0 Assigned ID: 379 ----- Attempting Submission 1 (Fri Apr 07 02:52:10 GMT 2017) ----- HST Phase I Proposal 379 (rsoria_hlx1.apt) failed submission. ----- Attempting Submission 2 (Fri Apr 07 02:55:04 GMT 2017) ----- When running the BOT, I get red lights for the ACS-SBC exposure (orbit 1), as "exceeding Health and Safety limit" based on an assumed total count rate on the chip in the F140LP filter SAME COMMENTS FOR RESUBMISSION However, when looking at the detailed tables of the count rates, I see that the near-UV flux was estimated from the optical flux of the galaxy ESO243-49 in the Guide Star Catalog, extrapolated to the near-UV assuming an O5V spectrum. I know that the O5V spectrum is assumed as worst-case-scenario when no other spectral information is available. However, in this case the assumption of such spectrum is clearly nonsense, because ESO243-49 is an early-type galaxy with an old stellar population and very little emission in the near-UV. So there is absolutely no chance that the near-UV flux will be anywhere near the safety limit. If you don't believe me, you can easily look at the 2010, 2012 and 2013 ACS observations in the same filter and see that it's faint and perfectly safe. 1815632337 ----- Attempting Submission 1 (Wed Jul 19 04:03:33 GMT 2017) ----- HST Phase II Proposal 15086 (rsoria_15086_hlx1_phase2.apt) successfully submitted. Receipt: # 15086-1 ----- Attempting Submission 2 (Thu Jul 20 01:05:09 GMT 2017) ----- Age and mass of the star cluster around the intermediate-mass black hole HLX-1 We propose to study the optical counterpart of the intermediate-mass black hole (IMBH) HLX-1, about 3 years after its last X-ray outburst. Previous HST observations taken at epochs closer to an outburst show a variable near-UV/blue component, plus a constant red/near-IR component. The redder component probably comes from an old stellar population around the black hole; the bluer component may be a combination of emission from an irradiated accretion disk, and from a young stellar population. Their relative contributions and the age of the stellar population(s) are still subject of debate. By re-observing the system when the irradiated component is minimal, we will determine whether the near-UV/blue optical emission has declined even further and whether the red/near-IR optical emission has stayed approximately constant. This will tell us whether the optical counterpart is a massive star cluster, and place a strong upper limit to the young stellar population around the IMBH. Having determined the constant contribution of the stellar emission, we will then insert it into broad-band models of the emission in outburst, and obtain a better estimate of the accretion disk parameters, constraining formation and evolution scenarios for the IMBH. We will use the same set of filters as in previous HST observations, for direct comparison of brightness and colors: F140LP (ACS SBC); F300X, F336W, F390W, F555W, F621M, F775W (WFC3 UVIS); F105W, F160W (WFC3 IR). We request a total of 7 orbits. Our proposed observations are a simple, straight-forward imaging of a point-like source, the optical counterpart of HLX-1 (likely, an unresolved star cluster), in the halo of the S0 galaxy ESO243-49. We want a broad-band coverage from the near-UV to the near-IR, to constrain the age of the stellar population and the contribution of X-ray irradiation. We will use the F140LP filter of ACS SBC, six filters of WFC3 UVIS (F300X, F336W, F390W, F555W, F775W) and two filters of WFC3 IR (F105W and F160W). This is exactly the same set of filters used for the HST observations in 2012 and 2013 (and most of them were also used in 2010), see Table 1 in the Phase I scientific justification. This will make it easy to look for variability from the previous epochs; in particular, we want to test whether there is further decrease of the near-UV/near-IR flux ratio. In 2012 and 2013, one orbit was allocated for the ACS image, and 4 orbits for the 8 WFC3 filters. We report on those results in Soria et al. (2017). This time we request 7 orbits instead of 5. The reasons for the increased time request are: i) we want to test whether the optical source keeps declining, as the X-ray outbursts get shorter and less frequent. We want to be able to constrain a brightness decline as small as about half a magnitude in U and V, within the uncertainties of the 2013 and 2017/8 observation. Also, in the IR filters, the source was only detected at a signal-to-noise ratio 7, because of the strong diffuse emission from the halo of ESO243-49 and the lower spatial resolution: this made it diffcult to fit the spectrum and constrain the age of the old stellar component; ii) the small increase in target visibility (56 min per orbit instead of 55) compared