The Location and Kinematics

1
The Location and Kinematics of HI Absorbing
Gas in GPS and CSS Radio Galaxies
René Vermeulen Astron/NFRA, Dwingeloo, NL
Work with Y.M. Pihlström, W. Tschager, W.H. de
Vries, A. Labiano, P.D. Barthel, S.A. Baum, R.
Braun, M.N. Bremer, J.E.
Conway, G.K. Miley, C.P. ODea, H.J.A.
Röttgering, R.T. Schilizzi,
I.A.G. Snellen, G.B. Taylor.
2
CSO/GPS/CSS radio galaxies
Total radio extent is sub-galactic (?15
kpc). Radio structure dominated by lobes
core may show free-free absorption. Now usually
thought to be young sources (?104-105
years), rather than frustrated (e.g., based on
observed velocities). But morphology is often
distorted, and there is other evidence for a
dense environment (ionised gas in optical, RM,
X-rays, free-free absorption).
3
CSO/GPS/CSS radio galaxies
Studing gaseous environment of CSO/GPS/CSS radio
galaxies is very interesting --- What are
conditions conducive to the birth of radio
sources ? --- Feeding of the engine (infalling
gas). --- Jet formation mechanisms (collimation,
acceleration), and propagation through the
ISM. --- Influence of the radio jets on their
galactic environment.
4
Studing the neutral gas through HI absorption
Good technique because sensitivity is independent
of distance. Needs bright radio structure to act
as background. This is available at the right
place in the compact radio sources. Jet/environme
nt interactions are also likely sites of
bright radio emission which can be studied.
5
Studing the neutral gas through HI absorption
Good technique because sensitivity is independent
of distance. Needs bright radio structure to act
as background. This is available at the right
place in the compact radio sources. Jet/environme
nt interactions are also likely sites of
bright radio emission which can be studied.
Most powerful CSO/GPS/CSS are at 0.2 lt z lt 1.
But this is outside L-band 21cm range.
6
HI absorption line survey at the WSRT
UHF-high receivers Wideband 750-1200 MHz, 0.2 lt
z lt 0.9.
Interferometer superior RFI rejection and
spectral calibration.
3C213.1
0.1
7
HI absorption line survey at the WSRT
Vermeulen et al., Pihlström et al., 2003 AA in
press. Sample all known compact sources (CSO,
GPS, CSS) 19 detections out of 57 targets free
of RFI at 0.2 lt z lt 0.9
8
Larger sources, lower column densities
N(HI) ? 1020.2 (LS)-0.33
9
Line width typically 100-200 km/s
Some sources have narrow secondary line components
10
Line width typically 100-200 km/s
FWHM is not strongly dependent on linear size
Some sources have narrow secondary line components
11
Infall or outflow ?
500
-500
? outflow infall ?
van Gorkom et al. 1989 8 nearby radio galaxies
12
Infall or outflow ?
500
-500
? outflow infall ?
? outflow infall ?
Our sample 19 compact sources at 0.2 lt z lt 0.9
van Gorkom et al. 1989 8 nearby radio galaxies
Optical redshifts may be imprecise but should not
be biased
13
Infall or outflow disks/tori or
interaction/entrainment ?
Imaging of HI absorption in several nearby
sources shows a circumnuclear, possibly toroidal
or disk-like distribution. But in other nearby
sources, HI absorption has been found in
jet/cloud interaction regions (e.g. Morganti et
al.).
14
Infall or outflow disks/tori or
interaction/entrainment ?
Imaging of HI absorption in several nearby
sources shows a circumnuclear, possibly toroidal
or disk-like distribution. But in other nearby
sources, HI absorption has been found in
jet/cloud interaction regions (e.g. Morganti et
al.).
NGC1052 A detailed look shows complexity.
15
NGC 1052 closely resembling a GPS/CSS/CSO
Vermeulen et al. 2003
Elliptical Galaxy, LINER optical spectrum.
cz1474 km/s From starlight and emission
lines. gt 1 mas 0.1 pc (D22 Mpc H065
km/s/Mpc).
Bright radio source (1Jy).
Flat/inverted radio spectrum ..... like a
GPS. Twin radio jets, lobes spanning 3 kpc
..... like a CSS. Bright twin inner jets, knots
..... like a CSO.
16
NGC1052 3 HI components, mostly local to AGN,
redshifted
17
NGC1052 3 HI components, mostly local to AGN,
redshifted
"Low velocity" HI broad 1440 - 1560 km/s, peak
depth 2 Asymmetrically straddles
vsys. Galactic scale ?
