APM 08279+5255: Keck near- and mid-infrared high-resolution imaging

Citation
E. Egami et al., APM 08279+5255: Keck near- and mid-infrared high-resolution imaging, ASTROPHYS J, 535(2), 2000, pp. 561-574
Citations number
35
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
535
Issue
2
Year of publication
2000
Part
1
Pages
561 - 574
Database
ISI
SICI code
0004-637X(20000601)535:2<561:A0KNAM>2.0.ZU;2-5
Abstract
We present Keck high-resolution near-IR (2.2 mu m; FWHM similar to 0."15) a nd mid-IR (12.5 mu m; FWHM similar to 0."4) images of APM 08279 + 5255, a z = 3.91 IR-luminous broad absorption line quasi-stellar object with a prodi gious apparent bolometric luminosity of 5 x 10(15) L., the largest known in the universe. The K-band image shows that this system consists of three co mponents, all of which are likely to be the gravitationally lensed images o f the same background object, and the 12.5 mu m image shows a morphology co nsistent with such an image configuration. Our lens model suggests that the magnification factor is similar to 100 from the rest-frame UV to mid-IR, w here most of the luminosity is released. The intrinsic bolometric luminosit y and IR luminosity of APM 08279 + 5255 are estimated to be 5 x 10(13) L. a nd 1 x 10(13) L., respectively. This indicates that APM 08279 + 5255 is int rinsically luminous, but it is not the most luminous object known. As for i ts dust contents, little can be determined with the currently available dat a because of the uncertainties associated with the dust emissivity and the possible effect of differential magnification. We also suggest that the len sing galaxy is likely to be a massive galaxy at z similar to 3.