We have studied a spectrum of Q0122+0338 (z(e) similar to 1.202) obtained by the Faint Object Spectrograph (FOS) on board the Hubble Space Telescope (HST). We present the analysis of three associated (z(a) similar to z(e)) absorption systems at z = 1.207, 1.199, and 1.166. The most complex of these, at z(a) similar to 1.207, shows strong absorption from the highly ionized transitions of Ly alpha, Ly beta, N v, O VI, Si III, Si IV, and possibly P v. We derive (minimal) ionic column densities for this system of N(H I) = 10(15.3) cm(-2), N(N V) = 10(14.8) cm(-2), N(O VI) = 10(15.4) cm(-2), N(Si III)= 1013.3 cm(-2), and N(Si III) = 10(13.7) cm(-2). BY comparing the derived column densities with those predicted from numerical photoionization models, we find that conditions in the absorbing gas are consistent with an absorber with a metallicity similar to 2 Z. and a total absorbing column density of N(H) similar or equal to 2 x 10(19) cm(-2). The kinematics of the absorption lines in the z(a) similar to 1.207 system suggests that a correlation exists between the relative velocity and the creation ionization potential energy for each transition. This is evidence that a complex, multicomponent absorber exists. Although the location of the absorber is uncertain (intrinsic vs. intervening), we consider the origin of this absorption system using the available data and discuss how the high ionization and high metallicity indicate that the absorber may be intrinsic to Q0122+0338.
Hubble space telescope observations of the associated absorption-line systems in Q0122+0338
Savaglio S.Membro del Collaboration Group
;
2000-01-01
Abstract
We have studied a spectrum of Q0122+0338 (z(e) similar to 1.202) obtained by the Faint Object Spectrograph (FOS) on board the Hubble Space Telescope (HST). We present the analysis of three associated (z(a) similar to z(e)) absorption systems at z = 1.207, 1.199, and 1.166. The most complex of these, at z(a) similar to 1.207, shows strong absorption from the highly ionized transitions of Ly alpha, Ly beta, N v, O VI, Si III, Si IV, and possibly P v. We derive (minimal) ionic column densities for this system of N(H I) = 10(15.3) cm(-2), N(N V) = 10(14.8) cm(-2), N(O VI) = 10(15.4) cm(-2), N(Si III)= 1013.3 cm(-2), and N(Si III) = 10(13.7) cm(-2). BY comparing the derived column densities with those predicted from numerical photoionization models, we find that conditions in the absorbing gas are consistent with an absorber with a metallicity similar to 2 Z. and a total absorbing column density of N(H) similar or equal to 2 x 10(19) cm(-2). The kinematics of the absorption lines in the z(a) similar to 1.207 system suggests that a correlation exists between the relative velocity and the creation ionization potential energy for each transition. This is evidence that a complex, multicomponent absorber exists. Although the location of the absorber is uncertain (intrinsic vs. intervening), we consider the origin of this absorption system using the available data and discuss how the high ionization and high metallicity indicate that the absorber may be intrinsic to Q0122+0338.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.