Deep and sharp imaging with LOFAR: revealing the evolution of AGN - - PowerPoint PPT Presentation

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Deep and sharp imaging with LOFAR: revealing the evolution of AGN - - PowerPoint PPT Presentation

Feb 05, 2024 342 likes •682 views

Deep and sharp imaging with LOFAR: revealing the evolution of AGN Wendy L. Williams (Hertfordshire) Huub R ottgering (Leiden), Gaby Calistro Rivera (Leiden), Reinout van Weeren (CfA), LOFAR Surveys Team Science at Low Frequencies III

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Deep and sharp imaging with LOFAR: revealing the evolution of AGN

Wendy L. Williams (Hertfordshire)

Huub R¨

  • ttgering (Leiden), Gaby Calistro Rivera (Leiden), Reinout van Weeren (CfA),

LOFAR Surveys Team

Science at Low Frequencies III – Pasadena, CA, USA Dec 2016

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motivation

Wendy L. Williams LOFAR Radio AGN

Important for galaxy formation and evo- lution

  • Heating from radio jets provides a

means to balance cooling of the hot halo gas

  • Stops star formation
  • Self-regulating feedback

e.g. Croton+ 2006

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2 types of radio agn

Wendy L. Williams LOFAR Radio AGN

High Excitation (HERGs)

  • Typical AGN
  • With an accretion disk
  • Strong emission lines
  • X-ray
  • IR/sub-mm dusty torus
  • cold/radiative mode

Low Excitation (LERGS)

  • Atypical
  • Missing all the emission

associated with an accretion disk

  • Accretion of hot gas...
  • hot/jet mode

Hine & Longair 1979 Laing+ 1994

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the local population

Wendy L. Williams LOFAR Radio AGN

  • SDSS DR7 + NVSS/FIRST
  • > 18, 000 radio sources
  • Both HERGs & LERGs are

found over most of the range of luminosities

  • LERGs dominate at low

powers

Best & Heckman 2012

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what don’t we know

Wendy L. Williams LOFAR Radio AGN

  • How important are the different accretion modes in terms of

galaxy evolution?

  • How do they evolve with redshift?
  • How efficient is the feedback?
  • We can look at how the radio-loudness depends on:
  • Mass
  • Star formation
  • Galaxy type (e.g. colour)
  • Ionisation state

...All over cosmic time

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the population at higher z

Wendy L. Williams LOFAR Radio AGN

HERGs evolve strongly LERGs are only weakly evolving

Best+ 2014 also Pracy+ 2015

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what do we need?

Wendy L. Williams LOFAR Radio AGN

  • 1. LARGE SAMPLES of Radio Galaxies
  • Going out to higher z
  • LOFAR
  • Steep spectra
  • Live longer
  • High sensitivity and resolution (0.1 mJy, 5” @ 150 MHz)
  • Wide field of view

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what do we need?

Wendy L. Williams LOFAR Radio AGN

  • 1. LARGE SAMPLES of Radio Galaxies
  • Going out to higher z
  • LOFAR
  • Steep spectra
  • Live longer
  • High sensitivity and resolution (0.1 mJy, 5” @ 150 MHz)
  • Wide field of view
  • 2. Matched to excellent multi-wavelength data
  • z, mass, SFR,... from photometry
  • Excitation state... from spectroscopy(?)
  • Famous extra-galactic deep fields

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direction-dependent ionospheric calibration

Wendy L. Williams LOFAR Radio AGN

“Facet”-based direction- dependent calibration van Weeren, WLW+ 2016

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bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

“Facet”-based direction-dependent calibration 150 MHz 40 MHz bandwidth 8 hr observation 5.6x7.4′′ ∼ 120 µJy/beam 2.44 deg radius ∼ 19 deg2 LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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SLIDE 12

bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

LOFAR Bo¨

  • tes HBA image

WLW+ 2016

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the bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

