Integral Field Spectroscopy of the Extended Emission-Line Region of 4C 37.43
Abstract
We present Gemini integral field spectroscopy and Keck II long-slit spectroscopy of the extended emission-line region (EELR) around the quasar 4C 37.43. The velocity structure of the ionized gas is complex and cannot be explained globally by a simple dynamical model. The spectra from the clouds are inconsistent with shock or ``shock + precursor'' ionization models, but they are consistent with photoionization by the quasar nucleus. The best-fit photoionization model requires a low-metallicity [12+log(O/H)<~8.7] two-phase medium, consisting of a matter-bounded diffuse component with a unity filling factor (N~1 cm-3, T~15,000 K), in which are embedded small, dense clouds (N~400 cm-3, T~104 K). The high-density clouds are transient and can be regenerated through compressing the diffuse medium by low-speed shocks (VS<~100 km s-1). Our photoionization model gives a total mass for the ionized gas of about 3×1010 Msolar, and the total kinetic energy implied by this mass and the observed velocity field is ~2×1058 erg. The fact that luminous EELRs are confined to steep-spectrum radio-loud QSOs, yet show no morphological correspondence to the radio jets, suggests that the driving force producing the 4C 37.43 EELR was a roughly spherical blast wave initiated by the production of the jet. That such a mechanism seems capable of ejecting a mass comparable to that of the total interstellar medium of the Milky Way suggests that ``quasar-mode'' feedback may indeed be an efficient means of regulating star formation in the early universe.
Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina). Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the financial support of the W. M. Keck Foundation.- Publication:
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The Astrophysical Journal
- Pub Date:
- September 2007
- DOI:
- 10.1086/520530
- arXiv:
- arXiv:0705.4365
- Bibcode:
- 2007ApJ...666..794F
- Keywords:
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- Galaxies: Abundances;
- Galaxies: Evolution;
- Galaxies: ISM;
- Galaxies: Quasars: Emission Lines;
- Galaxies: Quasars: Individual: Alphanumeric: 4C 37.43;
- Astrophysics
- E-Print:
- Accepted by ApJ. 13 pages including 6 figures and 3 tables