Reference : HST observations of the QSO pair Q1026-0045A,B
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
HST observations of the QSO pair Q1026-0045A,B
Petitjean, Patrick [Institut d'Astrophysique de Paris - CNRS, 98bis Boulevard Arago, F-75014 Paris, France; UA CNRS 173-DAEC, Observatoire de Paris-Meudon, F-92195 Meudon Principal Cedex, France]
Surdej, Jean mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Smette, Alain [NASA-Goddard Space Flight Center, Code 681, Greenbelt, MD 20771, USA]
Shaver, Peter [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen, Germany]
Muecket, Jan [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany]
Remy, Marc [Institut d'Astrophysique, Universitede Liege, Avenue de Cointe 5, B-4000 Liege, Belgium]
Astronomy and Astrophysics
EDP Sciences
Yes (verified by ORBi)
Les Ulis
[en] The spatial distribution of the Lyalpha forest is studied using new HST data for the quasar pair Q 1026-0045 A and B at z_em = 1.438 and 1.520 respectively. The angular separation is 36 arcsec and corresponds to transverse linear separations between lines of sight of ~ 300h(-1}_{50) kpc (q_o = 0.5) over the redshift range 0.833 < z < 1.438. From the observed numbers of coincident and anti-coincident Lyalpha absorption lines, we conclude that, at this redshift, the Lyalpha structures have typical dimensions of ~ 500h(-1}_{50) kpc, larger than the mean separation of the two lines of sight. The velocity difference, Delta V, between coincident lines is surprisingly small (4 and 8 pairs with Delta V < 50 and 200 km s(-1) respectively). Metal line systems are present at z_abs = 1.2651 and 1.2969 in A, z_abs = 0.6320, 0.7090, 1.2651 and 1.4844 in B. In addition we tentatively identify a weak Mg ii system at z_abs = 0.11 in B. It is remarkable that the z_abs = 1.2651 system is common to both lines of sight. The system at z_abs = 1.4844 has strong O vi absorption. There is a metal-poor associated system at z_abs = 1.4420 along the line of sight to A with complex velocity profile. We detect a strong Lyalpha absorption along the line of sight to B redshifted by only 300 km s(-1) relatively to the associated system. It is tempting to interpret this as the presence of a disk of radius larger than 300h(-1}_{50) kpc surrounding quasar A. Based on observations obtained with the NASA/ESA Hubble Space Telescope by the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555
Researchers ; Professionals
The authors thank SAO/NASA ADS Astronomy Abstract Service for their deposit authorization and EDP Sciences for the publication

File(s) associated to this reference

Fulltext file(s):

Open access
Petitjean_A&A_1998_334_L45_L48.pdfPublisher postprint163.88 kBView/Open

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.