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