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    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID 2344c
                                                       Report Date: 09-May-96:17:03
                                                       Version: **********
                                                       Check-in Date: **********

1.Proposal Title:
HIGH VELOCITY LYMAN ALPHA ABSORPTION IN THE VELA REMNANT
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2. Scientific Category   3. Proposal For  4. Proposal Type        5. Continuation ID
INTERSTELLAR MEDIUM         GO                                       <none>
Sub Category

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6. Principal Investigator   Institution                    Country    Telephone
Dr. Edward B. Jenkins       PRINCETON UNIVERSITY           USA        609-258-3826
ASTRONOMER
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7. Abstract
To detect the primary supernova shock in the intercloud medium of the Vela Remnant
we propose to look for very high velocity (500<v<1500 km s^{-1}) components of Lyman
alpha in absorption. Models by Cowie et al. indicate that such line may be
detectable, and we have seen possible components of HI and O VI near 400 km s^{-1}
with Copernicus satellite.
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8. Scientific Key Words:   SUPERNOVA REMNANT, SHOCKWAVES
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9. Est obs time (hours) pri: 1.00     par: 0       10. Num targs pri: 2      par: 0
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11. Instruments requested:  HRS
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I. GENERAL FORM    Proposal 2344c
PI: Dr. Edward B. Jenkins
Proposal Title:
HIGH VELOCITY LYMAN ALPHA ABSORPTION IN THE VELA REMNANT
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1. Proposers:
Proposers                        Institution                       Country       ESA
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Dr. George Wallerstein           WASHINGTON, UNIVERSITY OF         USA
P.I. Edward B. Jenkins           PRINCETON UNIVERSITY              USA
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  3. Description of proposed observations.
  A SHORT DESCRIPTION OF THE PROPOSED OBSERVATIONS We will use the intermediate
 dispersion (Grating 160M) on GHRS to detect high velocity, weak L-alpha
 absorption lines at a signal-to-noise ratio of 200. Our spectral coverage will be
 from 1209 to 1244 A to include the N V line at 1238 A.  Fluxes were obtained from
 IUE spectra for L-alpha +/- 1000 km/s and combined with sensitivity data for
 G160M (table 2 of the 3/14/91 update on GHRS) performance) to derive exposure
 times.  To be certain that the continuum is not saturated, two exposures (each
 with the substep pattern routine) will provide a total of 40,000 counts at DELTA
 V = 1000 km/s and about 60,000 counts in the continuum.  To achieve the required
 high S/N = 200, we need to use the D2 detector and use the FP-SPLIT mode with 4
 sub-exposures.  We will use two such FP-SPLITs separated by 2 A. (Note: this
 strategy may be revised after we've had a chance to investigate the optimum
 spacing of all sub-exposures)
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  4. Justification of need for HST observations.
  THE NEED FOR CAPABILITIES OF HST Since we must observe ground level lines of
 hydrogen, only uv observations are useful.  With Copernicus we detected a line at
 1024.46A in HD 74455, which may be L-beta at a velocity of -360 km/s.
 Unfortunately, we did not confirm this identification by observing other Lyman
 lines. Spectra recorded by IUE do not have sufficient signal-to-noise ratios to
 accomplish our objective.
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  5. Description of special scheduling requirements.
  JUSTIFICATION OF EXPOSURE AND SPACECRAFT TIME ESTIMATES Sample exposure time:
 For HD 74455 the flux at DELTA V = 1000 km/s is 1.5E-10 ergs cm^-2 s^-1 A^-1
 which may be combined with the table for G160M, 2.0" aperture, at 1215 A, viz.
 4E+11 to yield an exposure of 11.1 minutes for 4E4 counts. Overhead is calculated
 as 15 minutes for the acquisition of each of the 4 stars plus 4 carrousel motions
 at one minute each.
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  7. Data reduction and analysis plans.
  PLANS FOR DATA REDUCTION AND ANALYSIS We think that it is very likely that the
 capabilities of the SDAS/IRAF analysis system will satisfy our reduction
 requirements.  We intend to familiarize ourselves with this system during one or
 more visits to the STScI in the early phases of the program.  If it is not too
 difficult, we may try to install this software on our own computer systems and
 continue to work on our data at our home institutions.  If this is not feasible,
 we will complete our reductions during subsequent visits to the STScI. Present
 systems at our home institutions are a VAX/8350, Sun and Convex at Princeton, and
 a VAX/780 and MicroVAX cluster at the University of Washington.  IRAF is
 currently up and running at the University of Washington.
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 10. Resources to be supplied by investigator's institution(s).
  VAX/8350, Sun-4 and Convex computers at Princeton VAX/780, and MicroVAX cluster
 at the University of Washington
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11. Address Information
Name:  EDWARD B. JENKINS                                   Category: PI
Institution: PRINCETON UNIVERSITY
