X-ray and optical detection of the radio bent jet in 3C 17

Radio Galaxies in the Chandra Era

F. Massaro&

D. E. Harris, M. Chiaberge, P. Grandi, F. D. Macchetto, S. A. Baum, C. P. O‘Dea, A. Capetti

X-ray jets in the Chandra archive

3C 273 (Marshall et al. 2001)

PKS 1127-145 (Siemiginowska et al. 2002)

3C 327 (Hardcastle et al. 2007) 3C 321 (Evans et al. 2007)

X-ray jets in the Chandra archive

Centaurus A (Kraft et al. 2002)

PKS 1354+195 (Sambruna et al. 2002)

and a lot of other examples may be foundon the www-hea.harvard.edu/XJET webpage (see Cheung poster at this conference for details)

Radio bent jets detected in X-rays

PKS 0637-752 (Schwartz et al. 2000)

3C 120 (Harris et al. 1999)

0827+243 (Jorstad et al. 2004)

3C Chandra snapshot at z<0.3

3C 105

(see Massaro et al. poster at this conference for details)

3C 332

3C 171

8 ksec of exposure!!!

The case of 3C 17: X-ray detection

z ~ 0.22 ---> 1’’ ~ 3.5 kpc 8 ksec of exposure!!!

The case of 3C 17: radio morphology L band --> 1.4 GHz

U band15 GHz

C band --> 4.5 GHz(Morganti et al. 1999)

VLBI observations show that inner jet and the large scale one are aligned.(Giovannini et al. in prep.)

The case of 3C 17: radio classification

FR II

3C 17

FR I BLRGFR I vs FRII ??

Laing et al. 2007

QuickTime™ e undecompressore TIFF (Non compresso)

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(Pradio) vs (V Mag) plot(Owen et al. 1984)

Lradio ~ 26.9 Watt/sM ~ -19.1

Synchrotron model

Parameters:- magnetic field ---> (Hp. equipartition)- electron distribution = slope and Lorentz factor ---> (Hp. Power-law)- electron density and Volume (measured) = electron number- beaming factor ---> (Hp. Set to 1, no beaming)

The knot 3.7’’

Synchrotron model can describe the spectrum of k37under the assumption of equipartition.

The knot 11.3’’

The X-ray spectrum cannot be explained using asynchrotron or a IC/CMB model.

The rise of the spectrum could be a feature ofbent jets (see also 3C 120, Harris et al. 2001)

Similarities to 3C 120

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QuickTime™ e undecompressore TIFF (Non compresso)

sono necessari per visualizzare quest'immagine.

3C 120

Zoom of 3C 120

3C 17

3C 17

3C 120 spectrum

Harris et al. 2004

The IR-optical-UV HST imagesInfrared

The IR-optical-UV HST images

Optical

The linear object

1. This object could be a foreground or a background galaxy

2. This emitting region could arise form the interaction of the jet and some other pre-existing entity (e.g. HI cloud).

3. This emitting region could come from as yet unknown property of the jet (e.g. a transition region from a jet dominated by Poynting flux to electrons).

4. This source could be an edge on spiral galaxy and it is a companion of 3C 17.

Conclusions and open questions

F. Massaro et al. 2008 ApJ in prep.

- During the 3C Chandra snapshot radio galaxies program at z<0.3 we detected the X-ray emission from two knots in the bent jet in 3C 17.

- A linear object at about 7’’ has been detected in the IR-to-UV HST images

- The emission of the knot at 11.3’’ seems to have a different behaviour in the X-rays. FLAT spectrum where the jet is curving!!! (A deeper X-ray observation needed)

- The emission of the knot at 3.7’’ can be described in terms of synchrotron radiation assuming the equipartition between particle and magnetic field.

This source is peculiar because:- it is perpendicular to the radio jet- it lies at the beginning of the radio jet- There is no emission of the jet before its location- There is a “hole” in the optical HST image

Acknoledgments and creditsWe thank A. Siemiginowska and J. Mc Dowell for her help in the use of the Chandra CIAO data reduction analysis software.

We are grateful to R. Morganti for giving us her VLA map of 3C~17.

F. Massaro is grateful to G. Migliori and S. Bianchi for their suggestions in theChandra data analysis, and to E. Liuzzo and S. Giacintucci for the VLAData reduction suggestions.

This research has made use of the NASA/IPACExtragalactic Database (NED) which is operated by the Jet PropulsionLaboratory, California Institute of Technology, under contract withthe National Aeronautics and Space Administration.

This research has made use of NASA's Astrophysics Data System and SAOImageDS9, developed by the Smithsonian Astrophysical Observatory.

The work at SAO is supported by NASA-GRANT GO8-9114A.