27-Sept. 2001 ATNF Synthesis Workshop

Spectral Line Image Spectral Line Image Analysis Analysis and Visualizationand Visualization

BBäärbel Koribalskirbel Koribalski

(ATNF, CSIRO)(ATNF, CSIRO)

27-Sept. 2001 ATNF Synthesis Workshop

Interesting spectral Interesting spectral lines, lines, e.g.e.g.

HIHI (21-cm, 1420.405 MHz)(21-cm, 1420.405 MHz) !!! !!! = neutral atomic = neutral atomic hydrogen hydrogen

HCNHCN (3mm, 89632 MHz)(3mm, 89632 MHz) = molecular hydrogen cyanid= molecular hydrogen cyanid

SiOSiO (3mm, 86243 MHz)(3mm, 86243 MHz) = maser line= maser line

… … many, many, many moremany, many, many more

27-Sept. 2001 ATNF Synthesis Workshop

Let’s concentrate on HI :Let’s concentrate on HI : There is lots of neutral hydrogen gas There is lots of neutral hydrogen gas

in galaxies -> in galaxies -> HI is easyHI is easy to detect to detect HI traces the HI traces the large-scale structure and large-scale structure and

kinematicskinematics of galaxies of galaxies HI rotation curveHI rotation curve -> gas and total -> gas and total

massmass HI also traces HVCs and tidal gas HI also traces HVCs and tidal gas

clouds -> study clouds -> study galaxy collisionsgalaxy collisions HI emission and absorption studiesHI emission and absorption studies

27-Sept. 2001 ATNF Synthesis Workshop

1. Experiment 1. Experiment (quick and (quick and dirty)dirty)

HI snapshot observationsHI snapshot observations e.g., observe 5 galaxies for 10 min. e.g., observe 5 galaxies for 10 min.

each plus nearby phase each plus nearby phase calibrator(s)calibrator(s)

repeat 12 times to obtain 12-hour repeat 12 times to obtain 12-hour uv-coverageuv-coverage

make imagesmake images get galaxy positionsget galaxy positions

27-Sept. 2001 ATNF Synthesis Workshop

The new galaxyThe new galaxy HIPASS J1559-HIPASS J1559-61016101

27-Sept. 2001 ATNF Synthesis Workshop

The new galaxyThe new galaxy

HIPASS J1559-6101:HIPASS J1559-6101: but where is it ?but where is it ?

Optical DSS image centered on the HIPASS position

27-Sept. 2001 ATNF Synthesis Workshop

ATCA HI snapshot ATCA HI snapshot observationobservation

5 x 10 min. data

e.g. in miriad

• atlod

• uvplot

vis=my.uv axis=uu,vv options=nobasedevice=/xw

27-Sept. 2001 ATNF Synthesis Workshop

1) Find the signal !

• atlod in = *.C942 out=my.uv options=hanning,bary

• uvsplit vis=my.uv

• uvspec vis=mygal.1402 interval=1000 device=/xw options=nobase,avall

Uncalibrated HI spectrum

27-Sept. 2001 ATNF Synthesis Workshop

HI emission approx. in channels 155 - 170

27-Sept. 2001 ATNF Synthesis Workshop

2) Calibration

3) Continuum subtraction• mfcal

• gpcopy

• gpcal

• gpboot

• uvlin

Calibrated & continuum- subtracted

HI spectrum

27-Sept. 2001 ATNF Synthesis Workshop

HI emission in the velocity range 4080 - 4140 km/s

27-Sept. 2001 ATNF Synthesis Workshop

“dirty” channel maps (before cleaning)

task invert

27-Sept. 2001 ATNF Synthesis Workshop“dirty” beam

27-Sept. 2001 ATNF Synthesis WorkshopCLEANed channel maps

tasks clean & restor

27-Sept. 2001 ATNF Synthesis Workshop

HIPASS J1559-HIPASS J1559-

6101:6101: Good position, Good position, but no optical but no optical counterpart.counterpart.

ZOA

27-Sept. 2001 ATNF Synthesis Workshop

Moment mapsMoment maps … … are very are very usefuluseful

= intelligent cube compression= intelligent cube compression 0. mom0. mom = integrated HI intensity = integrated HI intensity1. mom1. mom = mean HI velocity field = mean HI velocity field2. mom2. mom = mean HI velocity dispersion = mean HI velocity dispersion -> see Chapter 12.11-> see Chapter 12.11

task task momnt momnt or or xmom xmom in in AIPSAIPS; ; task task moment moment in in MIRIADMIRIAD; etc.; etc.

