Query : 1997A&A...325..877R

1997A&A...325..877R - Astronomy and Astrophysics, volume 325, 877-880 (1997/9-3)

Gravitational microlensing of large sources including shear term effects.


Abstract (from CDS):

The standard deviation δm of the variations in magnitude due to microlensing is calculated for the case when the angular radius (θs) of the source is much larger than that of the Einstein ring (θo) for the microlens, (θs≥5θo ). An external shear γ different from zero is included in the calcuations. We find that a shear term usually has the effect of reducing the value of δm, and in all cases δm is smaller than the analytical approximation for the case γ=0 given by Refsdal and Stabell (1991A&A...250...62R), (RS). Thus the approximation can still be used to estimate an upper limit of the source size if δm is available from observations. We argue that microlensing effects on the radio core of QSO 0957+561 may be of importance for the modelling of that system, and hence for the value of the Hubble parameter, even if the core radius is as large as one light year.

Abstract Copyright:

Journal keyword(s): quasars: general - quasars: individual: QSO 0957+561 - gravitational lensing

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
1 8C 0958+561 QSO 10 01 20.6918953728 +55 53 55.593949272   17.16 16.95     ~ 714 3
2 QSO B0957+5608B QSO 10 01 20.8375795656 +55 53 49.543053252   17.16 16.95     ~ 274 1
3 QSO J2240+0321 QSO 22 40 30.234 +03 21 30.63           ~ 655 1
4 Z 378-15 G 22 40 30.23447 +03 21 30.6290           ~ 629 0

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