Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2011-05-17
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
9 pages, 7 figures, PASJ accepted
Scientific paper
A careful analysis of the Suzaku data of the giant radio galaxy DA 240, of which the size is 1.48 Mpc, revealed diffuse X-ray emission associated with its east lobe. The diffuse X-ray spectrum was described with a simple power-law model with a photon index of 1.92 (-0.17+0.13) (-0.06+0.04), where the first and second errors represent the statistical and systematic ones. The agreement with the synchrotron radio photon index, 1.95 +- 0.01 in 326 -- 608.5 MHz, ensures that the excess X-ray emission is attributed to the inverse Compton emission from the synchrotron-radiating electrons, boosting up the cosmic microwave background photons. From the X-ray flux density, 51.5 +-3.9 (-5.4+6.2) nJy at 1 keV derived with the photon index fixed at the radio index, in comparison with the synchrotron radio intensity of 10.30 +- 0.12 Jy at 326 MHz, the magnetic and electron energy densities was estimated as u_m = (3.0 +-0.2 +-0.4) \times 10^(-14) ergs/cm3 and u_e = (3.4 (-0.2+0.3) (-0.4+0.5)) \times 10^(-14) ergs/cm3 integrated over the electron Lorentz factor of 10^3 -- 10^5, respectively. Thus, the east lobe is found to reside in an equipartition condition between the electrons and magnetic field parametrized as u_e/u_m = 1.1 (-0.1+0.2) (-0.2+0.4). The east lobe of DA 240 is indicated to exhibit the lowest value of u_e, among all the X-ray detected lobes of radio galaxies. A comparison of the energetics in the giant radio galaxies with a size of about 1 Mpc to those in the smaller objects suggests a possibility that radio galaxies lose their jet power, as they evolve from 100 kpc to 1 Mpc.
Isobe Naoki
Seta Hiromi
Tashiro Makoto S.
No associations
LandOfFree
Suzaku measurement of electron and magnetic energy densities in the east lobe of the giant radio galaxy DA 240 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Suzaku measurement of electron and magnetic energy densities in the east lobe of the giant radio galaxy DA 240, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suzaku measurement of electron and magnetic energy densities in the east lobe of the giant radio galaxy DA 240 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-52994