Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2009-05-08
Astrophys.J. 697:1010-1019,2009
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Scientific paper
10.1088/0004-637X/697/2/1010
The four-image gravitationally lensed quasar QSO 2237+0305 is microlensed by stars in the lens galaxy. The amplitude of microlensing variability can be used to infer the relative size of the quasar as a function of wavelength; this provides a test of quasar models. Toward this end, we present Spitzer Space Telescope Infrared Spectrograph and Infrared Array Camera (IRAC) observations of QSO 2237+0305, finding the following. (1) The infrared (IR) spectral energy distribution (SED) is similar to that of other bright radio-quiet quasars, contrary to an earlier claim. (2) A dusty torus model with a small opening angle fits the overall shape of the IR SED well, but the quantitative agreement is poor due to an offset in wavelength of the silicate feature. (3) The flux ratios of the four lensed images can be derived from the IRAC data despite being unresolved. We find that the near-IR fluxes are increasingly affected by microlensing toward shorter wavelengths. (4) The wavelength dependence of the IRAC flux ratios is consistent with the standard quasar model in which an accretion disk and a dusty torus both contribute near 1 micron in the rest frame. This is also consistent with recent IR spectropolarimetry of nearby quasars.
Agol Eric
Gogarten Stephanie
Gorjian Varoujan
Kimball Amy
No associations
LandOfFree
Spitzer observations of a gravitationally lensed quasar, QSO 2237+0305 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spitzer observations of a gravitationally lensed quasar, QSO 2237+0305, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spitzer observations of a gravitationally lensed quasar, QSO 2237+0305 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-703253