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Dr Katherine Inskip

Extended Emission Line Regions: Nature, origins & implications. Dr Katherine Inskip Montse Villar-Mart í n (IAA Granada) Clive Tadhunter, Joanna Holt, Dan Dicken (Sheffield) Raffaella Morganti (ASTRON) Friday 20 th October 2006. The data. PKS1932-46 VIMOS data:

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Dr Katherine Inskip

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  1. Extended Emission Line Regions: Nature, origins & implications Dr Katherine Inskip Montse Villar-Martín (IAA Granada)Clive Tadhunter, Joanna Holt, Dan Dicken (Sheffield) Raffaella Morganti (ASTRON) Friday 20th October 2006

  2. The data • PKS1932-46 • VIMOS data: • ~210 minutes over 3 nights • Includes useful emission lines: H – [SII]6731 • PKS2250-41 • VIMOS data: • ~200 minutes over 4 nights (and several months…!) • Includes useful emission lines: [OII]3727 – [SII]6731 • Long-slit optical FORS1 spectrum at PA~70° (offset from radio axis) • Also have Spitzer photometry of both sources, and optical/IR imaging The Central Engine of Active Galactic Nuclei

  3. So, what can we learn? • Distribution of line-emitting material • Ionization state of the gas • Density and temperature diagnostics • Gas kinematics – relative velocities and line widths • Pros: all the usual tools/results of narrow-band imaging and long-slit spectra, plus the ability to tune into regions of interest. • Cons: Targeted observations give better depth, and a less restrictive FOV. The Central Engine of Active Galactic Nuclei

  4. PKS1932–464 • PA -9° spectra (63° offset from radio axis) show 150kpc knotty, star-forming EELR. • FRII radio galaxy at z=0.231RA: 19h35m56.6s: -46°2041.8 (J2000) The Central Engine of Active Galactic Nuclei

  5. IFU fly-through: PKS1932-46 The Central Engine of Active Galactic Nuclei

  6. IFU fly-through: PKS1932-46 The Central Engine of Active Galactic Nuclei

  7. PKS1932-46: – fitting the [OIII] emission • Host galaxy at z=0.23; • extension to E, +further emission just beyond radio lobe • More blobs in surrounding IGM, including star-forming blobs to south • Possible companion galaxy to NE The Central Engine of Active Galactic Nuclei

  8. PKS1932-46: – fitting the [OIII] emission • Northern blob bright in [OII]3727  shocks?… but from what? • Relative velocities vary by ~600kms-1… but generally line widths suggest quiescent material. • O and S line ratios consistent with ne~100cm-3 and T ~ few 104K. Line width Line shift The Central Engine of Active Galactic Nuclei

  9. 24m 70m The companion galaxy… • z=0.229 (cf. 0.231 for PKS1932-46) • [OIII]/H ~1  star formation! Also, v. bright in Spitzer data. • Narrow blueshifted emission around PKS1932-46 host galaxy – same redshift as companion • Obvious question: Is this an interacting system? Did interaction trigger AGN activity? • Clearly a very messy system! The Central Engine of Active Galactic Nuclei

  10. IFU fly-through: PKS2250-41 • FRII radio galaxy at z=0.308 RA: 22h53m03.1s : -40°5746 (J2000) [OIII]5007 (left) and [OII]3727 (right) The Central Engine of Active Galactic Nuclei

  11. IFU fly-through: PKS2250-41 • FRII radio galaxy at z=0.308 RA: 22h53m03.1s : -40°5746 (J2000) [OIII]5007 (left) and [OII]3727 (right) The Central Engine of Active Galactic Nuclei

  12. IFU fly-through: PKS2250-41 • FRII radio galaxy at z=0.308 RA: 22h53m03.1s : -40°5746 (J2000) [OIII]5007 (left) and [OII]3727 (right) The Central Engine of Active Galactic Nuclei

  13. As expected, we can clearly pinpoint shocked region near hotspot. Elsewhere, gas appears photoionized. [OII]3727Å • [OII]/[OIII] PKS2250-41: – EELR Ionization State • [OIII]5007Å The Central Engine of Active Galactic Nuclei

  14. PKS2250-41: – EELR [OIII] kinematics Narrow line regions (~150-220kms-1) with broad-ish (400-500kms-1) blue wings: Observed near hotspots and towards centre of EELRIonization state suggests shocks/post-shock gas Also see broadening on south side of EELR, seemingly unconnected with radio source kinematics/shock ionization • Most extreme line widths observed near AGN and along jet axis, not near hotspot. • Distant regions – narrow line widths. • Apparent rotating structure. • Similar kinematics observed in FORS1 spectrum The Central Engine of Active Galactic Nuclei

  15. [OIII] image, not continuum subtracted FORS1 spectrum of PKS2250-41: – the very extended emission line region [OIII] image Cont. image Ionized gas pointing towards the nearby galaxy ~ 12’’ or 54 kpc The Central Engine of Active Galactic Nuclei

  16. The faint emission in the western lobe: Balmer absorption detected in companion galaxy suggests similar redshifts The Central Engine of Active Galactic Nuclei

  17. Concluding thoughts… • Radio source/EELR interactions fairly well understood, but… • Origin of EELR gas is not! • Links with questions of AGN triggering and galaxy growth. • Many similarities between PKS2250-41 and PKS1932-46: • Radio source strongly interacting with EELR • Can we disentangle cause/effect when it comes to clumpy IGM/halo material? The Central Engine of Active Galactic Nuclei

  18. Concluding thoughts… • similarities cont.: • Strong potential for merger/interactions in local environment • Both sources have close companions, and emission from blobs lying well off the radio axis • Gas kinematics – narrow FWHM at a variety of velocity offsets • Other activity: • Evidence for star formation in blobs • Overall: • radio galaxy halos are interesting, unsettled environments, with a lot of physics going on – and it’s not just shocks! • Potential to greatly improve our understanding of the triggering process and links to interactions, and ongoing AGN-related feedback The Central Engine of Active Galactic Nuclei

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