origin of warm absorbers in ngc 7469

Origin of Warm Absorbers in NGC 7469

Sudip Chakraborty

TIFR

January 21, 2016

In collaboration with: Prof. A. R. Rao, TIFR and Prof. Smita Mathur, OSU

Sudip Chakraborty (TIFR) Origin of Warm Absorbers in NGC 7469 January 21, 2016 1 / 21

AGN: Out�ows

Image Courtesy:

bowshooter.blogspot.in

1990's (Mathur et al. [1995])

Absorption lines, blueshifted

Low velocity out�ow: WarmAbsorber (WA)

Ultra-Fast Out�ows (UFO)


Aim of the work

Origin of Warm Absorbers in NGC 7469

Thickness and geometry

Mass/energy budget

E�ect on the host galaxy (Speculative)


AGN out�ow

Figure : NGC 4051 (Krongold et al. [2007])


Motivation

AGN feedback : SMBH Host galaxy (M-σ)

Jets: possible, but only seen in ∼ 10% of all AGN

Out�ows: much more common

Mass/energy out�ow rate: needed Quantities

Distance of out�ow base from SMBH: �origin radius� of out�ow


Base radius of out�ow: degeneracy and how to break it

Photoionization equilibrium

ξ = ionizing photon �uxcne

=

´∞ν0

Lνhν

dν

4πcneR2 = Q4πcneR2

Degeneracy in ne and R

XMM-Newton

Change in continuum luminosity�nite time−→ change in absorber ξ

Equilibration time: teq ∼ 1

αne

Method: not implemented widely yet: noted example: NGC 4051(Krongold et al. [2007])


NGC 7469: light curve

0 10000 20000 30000 40000 50000 60000 70000 80000 90000

Time(s)

16

17

18

19

20

21

22

23

Rate

(countss−

1)

NGC 7469 light curve

XMM-Newton EPIC Data


NGC 7469: spectrum

10.5 2 50.01

0.1

1

norm

aliz

ed c

ount

s s−

1 ke

V−

1

Energy (keV)

NGC 7469 EPIC−pn continuum with best fit

0.1 1 10

10−4

10−3

0.01

Pho

tons

cm

−2

s−1

keV

−1

Energy (keV)

Current Theoretical Model

10.5 2 5

−2

0

2

4

(dat

a−m

odel

)/er

ror

Energy (keV)

Square root of chi−squared for each channel

17

18

19

20

21

22

23

Rate

(counts/s)

NGC 7469 light curve

18

19

20

21

22

23

Rate

(counts/s)

selected points

0 10000 20000 30000 40000 50000 60000 70000 80000 90000

Time(s)

2

1

0

1

2

3

4

log(ξ)

log(ξ)

Time resolved spectroscopy of NGC 7469 Warm Absorber


Absorption Measure Distribution (AMD)

AMD =dNH

d(log ξ)

Two distinct phase:

High Ionization Phase (HIP)Low Ionization Phase (LIP)

Similar distinct phases observedbefore (Holczer et al.[2007],Blustin et al. [2007])


Calculation: neR2

ξ = Q4πcneR2

log ξ(t) = log Q(t)− log (4π c ne R2) =

log{

[C (t)/Ae� ](4πD2

)}− log

(4π c ne R

2)

HIP: neR2 ' 4.4× 1041 cm−1

LIP: neR2 ' 2.7× 1043 cm−1


txi ,x i+1

eq ∼ 1

αrec(x i ,Te)eqne× 1

[αrec(x i−1,Te)/αrec(x i ,Te)]eq + (nX i+1/nX i )

(ref: Nicastro et al. [1999])

teq

Given by: timescale shorter thanthe shortest time intervalseparating spectra with large�ux changes

HIP: teq < 7 ks

LIP: teq < 5 ks

ne

Most abundant ions: OVI−VIIIand FeXVIII−XX (Blustin et al.[2007])

HIP: nHIP > 6.2× 106 cm−3

LIP: nLIP > 8.7× 106 cm−3


Calculation: R

HIP: RHIP < 0.09 pc

LIP: RLIP < 0.57 pc

�Torus�: 0.064 pc(Suganuma et al. [2006])

NGC 7469 out�ow: �Torus� origin?

