8th HEAD Meeting, 8-11 September, 2004
Session 4 Jets and Blazars
Poster, Wednesday, September 8, 2004, 9:00am-10:00pm

## [4.18] The Discovery of Extended Thermal X-ray Emission from PKS 2152-699: Evidence for a Jet-cloud' Interaction

C. Ly (Steward Obs/U. Arizona), D. S. De Young (NOAO), J. Bechtold (Steward Obs/U. Arizona)

A \emph{Chandra} ACIS-S observation of PKS 2152-699 reveals thermal emission from a diffuse region around the core and a hotspot located 10\arcsec~northeast from the core. This is one of the first detections of thermal X-ray radiation from an extragalactic radio source. Two other hotspots located 47\arcsec~north-northeast and 26\arcsec~southwest from the core were also detected. Using a Raymond-Smith model, the first hotspot can be characterized with a thermal plasma temperature of 2.6\times106~K with an electron number density of 0.03~cm-3. These values correspond to a cooling time of about 3.3\times106~yr. In addition, an emission line from the hotspot, possibly \textsc{Fe xxv}, was detected at rest wavelength 10.04Å.

The thermal X-ray emission from the first hotspot is offset from the radio emission but is coincident with optical filaments detected with broadband filters of HST/WFPC2. The best explanation for the X-ray, radio, and optical emission is that of a jet-cloud' interaction.

The diffuse emission around the nucleus of PKS 2152-699 can be modeled as a thermal plasma with a temperature of 1.2\times107~K and a luminosity of 1.8\times1041~erg~s-1. This emission appears to be asymmetric with a small extension toward Hotspot A, similar to a jet. This extended emission is likely caused by the entrainment of hot gas in the inner ISM as the jet propagates outward. This work is supported by the NASA Arizona Space Grant Program and NOAO.