! File: 4402C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:10:23:53 coverpage: title_1: A STUDY OF THE ARCSECOND GRAVITATIONAL LENS 1422+321 CYCLE3HIGH sci_cat: QUASARS & AGN sci_subcat: GRAVITATIONAL LENSES proposal_for: GO pi_fname: CHRIS pi_mi: D. pi_lname: IMPEY pi_inst: STEWARD OBSERVATORY pi_country: USA pi_phone: 602-621-6522 hours_pri: 9.01 num_pri: 5 fos: Y funds_amount: 81920 funds_length: 12 off_fname: MICHAEL off_mi: A. off_lname: CUSANOVICH off_title: V.P. FOR RESEARCH off_inst: UNIVERSITY OF ARIZONA off_addr_1: ADMINISTRATION BLDG 601 off_addr_2: UNIVERSITY OF ARIZONA off_city: TUCSON off_state: AZ off_zip: 85721 off_country: USA off_phone: 602-621-3513 ! end of coverpage abstract: line_1: We propose spectroscopy and imaging of the four components of the line_2: candidate gravitational lens 1422+231. This is the brightest of the line_3: few known examples of subarcsecond multiply imaged quasars. It was line_4: selected from a survey of 1750 flat spectrum radio sources which line_5: should be particularly effective at finding subarcsecond lenses. line_6: With V = 16.5 (all components) and z = 3.62, this is one of the line_7: most apparently luminous objects in the universe. Spectroscopy line_8: of optical counterparts to the four radio components will clearly line_9: establish whether or not the system is a gravitational lens, and line_10: imaging with the FOC is very likely to identify the lens, even if line_11: it is a highly subluminous galaxy. Contamination due to spilled line_12: light is not a problem for the brightest three components, and for line_13: the faintest component, we will measure contamination due to the line_14: other three components with an offset sky exposure. A system with line_15: four components offers the prospect of a large number of constraints line_16: on the lensing model. Moreover, the radio sources are compact line_17: and highly polarized, and so very likely to be variable. 1422+231 line_18: could therefore be used in a VLA or VLBA monitoring campaign to line_19: derive a new estimate of the Hubble constant using up to three line_20: time delays. Confirmation of the lens can only be done from space. ! ! end of abstract general_form_proposers: lname: IMPEY fname: CHRIS title: PI mi: D. inst: STEWARD OBSERVATORY country: USA ! lname: FOLTZ fname: CRAIG mi: B. inst: MULTIPLE MIRROR TELESCOPE country: USA ! lname: BROWNE fname: IAN mi: W. inst: NUFFIELD RADIO ASTRONOMY LABORATORIES country: UNITED KINGDOM esa: Y ! lname: PATNAIK fname: ALOK mi: R. inst: NUFFIELD RADIO ASTRONOMY LABORATORIES country: UNITED KINGDOM esa: Y ! lname: SHAPIRO fname: IRWIN inst: HARVARD SMITHSONIAN CENTER FOR ASTROPHYSICS country: USA ! lname: REISS fname: ADAM inst: HARVARD SMITHSONIAN CENTER FOR ASTROPHYSICS country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We propose two observations of the candidate gravitational lens 1422+231. line_2: The first is spectroscopy of individual radio components A, B, C, and D using line_3: the FOS red side with grating G570H which gives wavelength coverage from 4600 to line_4: 6800 Angstroms. Exposure times are calculated assuming that the system is indeed line_5: a lens, and that the optical fluxes scale with the radio fluxes. Fluxes for the line_6: sum of A+B+C are taken from Figure 2. The 0.3 arcsec circular aperture will be line_7: used; any larger and the components will not be separated, any smaller is not line_8: practical with the degraded PSF of the HST. An integration time of 1500 seconds