The Origins of Short Gamma-Ray Bursts

Asking for ToO on GRB 100816a ----- Attempting Submission 2 (Fri Sep 12 19:52:12 GMT 2008) ----- ----- Attempting Submission 3 (Wed Apr 22 21:16:52 GMT 2009) ----- ----- Attempting Submission 4 (Thu Sep 17 20:45:41 GMT 2009) ----- ----- Attempting Submission 5 (Tue Aug 17 03:04:05 GMT 2010) ----- ----- Attempting Submission 6 (Tue Aug 17 12:10:08 GMT 2010) ----- Issues have been discussed and we have cleared submitting this as is with the program coordinator. There are no new issues with the Visit S1, which is the ToO we are now asking for. The Origins of Short Gamma-Ray Bursts During the past decade extraordinary progress has been made in determining the origin of long-duration gamma-ray bursts. It has been conclusively shown that these objects derive from the deaths of massive stars. Nonetheless, the origin of their observational cousins, short-duration gamma-ray bursts (SGRBs) remains a mystery. While SGRBs are widely thought to result from the inspiral of compact binaries, this is a conjecture. SGRBs have been found in elliptical galaxies, Abell Clusters, star-forming dwarfs and even an edge-on spiral. Whether they primarily result from an old population, a young population, or rapid evolution of binaries in globular clusters remains open. Here we propose to employ two related sets of observations which may dramatically advance our understanding of short bursts. The first is a variant of a technique that we pioneered and used to great effect in elucidating the origins of long-duration bursts. We will examine a statistical sample of hosts and measure the degree to which SGRB locations trace the red or blue light of their hosts, and thus old or young stellar populations. This will allow us to study the demographics of the SGRB population in a manner largely free of the distance dependent selection effects which have so far bedeviled this field. In the second line of attack we will use two targets of opportunity to obtain extremely precise positions of up to two nearby bursts -- one on a star-forming galaxy and the other on a elliptical. Observation of the star-formation galaxy could link at least some bursts directly to a young population; however, a discovery in later images of a globular cluster at the site of the explosion in an elliptical would provide revolutionary evidence that SGRBs are formed from compact binaries.

We propose to observe SGRB hosts where the location of the GRB is known to better than 0.2. In practice, these are GRBs with optical transients (OTs). The sample is derived from GRBs discovered since our last successful proposal, GO 11176, as well as two nearby GRBs which would be followed as ToOs. The positions of the last year’s GRBs have been obtained by early ground-based imaging, or in one case by a detection using the optical camera on Swift. Where we have VLT or Gemini detections of the optical transient, past experience shows we should be able to obtain relative astrometry between the ground and HST better than 0.05. The optical transient of GRB 070429B was only detected by the telescope on Swift. In this case, after taking an image with the CTIO 4-m to transfer the UVOT image to HST, we expect to have relative astrometry better than 0.2. The position of the optical transient of 070714B is from its discovery observations at the Liverpool Telescope. Here too our errors will be better than 0.2. Of course in the case of the ToOs (discussed in greater detail later) we should know the position of the GRB to better than an HST pixel. We will image all of last year’s hosts, and the star-forming ToO host, in “blue” and “red” filters. In cases where a redshift is known, we have chosen filters that will straddle the 4000 Å break. In other cases (primarily cases where the host magnitude is > 25), we have assumed that the redshift is comparable to or greater than one, and have chosen filters which should assure our two bands lie on opposite sides of the 4000 Å break. We will reach a SNR of 1.0 per pixel at 24 Vega mags per square arc-second in F160W in one orbit (about 25.6 mags AB) and 24.5 Vegamags in two orbits (we gain slightly over root two, as we use four dithers in both observations). Single orbits in F438W and F475W will reach a SNR of 1 per pixel at 24, and 24.7 B mag per square arc-second. The host of 071227, on which F438W must be used, is quite bright, so this depth should easily be sufficient. Similarly, two orbits of F606W on ACS will obtain a SNR of 1 on a (larger) ACS pixel at 25.2 R mag per square arc-second. COSMOLOGY 12 false 0.0 1.0 false false false false false false SUPPORTED GALAXY STAR FORMING REGION UNDESIGNATED R = 23.2 J2000 21 52 3.6800 -38 49 43.60 J2000 GALAXY UNDESIGNATED R = 27 J2000 17 50 58.5500 -68 55 27.20 J2000 GALAXY STAR FORMING REGION UNDESIGNATED R = 24.6 J2000 03 51 22.2300 +28 17 50.80 J2000 GALAXY ELLIPTICAL UNDESIGNATED R = 25 J2000 13 35 4.5500 -22 08 30.80 J2000 GALAXY STAR FORMING REGION UNDESIGNATED R = 19.3 J2000 03 52 31.2600 -55 59 3.50 J2000 GALAXY UNDESIGNATED J2000 00 00 0.0000 +00 00 0.00 J2000 GALAXY UNDESIGNATED J2000 00 00 0.0000 +00 00 0.00 J2000 EXT-STAR GAMMA RAY BURSTER J2000 00 00 0.0000 +00 00 0.00 J2000 WFC3/UVIS Imaging No No F475W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F606W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F475W WFC3/IR Imaging No No F160W ACS/WFC Imaging No No F606W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F438W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F438W WFC3/IR Imaging No No F160W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F606W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1

