dwarf galaxies in the canes venatici cloud
DESCRIPTION
Dwarf galaxies in the Canes Venatici Cloud. Roman UKLEIN, Dmitry MAKAROV and Lidia MAKAROVA SAO RAS, Russia. Nizhny Arkhyz, KChR, Russia September, 14 – 18, 2009. NDG 2009. Distribution of the galaxies with V LGTRANSCRIPT
Dwarf galaxies in the Canes Venatici Cloud
Roman UKLEIN,
Dmitry MAKAROV and
Lidia MAKAROVA
SAO RAS, RussiaNizhny Arkhyz, KChR, Russia
September, 14 – 18, 2009
NDG 2009
Distribution of the galaxies with VLG<550 km/s (Local Volume)
2h4h6h8h10h12h14h16h18h20h22h
0
+90
-90
50 100 150 200 250 300 350 400 450 500
Canes VenaticiCanes Venatici
VLG, km/s
VirgoVirgo
M81M81
CenACenA
Radial velocity histogram in the CVn region
100 200 300 400 500 600 700 800 900 10000
2
4
6
8
10
12
14
16
18
VLG
N
Distribution of the galaxies in the CVn
M94
25
30
35
40
45
50
55
11.5h
12h12.5h13h13.5h
150 200 250 300 350VLG, km/s
Advanced TRGB-method (Makarov+, 2006)
-1 0 1 2 3
19
20
21
22
23
24
25
26
F606W-F814W
F81
4W
DDO 099
23.14
19 20 21 22 23 24 25 26
0
0.5
1
19 20 21 22 23 24 25 26
-1.5
-1
-0.5
0
0.5
F814W
22 22.5 23 23.5 24 24.510
1
102
103
F814W
Color-Magnitude Diagrams
-1 0 1 2 3
18
19
20
21
22
23
24
25
26
27
28
F606W-F814W
F81
4W
UGC 8215
24.17
-1 0 1 2 3
19
20
21
22
23
24
25
26
F606W-F814W
F81
4W
UGC7298
24.17
-1 0 1 2 3
18
19
20
21
22
23
24
25
26
F606W-F814W
F81
4W
NGC4449
24.14
good badgood
Distance Errors
~ 5-6% up to 25%good bad
3D structure:
View on Supergalactic plane
-0.5
0
0.5
1
1.5
2
1.5 2 2.5 3 3.5 4 4.5 5
IC4182
NGC3738
NGC4214
NGC4244
NGC4449
M94
NGC5204
Super
Gal
actic
X (M
pc)
SuperGalactic Y (Mpc)
0
0.2
0.4
0.6
0.8
1
SGZ, Mpc
Old Hubble Diagram
0 1 2 3 4 5 6 7 80
100
200
300
400
500
600
Distance (Mpc)
VLG
(km
/s)
VLG
= 72 D
0 1 2 3 4 5 6 7 80
100
200
300
400
500
600
Distance (Mpc)
VLG
(km
/s)
VLG
= 72 D
New Hubble Diagram
0 1 2 3 4 5 6 7 80
100
200
300
400
500
600
Distance (Mpc)
VLG
(km
/s)
VLG
= 72 D
Vmed
= 297 km/s
R0 ~ 1 Mpc
New Hubble Diagram
The Mass Estimation
MethodTotal Mass,
1012 Msun
Zero-Velocity Surface 2.1
Virial Theorem 4.9
Projected Mass Estimator* 2.7
Average Mass Estimator* 3.0
Median Mass Estimator* 4.6
*Heisler, Tremaine & Bahcall (1985)
~3.5~3.5
Mass-to-Luminosity ratio
M / LM / LBB ~~ 100-200100-200
LB,total = 2.3·1010Lsun
Conclusions:
• The homogeneous distances to the galaxies in the CVn I Cloud were determined using advanced TRGB method.
• We clarify the spatial structure: the cloud is divided on the core and foreground outskirt. What’s farther?
• The dynamical mass of the CVn I Cloud much the same as masses of groups like Local Group.
TT HH AA NN K K YY OO U U FF OO R R YY OO UU R R
AA TT TT EE NN TT II OO NN !!
Properties of the CVn I galaxies
D
W
A
R
F
S
M/L estimation for nearby groups
Group M/L
Milky Way/M31 121/10.1 = 12
M81/NGC 2403 169/6.1 = 28
Cen A/M83 292/7.9 = 37
CVn Cloud 300/2 = 150
Luminosity Function
-22 -20 -18 -16 -14 -12 -10 -80
1
2
3
4
5
6
7
8
Mb, mag
N
Distance-Luminosity
-20 -18 -16 -14 -12 -10 -81.5
2
2.5
3
3.5
4
4.5
5
5.5
12.513 13.514 14.515 15.516 16.517
Mb, mag
D,
Mpc
NGC 4214