18
NGC1052 3 HI components, mostly local to AGN,
redshifted
"Patchy" HI narrow 3-15 km/s, depths 5
Several clouds in inner few pc region, extending
a few tenths of a pc each.
"Low velocity" HI broad 1440 - 1560 km/s, peak
depth 2 Asymmetrically straddles
vsys. Galactic scale ?
19
NGC1052 3 HI components, mostly local to AGN,
redshifted
"Patchy" HI narrow 3-15 km/s, depths 5
Several clouds in inner few pc region, extending
a few tenths of a pc each.
"Low velocity" HI broad 1440 - 1560 km/s, peak
depth 2 Asymmetrically straddles
vsys. Galactic scale ?
"High velocity" HI width 15-20 km/s, depth varies
25 - 0 annulus/torus 2 - 0.5 pc with central
hole ?
20
Infall or outflow disks/tori or
interaction/entrainment ?
Imaging of HI absorption in several nearby
sources shows a circumnuclear, possibly toroidal
or disk-like distribution. But in other nearby
sources, HI absorption has been found in
jet/cloud interaction regions (e.g. Morganti et
al.). NGC1052 shows 3 different regions with
neutral gas.
21
Infall or outflow disks/tori or
interaction/entrainment ?
Imaging of HI absorption in several nearby
sources shows a circumnuclear, possibly toroidal
or disk-like distribution. But in other nearby
sources, HI absorption has been found in
jet/cloud interaction regions (e.g. Morganti et
al.). NGC1052, z0.005, shows 3 different
regions with neutral gas.
In order to access HI at z?0.2, we have pushed
to have VLBI at UHF frequencies on the EVN.
22
VLBI at UHF Frequencies
750-1200 MHz, 0.2 lt z lt 0.9 for HI
F. Briggs I. Browne C. Carilli J. Conway G. de
Bruyn A. Kus K. Menten C. Moore R. Vermeulen
Effelsberg 100m purpose-built receiver
Jodrell Bank 76m "960MHz receiver"
Onsala 25m purpose-built receiver
Torun 32m purpose-built-receiver
Westerbork "94m" UHF receivers
Green Bank (140ft, GBT)
VLBA (down to 1140 MHz only)
23
Locus of absorption in Pearson-Readhead CSOs.
Flux-limited 6cm Pearson-Readhead of 65
sources contains 7 CSOs.
FWHM (km/s) 100 60 ? - 170 - 82
Name 0108388 0404768 0710439 1031567 1358
624 2021614 2352495
Peak optical depth 0.44 0.014
? lt0.0048 0.006 lt0.0013 0.017
24
0108388 HI in a free-free absorbing torus ?
852 MHz
44 absorption 94 km/s wide
25
0108388 HI in a free-free absorbing torus ?
WSRT
26
0108388 HI in a free-free absorbing torus ?
Not yet resolved by VLBI at UHF
WSRT Spectrum Carilli et al. 1997
WSRT
27
0108388 HI in a free-free absorbing torus ?
Not yet resolved by VLBI at UHF
WSRT
WSRT
Shows substantial free-free absorption.
VLBA
28
0108388 HI in a free-free absorbing torus ?
Not yet resolved by VLBI at UHF
WSRT
WSRT
Shows substantial free-free absorption.
VLBA
? HI absorption in pc-scale torus ?
29
0404768 HI in a jet/cloud interaction ?
886 MHz
1.4 absorption 60 km/s wide 0.3 absorption
150 km/s wide
30
0404768 HI in a jet/cloud interaction ?
150 pc
31
0404768 HI in a jet/cloud interaction ?
150 pc
Core has less total flux density than
absorption line. Absorption line detected on
EVN baselines.
32
0404768 HI in a jet/cloud interaction ?
150 pc
Core has less total flux density than
absorption line. Absorption line detected on
EVN baselines.
? Absorption must be in 100 pc-scale lobe
feature(s)
33
1031567 No HI because core undetectable ?
973 MHz
No HI detected
lt0.48 absorption
34
1031567 No HI because core undetectable ?
973 MHz
No HI detected
lt0.48 absorption
Core undetectable probably free-free absorbed.
35
1031567 No HI because core undetectable ?
973 MHz
No HI detected
lt0.48 absorption
Core undetectable probably free-free absorbed.
? A pc-scale torus may have neutral gas, but
there is no background to see it.
36
1358624 large-scale absorption ?
993 MHz
0.6 absorption 170 km/s wide
37
1358624 large-scale absorption ?
38
1358624 large-scale absorption ?
1667 MHz and 993 MHz structures are hard to
match. Line and continuum visibility seem to
show the same amount of compact and extended
structure (comparing EVN vs. Gb baselines).
