Spiral arms: trailing vs. leading
(from Binney & Tremaine, GD)
Swing amplification
(Toomre 1981)
(from Binney & Tremaine, GD)
Multiple spiral patterns
(Elmegreen et al. 1992)
Credit: M81: Stefan Seip/Adam Block/NOAO/AURA/NSF, http://www.noao.edu/outreach/aop/observers/m81.html
NGC 2841: Peter Kukol/Adam Block/NOAO/AURA/NSF, http://www.noao.edu/outreach/aop/observers/n2841.html
Grand-design spirals vs. flocculent (stochastic) spirals
M 81 SA(s)ab NGC 2841 SA(r)b
Kinematické hustotní vlnyKinematické hustotní vlny
Dráhy plynu a hvězd v galaxiích bez příčky a s příčkou
Hvězdy Plyn
Plyn
(Combes 2003)
Bars in spiral galaxies – Příčky ve spirálních galaxiích
“normal”
(unbarred)
barred
> 2/3 (and perhaps
more than 80%) of disk
galaxies are barred
PrstencePrstence
Rings in spiral galaxiesRings in spiral galaxies
(nuclear, inner, outer)(nuclear, inner, outer)
NGC 7020 (Buta & Combes 1996)
Příčková nestabilita (bar instability)
(from Binney & Tremaine, GD)
Hohl 1971, N=100 000
5
Dvojpříčky - Double barsDvojpříčky - Double bars
(baby bars, bars-in-bars)(baby bars, bars-in-bars)
Double bar in NGC 1433Double bar in NGC 1433
((B bandB band, Buta & Combes 1996) (, Buta & Combes 1996) (H bandH band, JCA, 1997), JCA, 1997)
Nuclear ring in NGC 1097
Nuclear spiral in NGC 1365 (H-band)Nuclear spiral in NGC 1365 (H-band)
(JCA 1997)
Interakce galaxií