2000A&A...357...37L


Query : 2000A&A...357...37L

2000A&A...357...37L - Astronomy and Astrophysics, volume 357, 37-50 (2000/5-1)

HST spectroscopy of the double QSO HS 1216+5032 AB.

LOPEZ S., HAGEN H.-J. and REIMERS D.

Abstract (from CDS):

We report on Hubble Space Telescope Faint Object Spectrograph observations of the double QSO HS 1216+5032 AB (ze(A)=1.455; ze(B)=1.451, and angular separation θ=9.1"). The spectral coverage is 910Å to 1340Å in the QSO rest-frame. An unusual broad-absorption-line (BAL) system is observed only in the B component: maximum outflow velocity of ∼5000km/s; probably a mixture of broad and narrow components. Observed ions are: HI, CII, CIII, NIII, NV, OVI, and possibly SIV and SVI. We also discuss two outstanding intervening systems: (1) a complex CIV system at z=0.72 of similar strength in A and B, with a velocity span of 1500km/s along the lines of sight (LOSs; LOS separation: S{perpendicular}[z=0.72]≃75 h50–1kpc); and (2) a possible strong MgII system at z=0.04 observed in B only, presumably arising in a damped Lyα system. We assume HS 1216+5032 is a binary QSO but discuss the possibility of a gravitational lens system. The size of Lyα forest clouds is constrained using S{perpendicular}≃80h50–1kpc at redshifts between z=1.15 and 1.45. Four Lyα systems not associated with metal lines and producing lines with W0>0.17Å are observed in both spectra, while five appear in only one spectrum. This sample, although scarce due to the redshift path blocked out by the BALs in B, allows us to place upper limits on the transverse cloud sizes. Modelling the absorbers as non-evolving spheres, a maximum-likelihood analysis yields a most probable cloud diameter D=256 h50–1kpc and 2σ bounds of 172<D<896 h50–1kpc. If the clouds are modelled as filamentary structures, the same analysis yields lower transverse dimensions by a factor of two. Independently of the maximum-likelihood approach, the equivalent width differences provide evidence for coherent structures. The suggestion that the size of Lyα forest clouds increases with decreasing redshift is not confirmed. Finally, we discuss two za≃ze Lyα systems observed in both QSO spectra.

Abstract Copyright:

Journal keyword(s): galaxies: quasars: absorption lines - galaxies: quasars: general - cosmology: observations - galaxies: quasars: individual: HS 1216+5032

Simbad objects: 8

goto View the references in ADS

Number of rows : 8
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 QSO B0142-100 QSO 01 45 16.5958283760 -09 45 17.265131352   17.23 16.95     ~ 236 1
2 QSO B1104-181 QSO 11 06 33.3845199936 -18 21 23.829049296   15.8 15.9 15.7   ~ 312 1
3 [BDW2002] q1104-1805a LeQ 11 06 33.50 -18 21 24.0     16.8     ~ 47 0
4 [BDW2002] q1104-1805b LeQ 11 06 33.60 -18 21 26.0     18.8     ~ 43 0
5 [VV98] J121840.6+501545 QSO 12 18 40.4894445768 +50 15 43.445554884   19.17 18.78     ~ 32 0
6 QSO B1216+5032A QSO 12 18 41.0131484904 +50 15 35.866636452   17.34 17.09     ~ 47 0
7 LB 9605 QSO 15 19 13.3574417064 +23 46 57.662641056     18.41     ~ 33 0
8 LB 9612 QSO 15 19 19.4413069176 +23 46 03.346544604   17.65 17.28     ~ 79 0

To bookmark this query, right click on this link: simbad:objects in 2000A&A...357...37L and select 'bookmark this link' or equivalent in the popup menu


2022.05.24-01:41:22

© Université de Strasbourg/CNRS

    • Contact