gravitational lensing; quasars : individual : HE 2149-2745; cosmological parameters
Abstract :
[en] 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 Omega = 0.3, Lambda = 0.7 cosmology, and a chosen analytical lens model, our time-delay measurement yields a Hubble constant of H-0 = 66+/-8 km s(-1) Mpc(-1) (1sigma error) with an estimated systematic error of +/-3 km s(-1) Mpc(-1). Using non-parametric models yields H-0 = 65+/-8 km s(-1) Mpc(-1) (1sigma 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.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Burud, I.
Courbin, F.
Magain, Pierre ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Lidman, C.
Hutsemekers, Damien ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Kneib, J. P.
Hjorth, J.
Brewer, J.
Pompei, E.
Germany, L.
Pritchard, J.
Jaunsen, A. O.
Letawe, Géraldine ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
Angonin M.C., Remy M., Surdej J., Vanderriest C. A & A 1990, 233.
Burud I., Hjorth J., Jaunsen A.O. ApJ 2000, 544:117.
Courbin F., Magain P., Kirkove M., Sohy S. ApJ 2000, 539:1136.
Courbin F., Lidman C., Meylan G., Kneib J.-P., Magain P. A & A 2000, 360:853.
Gorenstein M.V., Shapiro I.I., Falco E.E. ApJ 1988, 327:693.
Hartig G.F., Baldwin J.A. ApJ 1986, 302:64.
Hjorth J., Burud I., Jaunsen A.O. ASP Conf. Ser., Gravitational Lensing: Recent progress and future goals, ed. T. Brainerd, & C. Kochanek, in press; 2001.
Hutsemékers D. A & A 1993, 280:435.
Kinney A.L., Calzetti D., Bohlin R.C. ApJ 1996, 467:38.
Kneib J.-P., Ellis R.S., Small I., Couch W.J., Sharples R.M. ApJ 1996, 471:643.
Koopmans L.V.E., De Bruyn A.G., Xanthopoulos E., Fassnacht C.D. A & A 2000, 356:391.
Krolik J. Princeton Series in Astrophysics, Active galactic nuclei: From the central black hole to the galactic environment, ed. J. P. Ostriker (Princeton University Press); 1999.
Kurtz M.J., Mink D.J. PASP 1998, 110:934.
Lidman C., Courbin F., Kneib J.-P. A & A 2000, 364.
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.