Active galactic nuclei in the sloan digital sky survey. I. Sample selection

Lei Hao, Michael A. Strauss, Christy A. Tremonti, David J. Schlegel, Timothy M. Heckman, Guinevere Kauffmann, Michael R. Blanton, Xiaohui Fan, James E. Gunn, Patrick B. Hall, Željko Ivezić, Gillian R. Knapp, Julian H. Krolik, Robert H. Lupton, Gordon T. Richards, Donald P. Schneider, Iskra V. Strateva, Nadia L. Zakamska, J. Brinkmann, Robert J. BrunnerGyula P. Szokoly

Research output: Contribution to journalReview article

Abstract

We have compiled a large sample of low-redshift active galactic nuclei (AGNs) identified via their emission-line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by stellar absorption lines, we developed an objective and efficient method of subtracting the stellar continuum from every galaxy spectrum before making emission-line measurements. The distribution of the measured Hα FWHM values of emission-line galaxies is strongly bimodal, with two populations separated at about 1200 km s -1. This feature provides a natural separation between narrow-line and broad-line AGNs. The narrow-line AGNs are identified using standard emission-line ratio diagnostic diagrams. There are 1317 broad-line and 3074 narrow-line AGNs identified from about 100,000 galaxy spectra selected over 1151 deg 2. This sample is used in a companion paper to determine the emission-line luminosity function of AGNs.

Original languageEnglish (US)
Pages (from-to)1783-1794
Number of pages12
JournalAstronomical Journal
Volume129
Issue number4
DOIs
StatePublished - Apr 1 2005

Fingerprint

active galactic nuclei
galaxies
diagram
diagrams
luminosity
continuums

Keywords

  • Galaxies: activegalaxies: Seyfert
  • Galaxies: starburst
  • Quasars: emission linessurveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Hao, L., Strauss, M. A., Tremonti, C. A., Schlegel, D. J., Heckman, T. M., Kauffmann, G., ... Szokoly, G. P. (2005). Active galactic nuclei in the sloan digital sky survey. I. Sample selection. Astronomical Journal, 129(4), 1783-1794. https://doi.org/10.1086/428485

Active galactic nuclei in the sloan digital sky survey. I. Sample selection. / Hao, Lei; Strauss, Michael A.; Tremonti, Christy A.; Schlegel, David J.; Heckman, Timothy M.; Kauffmann, Guinevere; Blanton, Michael R.; Fan, Xiaohui; Gunn, James E.; Hall, Patrick B.; Ivezić, Željko; Knapp, Gillian R.; Krolik, Julian H.; Lupton, Robert H.; Richards, Gordon T.; Schneider, Donald P.; Strateva, Iskra V.; Zakamska, Nadia L.; Brinkmann, J.; Brunner, Robert J.; Szokoly, Gyula P.

In: Astronomical Journal, Vol. 129, No. 4, 01.04.2005, p. 1783-1794.

Research output: Contribution to journalReview article

Hao, L, Strauss, MA, Tremonti, CA, Schlegel, DJ, Heckman, TM, Kauffmann, G, Blanton, MR, Fan, X, Gunn, JE, Hall, PB, Ivezić, Ž, Knapp, GR, Krolik, JH, Lupton, RH, Richards, GT, Schneider, DP, Strateva, IV, Zakamska, NL, Brinkmann, J, Brunner, RJ & Szokoly, GP 2005, 'Active galactic nuclei in the sloan digital sky survey. I. Sample selection', Astronomical Journal, vol. 129, no. 4, pp. 1783-1794. https://doi.org/10.1086/428485
Hao L, Strauss MA, Tremonti CA, Schlegel DJ, Heckman TM, Kauffmann G et al. Active galactic nuclei in the sloan digital sky survey. I. Sample selection. Astronomical Journal. 2005 Apr 1;129(4):1783-1794. https://doi.org/10.1086/428485
Hao, Lei ; Strauss, Michael A. ; Tremonti, Christy A. ; Schlegel, David J. ; Heckman, Timothy M. ; Kauffmann, Guinevere ; Blanton, Michael R. ; Fan, Xiaohui ; Gunn, James E. ; Hall, Patrick B. ; Ivezić, Željko ; Knapp, Gillian R. ; Krolik, Julian H. ; Lupton, Robert H. ; Richards, Gordon T. ; Schneider, Donald P. ; Strateva, Iskra V. ; Zakamska, Nadia L. ; Brinkmann, J. ; Brunner, Robert J. ; Szokoly, Gyula P. / Active galactic nuclei in the sloan digital sky survey. I. Sample selection. In: Astronomical Journal. 2005 ; Vol. 129, No. 4. pp. 1783-1794.
@article{a1b7a15b8e4e4589952f428e80ba49b1,
title = "Active galactic nuclei in the sloan digital sky survey. I. Sample selection",
abstract = "We have compiled a large sample of low-redshift active galactic nuclei (AGNs) identified via their emission-line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by stellar absorption lines, we developed an objective and efficient method of subtracting the stellar continuum from every galaxy spectrum before making emission-line measurements. The distribution of the measured Hα FWHM values of emission-line galaxies is strongly bimodal, with two populations separated at about 1200 km s -1. This feature provides a natural separation between narrow-line and broad-line AGNs. The narrow-line AGNs are identified using standard emission-line ratio diagnostic diagrams. There are 1317 broad-line and 3074 narrow-line AGNs identified from about 100,000 galaxy spectra selected over 1151 deg 2. This sample is used in a companion paper to determine the emission-line luminosity function of AGNs.",
keywords = "Galaxies: activegalaxies: Seyfert, Galaxies: starburst, Quasars: emission linessurveys",
author = "Lei Hao and Strauss, {Michael A.} and Tremonti, {Christy A.} and Schlegel, {David J.} and Heckman, {Timothy M.} and Guinevere Kauffmann and Blanton, {Michael R.} and Xiaohui Fan and Gunn, {James E.} and Hall, {Patrick B.} and Željko Ivezić and Knapp, {Gillian R.} and Krolik, {Julian H.} and Lupton, {Robert H.} and Richards, {Gordon T.} and Schneider, {Donald P.} and Strateva, {Iskra V.} and Zakamska, {Nadia L.} and J. Brinkmann and Brunner, {Robert J.} and Szokoly, {Gyula P.}",
year = "2005",
month = "4",
day = "1",
doi = "10.1086/428485",
language = "English (US)",
volume = "129",
pages = "1783--1794",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "4",

