coverpage: title_1: ECHELLE OBSERVATIONS OF THE LOW REDSHIFT LYMAN ALPHA FOREST IN 3C273 title_2: - CARRYOVER cont_id: 3477 sci_cat: QUASARS & AGN sci_subcat: QUASAR ABSORPTION proposal_for: GO/CAR pi_fname: RAY pi_mi: J. pi_lname: WEYMANN pi_inst: CARNEGIE OBSERVATORIES pi_country: USA pi_phone: 202-387-6406 hours_pri: 5.80 num_pri: 1 hrs: Y funds_amount: 10369 funds_length: 12 off_fname: JOHN off_lname: LIVELY off_title: DIR, ADM & FINANCE off_inst: CARNEGIE INSTITUTION OF WASHINGTON off_addr_1: 1530 P STREET NW off_city: WASHINGTON off_state: DC off_zip: 20005 off_country: USA off_phone: 202 387 6406 ! end of coverpage abstract: line_1: We will observe a Lyman alpha forest absorption line in 3C273 at line_2: very high (approx 4 km/s) resolution using the GHRS Echelle-A line_3: Grating and the large science aperture. Our objective is to understand line_4: the nature of the (formal) super-thermal doppler parameters frequently line_5: found in the Lyman alpha forest, and confirm that such doppler line_6: parameters actually occur at very low redshifts. In particular, we will line_7: search for sub-components and/or departures from a Voigt profile in the line_8: line. ! ! end of abstract general_form_proposers: lname: WEYMANN fname: RAY title: PI mi: J. inst: CARNEGIE OBSERVATORIES country: USA ! lname: MORRIS fname: SIMON mi: L. inst: CARNEGIE OBSERVATORIES country: USA ! lname: CARSWELL fname: ROBERT mi: F. inst: INSTITUTE OF ASTRONOMY country: UK ! lname: GILLILAND fname: RONALD mi: L. inst: CARNEGIE OBSERVATORIES country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 2 line_1: We will use the LSA and the GHRS Echelle-A giving $sim$4 km s$^{-1}$ line_2: resolution (FWHM) and 6.5{AA} coverage. The wavelength region chosen line_3: covers the SII $lambda$1250.5 and $lambda$1253.8 lines from the galactic line_4: halo and also redshifted Lyman $alpha$ lines at 1251.46{AA} and line_5: 1255.7{AA}. 16 exposures of 1305.6 seconds each will be taken, all line_6: with FP-SPLIT=4 and STEP-PATT=7. This will allow removal of the GIMP line_7: drift, identification of photocathode features and good sampling of the line_8: LSA PSF. ! question: 3 section: 1 line_1: As described in the scientific justification, these observations line_2: require high spectral resolution in the far UV, and are impossible with line_3: any other satellite or ground based telescope. ! question: 4 section: 1 line_1: We have carried out simulations using various observing strategies in line_2: order to determine the most appropriate HRS configuration. line_3: In Figure 1 we show the results of typical simulations for various line_4: assumed true profiles. The two configurations considered line_5: were: line_7: item{1)} Echelle A and LSA (left panels) line_8: item{2)} G160M with SSA (right panels) line_10: All the simulations are for the {it same line_11: on-target integration time}, namely 6 hours. line_13: The Echelle A object count rate was assumed to be 0.021 line_14: counts/sec/diode based upon the most recent HRS calibration data and line_15: the known flux of 3C273, with a (typical) background rate of 0.009 line_16: counts/sec/diode. The G160M count rate used was that observed for GTO line_17: 1140, scaled by a LSA/SSA throughput ratio of 4.0. The PSFs were taken line_18: from Gilliland {it et al.} (1991). line_20: The four profiles in both the left and right panels represent four line_21: different input profiles based upon different assumptions about the line_22: non-thermal contribution to the broadening. In all cases a thermal line_23: component to the doppler parameter of 15 km s$^{-1}$ was assumed. The ! question: 4 section: 2 line_1: column density of the cloud(s) and the free velocity parameters were line_2: adjusted so that a best-fit single Voigt profile to the input profile line_3: yielded the column density and doppler parameter found in the initial line_4: G160M observation (namely, log N=13.48, b=36 km s$^{-1}$.): line_6: item{A)} A homogenous cloud with no bulk velocity and gaussian line_7: ``turbulent'' velocity (i.e. a perfect Voigt profile). line_8: item{B)} Two line_9: separate identical homogeneous clouds separated in velocity. line_10: item{C)} Three separate identical homogenous clouds with identical line_11: velocity separations. line_12: item{D)} A homogenous cloud with bulk line_13: velocity increasing linerarly from the center to the front and back line_14: surfaces. line_16: Inspection of Figure 1 shows, and formal analysis confirms, that the line_17: Echelle-A (side 1) is the preferred choice. The analysis also shows line_18: that cases A, B, and D can be distinguished from each other after 6 line_19: hours of exposure with Echelle-A, although C and D are only marginally line_20: distinguishable. With G160M (side 2) and the SSA it is possible to line_21: distinguish cases A from B and A from C, but not A from D nor C from D. line_22: We note that no attempt at deconvolution has been attempted in these line_23: simulations. ! question: 5 section: 1 line_1: line_2: The detector background count rate will be a significant contribution line_3: to the total noise in the reduced spectrum, and so the exposures should line_4: be taken at times when that background is low (i.e. {it not} during or line_5: near SAA transit). ! !end of general form text general_form_address: lname: WEYMANN fname: RAY mi: J. category: PI inst: CARNEGIE OBSERVATORIES addr_1: 813 SANTA BARBARA ST. city: PASADENA state: CA zip: 91101 country: USA phone: 818 304 0223 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: 3C273.0 name_2: PG1226+023 descr_1: E,314,321 pos_1: RA=12H 26M 33.35S +/- 0.5", pos_2: DEC=+02D 19' 42.4" +/- 0.5" equinox: 1950 rv_or_z: Z=0.158 comment_1: F-CONT FLUX FROM IUE DATA. fluxnum_1: 1 fluxval_1: V=12.8 +/- 0.3 fluxnum_2: 2 fluxval_2: F-CONT(1300)=3.5 +/- 0.5 E-13 fluxnum_3: 3 fluxval_3: F-CONT(2700)=1.2 +/- 0.2 E-13 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: 3C273.0 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-N2 num_exp: 1 time_per_exp: 27.4S fluxnum_1: 1 fluxnum_2: 2 priority: 1 param_1: BRIGHT=RETURN, param_2: MAP=END-POINT, req_1: ONBOARD ACQ FOR 2-12; req_2: CYCLE 4 /1-12; comment_1: STEP TIME = 0.2 SEC ! linenum: 2.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 54.4S priority: 1 param_1: STEP-PATT=7 req_1: CALIB FOR 3-12; SEQ 2-3 NO GAP; ! linenum: 3.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 4.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 5.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 6.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 7.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 8.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 9.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 10.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 11.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! linenum: 12.000 targname: 3C273.0 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-A wavelength: 1250-1257 num_exp: 1 time_per_exp: 1958.2S s_to_n: 5 fluxnum_1: 2 priority: 1 param_1: FP-SPLIT=STD, param_2: STEP-PATT=7 ! ! ! end of exposure logsheet ! No scan data records found