line_9: will give a S/N = 15 per resolution element in the continuum at 4800 Angstroms line_10: for components A and B, and 3000 seconds will give S/N = 14 for component C. line_11: High S/N spectra of A, B, and C are essential to confirm the lens hypothesis. line_12: High redshift quasars generally have similar continuum shapes, and there is line_13: already one case of an (unlensed) quasar pair with virtually identical spectra line_14: and a small velocity difference (Djorgovski et al. 1987, Ap.J., 321, L17). line_15: Limited S/N has so far hampered the interpretation of one other subarcsecond line_16: lens (Bahcall et al. 1992, in press); we note however that 1208+101 is line_17: considerably fainter than our candidate system. If D is a lens component, an line_18: integration time of 6200 seconds will be used to get a S/N = 7 in the putative line_19: Lyman-alpha line, allowing a clear-cut test of this fourth component. The PSF line_20: will give contamination between spectra of the different components, but it is ! question: 3 section: 2 line_1: generally small. A and B are contaminated by 5%, and C is contaminated 12% by line_2: the sum of A and B. The contamination of D is severe, the expected flux is line_3: increased by 200% by the sum of A plus B plus C. We therefore will take a line_4: "sky" exposure at a position which is on the opposite side of A+B from D, to line_5: determine the amount of spilled light directly. Although the PSF has azimuthal line_6: varations of 30-40%, this procedure, plus the high S/N we will obtain on A,B, line_7: and C, will allow us to unequivocally determine whether or not D has Lyman-alpha line_8: with the same equivalent width as components A, B, and C. The exposure times are line_9: slightly amended from phase 1 to conform to a smaller amount of spacecraft time. ! question: 4 section: 1 line_1: The small separation of the components of this candidate gravitational lens line_2: system mean that observations from HST are essential for these observations. line_3: The overall extent of the radio source is 1.3 arcsec, the separation between line_4: A and B is 0.5 arcsec, and the separation between B and C is 0.8 arcsec (see line_5: Figure 1). While imaging of 1422+231 might be possible from the ground under line_6: the very best conditions, FOC observations still offer substantial advantages. line_7: Since the PSF gives a core of 10% of the image flux with a FWHM of only 0.07 line_8: arcsec, the bright components A, B, and C are expected to be well separated. line_9: Moreover, the presence of three bright point sources in the field means that line_10: image deconvolution will be well constrained, which is an advantage in the line_11: search for the lens. Confirmation of the 1422+231 system as a gravitational line_12: lens relies mostly on spectroscopy of components A, B, and C. The capabilities line_13: of HST in making this observation are unique, no ground-based facility can line_14: compete. Successful HST confirmation of the lens system will lead to important line_15: ground-based follow-up at radio wavelengths. The lens conponents are well line_16: separated with the VLA or VLBA, and are compact and polarized. Compactness line_17: and high polarization implies that they are also highly likely to be variable. line_18: A radio monitoring program offers the exciting possibility of a new geometric line_19: determination of the Hubble Constant, in a system where up to three time delays line_20: can be measured. ! question: 4 section: 2 