with 2010 and 2013 makes it just long enough to efficiently spread the six WFC3 UVIS observations over 4 orbits, with 4-point box dithering and >339s per exposure, without buffer dumps. Our suggested plan for the observations is: VISIT 1: -- orbit 1 for WFC3 IR F105W, with WFC3-IR-DITHER-BOX-MIN, 2600s; -- orbit 2 for WFC3 IR F160W, with WFC3-IR-DITHER-BOX-MIN, 2800s; VISIT 2: -- orbit 1 for ACS SBC F140LP, 4-point box dithering, 2700s of effective exposure time; -- orbit 2 for WFC3 UVIS F300X, with UV flashing and WFC3-UVIS-DITHER-BOX, approximately 1600s split into 4 exposures of 400s each. Then, the first 2 exposures in the F336W filter, also with UV flashing and dithering, about 400s each; -- orbit 3 for the last 2 exposures in the F336W filter, with UV flashing and dithering, about 400s each, total of 1600s (including those of orbit 4). Then, all 4 exposures for F390W, dithered, 400s each, total of 1600s; -- orbit 4 for WFC3 UVIS F555W, about 1600s split into 4 dithered exposures of 400s each. Then, the first 2 exposures in the F621M filter, also with dithering, about 400s each; -- orbit 5 for the last 2 dithered exposures in the F621M filter, 4000s each, total of 1600s. Then, all 4 dithered exposures for F775W, 400s each, total of 1600s. With this strategy, based on the Exposure Time Calculator and on our experience of the previous HST observations with the same set-up, we will reach signal-to-noise >10 in all filters, even if the brightness decline continues as seen between 2010 and 2013. Stellar Populations Massive Black Holes And Their Host Galaxies 6 false true false false false false SUPPORTED STELLAR CLUSTER ACCRETION DISK GLOBULAR CLUSTER J2000 J2000 U=24, I=24.5 ACS/SBC Imaging No No F140LP WFC3/UVIS Imaging No No F300X WFC3/UVIS Imaging No No F336W WFC3/UVIS Imaging No No F390W WFC3/UVIS Imaging No No F555W WFC3/UVIS Imaging No No F621M WFC3/UVIS Imaging No No F775W WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F160W POS-TARG DITHER 0.179 LINE 0.116 false false 63.65 4 20.02 ACS-SBC-DITHER-BOX 1 false POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 2 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 3 false C:\Users\Robert\Documents\hst25\OP-cache\rsoria_15086_hlx1_phase2_rev-v01.xml The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15086 :visit-id "01" :proposal-version -1 :trans-version "20170613" :date "20-Jul-2017 08:39:44.0" :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 2158704 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15086 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15086 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2840 :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 3345 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15086 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3040 :al-overhead-at-end 0 :internal-dur-at-end 519 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) true 2 0 C:\Users\Robert\Documents\hst25\OP-cache\rsoria_15086_hlx1_phase2_rev-v02.xml The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15086 :visit-id "02" :proposal-version -1 :trans-version "20170613" :date "20-Jul-2017 08:57:45.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 5 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 7004096 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15086 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Obset :proposal-id 15086 :visit-id "02" :obset-id "A2" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15086 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 3009 :al-overhead-at-end 0 :internal-dur-at-end 117 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15086 :visit-id "02" :orbit-number 2 :pcs-time 333 :si-vis-utilization 3012 :al-overhead-at-end 123 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15086 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3119 :al-overhead-at-end 122 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15086 :visit-id "02" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3123 :al-overhead-at-end 121 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15086 :visit-id "02" :orbit-number 5 :pcs-time 222 :si-vis-utilization 3123 :al-overhead-at-end 121 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3345 :pcs-gap 0 ) true 5 0 ACS.im.1011860 ETC run done using the well-determined Vega brightness in the U band and the best-fitting model spectrum. ACS.im.1011865 ETC run done using the observed flux density at 1500 Ang, from 2013. The two runs give essentially the same result, S/N = 10 for the requested exposure time. This is our best estimate of how the source will look like in 6 months' time. However, it could turn out to be a factor of 2 brighter or fainter, so the S/N could be ~7 or ~15.