The environment of PDS456
Abstract
I present optical spectroscopic and narrow-band imaging data on the luminous, low redshift (z=0.184) quasar, PDS456, and its environment. This quasar has been the subject of multiple X-ray observations over the past ~15 years, which show strong variability and a high velocity outflow (e.g. Reeves et al. 2014 and references therein). Radio continuum, CO(1-0) and sub-millimeter data reveal both ULIRG- and quasar-like properties and suggest that the object is in a transient phase of evolution from a ULIRG to a bona fide quasar (Yun et al 2004). On a K-band image, there are three compact sources to the southwest of the quasar and within 2-3" from it (~10 kpc if at the quasar redshift) which Yun et al. propose may be remnants of a merger or interaction.A 3200-10000 angstrom spectroscopic observation with the Multi-Object Double Spectrograph (MODS1) at the Large Binocular Telescope (LBT), with the slit position angle set to capture both the quasar and the fainter K-band source, reveals, at an angular separation of ~6" from the quasar and in the same direction as the K-band source, a compact narrow emission line region, with lines of H-alpha, [NII], [SiII], [OII], H-beta, and [OIII], at the quasar redshift. To determine a more precise location for this narrow line emitting region and to look for others, narrow-band imaging, through redshifted H-alpha (7780/84) and continuum filters, was obtained using the 90Prime camera at the Bok 2.3-m telescope. The contribution of these data to our understanding of this intriguing quasar will be discussed.
- Publication:
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American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22514418K