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Title: Extreme Gas Kinematics in the z=2.2 Powerful Radio Galaxy MRC1138-262: Evidence for Efficient AGN Feedback in the Early Universe?

Abstract

To explain the properties of the most massive low-redshift galaxies and the shape of their mass function, recent models of galaxy evolution include strong AGN feedback to complement starburst-driven feedback in massive galaxies. Using the near-infrared integral-field spectrograph SPIFFI on the VLT, we searched for direct evidence for such a feedback in the optical emission line gas around the z = 2.16 powerful radio galaxy MRC1138-262, likely a massive galaxy in formation. The kpc-scale kinematics, with FWHMs and relative velocities {approx}< 2400 km s{sup -1} and nearly spherical spatial distribution, do not resemble large-scale gravitational motion or starburst-driven winds. Order-of-magnitude timescale and energy arguments favor the AGN as the only plausible candidate to accelerate the gas, with a total energy injection of {approx} few x 10{sup 60} ergs or more, necessary to power the outflow, and relatively efficient coupling between radio jet and ISM. Observed outflow properties are in gross agreement with the models, and suggest that AGN winds might have a similar, or perhaps larger, cosmological significance than starburst-driven winds, if MRC1138-262 is indeed archetypal. Moreover, the outflow has the potential to remove significant gas fractions ({approx}< 50%) from a > L* galaxy within a few 10 to 100more » Myrs, fast enough to preserve the observed [{alpha}/Fe] overabundance in massive galaxies at low redshift. Using simple arguments, it appears that feedback like that observed in MRC1138-262 may have sufficient energy to inhibit material from infalling into the dark matter halo and thus regulate galaxy growth as required in some recent models of hierarchical structure formation.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
964108
Report Number(s):
UCRL-JRNL-233050
TRN: US200922%%102
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Journal Article
Journal Name:
The Astrophysical Journal, vol. 650, no. 2, October 20, 2006, pp. 693-705
Additional Journal Information:
Journal Volume: 650; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
99 GENERAL AND MISCELLANEOUS; FEEDBACK; GALAXIES; NONLUMINOUS MATTER; SHAPE; SPATIAL DISTRIBUTION; UNIVERSE

Citation Formats

Nesvadba, N H, Lehnert, M D, Eisenhauer, F, Gilbert, A M, Tecza, M, and Abuter, R. Extreme Gas Kinematics in the z=2.2 Powerful Radio Galaxy MRC1138-262: Evidence for Efficient AGN Feedback in the Early Universe?. United States: N. p., 2007. Web.
Nesvadba, N H, Lehnert, M D, Eisenhauer, F, Gilbert, A M, Tecza, M, & Abuter, R. Extreme Gas Kinematics in the z=2.2 Powerful Radio Galaxy MRC1138-262: Evidence for Efficient AGN Feedback in the Early Universe?. United States.
Nesvadba, N H, Lehnert, M D, Eisenhauer, F, Gilbert, A M, Tecza, M, and Abuter, R. 2007. "Extreme Gas Kinematics in the z=2.2 Powerful Radio Galaxy MRC1138-262: Evidence for Efficient AGN Feedback in the Early Universe?". United States. https://www.osti.gov/servlets/purl/964108.
@article{osti_964108,
title = {Extreme Gas Kinematics in the z=2.2 Powerful Radio Galaxy MRC1138-262: Evidence for Efficient AGN Feedback in the Early Universe?},
author = {Nesvadba, N H and Lehnert, M D and Eisenhauer, F and Gilbert, A M and Tecza, M and Abuter, R},
abstractNote = {To explain the properties of the most massive low-redshift galaxies and the shape of their mass function, recent models of galaxy evolution include strong AGN feedback to complement starburst-driven feedback in massive galaxies. Using the near-infrared integral-field spectrograph SPIFFI on the VLT, we searched for direct evidence for such a feedback in the optical emission line gas around the z = 2.16 powerful radio galaxy MRC1138-262, likely a massive galaxy in formation. The kpc-scale kinematics, with FWHMs and relative velocities {approx}< 2400 km s{sup -1} and nearly spherical spatial distribution, do not resemble large-scale gravitational motion or starburst-driven winds. Order-of-magnitude timescale and energy arguments favor the AGN as the only plausible candidate to accelerate the gas, with a total energy injection of {approx} few x 10{sup 60} ergs or more, necessary to power the outflow, and relatively efficient coupling between radio jet and ISM. Observed outflow properties are in gross agreement with the models, and suggest that AGN winds might have a similar, or perhaps larger, cosmological significance than starburst-driven winds, if MRC1138-262 is indeed archetypal. Moreover, the outflow has the potential to remove significant gas fractions ({approx}< 50%) from a > L* galaxy within a few 10 to 100 Myrs, fast enough to preserve the observed [{alpha}/Fe] overabundance in massive galaxies at low redshift. Using simple arguments, it appears that feedback like that observed in MRC1138-262 may have sufficient energy to inhibit material from infalling into the dark matter halo and thus regulate galaxy growth as required in some recent models of hierarchical structure formation.},
doi = {},
url = {https://www.osti.gov/biblio/964108}, journal = {The Astrophysical Journal, vol. 650, no. 2, October 20, 2006, pp. 693-705},
number = 2,
volume = 650,
place = {United States},
year = {Tue Jun 26 00:00:00 EDT 2007},
month = {Tue Jun 26 00:00:00 EDT 2007}
}