the interplay between radio jets and ism in sub-kpc radio sources

Raffaella Morganti Extragalactic jets, Girdwood (May 2007)

The interplay between The interplay between radio jets and ISM in sub-radio jets and ISM in sub-

kpc radio sourceskpc radio sourcesevolution of jets interacting with their evolution of jets interacting with their

environment as seen in small and environment as seen in small and intermediate scale objects intermediate scale objects

Raffaella MorgantiRaffaella MorgantiASTRON, DwingelooASTRON, Dwingeloo

Kapteyn Inst. GroningenKapteyn Inst. Groningen

Clive Tadhunter, Tom Oosterloo, Joanna Holt, Bjorn Emonts


Characteristics and effects of jet-ISM interaction: why important?

• Effect of the ISM on the radio jet: doesn’t care? momentarily disrupt? frustrated? destroyed?

• Effects of the jets on the surrounding ISM: gas outflow clearing the circum-nuclear regions?

Interaction radio jets/ISM is one of the possible mechanisms for triggering outflows (together with radiation pressure and starburst winds)

important for the evolution of the host galaxy


Following a hierarchical scenario:

evolution of AGN vs host galaxy

Start of merger-1 billion yr

Advanced merger: gas driventowards nucleus; starburst-0.5 billion yr

Quasar and jet activity drives gas out of galaxyNow

RelaxedE-galaxy+1 billion yr

from Clive Tadhunter

onset of radio activity related to accretion or merger -> but variety of conditions in the merger


Initial phase of AGN can be crucial in the evolution of the host galaxy

in radio-loud objects we know which one are YOUNG AGN (e.g. CSS/GPS)

thus we can study their effect on the medium


We use the (kinematics of the) gas to We use the (kinematics of the) gas to trace what is happening in the trace what is happening in the

central regions of active galaxiescentral regions of active galaxies

• Atomic neutral hydrogen • Ionised gas• Molecular gas (talk Patrick Ogle)

complementary information


Gas in (the centre of) early-type (field) galaxies:

important and very common component

In general (not only AGN selected early-type):

• Ionised gas -> ~70% detected, complex kinematics, kinematical decoupled cores etc. -> external origin of the gas in many cases (but not all!)

• Neutral hydrogen emission (on large scale) absorption (for radio-loud): can explore the small scales comparison compact/extended


HI in EMISSION: 70% detection rate for deep observations (down to few x 106 Msun)

HI in early-type galaxies200

k pcATCA data

HI total intensity + optical

Serra et al. 2005

(van Langevelde et al. 2000)

NGC 4261

HI in ABSORPTION: detected in ~30% of radio loud


How about sub-kpc (CSS/GPS) radio sources:

• is gas (ionised/neutral) present? and how compares to what found in large radio galaxies?

• are they (CSS/GPS) really moving through a dense medium?

• kinematics of the gas?


- Typical optical depth for radio galaxies: ~0.01 – 0.05

- High optical depth 0.1-0.2 detected in Seyferts and small/young sources.

- High detection rate of HI in CSS/GPS (e.g. Vermeulen et al. 2005) (not so clear for HFP Orienti et al. 2006)

)1( eScS cf −=Δ

upper limits

optical depth

Gallimore et al.

Vermeulen et al.

Morganti et al.

Typical HI column densities: 1019 - few times 1020 cm-2

for Tspin=100 K BUT Tspin can be up to few 1000 K

Atomic neutral hydrogen in large vs compact radio sources

Narrow (100-200 km/s) absorption component, associated with settled gas (e.g. circum-nuclear disks, halo, clouds e.g. see 4C12.50)

BUT NOT THE FULL STORY!


radio jet

The nuclear regionsprobed by the HI

extra-gas surrounding the AGN,e.g. left over from the merger that triggered the AGN

HI absorption from the torus or from circumnuclear disks

Cygnus A

Conway & Blanco 1995

~150 km/s

fast HI outflows

1400 km/s

WSRT Morganti et al. 2003

shocks


WSRT observations of broad HI absorption

Up to 2000 km/s width, optical depth <<1% Column density few times 1021 cm-2 (for Tspin = 1000 K)Mostly blueshifted HI outflows - Morganti, Oosterloo, Tadhunter A&A 2005

