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Microlensing results from APO monitoring of the double quasar Q0957+561A,B between 1995 and 1998

Joachim Wambsganss·Robert W. Schmidt·Wesley N. Colley·Tomislav Kundic·Edwin L. Turner
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Abstract

If the halo of the lensing galaxy 0957+561 is made of massive compact objects (MACHOs), they must affect the lightcurves of the quasar images Q0957+561 A and B differently. We search for this microlensing effect in the double quasar by comparing monitoring data for the two images A and B - obtained with the 3.5m Apache Point Observatory from 1995 to 1998 - with intensive numerical simulations. This way we test whether the halo of the lensing galaxy can be made of MACHOs of various masses. We can exclude a halo entirely made out of MACHOs with masses between 10e(-6) Msun and 10e(-2) Msun for quasar sizes of less than 3*10e(14)cm (h = 0.6), hereby extending previous limits upwards by one order of magnitude.

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Joachim Wambsganss, Robert W. Schmidt, Wesley N. Colley, Tomislav Kundic, Edwin L. Turner. 2000-10-12. Microlensing results from APO monitoring of the double quasar Q0957+561A,B between 1995 and 1998. https://arxiv.org/abs/astro-ph/0010232

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