2002A&A...383...71B


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.28CET05:59:44

2002A&A...383...71B - Astronomy and Astrophysics, volume 383, 71-81 (2002/2-3)

An optical time-delay for the lensed BAL quasar HE 2149-2745.

BURUD I., COURBIN F., MAGAIN P., LIDMAN C., HUTSEMEKERS D., KNEIB J.-P., HJORTH J., BREWER J., POMPEI E., GERMANY L., PRITCHARD J., JAUNSEN A.O., LETAWE G. and MEYLAN G.

Abstract (from CDS):

We present optical V and i-band light curves of the gravitationally lensed BAL quasar HE 2149-2745. The data, obtained with the 1.5 m Danish Telescope (ESO-La Silla) between October 1998 and December 2000, are the first from a long-term project aimed at monitoring selected lensed quasars in the Southern Hemisphere. A time delay of 103±12 days is determined from the light curves. In addition, VLT/FORS1 spectra of HE 2149-2745 are deconvolved in order to obtain the spectrum of the faint lensing galaxy, free of any contamination by the bright nearby two quasar images. By cross-correlating the spectrum with galaxy-templates we obtain a tentative redshift estimate of z=0.495±0.01. Adopting this redshift, a Ω=0.3, Λ=0.7 cosmology, and a chosen analytical lens model, our time-delay measurement yields a Hubble constant of H0=66 ±8km/s/Mpc (1σ error) with an estimated systematic error of ±3km/s/Mpc. Using non-parametric models yields H0=65±8km/s/Mpc (1σ error) and confirms that the lens exhibits a very dense/concentrated mass profile. Finally, we note, as in other cases, that the flux ratio between the two quasar components is wavelength dependent. While the flux ratio in the broad emission lines - equal to 3.7 - remains constant with wavelength, the continuum of the brighter component is bluer. Although the data do not rule out extinction of one quasar image relative to the other as a possible explanation, the effect could also be produced by differential microlensing by stars in the lensing galaxy.

Abstract Copyright:

Journal keyword(s): gravitational lensing - quasars: individual: HE 2149-2745 - cosmological parameters

Simbad objects: 7

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Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 8C 0958+561 QSO 10 01 20.6915852239 +55 53 55.595776916   17.16 16.95     ~ 701 3
2 QSO B1104-181 QSO 11 06 33.39 -18 21 23.8   15.8 15.9 15.7   ~ 302 1
3 QSO B1115+080A QSO 11 18 16.951 +07 45 58.23   16.61 16.44     ~ 627 2
4 QSO J1415+1129 QSO 14 15 46.25 +11 29 43.4   17.63 17.23     ~ 599 1
5 QSO B1600+4344 QSO 16 01 40.4818 +43 16 47.394   22.12 21.92     ~ 177 1
6 NVSS J160914+653229 rG 16 09 13.96 +65 32 28.8     19.4     ~ 192 1
7 QSO B2149-2745 QSO 21 52 07.4534 -27 31 49.718   18.70 18.39     ~ 97 2

    Equat.    Gal    SGal    Ecl

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2020.10.28-05:59:44

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