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The nuclear starburst of M83
revealed with SINFONI
M83
large SAB(s)c, distance 4.5 Mpc
Liesbeth Vermaas
Paul van der Werf
(Leiden Observatory)
= optical peak
× = center K-isophotes
nuclear starburst - offset from optical nucleus
Questions: - Double nucleus? center K-isophotes
×
1. - Where is the dynamical center?
Conclusions from SINFONI data:
- dynamical nucleus offset from optical peak by 3″
- no mass concentration detected at dynamical nucleus
- mass of optical peak ~108 M (dynamics)
K-band isophotes
(Thatte et al. 2000)
VLT/SINFONI: near-IR 1-2.5 μm
integral field spectroscopy
M83: nuclear starburst
3 pointings in central 15''x15'' = 330x330 pc
8'' = 175 pc
Brγ
young stars
K-band
(super)giants
H2 flux
15'' = 330 pc
2''
starburst offset!
44 pc
= optical peak
Gas dynamics from H2 (2.12μm)
H2 velocity
H2 flux
×
×
(P,V) diagram
-optical peak
( ) offset
= optical
peak 3''
-from dynamical
nucleus
(×)
× = dynamical
nucleus
-inner-outer edge 2.5 - 5.0''
-from dynamical nucleus (×)
-i=24°, PA=50° and position
-adopted from CO observations
-by Sakamoto et al. 2004
velocity (km/s)
Ring in M83:
×
rotating ring
position
= optical peak
× = dynamical nucleus
Stellar dynamics from CO-absorption (2.29μm)
stellar velocity [-80,80] km/s
velocity dispersion σ [0,80] km/s
σ:
H2
NO CLEAR
PEAK!
×
×
Conclusions:
- dynamical nucleus (×) offset from optical peak ( ) by 3"
- no mass concentration detected at dynamical nucleus
- mass of optical peak ( ) ~108 M (dynamics)