0 Assigned ID: 893 ----- Attempting Submission 1 (Fri Apr 11 21:49:59 GMT 2014) ----- 0 ----- Attempting Submission 1 (Wed Jul 23 11:29:14 GMT 2014) ----- HST Phase II Proposal 13858 (HST_SLSN-R_hosts_phaseII.apt) successfully submitted. ----- Attempting Submission 2 (Tue Sep 16 07:31:36 GMT 2014) ----- The environment of the rarest and most energetic supernovae: do pair-instability explosions exist in the nearby Universe? We propose imaging of the host galaxies of super-luminous supernovae (SLSNe) of the rarest class, SLSN-R. These SNe are several magnitudes brighter than typical core-collapse SNe and their late-time light curves follow the 56Co radioactive decay. The physical process that leads to their explosion is under debate. Observationally, the more likely possibility is that SLSN-R are the product of stars with cores more massive than several tens of solar masses, that explode due to pair-production instability. However, such pair instability supernovae (PISNe) are theoretically easier to form from zero-metallicity population III stars at high redshifts, that could develop the massive cores required. Local pockets of low-metallicity gas or highly dense stellar clusters may allow PISNe to form at low redshift, but this has not been observationally confirmed. Our pilot HST program targeting a single SLSN-R (PTF10nmn) surprisingly showed it occurred well away from the host's most intense star formation, in a lower-metallicity region, up to 10 times lower than would have been measured using ground-based data alone. Here, we propose to target 4 additional SLSNe-R (out of a total of 6 events), all nearby candidate PISNe homogeneously selected from the Palomar Transient Factory wide-field survey, among thousands of classified SNe. The accurate location of these SNe with respect to their host galaxies and star-forming regions can provide invaluable information on the (typical?) environment of these events. This is crucial to both address the question of the existence of PISNe in the nearby Universe and to investigate the physical nature of these rare, extreme and debated explosions. The targets are 4 host galaxies of superluminous supernovae, each one to be observed for 1 orbit. PTF11hrq and PTF12dam are brighter (V~19.2-19.4) and we will observe them with WCF3/UVIS, with three filters (F625W, F336W and F225W). The two fainter galaxies (iPTF13dcc with V~23.6 and iPTF13ehe with 21) still host the ongoing supernova (equal in brightness or fainter than the galaxy) and we will observe them with ACS with one filter (F625W). We intend to divide each orbit in a few sub-exposures and dither them to correct for cosmic rays and bad pixels. RESOLVED STELLAR POPULATIONS Default false true false false false SUPPORTED GALAXY DWARF COMPACT STAR FORMING REGION J2000 J2000 GALAXY DWARF COMPACT STAR FORMING REGION STARBURST J2000 J2000 STAR SUPERNOVA J2000 J2000 SN still present with V~23.5 STAR SUPERNOVA J2000 J2000 V > 21, SN still present with V~21 WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F225W ACS/WFC Imaging No No F625W ACS/WFC Imaging No No F625W POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1 false POS-TARG DITHER 0.265 LINE 0.187 false false 69.05 4 20.67 ACS-WFC-DITHER-BOX 2 false /Users/al/proposals/HST/c22/PISN_c22/PHASEII/OP-cache/HST_SLSN-R_hosts_phaseII-v01.xml The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13858 :visit-id "01" :proposal-version -1 :trans-version "20140605" :date "21-Jul-2014 15:08:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 422320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13858 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13858 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2908 :al-overhead-at-end 172 :internal-dur-at-end 498 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3241 :pcs-gap 0 ) true 1 0 /Users/al/proposals/HST/c22/PISN_c22/PHASEII/OP-cache/HST_SLSN-R_hosts_phaseII-v02.xml The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13858 :visit-id "02" :proposal-version -1 :trans-version "20140605" :date "21-Jul-2014 15:08:45.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 422320 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13858 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13858 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3025 :al-overhead-at-end 172 :internal-dur-at-end 498 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3358 :pcs-gap 0 ) true 1 0 /Users/al/proposals/HST/c22/PISN_c22/PHASEII/OP-cache/HST_SLSN-R_hosts_phaseII-v03.xml The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13858 :visit-id "03" :proposal-version -1 :trans-version "20140605" :date "15-Sep-2014 15:49:26.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13858 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13858 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2889 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3222 :pcs-gap 0 ) true 1 0 /Users/al/proposals/HST/c22/PISN_c22/PHASEII/OP-cache/HST_SLSN-R_hosts_phaseII-v04.xml The scheduling data was generated by CASM 22.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 13858 :visit-id "04" :proposal-version -1 :trans-version "20140605" :date "15-Sep-2014 16:06:48.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13858 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13858 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3239 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3572 :pcs-gap 0 ) true 1 0