshift of 0.104. We carry out a number of tests to show that (1) our star-galaxy separation criterion is effective at eliminating nearly all stellar contamination while removing almost no genuine galaxies, (2) the fraction of galaxies eliminated by our surface brightness cut is very small (∼0.1%), (3) the completeness of the sample is high, exceeding 99%, and (4) the reproducibility of target selection based on repeated imaging scans is consistent with the expected random photometric errors. The main cause of incompleteness is blending with saturated stars, which becomes more significant for brighter, larger galaxies. The SDSS spectra are of high enough signal-to-noise ratio (S/N > 4 per pixel) that essentially all targeted galaxies (99.9%) yield a reliable redshift (i.e., with statistical error less than 30 km s-1). About 6% of galaxies that satisfy the selection criteria are not observed because they have a companion closer than the 55″ minimum separation of spectroscopic fibers, but these galaxies can be accounted for in statistical analyses of clustering or galaxy properties. The uniformity and completeness of the galaxy sample make it ideal for studies of large-scale structure and the characteristics of the galaxy population in the local universe.

AB - We describe the algorithm that selects the main sample of galaxies for spectroscopy in the Sloan Digital Sky Survey (SDSS) from the photometric data obtained by the imaging survey. Galaxy photometric properties are measured using the Petrosian magnitude system, which measures flux in apertures determined by the shape of the surface brightness profile. The metric aperture used is essentially independent of cosmological surface brightness dimming, foreground extinction, sky brightness, and the galaxy central surface brightness. The main galaxy sample consists of galaxies with r-band Petrosian magnitudes r ≤ 17.77 and r-band Petrosian half-light surface brightnesses μ50 ≤ 24.5 mag arcsec-2. These cuts select about 90 galaxy targets per square degree, with a median redshift of 0.104. We carry out a number of tests to show that (1) our star-galaxy separation criterion is effective at eliminating nearly all stellar contamination while removing almost no genuine galaxies, (2) the fraction of galaxies eliminated by our surface brightness cut is very small (∼0.1%), (3) the completeness of the sample is high, exceeding 99%, and (4) the reproducibility of target selection based on repeated imaging scans is consistent with the expected random photometric errors. The main cause of incompleteness is blending with saturated stars, which becomes more significant for brighter, larger galaxies. The SDSS spectra are of high enough signal-to-noise ratio (S/N > 4 per pixel) that essentially all targeted galaxies (99.9%) yield a reliable redshift (i.e., with statistical error less than 30 km s-1). About 6% of galaxies that satisfy the selection criteria are not observed because they have a companion closer than the 55″ minimum separation of spectroscopic fibers, but these galaxies can be accounted for in statistical analyses of clustering or galaxy properties. The uniformity and completeness of the galaxy sample make it ideal for studies of large-scale structure and the characteristics of the galaxy population in the local universe.

KW - Galaxies: distances and redshifts

KW - Galaxies: photometry

KW - Surveys

UR - http://www.scopus.com/inward/record.url?scp=0012334827&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0012334827&partnerID=8YFLogxK

U2 - 10.1086/342343

DO - 10.1086/342343

M3 - Review article

AN - SCOPUS:0012334827

SN - 0004-6256

VL - 124

SP - 1810

EP - 1824

JO - Astronomical Journal

JF - Astronomical Journal

IS - 3 1761

ER -

Spectroscopic target selection in the sloan digital sky survey: The main galaxy sample

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Keywords

ASJC Scopus subject areas

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