Impact of a Relativistic Jet on the host galaxy environment Aneta - - PowerPoint PPT Presentation

Impact of a Relativistic Jet

• n the host galaxy environment

Aneta Siemiginowska

Harvard-Smithsonian Center for Astrophysics Tom Aldcroft (CfA) Doug Burke (CfA) Teddy Cheung (NRL) Lukasz Stawarz (JAXA) Joanna Holt (Leiden) Marek Jamrozy (Jagiellonian) Dan Evans (CfA)

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Why?

feedback

RELATIVISTIC OUTFLOWS ARE IMPORTANT!

Radio-mode feedback needed in formation of galaxies

Croton et al 2006

Too many bright galaxies if no AGN radio-mode heating

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Signatures?

Signatures of radio-ICM interactions in clusters and groups: cavities, bubbles, ripples, shocks Large Scales outside the host galaxy

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Signatures => z~0

Radar Map of the System in the central New York State Evolution of the System => moving towards Boston

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Radio Source: Sites of Interactions

5GHz VLA Radio X-ray Image

Radio source: jet, knots, hot spots, lobes X-ray source: AGN nucleus, diffuse structures, jet, knots, hot spots

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Outline

• Motivation
• Important at high redshift during the galaxy formation
• radio mode feedback - evidence in clusters
• details can be observed and study only in low redshift

galaxies

• Chandra X-ray view of a low z galaxy
• Complex morphology
• Interaction sites between the radio source and ISM
• Physical properties of the features
• What did we learn?

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Restarted Radio Galaxy

1.4GHz VLA D-array contours /DSS image. The size of the halo is ~8 arcmin (640 kpc)

OLD (>200 Myr) Large scale radio halo

Jamrozy et al 2007

YOUNG (< 33Myr) Central Radio Source

1.4GHz VLA B-array map of the central ~50 arcsec (~55 kpc) radio structure

Elliptical Galaxy with traces of a merger z=0.064, 1~arcsec=1.12 kpc HST optical image Sub-structures

FRI/FRII morphology L(radio) = 9e41 erg/s

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

X-ray View: Chandra Observations

Chandra ACIS-S 280 ksec exposure

Total number of counts in 0.5-7keV band in the entire source = 8670

X-ray/Radio

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

X-ray Emission

• Soft X-rays covers the

entire central radio source.

• Only a strong nucleus

and the southern Hot Spot visible in the Hard X-rays

Nucleus Hot Spot

Arm

Jet

Hot Spot North

South SOFT HARD

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

X-ray Morphology: Sites of interactions?

X-rays along the jet-line

Radio X-rays Core Hot Spot North South

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Velocity of [OIII] emitting gas

North South

X-rays R adio 700 km/s

blueshift

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Multi-band Summary

• Radio features occur in pairs
• X-ray peaks occur as single features
• The Southern Hot Spot is the brightest

feature in radio and X-rays.

• Radio and X-rays peaks are offsets in

the secondary features, while the strongest emission sites are aligned.

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

AGN Nucleus

• Nucleus is highly absorbed

NH = (3.95 ±0.33)x1023 cm-2

• Power law model:

Γ =1.70 (+0.38/-0.36)

• Soft component unabsorbed
• hot thermal emission:
• kT=6.8 ±2.5 keV
• X-ray luminosity corrected for

absorption: Lx(2-10keV) = 5.0±0.5 x1043erg/s Entire Central region - thermal emission with kT =0.59 ±0.04 keV

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Radio-X-ray Morphology: Jet

X-ray Jet emission is detected to the South, although the emission is not continuous, but in form of enhancements along the radio jet. The continuous emission is only visible in the central region but it is hard to disentangle it from the diffuse thermal emission of the hot gas there.

X-ray - Radio Offsets

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

X-ray/Radio

Northern Lobe

Northern Hot Spot is very soft and well fit by a thermal model with kT=0.54±0.5 keV. The Hot Spot X-ray emssion is absorbed => NH ~1021 cm-2 The X-ray luminosity corrected for absorption: Lx(0.5-2keV) = 1.7x1041 erg/s. The HS X-ray emission disappears in the hard band. The origin of this hot spot is most likely related to the jet interaction and heating of large amount of gas there. The gas is at the temperatures similar to the temperatures of the gas in the central region.

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Southern Hot Spot

• Southern Hot Spot is very

bright in X-rays.

• It is hard in contrast to the

Northern HS.

• The total X-ray luminosity:

Lx(0.5-10keV) = 1.3x1041 erg/s.

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

X-ray Properties Summary

The soft 0.5-2 keV X-ray emission spreads over the entire radio source with several emission regions: Central diffuse emission, Southern jet, Hot Spot and some diffuse emission related to the Southern Lobe. To the North the strong diffuse X-rays correspond to the Northern Radio Lobe and Hot Spot. Nucleus is highly absorbed and dominates the hard (2-7 keV) emission. We measure NH = 3.95 (0.27/-0.33) x 1023 cm-2 and a power law slope of Γ=1.70 (+0.38/-0.36) with the hard unabsorbed X-ray luminosity equal to Lx(2-10keV) = 5.0±0.5 x1043 erg/s The X-ray emission of the Northern Hot spot is very soft and well fit by a thermal model with kT=0.54±0.5 keV. The HS is also absorbed with NH ~1021 cm-2 and the unabsorbed luminosity is equal to Lx(0.5-2keV) = 1.7x1041 erg/s. The HS emission disappears in the hard

• band. The origin of this hot spot is most likely related to the jet interaction and heating of large

amount of gas there. The X-ray emission of the Southern Hot Spot is extremely bright in X-rays. It is also hard in contrast to the Northern HS. The total luminosity of this HS is equal to Lx(0.5-10keV) = 1.3x1041 erg/s. X-ray Jet emission is detected to the South, although the emission is not continuous, but in form of enhancements along the radio jet. The continues emission is only visible in the central region but it is hard to disentangle it from the diffuse thermal emission of the hot gas there.

HEPRO III Barcelona July 1, 2011 Aneta Siemiginowska

Summary and Conclusions

• X-ray emission identifies the sites of interactions between the

radio source and the ISM.

• An absorbed AGN nucleus is powering the jet. It is relatively

powerful with the unabsorbed luminosity > 5x1043 erg/s, but the accretion state of the central BH is still not clear, as the optical emission is buried within the dust.

• There is a strong morphological correspondence between the

main radio source components and the detected X-ray emission features suggesting that the radio source heats up the gas and dissipate the initial jet energy.