~0.003

~1500 km/s

~0.004 ~0.0023

~0.0005 ~0.006 ~0.002

~1400 km/s ~1000 km/s

~800 km/s ~2000 km/s~2000 km/s

~600 km/s


• Radio sources with detected fast HI outflows are either mainly compact/young or large with steep-spectrum cores (considered to be objects with restarted radio activity: 3C293 and 3C236)

All with rich ISM (CO, farIR....)

• Outflows detected in off-nuclear regions: jet-ISM interactionOutflows detected (with similar characteristics) both in ionised AND neutral gas!


The case of 3C305

WSRTVLA

core

500 km/s

VLAHI

•The broad HI absorption is found off-nucleus at the location of the radio lobe (about 1.6kpc

from the nucleus)•column density 2x1021 cm-2 (for Tspin=1000K)

•Mass outflowing gas ~106 Msun

Morganti, Oosterloo, Tadhunter, van Moorsel & Emonts 2005 A&A

1 kpc


Jet-driven outflows can have an impact on the evolution of a galaxy comparable to starburst-driven superwinds

• Bulk kinetic energy: ~ few x 1057 erg (over a lifetime of a radio jet)

Rupke, Veilleux, Sanders 2002, 2005

Radio Galaxies

Mass outflow rate between a few and ~50 Msun/yr

comparable (lower end) to that found in Ultraluminous IR galaxies

Relevant impact in the evolution of the galaxy?


Comparison between young (compact) and extended radio sources

• 14 powerful CSS/GPS from 3C/4C-2Jy samples

• 11/14 show evidence for fast outflows

– systemic to broadest component

– different distributions: K-S test significance: 99.9%

• size is important

Histograms: systemic-broadest

Num

ber

of s

ourc

esN

umbe

r of

sou

rces

Extended radio sources (Taylor 2004)

Compact radio sources (Holt 2005)

Shift (km s-1)

Shift (km s-1)

GPS

CSS

Other

Holt (2005)

PhD work of Joanna Holt

Ionised gas


General results on ionized and neutral General results on ionized and neutral hydrogen in compact sources hydrogen in compact sources

Indication of a rich medium around these objects?

• Broader & blueshifted optical emission lines are associated with compact radio sources: fast outflow of ionised gas very common

• Higher HI column density and fast HI outflows detected (produced by the interaction between the radio jet and the surrounding dense medium)


Detailed study of two objects and the connection atomic neutral - ionised gas


-450 km/s

-2000 km/s

[OIII] ProfilesWHT+ISIS

Holt et al. 2002

HST [OIII] VLBI

Compact and powerful radio galaxy (P5GHz = 10

26 W Hz-1)

Far-IR bright, LIR~2x1012 Lsun

Large amount of CO, ~ 1010 Msun

Very rich ISM

4C12.50 and its unfriendly medium


AGN feedback: outflowsExtended [O II]3727 emission

Deep HI 21cm absorption (Mirabel 89,

Morganti et al 03)

[O III] emission in the

nucleus

broad

narrow

intermediateblueshift ~ 400 km s-1

blueshift ~ 2000 km s-

1

(Holt et al 03a,b)


AGN feedback: outflowsExtended [O II]3727 emission

Deep HI 21cm absorption (Mirabel 89,

Morganti et al 03)

[O III] emission in the

nucleus

(Morganti et al 03)

(Holt et al 03a,b)


Observer’s L.O.S.

quiescent halo emitting narrow component

narrow component

broad component

intermediate component

obscured quasar

bi-polar radio jets

bi-polar radio jets

The broadest components are the most highly reddened & higher density (> 5000 cm-3)

Bow shock

Jet

HI clouds

[OIII] clouds

Shocked clouds

[OII]-emitting cocoon

Far side of galaxy, completely obscured from view

Stratified outflow

Upper limit for the total mass of line emitting gas (kinematically disturbed component combined) < 106 Msun

- too low for frustrating, confining the source


radio jethigh densitycloud

2D simulationsBicknell et al. 2003

4C12.50

Core

black=WSRTred = VLBI

Integrated HI profile

Mass of the HI cloud ~105-6 Msun

High column density (NH~10

22 cm-2)HI absorption

Global VLBI

Morganti, Oosterloo, Vermeulen et al. 2004

HI at the systemic tracing a clumpy medium

Case of 4C12.50: the jet is “fighting” its way out of a rich medium?