line_1: line_2: Figure 2 shows the flux density of the sum of the three brightest components A, line_3: B, and C. The FOS exposure time calculations are based on the assumption that line_4: the relative fluxes of all four components is given by their relative radio line_5: fluxes (this assumption is confirmed by recent, unpublished imaging of the line_6: system in the near infrared). Count rates are calculated at two wavelength, line_7: in the middle of the continuum shortward of Lyman-alpha at 4800 Angstroms, line_8: and at the half power of the Lyman-alpha line around 5700 Angstroms. The line_9: calculated count rates for components A, B, C, and D are 0.18, 0.18, 0.088, line_10: and 0.0044 ct/s/diode at 4800 Angstroms, and 0.60, 0.60, 0.30, and 0.015 line_11: ct/s/diode at 5700 Angstroms (this assumes that all the components have line_12: Lyman-alpha with the same equivalent width). The exposure times are calculated line_13: to give S/N = 15 for components A (1500 sec), B (1500 sec), and C (3000 sec), line_14: and to give S/N = 7 at half power of the predicted Lyman-alpha line in component line_15: D (6200 sec). ! question: 5 section: 1 line_1: Real time interactive acquisition of the first of the four gravitational len line_2: images is required. The necessity for this scarce resource was confirmed in line_3: consultations with the FOS support scientists and the USB technical assistant line_4: for this program, and was recognized in the internal Phase 1 review of this line_5: proposal. The requirement is based on the fact that the four lens images are line_6: contained within an area of only 1 arcsecond, and three of them are of similar line_7: brightness. The VLBI radio positions are extremely accurate (better than 50 line_8: milliarcseconds absolute), and the field is visually distinctive, so real time line_9: recognition and centering should be straightforward. The 0.3 arcsecond FOS line_10: aperture is required to meet the scientific goals of the project. Having line_11: acquired the first of the four images, the other three can be located by line_12: offsetting. The differential positions of the four components are known to line_13: better than 10 milliarcseconds. line_15: Acquisition now being done with a blind pointing from an offset star. ! question: 7 section: 1 line_1: Standard calibration of the FOS spectra and FOC images is requested. The PI and line_2: MMT co-I have extensive experience in spectroscopic reduction and anaylsis. The line_3: most critical issue in the spectroscopic part of this proposal is the issue of line_4: contamination between the quasar images due to the degraded PSF of the HST. We line_5: will calculate this effect from the FOC images directly, but will check the line_6: contamination of the faintest component D directly with an "off" exposure with line_7: the FOS, designed to directly measure the contamination in the spectrum line_8: of D due to spilled light from the brighter quasar components. We will use line_9: standard image deconvolution techniques on the FOC images, guided by the line_10: three bright and (presumably) unresolved point sources (components A,B,C). line_11: The PSF has a sufficiently sharp core that all four components will be well line_12: separated. One graduate student at the University of Arizona will be involved line_13: in the reduction and analysis. ! question: 9 section: 1 line_1: a. List HST program numbers and titles: line_2: GO Program 2524 "Spectropolarimetry of Bright Quasars" - not related line_3: GO