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!