39
1358624 large-scale absorption ?
1667 MHz and 993 MHz structures are hard to
match. Line and continuum visibility seem to
show the same amount of compact and extended
structure (comparing EVN vs. Gb baselines).
? HI absorption probably covers most of the
(lobe) structure.
40
2021614 no HI because core undetectable ?
1157 MHz
No HI detected
lt0.13 absorption
41
2021614 no HI because core undetectable ?
1157 MHz
No HI detected
lt0.13 absorption
Core undetectable at low frequency probably
free-free absorbed.
42
2021614 no HI because core undetectable ?
1157 MHz
No HI detected
lt0.13 absorption
Core undetectable at low frequency probably
free-free absorbed.
? A pc-scale torus may have neutral gas, but
there is no background to see it.
43
2352495 circumnuclear HI ?
1147 MHz
1.7 absorption 82 km/s wide 1.2 absorption
13 km/s wide
44
2352495 circumnuclear HI ?
50 pc
45
2352495 circumnuclear HI ?
50 pc
All of the absorbed flux density is from the
inner component.
46
2352495 circumnuclear HI ?
50 pc
The inner component is mostly an inner Northern
jet, lt50 pc.
47
2352495 circumnuclear HI ?
All of the absorbed flux density is from the
inner Northern jet, lt50 pc.
48
2352495 circumnuclear HI ?
All of the absorbed flux density is from the
inner Northern jet, lt50 pc.
? Circumnuclear HI, in a 10 pc scale torus ?
49
Locus of absorption PR-CSOs.
Flux-limited 6cm Pearson-Readhead of 65
sources contains 7 CSOs.
Tentative Scenario Torus Interaction ? FFA
Torus Interaction FFA Torus Torus
FWHM (km/s) 100 60 ? - 170 - 82
Name 0108388 0404768 0710439 1031567 1358
624 2021614 2352495
Peak optical depth 0.44 0.014
? lt0.0048 0.006 lt0.0013 0.017
50
2050364 another complex case
1048 MHz
16.1 absorption 16 km/s wide 4.4 absorption
32 km/s wide
51
2050364 another complex case
with A. Labiano
52
2050364 another complex case
53
2050364 another complex case
Deepest absorption only shifts 10 km/s over
several hundred pc.
54
2050364 another complex case
Deepest absorption only shifts 10 km/s over
several hundred pc.
? (Sub)galactic scale flow
55
2050364 another complex case
Deepest absorption only shifts 10 km/s over
several hundred pc. Shallow higher velocity
absorption seen only to the West.
? (Sub)galactic scale flow
56
2050364 another complex case
Is 2050364 a classical Compact Double or a bent
Core-Jet source ?
1.05 GHz
57
2050364 another complex case
Is 2050364 a classical Compact Double or a bent
Core-Jet source ?
0.6 GHz
Lazio Fey 2001
58
2050364 another complex case
Is 2050364 a classical Compact Double or a bent
Core-Jet source ?
0.6 GHz
1.6 GHz
Lazio Fey 2001
59
2050364 another complex case
Is 2050364 a classical Compact Double or a bent
Core-Jet source ?
0.6 GHz
1.6 GHz
Lazio Fey 2001
8.4 GHz
60
2050364 another complex case
Is 2050364 a classical Compact Double or a bent
Core-Jet source ?
0.6 GHz
1.6 GHz
Lazio Fey 2001
Flattest spectrum, most compact core inner jet
?
Shock/bend in jet ?
Steepest spectrum, most extended continuation of
jet
8.4 GHz
61
2050364 another complex case
Deepest absorption only shifts 10 km/s over
several hundred pc. Shallow higher velocity
absorption seen only to the West.
? (Sub)galactic scale flow
62
2050364 another complex case
Deepest absorption only shifts 10 km/s over
several hundred pc. Shallow higher velocity
absorption seen only to the West.
? (Sub)galactic scale flow gets disturbed
towards the core ?
63
3C49 Larger scale source with HI in one radio
lobe
877 MHz
1.7 absorption 7 km/s wide 1.4 absorption
35 km/s wide
64
3C49 Larger scale source with HI in one radio
lobe
65
3C49 Larger scale source with HI in one radio
lobe
All of the HI aborption is in 1 lobe
66
3C49 Larger scale source with HI in one radio
lobe
All of the HI aborption is in 1 lobe
? HI is associated with aligned OII emission
in a sub-kpc sized lobe.
67
Summary
WSRT survey detected HI absorption in 1/3 of
compact sources wide range of opacities ? ?
