We present Multi Unit Spectroscopic Explorer (MUSE) observations in the core of the Hubble Frontier Fields (HFF) galaxy cluster MACSJ1149.5+2223 where the first magnified and spatially resolved multipleimages of supernova (SN) “Refsdal” at redshift 1.489 weredetected. Thanks to a Director's Discretionary Time program with theVery Large Telescope and the extraordinary efficiency of MUSE wemeasure 117 secure redshifts with just 4.8 hr of total integration timeon a single 1 arcmin^2 target pointing. We spectroscopicallyconfirm 68 galaxy cluster members with redshift values ranging from0.5272 to 0.5660 and 18 multiple images belonging to seven backgroundlensed sources distributed in redshifts between 1.240 and 3.703.Starting from the combination of our catalog with those obtained fromextensive spectroscopic and photometric campaigns using the Hubble SpaceTelescope (HST) we select a sample of 300 (164 spectroscopic and 136photometric) cluster members within approximately 500 kpc from thebrightest cluster galaxy and a set of 88 reliable multiple imagesassociated with 10 different background source galaxies and 18 distinctknots in the spiral galaxy hosting SN “Refsdal.” We exploitthis valuable information to build six detailed strong-lensing modelsthe best of which reproduces the observed positions of the multipleimages with an rms offset of only 0.″26. We use these models toquantify the statistical and systematic errors on the predicted valuesof magnification and time delay of the next emerging image of SN“Refsdal.” We find that its peak luminosity should occurbetween 2016 March and June and should be approximately 20% fainter thanthe dimmest (S4) of the previously detected images but above thedetection limit of the planned HST/WFC3 follow-up. We present ourtwo-dimensional reconstruction of the cluster mass density distributionand of the SN “Refsdal” host galaxy surface brightnessdistribution. We outline the road map toward even better strong-lensingmodels with a synergetic MUSE and HST effort.
The Story of Supernova “Refsdal” Told by Muse
Mercurio A;
2016-01-01
Abstract
We present Multi Unit Spectroscopic Explorer (MUSE) observations in the core of the Hubble Frontier Fields (HFF) galaxy cluster MACSJ1149.5+2223 where the first magnified and spatially resolved multipleimages of supernova (SN) “Refsdal” at redshift 1.489 weredetected. Thanks to a Director's Discretionary Time program with theVery Large Telescope and the extraordinary efficiency of MUSE wemeasure 117 secure redshifts with just 4.8 hr of total integration timeon a single 1 arcmin^2 target pointing. We spectroscopicallyconfirm 68 galaxy cluster members with redshift values ranging from0.5272 to 0.5660 and 18 multiple images belonging to seven backgroundlensed sources distributed in redshifts between 1.240 and 3.703.Starting from the combination of our catalog with those obtained fromextensive spectroscopic and photometric campaigns using the Hubble SpaceTelescope (HST) we select a sample of 300 (164 spectroscopic and 136photometric) cluster members within approximately 500 kpc from thebrightest cluster galaxy and a set of 88 reliable multiple imagesassociated with 10 different background source galaxies and 18 distinctknots in the spiral galaxy hosting SN “Refsdal.” We exploitthis valuable information to build six detailed strong-lensing modelsthe best of which reproduces the observed positions of the multipleimages with an rms offset of only 0.″26. We use these models toquantify the statistical and systematic errors on the predicted valuesof magnification and time delay of the next emerging image of SN“Refsdal.” We find that its peak luminosity should occurbetween 2016 March and June and should be approximately 20% fainter thanthe dimmest (S4) of the previously detected images but above thedetection limit of the planned HST/WFC3 follow-up. We present ourtwo-dimensional reconstruction of the cluster mass density distributionand of the SN “Refsdal” host galaxy surface brightnessdistribution. We outline the road map toward even better strong-lensingmodels with a synergetic MUSE and HST effort.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
