Open AccessA Chandra observation of the X‐ray environment and jet of 3C 31
Author(s) -
Hardcastle M. J.,
Worrall D. M.,
Birkinshaw M.,
Laing R. A.,
Bridle A. H.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05513.x
Subject(s) - physics , astrophysics , galaxy , quasar , active galactic nucleus , radio galaxy , jet (fluid) , population , particle acceleration , astronomy , spectral line , acceleration , classical mechanics , demography , sociology , thermodynamics
We have used a deep Chandra observation of the central regions of the twin‐jet Fanaroff–Riley class I (FRI) radio galaxy 3C 31 to resolve the thermal X‐ray emission in the central few kpc of the host galaxy, NGC 383, where the jets are thought to be decelerating rapidly. This allows us to make high‐precision measurements of the density, temperature and pressure distributions in this region, and to show that the X‐ray emitting gas in the centre of the galaxy has a cooling time of only 5×10 7 yr . In a companion paper, these measurements are used to place constraints on models of the jet dynamics. A previously unknown one‐sided X‐ray jet in 3C 31, extending up to 8 arcsec from the nucleus, is detected and resolved. Its structure and steep X‐ray spectrum are similar to those of X‐ray jets known in other FRI sources, and we attribute the radiation to synchrotron emission from a high‐energy population of electrons. In situ particle acceleration is required in the region of the jet where bulk deceleration is taking place. We also present X‐ray spectra and luminosities of the galaxies in the Arp 331 chain of which NGC 383 is a member. The spectrum and spatial properties of the nearby bright X‐ray source 1E 0104+3153 are used to argue that the soft X‐ray emission is mostly due to a foreground group of galaxies rather than to the background broad absorption‐line quasar.