false

POS-TARG DITHER 0.265 LINE 0.187 false false 69.05 4 20.67 ACS-WFC-DITHER-BOX 2

false

POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 3

false

POS-TARG DITHER 0.604 LINE false false 3 41.788 WFC3-IR-DITHER-LINE 4

false

The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013860434 1272244375000 243.7581832027028 (Tic-Visit :proposal-id 11669 :visit-id "01" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:39.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2129856 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3024 :al-overhead-at-end 0 :internal-dur-at-end 65 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3088 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3301 :pcs-gap 0 ) true 2 2 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013861339 1277386469000 6.816752491152101 (Tic-Visit :proposal-id 11669 :visit-id "02" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:41.0" :trans-errors '(:WARNINGS 1 :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 1114160 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3302 :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 3599 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3302 :al-overhead-at-end 0 :internal-dur-at-end 179 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3599 :pcs-gap 0 ) true 2 1 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013862538 1250451497000 258.74761956795123 (Tic-Visit :proposal-id 11669 :visit-id "03" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:42.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1990592 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2863 :al-overhead-at-end 0 :internal-dur-at-end 65 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3072 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 2 1 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013866452 1273317920000 64.2441763734939 (Tic-Visit :proposal-id 11669 :visit-id "04" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:46.0" :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 1044512 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2902 :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 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2902 :al-overhead-at-end 0 :internal-dur-at-end 711 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 2 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013867689 1276284360000 200.09356418474925 (Tic-Visit :proposal-id 11669 :visit-id "05" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:47.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2129856 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3024 :al-overhead-at-end 0 :internal-dur-at-end 65 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3511 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "05" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3292 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3511 :pcs-gap 0 ) true 2 1 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013868660 1277917089000 14.837532710767192 (Tic-Visit :proposal-id 11669 :visit-id "06" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:48.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1421120 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3274 :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 3599 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "06" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3392 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3599 :pcs-gap 0 ) true 2 2 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013869555 1249837447000 115.26038738115398 (Tic-Visit :proposal-id 11669 :visit-id "07" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:49.0" :trans-errors '(:WARNINGS 2 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1421120 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "07" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2946 :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 3249 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "07" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3062 :al-overhead-at-end 0 :internal-dur-at-end 349 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3249 :pcs-gap 0 ) true 2 2 Timing link suitability includes constraints ([09 After 08 by at least 60.0 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013870388 (Tic-Visit :proposal-id 11669 :visit-id "08" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:50.0" :trans-errors '(:WARNINGS 1 :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 1443744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "08" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2902 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 1 This is a rapid Target of Opportunity observation. Timing link suitability includes constraints ([09 After 08 by at least 60.0 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013872306 (Tic-Visit :proposal-id 11669 :visit-id "09" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:51.0" :trans-errors '(:WARNINGS 1 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 3434368 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "09" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2863 :al-overhead-at-end 0 :internal-dur-at-end 65 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "09" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3013 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "09" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3012 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 3 1 This is a Target of Opportunity follow up observation. We will probably want to schedule it about a year after we trigger observations on the rapid Target of Opportunity visit 8. Timing link suitability includes constraints ([11 After 10 by at least 60.0 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013873189 (Tic-Visit :proposal-id 11669 :visit-id "10" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:52.0" :trans-errors '(:WARNINGS 1 :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 1443744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "10" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2902 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 1 This is a rapid Target of Opportunity observation. Timing link suitability includes constraints ([11 After 10 by at least 60.0 days]) The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. 1282013874415 (Tic-Visit :proposal-id 11669 :visit-id "11" :proposal-version -1 :trans-version "20100505" :date "16-Aug-2010 22:57:53.0" :trans-errors '(:WARNINGS 4 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 2598704 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "11" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2902 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "11" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3014 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "11" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3014 :al-overhead-at-end 116 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11669 :visit-id "11" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3014 :al-overhead-at-end 116 :internal-dur-at-end 354 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 4 4 This is a Target of Opportunity follow up observation. We will probably want to schedule it about a year after we trigger observations on the rapid Target of Opportunity visit 10. The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /private/var/folders/U7/U7EpVZ9NHJe91f-zXie+mk++4y2/-Tmp-/OPVisit7666293826454135878.xml 1282046877461 ToO Observation of GRB 100816a based on Visit 8 (Tic-Visit :proposal-id 11669 :visit-id "S1" :proposal-version -1 :trans-version "20100505" :date "17-Aug-2010 08:07:57.0" :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 1443744 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11669 :visit-id "S1" :obset-id "S1" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11669 :visit-id "S1" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :al-overhead-at-end 116 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 1 0 This is a rapid Target of Opportunity observation.