Same conclusion: Blustin et al. [2007]


Calculation: Thickness of the wind

∆R

R' 1.23NH

(neR2)1/2n1/2e

NH :

HIP: 3.8× 1021 cm−2

LIP: 2.6× 1021 cm−2

HIP: ∆RR|HIP ' 1.9× 10−3

LIP: ∆RR|LIP ' 3× 10−4

Thin wind


Mass-Energy Budget of NGC 7469: I

Mo ' 2πmp NH vr Rcos2 δ sinφ

cos(φ− δ)= 2πmp NH vr R f (φ, δ)


Mass-Energy Budget of NGC 7469: II

�� δ (° )

��

��

�

��

� (ϕ�δ )

� (ϕ �δ )= �� δ �� ϕ�� (ϕ-δ )

ϕ = ��°

ϕ = ��°

ϕ = ��°

ϕ = ��°

ϕ = ��°

ϕ = ��°

δ = 300,φ = 750,vHIP = 650 km s−1,vLIP = 2300 km s−1 (Blustinet al. [2007]), f (φ, δ) ' 1

Average mass out�ow rate:8× 10−3M� yr−1

Accretion rate:5× 10−2M� yr−1(Chiang andBlaes [2004])

Mo

Macc

' 0.15


Conclusions

1 WA out�ow in NGC 7469 might be originating from the �Torus�

2 The out�ow is geometrically thin


References

A. J. Blustin, G. A. Kriss, T. Holczer, E. Behar, J. S. Kaastra, M. J. Page,S. Kaspi, G. Branduardi-Raymont, and K. C. Steenbrugge. Themass-energy budget of the ionised out�ow in NGC 7469. A&A, 466:107�118, April 2007. doi: 10.1051/0004-6361:20066883.

J. Chiang and O. Blaes. Using Multiwavelength Observations to Estimatethe Black Hole Masses and Accretion Rates in Seyfert Galaxies. In G. T.Richards and P. B. Hall, editors, AGN Physics with the Sloan Digital Sky

Survey, volume 311 of Astronomical Society of the Paci�c ConferenceSeries, page 127, June 2004.

T. Holczer, E. Behar, and S. Kaspi. Absorption Measure Distribution of theOut�ow in IRAS 13349+2438: Direct Observation of ThermalInstability? ApJ, 663:799�807, July 2007. doi: 10.1086/518416.

Y. Krongold, F. Nicastro, M. Elvis, N. Brickhouse, L. Binette, S. Mathur,and E. Jiménez-Bailón. The Compact, Conical, Accretion-Disk WarmAbsorber of the Seyfert 1 Galaxy NGC 4051 and Its Implications forIGM-Galaxy Feedback Processes. ApJ, 659:1022�1039, April 2007. doi:10.1086/512476.

S. Mathur, M. Elvis, and B. Wilkes. Testing Uni�ed X-Ray/UltravioletAbsorber Models with NGC 5548. ApJ, 452:230, October 1995. doi:10.1086/176294.

F. Nicastro, F. Fiore, G. C. Perola, and M. Elvis. Ionized Absorbers inActive Galactic Nuclei: The Role of Collisional Ionization andTime-evolving Photoionization. ApJ, 512:184�196, February 1999. doi:10.1086/306736.

M. Suganuma, Y. Yoshii, Y. Kobayashi, T. Minezaki, K. Enya, H. Tomita,T. Aoki, S. Koshida, and B. A. Peterson. Reverberation Measurementsof the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies. ApJ,639:46�63, March 2006. doi: 10.1086/499326.


NGC 7469: e�ect of out�ow on ISM

Typical lifetime∼ 108 years

Mout ' 7.5× 105M� = 0.06×MBH

Total KE: 1

2Moutv

2 ∼ 3× 1054 erg

Too small to completely unbind the ISM

Total KE: su�cient to disrupt the hot phase of ISM

Can stop the star formation


Conclusions

1 WA out�ow in NGC 7469 might be originating from the �Torus�

2 The out�ow is geometrically thin

3 Assuming a conical out�ow geometry:

1 Total KE: too small to completely unbind the ISM

2 Total KE: su�cient to disrupt the hot phase of ISM


NGC 7469: RGS spectrum


origin of warm absorbers in ngc 7469

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