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

1
The interplay between radio jets and ISM in
sub-kpc radio sources

• evolution of jets interacting with their
  environment as seen in small and intermediate
  scale objects

Raffaella Morganti ASTRON, Dwingeloo Kapteyn
Inst. Groningen
Clive Tadhunter, Tom Oosterloo, Joanna Holt,
Bjorn Emonts
2
Characteristics and effects of jet-ISM
interaction why important?

• Effect of the ISM on the radio jet doesnt 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
3
Following a hierarchical scenarioevolution of
AGN vs host galaxy
from Clive Tadhunter
Start of merger -1 billion yr
onset of radio activity related to accretion or
merger -gt but variety of conditions in the merger
Advanced merger gas driven towards nucleus
starburst -0.5 billion yr
Quasar and jet activity drives gas out of
galaxy Now
Relaxed E-galaxy 1 billion yr
4
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
5

• We use the (kinematics of the) gas to trace what
  is happening in the central regions of active
  galaxies
• Atomic neutral hydrogen
• Ionised gas
• Molecular gas (talk Patrick Ogle)

6
Gas in (the centre of) early-type (field)
galaxies important and very common component

• In general (not only AGN selected early-type)
• Ionised gas -gt 70 detected, complex kinematics,
  kinematical decoupled cores etc. -gt 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

7
HI in early-type galaxies
HI total intensity optical
ATCA data
HI in EMISSION 70 detection rate for deep
observations (down to few x 106 Msun)
HI in ABSORPTION detected in 30 of radio loud
200 kpc
Serra et al. 2005
8

• 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?

9
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)
Gallimore et al.

• - 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)

optical depth ?
Vermeulen et al.
Morganti et al.
upper limits
Typical HI column densities 1019 - few times
1020 cm-2
for Tspin100 K BUT Tspin can be up to few
1000 K
BUT NOT THE FULL STORY!
10
The nuclear regions probed by the HI
11
WSRT observations of broad HI absorption
1400 km/s
1000 km/s
1500 km/s
? 0.003
? 0.0023
? 0.004
2000 km/s
800 km/s
2000 km/s
? 0.0005
? 0.006
? 0.002
600 km/s
Up to 2000 km/s width, optical depth ltlt1 Column
density few times 1021 cm-2 (for Tspin 1000
K) Mostly blueshifted HI outflows - Morganti,
Oosterloo, Tadhunter AA 2005
12
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 interaction

Outflows detected (with similar characteristics)
both in ionised AND neutral gas!
13
The case of 3C305
1 kpc

WSRT VLA
VLA HI

• 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 Tspin1000K)
• Mass outflowing gas 106 Msun

core
500 km/s
Morganti, Oosterloo, Tadhunter, van Moorsel
Emonts 2005 AA
14

• 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?

Rupke, Veilleux, Sanders 2002, 2005

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

15
Comparison between young (compact) and extended
radio sources
Histograms systemic-broadest
Ionised gas

• 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

Extended radio sources (Taylor 2004)
Number of sources
Shift (km s-1)
Compact radio sources (Holt 2005)
CSS
GPS
Number of sources
Other
Holt (2005)
Shift (km s-1)
PhD work of Joanna Holt
16
General results on ionized and neutral 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)

17
Detailed study of two objects and the connection
atomic neutral - ionised gas
18
4C12.50 and its unfriendly medium
HST OIII
VLBI
Very rich ISM
OIII Profiles WHTISIS
-450 km/s
-2000 km/s
Holt et al. 2002
19
AGN feedback outflows
Extended O II3727 emission
narrow
Deep HI 21cm absorption (Mirabel 89, Morganti et
al 03)
intermediate
blueshift 400 km s-1
O III emission in the nucleus
broad
blueshift 2000 km s-1
(Holt et al 03a,b)
20
AGN feedback outflows
Extended O II3727 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)
21
Stratified outflow
quiescent halo emitting narrow component
narrow component
intermediate component
Far side of galaxy, completely obscured from
view
broad component
Observers L.O.S.
bi-polar radio jets
bi-polar radio jets
obscured quasar
The broadest components are the most
highly reddened higher density (gt 5000
cm-3)
Upper limit for the total mass of line emitting
gas (kinematically disturbed component combined)
lt 106 Msun - too low for frustrating, confining
the source
22
HI at the systemic tracing a clumpy medium Case
of 4C12.50 the jet is fighting its way out of
a rich medium?
Global VLBI
High column density (NH1022 cm-2) HI absorption
4C12.50
50pc
Core
Mass of the HI cloud 105-6 Msun
Morganti, Oosterloo, Vermeulen et al. 2004
23
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.
  OIII5007