~50pc


PKS 1549-79: an example of a radio source in the early-

stage of its evolution• Recent major merger: tidal tails in optical, young

stellar population (50-250 Myr)• Core-jet radio structure: close

to the line-of-sight• HI absorption surprisingly present• No broad permitted (optical) lines

but Pa in NIR• Broad blueshifted (outflowing)

component e.g. [OIII]5007

VLT+FORS1: Gunn r (Batcheldor et al. 2007)

(King 1996)

2.3 GHz

Broad [OIII](FWHM~1350km/s)blueshift ~ 680 km s-1

Narrow H(FWHM<400km/s) HI

centre

NTT+EMMI & VLT+FORS2

VLBI


PKS 1549-79: in a stage where the nucleus is still hidden (in the optical) by the gas/dust coming from the merger that

triggered the radio sourceObserver’s

L.O.S.

[O II]-emitting

disk/cocoon• young, small scale radio jets

• expanding through dense cocoon

• sweep aside gas and dust

• AGN driven outflow will eventually remove the gas

PKS1549-79AAT/IRIS2K-band

FWHM = 1950 ± 40 km/s


core

Tzioumis et al.

1.2GHz

[OII]

[OII]

~200 pc

Not enough sensitivity to detect broad HI, but the HI at the systemic velocity represents the cocoon around the radio source


.mass outflow rate:

0.12 < M < 12 M๏ yr-1

mass of ionised gas in the outflow : 1.9x104 < M๏ < 1.9x106

. energy flux: 5.1x1040 < E < 5.1x1042 erg s-1

Main problem: relatively modest warm gas outflow

• the warm-gas outflow is not large! more in cold/hot gas?

• not as large as expected in the quasars feedback model

• it will not be able to clear all gas

• amount of ionised gas: not large to stop the jet

1.5x10-6 < E/Ledd < 1.5x10-4

Only small fraction of accretion power

.


Results from the study of single objects

• Interaction important - many effects seen

• complex, stratified structure of the ionised gas outflow

• the gas masses do not seem to be large enough to frustrate the source

• but likely slowing down the evolution of the jets.

• mass outflow not enough as expected in feedback models ?


For nearby (z < 0.04) lower luminosity, compact sources the situation could be different (see also talk Giroletti)

not all GPS/CSS become large galaxies? but not necessarily because of the interaction? different evolution?

large amount of HI in emission around nearby CSS: connected to their origin?

BUT we don’t see large sources with such large HI disks.


• HI-rich compact radio sources do not grow into extended sources

(either because frustrated by the ISM in the central region of the galaxy or because the fuel stops before the source expands)

Remarkable trend: radio galaxies with large amounts (MHI >109 Msun) of extended (many tens of kpc up to 200 kpc!) HI disks all have a compact radio source

Emonts et al. 2006, astro-ph/0701438

Nearby (z<0.04) compact radio sources~1kpc ~1kpc

Giroletti et al. 2004Morganti et al. 2006

NGC 3894


Results

Powerful compact sources• Interaction important - many effects seen • complex, stratified structure of the ionised gas

outflow• the masse of the gas involved does not seem to be

large enough to frustrate the source• but likely slowing down the evolution of the

jets.

Nearby low-luminosity compact sources• different evolution? • some of them just fade away? do not grow to large

size

the interplay between radio jets and ism in sub-kpc radio sources

Documents

radio loudhow

large radio galaxies

radioloud objects

optical depth radio

restarted radio activity

interaction radio jetsism

settled gas

gas outflow