0.001 0.2, anticorrelated with linear size.
VLBI follow-up shows disks/tori and interactions
and flows (in and out).
In different objects
Within single objects
68
Summary
Could it be that ... ?? --- Disks/tori with HI
are ubiquitous, and are seen when the
core is prominent enough and/or the
lobes are close by (10 pc ?). --- Interactions
with clouds containing HI happen in some
sources. --- (Sub)galactic-sized flows can be
detected if sensitivity allows.
69
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70
Molecular gas 4 OH lines, non-LTE, velocity
regions
WSRT Spectrum
71
Molecular gas 4 OH lines
18cm WSRT observations. Vsys
1474 km/s
A) "Main lines" 1667 MHz and 1665 MHz 1)
0.2-0.3 centred on Vsys, width 30 km/s 2)
Red extension to 1570 km/s Together form
the "low velocity" system ? 1667/1665 line
ratio close to 1 1 (non-LTE) Is there a
"patchy" system in OH ? 3) 0.2-0.4 feature
over 1600-1670 km/s Profile identical to
"high velocity HI system 1667/1665 ratio
near 1.8 1 (LTE ??)
72
Molecular gas 4 OH lines
18cm WSRT observations. Vsys
1474 km/s
B) "Satellite lines" 1612 MHz, 1720 MHz
Only detectable in "high velocity" system.
Peak depth 0.4 1612 MHz in absorption,
1720 MHz in emission. Mirror profiles.
Shock excited ?
73
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75
The inner jets two-sided near-relativistic
motions
Part of the 2cm VLBA Survey (Kellermann et al.
1998, AJ, 115, 1295).
10 observing epochs 1995 Jul - 2001 Feb.
Unambiguous 2-sided, probably linear
motions. Near-relativistic 0.78 0.12 mas/yr
0.26 0.04 c each side.
Thus jets near plane of sky, angle gt57.
Had to overcome "registration", "stroboscopic"
effects -- Central gap. -- Every few months new
features emerge. -- Flux densities vary up and
down as features move. Suggests patchy
surrounding medium.
76
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77
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78
Ionised gas in inner parsec disk/torus and more
?
Multi-wavelength VLBA observations
1997 July, frequencies 1.4, 1.6, 5, 8, 15, 22, 43
GHz.
Source almost symmetric at 43 GHz without
gap. Deepening, widening gap towards lower
frequencies -- "hole" in central 0.2-0.3 pc. --
western jet attenuated out to at least 1 pc. --
eastern jet also attenuated, but less deeply.
Steeply inverted spectra Free-Free Absorption.
?1 at 43 GHz, l 0.5 pc, T104 K ? ne105 cm-3
79
Atomic gas 3 components, mostly local,
redshifted

Vsys 1474 km/s
A) "Low velocity" component. broad 1440 -
1560 km/s, peak depth 2 Asymmetrically
straddles systemic velocity.
B) "Patchy" component. narrow 3-15 km/s,
depths 5 , in 1500 - 1570 km/s
C) "High velocity" component. width 15-20
km/s, depth overall 10
?0.02, l 0.5 pc, Tsp100 K ? nH100 cm-3
80
Atomic gas 3 components, mostly local,
redshifted
21cm VLBAY27 observations. Vsys
1474 km/s
A) "Low velocity" component. broad 1440 -
1560 km/s, peak depth 2 Asymmetrically
straddles systemic velocity. Visible
wherever s/n allows could be on galactic scales ?
B) "Patchy" component. narrow 3-15 km/s,
depths 5 , in 1500 - 1570 km/s
C) "High velocity" component. width 15-20
km/s, depth overall 10
81
Atomic gas 3 components, mostly local,
redshifted
21cm VLBAY27 observations. Vsys
1474 km/s
A) "Low velocity" component. broad 1440 -
1560 km/s, peak depth 2 Asymmetrically
straddles systemic velocity. Visible
wherever s/n allows could be on galactic scales ?
B) "Patchy" component. narrow 3-15 km/s,
depths 5 , in 1500 - 1570 km/s Several
features, extending few tenths of a pc each,
detected along the inner 2 pc of the eastern jet.
C) "High velocity" component. width 15-20
km/s, depth overall 10
82
Atomic gas 3 components, mostly local,
redshifted
21cm VLBAY27 observations. Vsys
1474 km/s
A) "Low velocity" component. broad 1440 -
1560 km/s, peak depth 2 Asymmetrically
straddles systemic velocity. Visible
wherever s/n allows could be on galactic scales ?
B) "Patchy" component. narrow 3-15 km/s,
depths 5 , in 1500 - 1570 km/s Several
features, extending few tenths of a pc each,
detected along the inner 2 pc of the eastern jet.
