! Proposal 6568, submission 1 ! PI: Carole Haswell ! Received Fri Feb 16 09:54:35 EST 1996 ! From: chaswell@star.maps.susx.ac.uk ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6568,v 3.1 1996/02/16 14:59:45 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6568,v 3.1 1996/02/16 14:59:45 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Roman ! Phone: 410-338-4479 , E-mail: aroman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0448.haswell.prop ! Date generated: Fri Dec 22 18:00:55 EST 1995 ! ! REVISION HISTORY: ! Feb-1996 CAH appended GO-6017 exposure logsheets to ! GO-6568 Template. ! ! 16-Feb-1996 CAH for phase 2 deadline ! cut last visit to reduce program to 22 orbits ! fixed AFTER requirement in (commented out) vis 8.! Proposal_Information ! Section 4 Title: OUTBURSTS IN BLACK HOLE X-RAY TRANSIENTS Proposal_Category: GO Scientific_Category: BINARIES AND STAR FORMATION Cycle: 6 Investigators PI_name: Carole Haswell PI_Institution: Columbia University CoI_Name: Keith Horne CoI_Institution: University of St. Andrews Contact: ! Y or N (designate at most one contact) CoI_Name: Chris Shrader CoI_Institution: NASA Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Wan Chen CoI_Institution: NASA Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Fuhua Cheng CoI_Institution: University of Maryland Contact: ! Y or N (designate at most one contact) CoI_Name: Mario Livio CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Mark Wagner CoI_Institution: Ohio State University (Lowell) Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) UV observations of soft X-ray transients (SXTs) will be made using the FOS. This is part of an extensive multiwavelength target of opportunity campaign to monitor newly discovered SXTs in outburst and throughout the subsequent decline. Recent work establishes that a high proportion of SXTs harbor black holes, so these observations provide an unrivalled opportunity to obtain high quality data from an accreting black hole. UV data is a keystone of our multiwavelength campaign because the disk regions of interest radiate predominantly in the UV. Emission lines will allow us to probe the kinematics of the inner disk region. We will determine the relative strengths of the reprocessed X-ray flux emitted in the UV, and the UV flux generated by viscous heating in the accretion flow. Multiwavelength observations will probe the physics of the accretion flow throughout the outburst. The observations will yield a detailed quantitative test of the thermal disk instability model for SXT outbursts. FOS work on Nova Muscae 1991 demonstrated the critical importance to this test of recording the UV and optical spectrum during the decline. The unique FOS/G160L capability for simultaneous 1100 -2500A spectra and optical photometry with 2s time resolution will be exploited: an HST / XTE coordinated echo-mapping experiment will measure the size of the reprocessing regions in the accretion disk, and thus probe morphology changes as the decline proceeds. Questions ! Free format text (please update) Observing_Description: We plan a total of 8 visits to the target throughout the decline from outburst. Since we do not yet know the coordinates of the target, we assume the average visibility window of 56 minutes, and use the standard ACQ/PEAK acquisition. (ACQ/BINARY is not suitable for such a variable target.) To calculate exposure times we assume a typical SXT lightcurve and E(B-V)=0.3, and demand at least 100 counts Angstrom ^-1 at the center of the spectrum, with a minimum 5 minutes exposure time for the high resolution gratings. The G160L exposures were fixed at 20m to give the longest possible 2s resolution data stream. Extra minutes were added or subtracted as necessary to pack the orbits; these adjustments will vary with the visibility window. On the first five visits, while the SXT is bright, the following high resolution modes: Blue/G130H, Blue/G190H, Red/G270H, Red/G400H, will obtain spectral coverage from 1100A to 4800A. We will operate in RAPID mode, with READ-TIME=6.18s. This allows us to monitor short timescale variability. Additionally, we will use FOS/BLUE/G160L to record simultaneous white light photometry (with order 0) and low spectral resolution UV spectroscopy (with order 1) at