27-Sept. 2001 ATNF Synthesis Workshop

Pair Pair (v_HI = 2676 (v_HI = 2676 km/s)km/s)

ATCA HI snap-shot observation

ESO122-IG002(v = 2744 km/s)

ESO122-IG001(v = 2598 km/s)

27-Sept. 2001 ATNF Synthesis Workshop

Group Group (v_HI = 2453 (v_HI = 2453 km/s)km/s)

ATCA HI snap-shot observation

NGC2222(v = 2602 km/s)

ESO161-G001(v = ?)

NGC2221(v = 2532? km/s)

27-Sept. 2001 ATNF Synthesis Workshop

2. Experiment 2. Experiment

deep HI observationsdeep HI observations e.g., observe 3 x 12 hours with e.g., observe 3 x 12 hours with

various arrays (375, 750, 1.5)various arrays (375, 750, 1.5) calibrate and combine datacalibrate and combine data find HI emission / absorption find HI emission / absorption make channel maps make channel maps (movies)(movies)

make moment maps etc.make moment maps etc.

27-Sept. 2001 ATNF Synthesis Workshop

The starburst galaxy NGC The starburst galaxy NGC 253253

bright spiral bright spiral galaxygalaxy

edge-on edge-on member of the member of the

Sculptor GroupSculptor Group large amount of large amount of

star formation in star formation in the nuclear regionthe nuclear region

27-Sept. 2001 ATNF Synthesis Workshop

NGC 253NGC 253

global HI global HI spectruspectrumm

27-Sept. 2001 ATNF Synthesis Workshop

V

E

L

O

C

I

T

Y

-200 km/s

+200 km/s

v_sys

How does the rotation curve look like ?

27-Sept. 2001 ATNF Synthesis Workshop

Radial distribution

Model velocity field: ``spider diagram’’

Rotation curve

27-Sept. 2001 ATNF Synthesis Workshop

The starburst galaxy NGC The starburst galaxy NGC 253253

HI intensity HI intensity distributiondistribution

HI velocity field (top)

27-Sept. 2001 ATNF Synthesis Workshop

NGC 253 movieNGC 253 movie (program (program krot)krot)

27-Sept. 2001 ATNF Synthesis Workshop

Channel maps of a model galaxy

Position velocity diagrams along

a) the major axis

b) the minor axis

27-Sept. 2001 ATNF Synthesis Workshop

The Circinus Galaxy: The Circinus Galaxy: channel channel mapsmaps

27-Sept. 2001 ATNF Synthesis Workshop

The Circinus GalaxyThe Circinus Galaxy

HI intensity HI intensity distributiondistribution

HI velocity field (top)

27-Sept. 2001 ATNF Synthesis Workshop

The Circinus GalaxyThe Circinus Galaxy

in ZOA, b = -4 degrin ZOA, b = -4 degr optically obscuredoptically obscured only discovered in only discovered in

1977 by K. 1977 by K. Freeman and Freeman and collaboratorscollaborators

starburst galaxystarburst galaxy active nucleusactive nucleus strong masersstrong masers

27-Sept. 2001 ATNF Synthesis Workshop

The galaxy pair The galaxy pair NGC4038/9NGC4038/9

““The Antennae’’The Antennae’’ nearby pair of nearby pair of

merging galaxiesmerging galaxies prominent tidal tails prominent tidal tails

in the optical and HIin the optical and HI star formation in the star formation in the

nuclear disksnuclear disks one companionone companion new dwarf galaxy in new dwarf galaxy in

formation formation

27-Sept. 2001 ATNF Synthesis Workshop

The galaxy pair NGC4038/The galaxy pair NGC4038/9 9

HI intensity HI intensity distributiondistribution

HI velocity field (top)

27-Sept. 2001 ATNF Synthesis Workshop

27-Sept. 2001 ATNF Synthesis Workshop

NGC7582/90/99: part of NGC7582/90/99: part of the Grus Quartettthe Grus Quartett

HI intensity HI intensity distributiondistribution

HI velocity field (top)

27-Sept. 2001 ATNF Synthesis Workshop

VX Sgr: VX Sgr: SiO maser @ 86.243 SiO maser @ 86.243 GHzGHz

ATCA – Narrabri

31 m baseline

SiO : 86.243 GHz

BW = 16 MHz

channels = 512

ATCA – Narrabri

31 m baseline

SiO : 86.243 GHz

BW = 16 MHz

channels = 512

SESTSEST

ATCAATCA

27-Sept. 2001 ATNF Synthesis Workshop

Highlight of the night !Highlight of the night ! (December 10th, (December 10th,

2000)2000)

ATCA - Narrabri

HCO+ : 89.188 GHz

BW = 32 MHz

channels = 128

31 m baseline

ATCA - Narrabri

HCO+ : 89.188 GHz

BW = 32 MHz

channels = 128

31 m baseline

HCO+ absorption in the galaxy Centaurus A

©ATCA

Cen A