0 Assigned ID: 481 ----- Attempting Submission 1 (Fri Apr 05 15:32:12 GMT 2019) ----- New submission following the suggestions of my Contact Scientist of my program (Russell Ryan) 1102704370 ----- Attempting Submission 1 (Tue Jul 09 12:33:41 GMT 2019) ----- ----- Attempting Submission 2 (Thu Aug 29 20:22:04 GMT 2019) ----- The characterization of star-forming galaxies impacting cosmic reionization is one of the primary scientific drivers of future space and ground missions. With the help of deep fields, currently we can study routinely their ultraviolet (UV) continuum and Lyman-alpha emission. However, to access the properties of their interstellar medium (ISM) absorbing gas is extremely difficult. The host galaxy of the long gamma-ray burst GRB130606A at z~6 is the only very high-redshift galaxy for which the Lyman-alpha emission, the continuum and the ISM gas absorption are detected. Thanks to the absorption lines present in the GRB afterglow spectrum, it was possible to determine the neutral hydrogen content, the metallicity and dust depletion of the host galaxy ISM along the GRB line of sight. At high redshift, long GRBs are thought to be associated with the bulk of star-forming galaxies. Therefore GRB130606A provides a unique global view on the UV properties of a typical faint high-redshift star forming galaxy. Indeed its Lyman-alpha luminosity is representative of Lyman-alpha emitters at these redshifts. Nonetheless we do not have enough information on its continuum properties to assess GRB130606A host place among the high-redshift galaxy population. We ask here for 4 orbits of HST time to obtain WFC3/F105W and F160W observations, so as to be able to determine the UV spectral slope of the galaxy and compare it to that of lyman-break galaxies at the same redshift and having similar absolute magnitudes. In addition to the characterization of the galaxy itself, these data will also be used to study for the first time of the counterparts of strong MgII absorbers at z>3. The host galaxy of GRB 130606A has been detected in the F140W filter of WFC3 with a magnitude of 26.34 (AB), and is compact (only marginally resolved). The aim of these observations is to determine the colours (in particular the rest-frame UV spectral slope 'beta') through observations in F105W and F160W. We therefore do not know the precise expected magnitudes in these bands, but can estimate extrema by assuming that F_lambda is proportional to lambda^beta, and -1 < beta < -3. In 7200s exposure time in F105W we then obtain a signal to noise in the range S/N=13-23 and in F160W we find a S/N=6-8 (note that because this is for varying spectral slope a minimum in one band corresponds to a maximum in the other, which offsets error introduced because of the uncertainty in this slope). This will enable us to measure beta to an accuracy of +/-0.3. To dither we will use a 2-points line pattern with a 3-point line sub-pattern, optimizing the exposure time. S. Vergani, A. De Cia, J. Japelj, A. Levan, J. McGuire, R. Salvaterra and N. Tanvir are expert of GRBs and GRB host galaxies. S.Vergani, A. De Cia, A. Levan, N. Tanvir are co-autors of the Hartog el al. 2015 paper on the VLT/X-shooter data of GRB130606A. H. Atek and J. Richards are expert of high-redshift galaxies. I. Schroetter is expert of MgII absorbers. S. Vergani is the PI of the MUSE observations of GRB130606A field. H. Atek, A. Levan, J. Richards and N. Tanvir are great experts of HST observations, including data reduction, anlysis and interpretation. A. Levan and N. Tanvir were the PI of ~35 HST proposals and they published the data in ~40 papers. N. Tanvir was the PI of the HST WFC3/F104W observations of GRB130606A field. J. McGuire is the first author of the paper reporting the results of these observations. Galaxies and the IGM 6 false false false false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY This object was generated by the targetselector and retrieved from the SIMBAD database.This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 WFC/F140W AB magnitude: 26.34 WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F160W POS-TARG DITHER DITHER 3 5.183 WFC3-IR-DITHER-LINE-3PT false false 0.605 2 41.859 POS-TARG LINE 41.788 1 true POS-TARG DITHER DITHER 4 5.183 WFC3-IR-DITHER-BOX-MIN false 74.653 true 0.365 0.572 2 41.859 POS-TARG WFC3-IR-DITHER-BLOB 18.528 2 true 1567109811978 /private/var/folders/hb/1jq88fr91ss5gm29xnn8z9300000gp/T/OPVisit6910975131191531932.xml The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15958 :visit-id "01" :proposal-version -1 :trans-version "20190514" :date "29-Aug-2019 22:16:51.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1044528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15958 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15958 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2575 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2928 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15958 :visit-id "01" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2575 :al-overhead-at-end 0 :internal-dur-at-end 234 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2928 :pcs-gap 0 ) true 2 0 1567109814046 /private/var/folders/hb/1jq88fr91ss5gm29xnn8z9300000gp/T/OPVisit5408874544886216381.xml The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15958 :visit-id "02" :proposal-version -1 :trans-version "20190514" :date "29-Aug-2019 22:16:53.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1949792 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15958 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15958 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2640 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3009 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15958 :visit-id "02" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2640 :al-overhead-at-end 0 :internal-dur-at-end 310 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3009 :pcs-gap 0 ) true 2 0