THE [O III] NEBULA OF THE MERGER REMNANT NGC 7252: A LIKELY FAINT IONIZATION ECHO*
@article{Schweizer2013THEI, title={THE [O III] NEBULA OF THE MERGER REMNANT NGC 7252: A LIKELY FAINT IONIZATION ECHO*}, author={François Schweizer and Patrick Seitzer and Daniel D. Kelson and Edward V. Villanueva and G. Aniano Carnegie Observatories and University of Michigan and Steward Observatory}, journal={The Astrophysical Journal}, year={2013}, volume={773}, pages={148} }
We present images and spectra of a ~10?kpc-sized emission-line nebulosity discovered in the prototypical merger remnant NGC?7252 and dubbed the [O III] nebula because of its dominant [O III] ?5007 line. This nebula seems to yield the first sign of episodic active galactic nucleus (AGN) activity still occurring in the remnant, ~220?Myr after the coalescence of two gas-rich galaxies. Its location and kinematics suggest it belongs to a stream of tidal-tail gas falling back into the remnant. Its…
Figures and Tables from this paper
21 Citations
An [O iii] search for extended emission around AGN with H i mapping: a distant cloud ionized by Mkn 1
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2020
Motivated by the discovery of large ionized clouds around AGN, and particularly the large fraction of those that are consistent with photoionized gaseous tidal debris, we searched for [O iii]…
UVIT observations of the star-forming ring in NGC 7252: Evidence of possible AGN feedback suppressing central star formation
- Physics
- 2018
Some post-merger galaxies are known to undergo a starburst phase that quickly depletes the gas reservoir and turns it into a red-sequence galaxy, though the details are still unclear. Here we explore…
HST Imaging of Fading AGN Candidates I: Host-Galaxy Properties and Origin of the Extended Gas
- Physics
- 2014
We present narrow- and medium-band HST imaging, with additional supporting ground-based data, for 8 galaxies identified as hosting fading AGN. These have AGN-ionized gas projected >10 kpc from the…
Imaging extended emission-line regions of obscured AGN with the Subaru Hyper Suprime-Cam Survey
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2018
Narrow-line regions excited by active galactic nuclei (AGN) are important for studying AGN photoionization and feedback. Their strong [O III] lines can be detected with broadband images, allowing…
COLD MOLECULAR GAS IN MERGER REMNANTS. I. FORMATION OF MOLECULAR GAS DISKS
- Physics
- 2014
We present the 1 kpc resolution 12CO imaging study of 37 optically selected local merger remnants using new and archival interferometric maps obtained with ALMA, CARMA, the Submillimeter Array, and…
Detecting the Rapidly Expanding Outer Shell of the Crab Nebula: Where to Look
- Physics
- 2013
We present a range of steady-state photoionization simulations, corresponding to different assumed shell geometries and compositions, of the unseen postulated rapidly expanding outer shell to the…
MUSE Reveals a Recent Merger in the Post-starburst Host Galaxy of the TDE ASASSN-14li
- Physics
- 2016
We present MUSE integral field spectroscopic observations of the host galaxy (PGC 043234) of one of the closest ($z=0.0206$, $D\simeq 90$ Mpc) and best-studied tidal disruption events (TDE),…
Fading AGN candidates: AGN histories and outflow signatures
- Physics
- 2016
We consider energy budgets and radiative history of 8 fading AGN, identified from mismatch between the ionizion of very extended (>10 kpc) ionized clouds and the luminosity of the nucleus viewed…
AGN photoionization of gas in companion galaxies as a probe of AGN radiation in time and direction
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2018
We consider active galactic nucleus (AGN) photoionization of gas in companion galaxies (cross-ionization) as a way to sample the intensity of AGN radiation in both direction and time, independent of…
Active Galactic Nucleus Ghosts: A Systematic Search for Faded Nuclei
- Physics
- 2020
Physical processes such as re-ignition, enhancement, and fading of active galactic nuclei (AGN) are not entirely understood because the timeline of these events is expected to last many years.…
References
SHOWING 1-10 OF 90 REFERENCES
A Hubble Space Telescope WFPC2 Investigation of the Nuclear Morphology in the Toomre Sequence of Merging Galaxies
- Physics
- 2003
We report on the properties of nuclear regions in the Toomre sequence of merging galaxies, based on imaging data gathered with the Hubble Space Telescope WFPC2 camera. We have imaged the 11 systems…
Ages and Metallicities of Young Globular Clusters in the Merger Remnant NGC 7252
- Physics
- 1998
Ultraviolet-to-visual spectra of eight young star clusters in the merger remnant and protoelliptical galaxy NGC 7252, obtained with the 4 m Blanco Telescope on Cerro Tololo, are presented. These…
The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black hole accretion events
- Physics
- 2011
Some active galactic nuclei (AGN) are surrounded by extended emission-line regions (EELRs), which trace both the illumination pattern of escaping radiation and its history over the light-travel time…
Extended Emission-Line Regions: Remnants of Quasar Superwinds?
- Physics
- 2008
We give an overview of our recent integral-field-unit spectroscopy of luminous extended emission-line regions (EELRs) around low-redshift quasars, including new observations of five fields. Previous…
Hubble Space Telescope discovery of candidate young globular clusters in the merger remnant NGC 7252
- Physics
- 1993
New, high-resolution images of the central region of NGC 7252 obtained with the Planetary Camera of the HST are presented. NGC 7252 is a prototypical example of a remnant of two merged disk galaxies.…
MASSIVE MOLECULAR OUTFLOWS AND NEGATIVE FEEDBACK IN ULIRGs OBSERVED BY HERSCHEL-PACS*
- Physics
- 2011
Mass outflows driven by stars and active galactic nuclei (AGNs) are a key element in many current models of galaxy evolution. They may produce the observed black-hole-galaxy mass relation and…
Low-ionization active galactic nuclei: X-ray or shock heated?
- Physics
- 1982
We evaluate narrow-line ratios for a wide variety of active galactic nuclei, including those claimed to be shock heated. In the context of a Seyfert photoionization model, the entire range of…
Cold, warm, and hot gas in the late-stage merger NGC 7252
- Physics
- 1994
We present the first observations of the neutral hydrogen distribution and x-ray emission in the prototypical merger remnant NGC 7252, the 'Atoms-for-Peace' galaxy. These data are supplemented by…
The host galaxies of active galactic nuclei
- Physics
- 2003
We examine the properties of the host galaxies of 22 623 narrow-line active galactic nuclei (AGN) with 0.02 < z < 0.3 selected from a complete sample of 122 808 galaxies from the Sloan Digital Sky…