the maximum possible time resolution. This G160L capability is unique, and will be lost after cycle 6. On the last three visits we drop the long G130H exposure and plan instead for a well-exposed G160L spectrum to cover the 1150 - 1600Angstrom region. The following table summarises our program: beginverbatim FOS t V blue blue red red blue orbits visit (days) mag G130H G190H G270H G400H G160L 1 0 13 5m 5m 26m 9m 20m 3 2 10 13.27 5m 5m 26m 9m 20m 3 3 20 13.54 5m 5m 26m 9m 20m 3 4 30 13.18 5m 5m 26m 9m 20m 3 5 60 14.63 8m 5m 26m 9m 17m 3 6 90 15.44 15m 26m 9m 20m 3 7 120 16.25 15m 26m 9m 20m 3 8 150 17.08 22m 26m 9m 64m 4 endverbatim The ``reuse target offset'' capability may improve the efficiency of some of our target acquisitions (Tony Keyes, 9:14:95), but is not guaranteed and would save only sim1 / 2 orbits, so we budget here for ACQ/PEAK. Therefore we would prefer any cuts to our program be specified in terms of orbits rather than visits. Our simultaneous XTE program is already approved with the above (same as cycle 5) visit schedule. We emphasise that in the case that the efficiency does improve, we would still be able to make excellent use of the full request: the signal -to-noise ratio of our data and duration of coverage would be enhanced, hence allowing us to better pursue our goals. Real_Time_Justification: The recurrence times of an individual sources vary greatly, and are unpredictable, hence we require Target of Opportunity Observations. There is a significant likelihood of a major transient event occurring during the duration of this proposal. Over the last 7 years four major events occurred, though the last one was GRO J0422, in cycle 3 (1993). This proposal was approved with High Priority for Cycles 4 and 5. In cycle 4 we did not trigger our program: we deemed the best target, GRO J1655-40, too highly reddened to be suitable for our expensive HST UV spectroscopy program. Prompt observations, within a week of discovery if possible, are desirable. If we miss the first weeks of the decay, we may fail to unequivocally test the disk instability model. As the source fades, data quality will decline; early observations hold the most potential for ground-breaking discoveries. We have in place XTE and GRO target of opportunity programs to observe SXTs. XTE and GRO will provide early detection, and subsequently monitor the X-ray intensity. Hence, ``real time'' planning of observations at other wavelengths is facilitated. At Lowell observatory we have immediate access to high quality ground-based observations. We will trigger the HST program if a major SXT, reaching ~ 1 Crab and/or V ~ 14, occurs. XTE will make observations simultaneously with HST for echo-mapping. The burden of coordinating schedules will fall upon XTE, which is far more flexible than HST. HST is needed for several reasons. By using the RAPID mode of the FOS, we will obtain higher time resolution than is possible with IUE (which will probably no longer be operational in Cycle 6), so we can monitor the expected rapid variations in emission from an accreting black hole. The echo -mapping observations we propose depend on this HST/FOS capability, as well as the unique ability to obtain simultaneous UV spectra and optical photometry with G160L. The IUE instruments have limited dynamic range and our observations require HST's superior sensitivity and resolution. Generic_Targets ! Section 5.3 Target_Number: 1 Target_Name: X-Ray-Transient Description: STAR, Interacting Binary, X-ray Novae, X-ray Transient, LMXB Criteria: RA = 12H +/- 12H, DEC = 0D +/- 90D Flux: V=13.0 Comments: New SXT will be followed thru decline. Until outburst, flux, E(B-V), etc unknown. Optical/IUE data -> planning. Assume Fnu=nu**1/3 spectrum V=13+(TIME/36.8days), E(B-V)=0.3 for calcs. ARBITRARY CUT TO 22 ORBITS FOR 16-Feb-1996 DEADLINE. WILL RESUBMIT OPTIMISED PROGRAM LATER. Visits ! Section 6 !------------------------------------------------------------------------------ ! VISIT ONE ASAP AFTER DISCOVERY ! V=13.00, E(B-V)=0.3 !------------------------------------------------------------------------------ Visit_Number: 1 Visit_Requirements: ! Section 7.1 BETWEEN 01-JUL-96 AND 06-JUL-96 ON HOLD ORIENT 30D TO 29D FROM NOMINAL ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN