Mapping of HI Distribution in NGC 1530

Chu, Thomas P.-H.

Supervisor : Dinh, Van Trung

Mapping of HI Distribution in NGC 1530

• Method of Observation

• Properties of NGC 1530

• Summary

Velocity

• Doppler effect

)1('c

vff

Channel Maps

Line Profile

-0.1

0

0.1

0.2

0.3

0.4

0.5

0 10 20 30 40 50

Channel

Jy

Butterfly Pattern

Moment

• Moment 0• Intensity

• Moment 1• Intensity weighted mean velocity

• Moment 2• Velocity width

V: velocityF: fluxI: intensity

dIF

d

d

I

I=

d

d

I

I)(=

22

NGC 1530• Position

• RA=04 23 26.800 • Dec=75 17 45.000

• Velocity• 2461±140 Km/sec

• Distance• 32.8Mpc

• Mass of HI :• 1.18*1010*M_sun

• Bar Size: 2.848’• Inclination: 45 ± 5˚

HI Observational Parameters.

• Date of observation:15-AUG-1997• Length of observation: 3 hours

• Synthesized beam: 21.02” * 16.97”

• Number of channels: 63

• Channel separation: 10.47 Km/sec

Major Axis=7’

Moment 1

Moment 2

Mass

Flux: 1.20294E+06 in JY/B*M/S

= 47584.651899 JY * M/S

Distance: Hubble’s Lawv=H*Distance => 2461=75*Distance

Distance=2461/75=32.813 Mpc

=>

SUN

SUNHI

M

M)M

10

25

1018.1

Flux)(Distance(1036.2

Argument

• Rotation or Inflow?

Rotation or Inflow?

Evidence from Maps

Calculation

• Bar Length: 27.17 Kpc

• Velocity of Flow: < 10.47 km/sec

• Time : >1.2*109 years

• Universe Age: 1.5*1010 years

Summary

Calculation

• Beam size: ~20” = 3180 pc

• Velocity of Flow: < 10.47 km/sec

• Wasting time: ~2.97*108years

Optical Image

Antenna

Continuum Image

Beam

Weighting

• Natural Weighting• Dk=1 => sensitivity

• Uniform Weighting• Dk=1/Ns(k) => angular resolution

• Robust:• Between Natural and Uniform

•

Moment 0 in different Robust

R=3R=5

R=-2 R=-4

R=-4

Moment 1 in different Robust

R=3R=5

R= -4R= -2

R= -2

Phase Calibrator

Phase Calibrator