Address:  PRINCETON OBSERVATORY
City: PRINCETON                                 State: NJ
Zip Code: 08544                                 Country: USA
Telephone:
Telex (or e-mail):
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TARGET LIST    a) Fixed Targets                                                                    ID = 2344c            [  4]
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 1 |     2      |           3           |              4             |  5     |   6    |  7  |              8
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Tar|   Target   |         Target        |            Target          |Coord   | Radial |Acqui|FLX|     Flux data
No |    Name    |       Description     |           Position         |Eqnx    |  Vel.  |Prblm|REF|
   |            |                       |                            |        |        |     |   |
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1   HD74455A     STAR; TYPE=B1.5 V       RA = 8H 40M 38.9S +/- .5" ,  1950     V=+58          1   V = 5.51, B-V = -0.18, TYPE = B1.5
                                         DEC = -47D 55' 07.7" +/- .5"                         2   V
                                                                                                  F-CONT(1211.6) = 1.8 +/- .2 E-10
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2   HD75821A     STAR; TYPE=O9.5 II      RA = 8H 48M 51.59S +/- .2" , ^        V=+8           1   V=5.10, B-V=-0.21, TYPE = O9.5 II
                                         DEC = -46D 20' 29.0" +/- .2"                         2   F-CONT(1211.6) = 7. +/- 2. E-10
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EXPOSURE LOGSHEET                                                                                  ID = 2344c            [  5]
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 1      |   2   |      3    |  4   |   5   |   6   |    7   |   8   |       9       |10 |   11  |   12    |13 |14|        15
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  Line  |  Seq  |   Target  |Instr | Oper. | Aper  |Spectral|Central|   Optional    |Num|  Time |   S/N   |Flx|Pr|     Special
 Number | Name  |    Name   |Config| Mode  |or FOV |Element |Waveln.|  Parameters   |Exp|       |Rel. Time|Ref|  |   Requirements
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1                HD74455A    HRS    ACQ     2.0     MIRROR-A2        FAINT=3400      1   5S                1   2  ONBOARD ACQ FOR
                                                                     SEARCH-SIZE=5                                1.3-1.4
                                                                                                                  CYCLE 1 / 1.0-1.4
     Comments: COMPUTED RATE = 38.7K C/S,
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1.3              ^           HRS    ACCUM   2.0     G160M    1225.50 STEP-PATT=3     1   6M      150       2   1
                                                             0       FP-SPLIT=DSFOUR
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1.4              ^           HRS    ACCUM   2.0     G160M    1227.50 STEP-PATT=3     1   6M      150       2   1
                                                             0       FP-SPLIT=DSFOUR
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2                HD75821A    HRS    ACQ     2.0     MIRROR-A2        FAINT=6306      1   5S                1   1  ONBOARD ACQ FOR
                                                                     SEARCH-SIZE=5                                2.2-2.3
                                                                                                                  CYCLE 1 / 2.0-2.3
     Comments: COMPUTED RATE = 83.95K C/S,
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2.2              ^           HRS    ACCUM   2.0     G160M    1225.50 STEP-PATT=3     1   6M      295       2   1
                                                             0       FP-SPLIT=DSFOUR
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2.3              ^           HRS    ACCUM   2.0     G160M    1227.50 STEP-PATT=3     1   6M      295       2   1
                                                             0       FP-SPLIT=DSFOUR
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            Summary Form for Proposal 2344c                                                                              [  6]

  Item                          Used in this proposal
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  Configurations                HRS
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  Opmodes                       ACQ ACCUM
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  Optional Parameters           FAINT=3400 SEARCH-SIZE=5 STEP-PATT FP-SPLIT FAINT=6306
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  Proposal for                  GO
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  S/C Hours                     1.00
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  Scientific Category           INTERSTELLAR MEDIUM
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  Scientific Sub-category      <none>
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  Special Requirements          ONBOARD ACQ FOR 1.3-1.4; CYCLE 1 / 1.0-1.4; ONBOARD ACQ FOR 2.2-2.3; CYCLE 1 / 2.0-2.3;
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  Spectral Elements             MIRROR-A2 G160M
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  Target Names                  HD74455A HD75821A
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