0 Assigned ID: 1471 ----- Attempting Submission 1 (Fri Mar 01 13:30:11 GMT 2013) ----- 0 ----- Attempting Submission 1 (Thu Jun 27 14:55:03 GMT 2013) ----- Unravelling the evolution and accretion morphology of an extraordinary black hole X-ray binary The process of accretion via an accretion disk is a fundamental aspect of several areas of Astrophysics. Ultraviolet (UV) observations of quiescent X-ray binaries offer the unique opportunity to study cool, gaseous accretion disks around black holes in a very low mass-accretion regime. We propose to study the quiescent accretion disk of the recently discovered Galactic black hole X-ray binary Swift J1357.2-0933, using FUV spectroscopic observations with the HST-COS. This stellar-mass black hole shares a set of properties that make it a unique target that can offer a new, unprecedented view of the quiescent accretion flow: the binary is viewed at high inclination and is located nearby (~1.6 kpc) at high Galactic latitude (b=+50 deg), which causes an unprecedented low reddening of E(B-V)=0.02 mag. Furthermore, Swift J1357.2-0933 has a very short orbital period of only ~2.8 hr, which points towards an unusual evolutionary history. The proposed HST-COS FUV spectroscopic observations will be employed to study the accretion morphology using the continuum emission, whereas the line emission patterns and abundances serve as a tracer of emission site of the UV radiation and the evolutionary stage of the binary. The cold quiescent accretion disk in LMXBs is expected to peak in the UV band, with most ionized emission lines occurring in the FUV between ~1200-1700 A. Investigation of the quiescent accretion stream in Swift J1357.2-0933 thus benefits most from spectroscopic observations with the HST/COS. Given the expected faintness of our target we propose to use the COS with the low-resolution G140L grating to obtain the best possible S/N. The resolving power of the low-resolution grating is sufficient to resolve the expected ionized emission lines (which have typical widths of ~10 A), and to determine whether these lines are single or double peaked. We propose to use the 1105 A setting that provides continuous coverage between 1118-2251 A in segment A, while segment B is switched off. We used the online HST-COS exposure time calculators (v. 21.1). We model our point source with a F_lambda propto lambda^-1 spectral energy distribution. We normalize the continuum flux to F_lamdba= 6E-18 erg/cm2/s/A at 3560 A, which is inferred from SDSS observations of the quiescent counterpart of Swift J1357.2-0933 (ATel #3140). The reddening towards our target is E(B-V))=0.02 mag. We require a S/N of 2 for the continuum emission, which is similar to that achieved in HST/COS spectroscopic observations of the quiescent black hole X-ray binary A0620-00 (Froning et al. 2011); the S/N for the emission lines will be higher. We propose to use different FP-POS positions to reduce fixed-pattern noise and to minimize long-term gain sag. The source position is accurately known (to within 0.3 arcsec; ATel #3147), so target acquisition can be performed using ACQ/IMAGE (a S/N of 40 was assumed for the exposure time calculation). The total observing time of 9 orbits is spread over two visits. HOT STARS 12 false true 0.0 0.0 false false false AVAILABLE STAR LMXB X-RAY TRANSIENT J2000 J2000 UNIDENTIFIED BLANK FIELD "This target is a blank piece of sky which is the bright object safe pointing and is 9.819 arcseconds away at a PA 114.4 degrees from SWIFTJ1357.2-0933. J2000 UNIDENTIFIED BLANK FIELD This target is a blank piece of sky which is the bright object safe pointing and is 9.82 arcseconds away at a PA 179.4 degrees from SWIFTJ1357.2-0933. J2000 COS/FUV Spectroscopic No No G140L 1105 COS/FUV Spectroscopic No No G140L 1105 The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. This should be scheduled in evening-local time. Flags need to be cleared during the work day. 1405635173000 113.40051269499997 (Tic-Visit :proposal-id 13284 :visit-id "01" :proposal-version -1 :trans-version "20130502" :date "26-Jun-2013 21:52:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 721920 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13284 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 442 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) false 5 0 This is for BOP checking the safe target only and should not execute onboard HST. (Tic-Visit :proposal-id 13284 :visit-id "01" :proposal-version -1 :trans-version "20130502" :date "26-Jun-2013 21:52:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 721920 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13284 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "01" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 442 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) false 5 0 The scheduling data was generated by CASM 21.2. CASM was run in Phase II mode. This should be scheduled in evening-local time. Flags need to be cleared during the work day. (Tic-Visit :proposal-id 13284 :visit-id "02" :proposal-version -1 :trans-version "20130502" :date "26-Jun-2013 21:55:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 565376 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13284 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 442 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) false 4 0 This is for BOP checking the safe target only and should not execute onboard HST. (Tic-Visit :proposal-id 13284 :visit-id "02" :proposal-version -1 :trans-version "20130502" :date "26-Jun-2013 21:55:21.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "31" :si-bright-earth-limb-angle 20.0 :data-volume 565376 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 13284 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 114 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) (Tic-Orbit :proposal-id 13284 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3011 :al-overhead-at-end 0 :internal-dur-at-end 442 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3233 :pcs-gap 0 ) false 4 0 This visit allocates and sets up the safe position offset slot for Visit01 which will use that slot. This S/C visit should go earlier inthe week while Visit01 will be at least 3 days later. The S/C visit will contain only 1 exposure. 1405327540000 113.40051269499997 false -1 -1 This visit allocates and sets up the safe position offset slot for Visit02 which will use that slot. This S/C visit should go earlier inthe week while Visit02 will be at least 3 days later. The S/C visit will contain only 1 exposure. false -1 -1