The Supermassive Black Hole in NGC 4258 Distance, Mass and measuring the black hole bulge mass ratio
Group 1: Rubén Herrero-Illana Joachim Janz Sara Lindgren Paulo Santos NGC 4258 (M106)
12:18:57.5 +47:18:14
7.44 Mpc
H2O megamaser
Observations VLBA
20m
NOT
Aim: Physical properties by using the water MASER Megamasers Megamasers Megamasers Megamasers Megamasers Megamasers Megamasers Very Long Baseline Array
Observations at 22 GHz Bandwidth: 16 MHz Resolution: 31.25 KHz Redshifted + Systemic masers VLBA Data Reduction
Calibration: AIPS + ParselTongue Imaging and deconvolution: CASA VLBA Data Cubes
Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level
Redshifte d VLBA Data Cubes
Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level
Systemic VLBA Results
Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level So far… so good So far… so good So far… so good 20-m single dish
Gaussian fit 15.2 ± 0.1 km/s per year 5.2 ± 0.1 km/s per year
Cross-correlation 5 km/s per year
1.6
1.4
1.2
1 ] y J [
y
t 0.8 i s n e t n
I 0.6
0.4
0.2
0
500 495 490 485 480 475 470 465 460 velocity [km/s] Result - VLBA and 20-m telescope
Velocity: 956.6 ± 99.3 km/s
Angular distance: -4.53 ± 2.18 milli-arcsec
Distance to the NGC4258: 8.51 ± 5.93 Mpc
Acceleration: 5.2 ± 0.1 km/s per year
Radius of the inner region: 0.19 ± 0.09 pc
Mass inside the inner radius: 3.98 ± 1.04 *107 M Nordic Optical Telescope
B, R, J, H and K band
M-to-L relation Bulge-disk decomposition
Calibrate with stars in the
sky frames and mag/arcsec2
1
1 1 1
1 1
1 1
2
5 4 3
7
9 8 6
compare with 2MASS 0
2
GALFIT software 0 Bulge – Sérsic fit
4
0
a
Disk – Exponential fit r
c
s
e
c
6 Integral of profile to 0 obtain the luminosity in
O
E
8
x
b
0
2
p
s
S
M
M
o the K-band in the bulge e
e
n
r
o
A
v
r
e
d
s
a
S
n
e
i
t
c
S
t
i
l
o
i
a
n
l
1
0
0 Compare with M-to-L relation from previous literature: Bell and de Jong, ApJ, 2001
• Mass-to-light ratio of ~1.3 LK vs log(Mbulge) from literature: Marconi and Hunt, ApJ, 2003
MK
1 1
1
8
9
1
1
1
1 2
0
9
.
.
-
2
1
0
.
.
.
5 5
2
5 5
5
8
-
2
7
-
2
6
-
2
5
-
2
l
4
o
g
(
B
M
)
-
2
3
-
M
2
2
a
r
c
o
-
n
2
i
1
a
n
d
-
2
H
0
u
n
t
2
-
1
0
9
0
3 Black hole to bulge mass relation
Bulge mass log(MBH)
8 9
7
6
1
9
7 8
6
.
.
. .
0
5 5
5
5
8
. 0.6*1010 M 5
M M B
9
-
.
a
R
a
r
c
n
o
d
0.3*1010 M n
H
i
9
a
.
.
n
5
d
H
u
n
1
t
0
2
0
l
0
o
3
g
1
(
b
0
M
u
.
l
5
g
)
e
1
1
1
1
.
5
1
2
1
2
.
5 Summary
This project Literature Velocity 956.6 ± 99.3 km/s 1080 ± 2 km/s Angular distance -4.53 ± 2.18 milli- -4.4 milli-arcsec arcsec Acceleration 5.2 ± 0.1 km/s per 10 km/s per year year Radius of the inner 0.19 ± 0.09 pc 0.13 pc region Distance to NGC4258 8.51 ± 5.93 Mpc 7.44 Mpc
Mass inside the inner 3.98 ± 1.04 *107 M 3.6*107 M radius Bulge mass 0.3-0.6 *1010 M 1.1 *1010 M