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Probing the Very Early Stage of Radio Source Evolution in NGC 1275 with VERA Hikaru Chida (Master Student)
Tokai University / NAOJ
Collaborators: Hiroshi Nagai, Mareki Honma (NAOJ),
Kyoshi Nishijima (Tokai University), Motoki Kino (KASI), Kazunori Akiyama (University of Tokyo/NAOJ),
GENJI Programme members
5.25 kpc
VLA 1.38 GHz (Pedlar + 1990)
1 kpc
VLA 1.38 GHz (Pedlar + 1990)
10 pc
VLBA 1.414 GHz (Taylor & Vermeulen 1996)
1.75 pc
VLBA 22GHz (Walker + 2000)
What is the radio galaxy NGC1275? - Central giant elliptical galaxy of the Perseus cluster
- z = 0.0176 (1 mas = 0.35 pc = 1.1×104 Rs)
When/where radio lobes were formed?
1 kpc
VLA 1.38 GHz (Pedlar + 1990)
10 pc
VLBA 1.414 GHz (Taylor & Vermeulen 1996)
1.75 pc
VLBA 22GHz (Walker + 2000)
What is the radio galaxy NGC1275? - Central giant elliptical galaxy of the Perseus cluster
- z = 0.0176 (1 mas = 0.35 pc = 1.1×104 Rs)
5.25 kpc
VLA 1.38 GHz (Pedlar + 1990)
VERA 22 GHz (Nagai + 2010)
- The jet activities have been reactivated
- New component (C3) was detected on sub-pc scales
(Nagai et al. 2010; Suzuki et al. 2011)
2007~newborn baby
- Start from Nov. 2010 - Instruments : VERA - Frequency : 22 GHz - Typical Interval : 2 weeks
Gamma-ray Emitting Notable AGN Monitoring by Japanese VLBI
We report on observations from 2011 to 2013
GENJI Programme
VLBI Monitor of γ-ray AGNs including NGC 1275 (Nagai et al. 2013)
Modified Julian DayModified Julian DayRadio flux (Jy)
Radio flux (Jy)
0
5
10
15
20
25
55600 55800 56000 56200 56400 56600
C1C320112011 20122012 20132013
C3 (new comp.) C1 (radio core)
C1 flux is almost constant. C3 flux was monotonically increased until 2011
relatively constant since 2012
Time variation in the radio flux of C3
Results (1)
Continuous injection of fresh electrons at C3 should be required. C3 is similar to that for hotspot.
C3C3(Newbown component)(Newbown component)
0.3 pc0.3 pc
2011 Jan 11 th2011 Jan 11 th
C1C1(core)(core)
1 light year1 light year
C3
vC3(app)= 0.22c +/- 0.01c
0.35 pc
C1 (radiocore)
Consistent with typical hotspot velocities of CSOs (Compact Symmetric Objects)
Motion of C3 Results (2)
Size evolution of C3 10000
10000
FWHM
of C
3(R s)
Distance from C1(Rs) 2000 25000
2007Oct.
2008Apr.
2012Sep.
expansion
expansion
constant
Results (3)
104
3×103
2.5×104 7×103
7×103
4×103
There are 2 phases 1.expansion phase 2.steady phase
steady Preliminary
We detected size evolution of newborn sources for the first time
What the nature of C3? 10000
10000
FWHM
of C
3(R s)
Distance from C1(Rs) 2000 25000
2007Oct.
2008Apr.
2012Sep.
expansion
expansion
constant
Discussion
104
3×103
2.5×104 7×103
7×103
4×103
Momentum balance Lj ∝ ρa vc3
2 * (FWHM)2
(Sheck et al. 2002, Kino&Kawakatsu 2005) Lj : total kinematic power ρa : density of interstellar medium v : C3 velocity
steady Preliminary
dece
lera
tion
(Nag
ai +
201
0)
FWHM expanding ∝ C3velocity deceleration Consistent with Hydro-Simulations.
Possible origin of long-term trend
0
10
20
30
40
50
60
70
55400 55600 55800 56000 56200 56400 56600
Fermi-Flux
GeV-γray weekly Fermi LAT
Analysis by F. D'Ammando
2011 2012 2013 γ-ra
y Fl
ux
(10
-8 p
h cm
-2 s
-1)
cos B
EGRET Fermi
radio
γ
time[year]
1970 1980 1990 2000 2010
flux
[Jy]
flux
[ph
cm-2
s-1
]
Future work
UV photonUV photon
radio(synchrotron)radio(synchrotron)
γ-ray(invers compton)γ-ray(invers compton)
mini-radio lobemini-radio lobe
Radiation from mini-radio lobe Stawarz et al. 2008
γ-ray flux have been increasing in a long-term Future work: We want to approach the relationship between radio lobe and γ-ray.
² We studied nature of C3 (10 years old). ² We observed NGC 1275 from 2011 to 2013.
(1) Flux increases C3 is hot-spot like component.
(2) Moved to the south with a velocity of ~0.2c Consistent with hotspot velocities of CSOs
(3) Size evolution of C3 was detected. Consistent with hydro-Simulations.
Summary
The hotspot and radio lobe can be formed at the immediate vicinity of the central SMBH in NGC 1275.
² γ-ray flux has been increasing from 2010 to 2013 In the future, we want to approach the relationship between mini radio lobe and γ-ray.
Thank you for the listening. Grazie mille!