  • NDWFS – BW ,R,I – 9.3 deg2
  • zBo¨
  • tes – z′
  • FLAMEX – J, Ks
  • SDWFS – irac 3.6, 4.5, 5.8, 8.0 µm
  • MAGES – mips 24 µm
  • GALEX – NUV, FUV
  • Chandra xBo¨
  • tes – X-Ray
  • Herschel HerMES – 250, 350, 500 µm

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the bo¨

  • tes field

Wendy L. Williams LOFAR Radio AGN

  • Spec-z (AGES)
  • mI < 21 mag
  • incomplete beyond z > 1
  • For ∼ 900, 000 sources
  • mI < 24 mag
  • Photo-z’s (EAZY)
  • Stellar masses, star formation

rates (FAST)

  • Rest-frame colours (InterRest)

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radio-optical matching

Wendy L. Williams LOFAR Radio AGN

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radio-optical matching

Wendy L. Williams LOFAR Radio AGN

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bo¨

  • tes sample

Wendy L. Williams LOFAR Radio AGN

Select LOFAR sample

  • Photo-z’s
  • 0.5 < z < 2.0
  • P150 > 1025 W/Hz
  • ∼ 1000 sources

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agn accretion modes from sed fitting

Wendy L. Williams LOFAR Radio AGN

AGNfitter https://github.com/GabrielaCR/AGNfitter

  • Including FIR Herschel data from HERMES
  • Components
  • Galaxy & starburst
  • IR torus & accretion disk

Calistro Rivera+ arXiv:1606.05648

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agn accretion modes from sed fitting

Wendy L. Williams LOFAR Radio AGN

  • AGN torus fraction
  • Fraction of IR light from torus

relative to Galaxy fTO = LTO LTO + LGA

  • Classify cold- vs hot-mode

(HERG vs LERG)

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agn accretion modes from sed fitting

Wendy L. Williams LOFAR Radio AGN

  • AGN torus fraction
  • Fraction of IR light from torus

relative to Galaxy fTO = LTO LTO + LGA

  • Classify cold- vs hot-mode

(HERG vs LERG)

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host galaxies of radio agn at moderate z

Wendy L. Williams LOFAR Radio AGN

Local sample – SDSS Colour vs mass HERGs/LERGs classified spectroscopically

WLW+ in prep

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host galaxies of radio agn at moderate z

Wendy L. Williams LOFAR Radio AGN

LOFAR sample Colour vs mass HERGs/LERGs classified photometrically

WLW+ in prep

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host galaxies of radio agn at moderate z

Wendy L. Williams LOFAR Radio AGN

WLW+ in prep

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radio loud fraction in the local universe

Wendy L. Williams LOFAR Radio AGN

  • Radio-loud fraction for HERGs is weakly mass-dependent ∝ M1.5
  • For LERGs it is strongly mass dependent ∝ M2.5

Best+ 2005 Janssen+ 2013

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radio-loud fraction

Wendy L. Williams LOFAR Radio AGN

WLW+ in prep

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evolving RLFs

Wendy L. Williams LOFAR Radio AGN

WLW+ in prep

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even more science

Wendy L. Williams LOFAR Radio AGN

quasars are smaller than radio galaxies – AGN unification

(cf. Barthel+ 89, Singal+ 14)

Morabito+ in prep

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even more science

Wendy L. Williams LOFAR Radio AGN

Low frequency spectra for AGN and starbursts – AGN steepen, starbursts flatten

Calistro Rivera+ in prep

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even more science

Wendy L. Williams LOFAR Radio AGN

FIR-radio correlation at 150 MHz – calibrating radio SFRs

Calistro Rivera+ in prep

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summary

Wendy L. Williams LOFAR Radio AGN

  • Combined with excellent multiwavelength data (LOFAR)

Radio Surveys have an important role in understanding the AGN population

  • LOFAR is now producing deep high-resolution images
  • LoTSS more soon...
  • The LOFAR Bo¨
  • tes sample shows
  • Radio AGN hosts at higher z are bluer, less massive
  • Radiative mode accretion becomes dominant at z >∼ 1,

LERGS begin to decline

  • Lots of exciting AGN/SF science in the works!

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