Program 3732 "Spectropolarimetry of Bright Quasars" - not related line_4: GO Program 3648 "Imaging of BL Lac Host Galaxies and Environments" - not related line_5: b. Summarize the main results obtained from previous related programs: line_6: GO Program 2524 - Cycle 1, data received and reduced, paper in preparation line_7: GO Program 3732 - Cycle 2, data received and reduced, paper in preparation line_8: GO Program 3648 - Cycle 2, data recieved and is currently being reduced ! question: 10 section: 1 line_1: The University of Arizona will provide central computing services (hard disks, line_2: networks, tape drives) in support of this project. One undergraduate will be line_3: able to work on this project through funds provided by the Arizona Space Grant. line_4: We will also be supported by the University of Arizona in follow-up ground-based line_5: activities, such as VLA and VLBA monitoring of the radio lens components for line_6: brightness variations that could lead to a new determination of the Hubble line_7: constant. ! !end of general form text general_form_address: lname: IMPEY fname: CHRIS mi: D. category: PI inst: Steward Observatory addr_1: STEWARD OBSERVATORY addr_2: UNIVERSITY OF ARIZONA city: TUCSON state: AZ zip: 85721 country: USA phone: 602-621-6522 telex: 467175 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: QSO1424P231-B name_2: PKS descr_1: E, 314, 323 pos_1: RA = 14H 24M 38.094S +/- 0.004S, pos_2: DEC = +22D 56' 00.59" +/- 0.05", equinox: 2000 pm_or_par: NO rv_or_z: Z=3.62 comment_1: SUBARCSECOND GRAVITATIONAL LENS comment_2: COMPONENT B, VLBI RADIO POSITION comment_3: UPDATED COORDS WILL COME FROM comment_4: WFPC IMAGES IN 5080. ACQUIRE comment_5: B THEN OFFSET TO OTHER COMPONENTS fluxnum_1: 1 fluxval_1: B = 18.4 +/- 0.2 fluxnum_2: 2 fluxval_2: B-V = 1.7 fluxnum_3: 3 fluxval_3: F-LINE(1216) = 5 +/- 1 E-15 ! targnum: 2 name_1: QSO1424P231-A name_2: PKS descr_1: E, 314, 323 pos_1: RA-OFF = 0.028S +/- 0.002S, pos_2: DEC-OFF = 0.320" +/- 0.010", pos_3: FROM 1 equinox: 2000 pm_or_par: NO rv_or_z: Z=3.62 comment_1: SUBARCSECOND GRAVITATIONAL LENS comment_2: COMPONENT A, VLBI RADIO POSITION comment_3: ACQUIRED BY OFFSET FROM COMPONENT B fluxnum_1: 1 fluxval_1: B = 18.4 +/- 0.2 fluxnum_2: 2 fluxval_2: B-V = 1.7 fluxnum_3: 3 fluxval_3: F-LINE(1216) = 5 +/- 1 E-15 ! targnum: 3 name_1: QSO1424P231-C name_2: PKS descr_1: E, 314, 323 pos_1: RA-OFF = -0.024S +/- 0.002S, pos_2: DEC-OFF = -0.750" +/- 0.010", pos_3: FROM 1 equinox: 2000 pm_or_par: NO rv_or_z: Z=3.62 comment_1: SUBARCSECOND GRAVITATIONAL LENS comment_2: COMPONENT C, VLBI RADIO POSITION comment_3: ACQUIRED BY OFFSET FROM COMPONENT B fluxnum_1: 1 fluxval_1: B = 19.1 +/- 0.2 fluxnum_2: 2 fluxval_2: B-V = 1.7 fluxnum_3: 3 fluxval_3: F-LINE(1216) = 2 +/- 1 E-15 ! targnum: 4 name_1: QSO1424P231-D name_2: PKS descr_1: E, 314, 323 pos_1: RA-OFF = 0.068S +/- 0.002S, pos_2: DEC-OFF = -0.810" +/- 0.010", pos_3: FROM 1 equinox: 2000 pm_or_par: NO rv_or_z: Z=3.62 comment_1: SUBARCSECOND GRAVITATIONAL LENS comment_2: COMPONENT D, VLBI RADIO POSITION comment_3: ACQUIRED BY OFFSET FROM COMPONENT B fluxnum_1: 1 fluxval_1: B = 22.4 +/- 0.2 fluxnum_2: 2 fluxval_2: B-V = 1.7 fluxnum_3: 3 fluxval_3: F-LINE(1216) = 12 +/- 5 E-17 ! targnum: 5 name_1: QSO1424P231-OFF name_2: PKS descr_1: E, 314, 323 pos_1: RA-OFF = -0.068S +/- 0.002S, pos_2: DEC-OFF = 0.810" +/- 0.010", pos_3: FROM 1 equinox: 2000 pm_or_par: NO rv_or_z: Z=3.62 comment_1: SUBARCSECOND GRAVITATIONAL LENS comment_2: MEASURE CONTAMINATION OF D comment_3: