TY - JOUR
T1 - A Lyα-only active galactic nucleus from the Sloan Digital Sky Survey
AU - Hall, Patrick B.
AU - Hoversten, Erik A.
AU - Tremonti, Christy A.
AU - Vanden Berk, Daniel E.
AU - Schneider, Donald P.
AU - Strauss, Michael A.
AU - Knapp, Gillian R.
AU - York, Donald G.
AU - Hutemékers, Damien
AU - Newman, P. R.
AU - Brinkmann, J.
AU - Frye, Brenda
AU - Fukugita, Masataka
AU - Glazebrook, Karl
AU - Harvanek, Michael
AU - Heckman, Timothy M.
AU - Ivezić, Željko
AU - Kleinman, S.
AU - Krzesinski, Jurek
AU - Long, Daniel C.
AU - Neilsen, Eric
AU - Niederste-Ostholt, Martin
AU - Nitta, Atsuko
AU - Schlegel, David J.
AU - Snedden, S.
PY - 2004/6
Y1 - 2004/6
N2 - The Sloan Digital Sky Survey has discovered a z = 2.4917 radio-loud active galactic nucleus (AGN) with a luminous, variable, low-polarization UV continuum, H I two-photon emission, and a moderately broad Lyα line (FWHM ≃ 1430 km s-1) but without obvious metal-line emission. SDSS J113658.36+024220.1 does have associated metal-line absorption in three distinct, narrow systems spanning a velocity range of 2710 km s-1. Despite certain spectral similarities, SDSS J1136+0242 is not a Lyman break galaxy. Instead, the Lyα and two-photon emission can be attributed to an extended, low-metallicity narrow-line region. The unpolarized continuum argues that we see SDSS 11136+0242 very close to the axis of any ionization cone present. We can conceive of two plausible explanations for why we see a strong UV continuum but no broad-line emission in this "face-on radio galaxy" model for SDSS J1136+0242: the continuum could be relativistically beamed synchrotron emission that swamps the broad-line emission, or more likely, SDSS J1136+0242 could be similar to PG1407+265, a quasar in which for some unknown reason the high-ionization emission lines are very broad, very weak, and highly blueshifted.
AB - The Sloan Digital Sky Survey has discovered a z = 2.4917 radio-loud active galactic nucleus (AGN) with a luminous, variable, low-polarization UV continuum, H I two-photon emission, and a moderately broad Lyα line (FWHM ≃ 1430 km s-1) but without obvious metal-line emission. SDSS J113658.36+024220.1 does have associated metal-line absorption in three distinct, narrow systems spanning a velocity range of 2710 km s-1. Despite certain spectral similarities, SDSS J1136+0242 is not a Lyman break galaxy. Instead, the Lyα and two-photon emission can be attributed to an extended, low-metallicity narrow-line region. The unpolarized continuum argues that we see SDSS 11136+0242 very close to the axis of any ionization cone present. We can conceive of two plausible explanations for why we see a strong UV continuum but no broad-line emission in this "face-on radio galaxy" model for SDSS J1136+0242: the continuum could be relativistically beamed synchrotron emission that swamps the broad-line emission, or more likely, SDSS J1136+0242 could be similar to PG1407+265, a quasar in which for some unknown reason the high-ionization emission lines are very broad, very weak, and highly blueshifted.
KW - Quasars: emission lines
KW - Quasars: general
KW - Quasars: individual (PG 1407+265, SDSS J113658.36+024220.1)
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U2 - 10.1086/420804
DO - 10.1086/420804
M3 - Article
AN - SCOPUS:3142674343
SN - 0004-6256
VL - 127
SP - 3146
EP - 3154
JO - Astronomical Journal
JF - Astronomical Journal
IS - 6 1782
ER -