VLTFORS1 Gunn r (Batcheldor et al. 2007)
VLBI
24
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
source
Observers 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

25
1.2GHz
200 pc
OII
OII
Tzioumis et al.
Not enough sensitivity to detect broad HI, but
the HI at the systemic velocity represents the
cocoon around the radio source
26
Main problem relatively modest warm gas outflow
. mass outflow rate 0.12 lt M lt 12 M?
yr-1 mass of ionised gas
in the outflow 1.9x104 lt M? lt
1.9x106 . energy flux
5.1x1040 lt E lt 5.1x1042 erg s-1




.
1.5x10-6 lt E/Ledd lt 1.5x10-4
Only small fraction of accretion power

• 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

27
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 ?

28
For nearby (z lt 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 dont see large sources with such
large HI disks.
29
Remarkable trend radio galaxies with large
amounts (MHI gt109 Msun) of extended (many tens of
kpc up to 200 kpc!) HI disks all have a compact
radio source
Nearby (zlt0.04) compact radio sources
NGC 3894
Giroletti et al. 2004
Morganti et al. 2006

• 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)

30
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

31
X
32
Cool gas can be produced in jet/cloud
interaction
Fragile et al. 2003
Simulations show that cooled fragmented clouds
(likely to collapse and form stars) do form as
result of the interaction
Mellema et al. 2002, Fragile et al.
2003
Cloud Denser and warmer subclouds
Evolution of clouds in radio galaxy cocoons
shock runs over a cloud
compression phase (overpressured cocoon)
fragmentation cooling
formation of dense, cool fragmented structures
looks promising
BUT can the fragmented clouds be
accelerated to such high velocities?
33
Ionized and neutral gas

• Broad HI absorption
• full width of 2000 km/s
• mostly blueshifted

"Deep" Absorption ? only 1, NH2x1020 cm-2 for
TSPIN100K
(already known from Mirabel 1989)
Broad absorption
34
The location of the HI outflows the case of the
radio-loud Seyfert IC 5063
0.5 kpc
Outflow located at the radio lobe (0.5 kpc from
the nucleus) jet-induced outflow
Morganti, Holt et al. submitted
35
AGN feedback outflows
Extended O II3727 emission
Deep HI 21cm absorption (Mirabel 89, Morganti et
al 03)
(Holt et al 03a,b)
36
Outflows in young radio sources
Ionised gas

• 11/14 show evidence for fast outflows
• systemic to broadest component
• different distributions K-S test
  significance 99.9
• size is important
• orientation may be important

Holt (2005)
37
Emonts et al. (from Spitzer archival data PI.
Armus)
38
4C12.50 and its unfriendly medium
VLT image (Batcheldor et al. 2007)
300 pc
Stanghellini et al.
39
Examples of gas in the centre of nearby
early-type galaxies
Integral field spectrograph SAURON
Kinematical decoupled cores The kinematics
changes in the very inner parts
McDermid et al. using Sauron and OASIS integral
field spectrographs
Integral field spectrograph OASIS
linear scale, between 50 and 100 pc/arcsec
40
Gas in (the centre of) early-type galaxies
important and very common component

• In general (not only AGN selected early-type)
• Ionised gas -gt 70 detected, complex kinematics,
  KDC etc. -gt 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

41
Case of the compact radio source OQ208

• known to have fast outflow in the
• broad emission lines (Marziani et al.)
• particularly rich medium from
• X-ray absorption
• radio jets possibly piercing their
• way through a Compton-thick medium
• pervading the nuclear environment
• (Guainazzi et al. 2004)

10 pc
Stanghellini et al. 1993
42
Radio sources with detected fast HI outflows are
mainly compact/young or large with
steep-spectrum cores (considered to be objects
with restarted radio activity 3C293 and
3C236) All sources with rich ISM
(CO, farIR....)