C) "High velocity" component. width 15-20
km/s, depth varies 25 - 0 - 10 - 5 - 0
annulus 2 - 0.5 pc with central hole,
continuous velocity gradient 10 km/s/pc ?
83
Where are the absorbers in NGC 1052 ?
Central hole of radius 0.5 pc in high-velocity
atomic gas. Corresponds to region of deepest
free-free absorption. gt Ionised inner region
! Agrees with X-ray low-energy absorption
spectra. OH molecular gas follows same
profile. But if edge-on disk, torus, annulus,
then expect no velocity gradients, and no
velocity offset from Vsys. And why are there
"high velocity" water masers (molecular
gas) within the Central Hole (0.1-0.2 pc western
jet) ? Is there CO in any of the velocity
systems ?
84
HI absorption line survey at the WSRT
UHF-high receivers Wideband 750-1200 MHz, 0.2 lt
z lt 0.9.
Interferometer superior RFI rejection and
spectral calibration.
Multi-channel backend IVC/DZB superior RFI
rejection
and velocity
resolution. Up to 1024 channels for all
baselines in 2 polarisations.
85
HI absorption line survey at the WSRT
Papers Vermeulen et al., Pihlström et al., 2003
AA in press. Sample all known compact sources
(CSO, GPS, CSS) 19 detections out of 57 targets
free of RFI at 0.2 lt z lt 0.9
86
Detection rate not flux density limited
87
Larger sources, lower column densities
N(HI) ? 1020.2 (LS)-0.33
88
Possible radial density profiles
Spherical Distribution
89
Possible radial density profiles
Dotted King profile unlikely
90
Possible radial density profiles
Dotted King profile unlikely
Solid spherical model
quite possible, best fit n ? r -1.25
91
Possible radial density profiles
Spherical Distribution
Disk
92
Possible radial density profiles
Dotted King profile unlikely
Disk model families quite possible
Solid spherical model
quite possible, best fit n ? r -1.25
93
2050364 a complex case ?
8.4 GHz
GPS at z0.35
Could this be a bent core-jet ??
Lazio Fey 2001
0.6 GHz
1.6 GHz
94
2050364 a complex case ?
Is 2050364 a Compact Double or a bent Core-Jet
source ?
0.6 GHz
Lazio Fey 2001
95
2050364 a complex case ?
1.0 GHz
8.4 GHz
Complex kinematics over several 100 pc.
0.6 GHz
1.6 GHz
96
2050364 another complex case
with A. Labiano
97
2050364 another complex case
98
0404768 absorption in a jet/cloud interaction ?
(beware the bandwidth...)
Core does not contain enough flux density for
the absorption depth ? must be ?100 pc-scale
lobe(s)
99
In disks/tori, interactions, or flows ? Infall or
outflow ?
Study individual examples
NGC 1052 at z0.005
Some CSO/GPS at higher z with UHF VLBI
Disks/tori and interactions and flows. Infall and
outflow.
In different objects
Within single objects
100
Infall or outflow disks/tori or
interaction/entrainment ?
HI observations in several nearby sources
suggested a circumnuclear, possibly toroidal or
disk-like distribution. e.g. NGC315, NGC1275,
NGC4261, Hydra-A, 4C31.04, NGC 3894,
1946708 But in several other nearby sources HI
has now also been found in jet/cloud interaction
regions (e.g. Morganti et al.)
GPS/CSS sources are unresolved with the WSRT, and
the HI absorption regions need to be imaged with
VLBI. In order to access HI at z?0.2, we have
developed VLBI at UHF frequencies on the EVN.
101
Advantages of spectroscopy with VLBI
VLBI arrays are very sensitive.
- Can combine the collecting area of the entire
Global Network.
Long baselines can circumvent RFI.
- Receivers often stay linear even with "typical
RFI". - For optimal calibration one needs
Good total power monitoring Good
uv-coverage and many stations
102
Locus of absorption PR-CSOs.
Flux-limited 6cm Pearson-Readhead of 65
sources contains 7 CSOs.
Est. ne (cm-3) 10000 10 ? - 10 - 1000
Tentative Scenario Torus Interaction ? FFA
Torus Interaction FFA Torus Torus
FWHM (km/s) 100 60 ? - 170 - 82
Name 0108388 0404768 0710439 1031567 1358
624 2021614 2352495
Est. N(H) (1020 cm-2 ) 7000 10 ? - 4 - 1000
Peak optical depth 0.44 0.014
? lt0.0048 0.006 lt0.0013 0.017