Radio counterpart of the lensed sub-mm emission in the cluster MS0451.6-0305: new evidence for the merger scenario - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Radio counterpart of the lensed sub-mm emission in the cluster MS0451.6-0305: new evidence for the merger scenario - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: SMM J04542-0301 is an extended ~1 arcmin sub-mm source located near thecore of the cluster MS0451.6-0305. It has been suggested that part of itsemission arises from the interaction between a LBG and two EROs at z~2.9 thatare multiply-imaged. However, the dramatic resolution difference between thesub-mm map and the optical-NIR images make it difficult to confirm thishypothesis. In this paper, we present a deep ~ 10 microJy-beam, highresolution ~2 arcsec 1.4 GHz radio map of the cluster core, in which we haveidentified 6 sources located within SMM J04542-0301. The strong lensing effectin the radio data has been quantified by constructing a new lens model of thecluster. The brightest and most extended of these sources RJ is located inthe middle of the sub-mm emission, and has no obvious counterpart in theoptical-NIR. Three other detections E1, E2 and E3 seem to be associated withthe images of one of the EROs. The last two detections CR1 and CR2, for whichno optical-NIR counterpart have been found, seem to constitute two relativelycompact emitting regions embedded in a ~5 arcsec extended radio source locatedat the position of the sub-mm peak. The presence of this extended component canonly be explained if it is being produced by a lensed region of dust obscuredstar formation in the center of the merger. A comparison between the radio andsub-mm data at the same resolution suggests that E1, E2, E3, CR1 and CR2 areassociated with the sub-mm emission. The radio observations provide strongobservational evidence in favor of the merger hypothesis. However, the questionif RJ is also contributing to the observed sub-mm emission remains open. Theseresults illustrate the promising prospects for radio interferometry and stronggravitational lensing to study the internal structure of SMGs.



Author: A. Berciano Alba, L.V.E. Koopmans, M.A. Garrett, O. Wucknitz, M. Limousin

Source: https://arxiv.org/







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