ACQUIRED BY OFFSET FROM COMPONENT B fluxnum_1: 1 fluxval_1: B = 22.6 +/- 0.2 fluxnum_2: 2 fluxval_2: B-V = 1.7 fluxnum_3: 3 fluxval_3: F-LINE(1216) = 8 +/- 5 E-17 ! targnum: 6 name_1: OFFSET-STAR descr_1: A pos_1: RA = 14H 24M 37.6S +/- 0.04S, pos_2: DEC = +22D 55' 44.0" +/- 0.5", equinox: 2000 pm_or_par: NO comment_1: OFFSET STAR. UPDATED COORDS comment_2: WILL BE PRIVDED BASED ON WFPC comment_3: EARLY ACQ IMAGE IN 5080. fluxnum_1: 1 fluxval_1: V = 18.1 +/- 0.2, TYPE=K0V ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: OFFSET-STAR config: FOS/RD opmode: ACQ/PEAK aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 4.5S fluxnum_1: 1 priority: 1 param_1: SCAN-STEP-Y=1.43, param_2: SEARCH-SIZE-X=1, param_3: SEARCH-SIZE-Y=3 req_1: CYCLE 3 / 1-6; req_2: ONBOARD ACQ FOR 1.1; req_3: REQ UPDATE / 1-6 comment_1: COORDS AND EXP. TIME comment_2: MAY BE UPDATED BASED comment_3: ON EARLY ACQ IMAGES comment_4: IN PROP 5080. ! linenum: 1.100 targname: OFFSET-STAR config: FOS/RD opmode: ACQ/PEAK aperture: 1.0 sp_element: MIRROR num_exp: 1 time_per_exp: 22.0S fluxnum_1: 1 priority: 1 param_1: SCAN-STEP-Y=0.707, param_2: SEARCH-SIZE-X=6, param_3: SEARCH-SIZE-Y=2 param_4: SCAN-STEP-X=0.707, req_1: ONBOARD ACQ FOR 1.2; comment_1: COORDS AND EXP. TIME comment_2: MAY BE UPDATED BASED comment_3: ON EARLY ACQ IMAGES comment_4: IN PROP 5080. ! linenum: 1.200 targname: OFFSET-STAR config: FOS/RD opmode: ACQ/PEAK aperture: 0.5 sp_element: MIRROR num_exp: 1 time_per_exp: 35.0S fluxnum_1: 1 priority: 1 param_1: SCAN-STEP-Y=0.354, param_2: SEARCH-SIZE-X=3, param_3: SEARCH-SIZE-Y=3 param_4: SCAN-STEP-X=0.354, req_1: ONBOARD ACQ FOR 1.3; comment_1: COORDS AND EXP. TIME comment_2: MAY BE UPDATED BASED comment_3: ON EARLY ACQ IMAGES comment_4: IN PROP 5080. ! linenum: 1.300 targname: OFFSET-STAR config: FOS/RD opmode: ACQ/PEAK aperture: 0.3 sp_element: MIRROR num_exp: 1 time_per_exp: 49.0S fluxnum_1: 1 priority: 1 param_1: SCAN-STEP-Y=0.144, param_2: SEARCH-SIZE-X=3, param_3: SEARCH-SIZE-Y=3 param_4: SCAN-STEP-X=0.144, req_1: ONBOARD ACQ FOR 2-6; comment_1: COORDS AND EXP. TIME comment_2: MAY BE UPDATED BASED comment_3: ON EARLY ACQ IMAGES comment_4: IN PROP 5080. ! linenum: 2.000 targname: QSO1424P231-B config: FOS/RD opmode: ACCUM aperture: 0.3 sp_element: G570H num_exp: 1 time_per_exp: 1500S s_to_n: 35 fluxnum_1: 1 priority: 1 req_1: SEQ 2-6 NO GAP; comment_1: COORDS MAY BE UPDATED comment_2: BASED ON EARLY ACQ comment_3: IMAGES IN PROP 5080. comment_4: S/N AT 6000 ANGSTROMS comment_5: BLOCKING FILTER WG 375 ! linenum: 3.000 targname: QSO1424P231-A config: FOS/RD opmode: ACCUM aperture: 0.3 sp_element: G570H num_exp: 1 time_per_exp: 1500S s_to_n: 35 fluxnum_1: 1 priority: 1 comment_1: S/N AT 6000 ANGSTROMS comment_2: BLOCKING FILTER WG 375 ! linenum: 4.000 targname: QSO1424P231-C config: FOS/RD opmode: ACCUM aperture: 0.3 sp_element: G570H num_exp: 1 time_per_exp: 3000S s_to_n: 35 fluxnum_1: 1 priority: 1 comment_1: S/N AT 6000 ANGSTROMS comment_2: BLOCKING FILTER WG 375 ! linenum: 5.000 targname: QSO1424P231-D config: FOS/RD opmode: ACCUM aperture: 0.3 sp_element: G570H num_exp: 1 time_per_exp: 6200S s_to_n: 8 fluxnum_1: 1 priority: 1 comment_1: S/N AT 6000 ANGSTROMS comment_2: BLOCKING FILTER WG 375 ! linenum: 6.000 targname: QSO1424P231-OFF config: FOS/RD opmode: ACCUM aperture: 0.3 sp_element: G570H num_exp: 1 time_per_exp: 3000S s_to_n: 8 fluxnum_1: 1 priority: 1 comment_1: S/N AT 6000 ANGSTROMS comment_2: BLOCKING FILTER WG 375 ! ! end of exposure logsheet ! No scan data records found