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For refcode 1991ApJ...381..373H:
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1991ApJ...381..373H SPECTROSCOPY OF SPATIALLY EXTENDED MATERIAL AROUND HIGH-REDSHIFT RADIO-LOUD QUASARS TIMOTHY M. HECKMAN, MATTHEW D. LEHNERT, GEORGE K. MILEY, AND WIL VAN BREUGEL Received 1991 March 18; accepted 1991 May 15 ABSTRACT We present the analysis of long-slit optical spectra taken of five high-redshift (z ~ 2-3) radio-loud quasars (QSRs), selected from the imaging survey of Heckman et al. We confirm that the QSRs have Ly{alpha} emission is spatially extended by at least several tens of kiloparsecs, with a luminosity of order 10^44^ ergs s^-1^. The gas is very active kinematically. After a subtraction of the seeing-scattered light from the broad-line region (BLR) of the central QSR, we find that line widths in the nebulae are 1000-1500 km s^-1^ (FWHM). The gas does not show any globally organized velocity gradient (i.e., velocities do not change by more than about 500 km s^-1^ over scales of tens of kiloparsecs). The line widths are close to the maximum possible for gas that is freely falling into the potential well of a very massive galaxy. Alternatively, we may be witnessing the explosive ejection of matter on a galactic scale by the QSR. The kinematic properties of the QSR nebulae are broadly similar to those of the nebulae associated with high-redshift radio galaxies. We confirm the suggestion of Foltz et al. that the nuclear He II {lambda}1640 emission line in QSRs is systematically narrower than other nuclear emission lines. We find that this narrow-lined, nuclear He II emission has a strength that correlates with the strength of the spatially extended Ly{alpha} emission, and suggest that the former probably arises in the inner (arcsec-scale) part of the Ly{alpha} nebula. This is consistent with the fact that the velocity of the spatially extended Ly{alpha} emission agrees well with the velocity of the narrow core of the nuclear Ly{alpha} profile. Selecting by the presence of strong narrow He II {lambda}1640 lines should be a good way to find high-z quasars with prominent Ly{alpha} nebulae. We discuss the implications of these results for the nature of the Z_abs_~Z_em_ systems in high-z QSRs. In three QSRs, the spatially extended Ly{alpha} is redshifted by of order 10^3^ km s^-1^ with respect to the C IV {lambda}1549 BLR profile (but exhibits no significant shift in the other two QSRs). We believe that this reflects a blueshift of the C IV lines with respect to QSR systemic velocity. This has implications for the interpretation of the BLR dynamics. We have likely (4-5{sigma}) detections of spatially extended He II {lambda}1640 in one QSR nebulae and C IV {lambda}1549 in another (each at 7%-10% of Ly{alpha}). These possible detections and the upper limits on other lines are consistent with the emission-line spectra of high-z radio galaxies. Our data are not good enough either to yield strong constraints on the metallicities in the nebulae or to discriminate decisively between, alternative ionization sources (photoionization by a standard active galactic nucleus continuum, photoionization by hot stars, shock heating, etc.). The probable He II detector is inconsistent with predictions of photoionization models for normal high-mass stars. The probable C IV detection means that at least some galaxy-scale sites in the early universe have nonprimordial chemical abundances. The probable detections of He II and C IV make it unlikely that the bulk of the spatially extended Ly{alpha} emission arises via resonant scattering of nuclear Ly{alpha} photons by neutral hydrogen surrounding the QSR. Subject headings: galaxies: formation - galaxies: internal motions - quasars
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