}

TY - JOUR

T1 - Active galactic nuclei in the sloan digital sky survey. I. Sample selection

AU - Hao, Lei

AU - Strauss, Michael A.

AU - Tremonti, Christy A.

AU - Schlegel, David J.

AU - Heckman, Timothy M.

AU - Kauffmann, Guinevere

AU - Blanton, Michael R.

AU - Fan, Xiaohui

AU - Gunn, James E.

AU - Hall, Patrick B.

AU - Ivezić, Željko

AU - Knapp, Gillian R.

AU - Krolik, Julian H.

AU - Lupton, Robert H.

AU - Richards, Gordon T.

AU - Schneider, Donald P.

AU - Strateva, Iskra V.

AU - Zakamska, Nadia L.

AU - Brinkmann, J.

AU - Brunner, Robert J.

AU - Szokoly, Gyula P.

PY - 2005/4/1

Y1 - 2005/4/1

N2 - We have compiled a large sample of low-redshift active galactic nuclei (AGNs) identified via their emission-line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by stellar absorption lines, we developed an objective and efficient method of subtracting the stellar continuum from every galaxy spectrum before making emission-line measurements. The distribution of the measured Hα FWHM values of emission-line galaxies is strongly bimodal, with two populations separated at about 1200 km s -1. This feature provides a natural separation between narrow-line and broad-line AGNs. The narrow-line AGNs are identified using standard emission-line ratio diagnostic diagrams. There are 1317 broad-line and 3074 narrow-line AGNs identified from about 100,000 galaxy spectra selected over 1151 deg 2. This sample is used in a companion paper to determine the emission-line luminosity function of AGNs.

AB - We have compiled a large sample of low-redshift active galactic nuclei (AGNs) identified via their emission-line characteristics from the spectroscopic data of the Sloan Digital Sky Survey. Since emission lines are often contaminated by stellar absorption lines, we developed an objective and efficient method of subtracting the stellar continuum from every galaxy spectrum before making emission-line measurements. The distribution of the measured Hα FWHM values of emission-line galaxies is strongly bimodal, with two populations separated at about 1200 km s -1. This feature provides a natural separation between narrow-line and broad-line AGNs. The narrow-line AGNs are identified using standard emission-line ratio diagnostic diagrams. There are 1317 broad-line and 3074 narrow-line AGNs identified from about 100,000 galaxy spectra selected over 1151 deg 2. This sample is used in a companion paper to determine the emission-line luminosity function of AGNs.

KW - Galaxies: activegalaxies: Seyfert

KW - Galaxies: starburst

KW - Quasars: emission linessurveys

UR - http://www.scopus.com/inward/record.url?scp=19944407582&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=19944407582&partnerID=8YFLogxK

U2 - 10.1086/428485

DO - 10.1086/428485

M3 - Review article

AN - SCOPUS:19944407582

VL - 129

SP - 1783

EP - 1794

JO - Astronomical Journal

JF - Astronomical Journal

SN - 0004-6256

IS - 4

ER -