8710( 5) - 09/04/01 09:37 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8710 Version: 5 Check-in Date: 04-Sep-2001 09:37:07 1.Proposal Title: Timing and proper motion measurement of the proposed optical counterpart of the nearby pulsar PSR1929+10. ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Roberto Mignani Space Telescope - European Coordinating Facility CoI: Dr. Patrizia Caraveo Istituto di Fisica Cosmica/CNR N CoI: Dr. Werner Becker Max-Planck-Institute fuer extraterr. N Physik CoI: Prof. Giovanni Bignami Agenzia Spaziale Italiana N ------------------------------------------------------------------------------------ 5. Abstract PSR1929+10 is an old (Tau ~ 10^6 yrs), nearby (~ 170 pc) isolated neutron star detected as an X-ray pulsar. A possible optical counterpart has been detected by the FOC but the identification still awaits confirmation. Optical observations of neutron stars include both young (~ 10^3-10^4 yrs) and middle-aged (~ 10^5 yrs) objects for which different emission models (e.g. magnetospheric and thermal) have been proposed. However, the general picture is far from being clear. A firm optical identification of PSR1929+10 would thus be crucial to understand the long term evolution of the optical luminosity of pulsars and to investigate possible turnovers in the emission physics. Here we propose to use the STIS NUV-MAMA detector to perform time-resolved imaging of the proposed counterpart with the double aim of (i) searching for periodicity at the radio period and (ii) measuring its expected displacement (~ 500 mas) along the known proper motion direction of the radio pulsar. A single MAMA observation would thus provide two independent and complementary proofs to secure the optical identification of PSR1929+10. ------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 2] Observations Description ------------------------ We plan to use the STIS/NUV-MAMA detector in TIMETAG mode to obtain time- resolved images of the PSR1929+10 candidate counterpart to perform a periodicity search at the radio period. Concerning the proper motion measurement, the high-resolution achievable with the NUV-MAMA (24 mas/px) would allow a very precise relative positioning of our target while its 25 " * 25 " imaging area will certainly include the several field objects by luck present in the much smaller FOC f.o.v. (see Fig 2c of Pavlov et al. 1996), to be used for relative astrometry measurements. The new STIS position will then be compared with the reference FOC one, obtained with a slightly better accuracy (14 mas/px)., To add spectral information in the NUV and to complement previous data obtained by the FOC @ 3 400 Angstrom, we propose to use the F25QTZ filter (Lambda=2500 Angstrom, Delta Lambda ~ 1000 Angstrom FWHM), preferred wrt the F25SRF2 one for its slightly lower induced background. Taking the available FOC/342W flux as a reference together with a realistic model spectrum, i.e. a T ~ 1.5 10^5 K blackbody (Pavlov et al. 1996) with an E(B-V)=0.16, we have used the STIS ETC to compute the exposure time required to achieve an adequate photon counting statistics to perform a precise timing analysis of our target. Using the above parameters and instrument configuration, we thus obtained a net of ~eq 250 source counts per orbit (~ 2300 s -- accounting for target visibility, GS acquisition and instrumental overheads), corresponding to a S/N ~ 5. We thus estimates that a total of five orbits, are required to complete our program. , The presence of the nearby bright star, probably an M type, should not represent a problem for our observation since the expected flux falls well below the bright object limits of the STIS NUV-MAMA. Real Time Justification ----------------------- As a reference for the timing analysis of PSR1929+10, we plan to take advantage of updated X-ray ephemeris, which will be provided by quasi-contemporary observations performed with the EPIC instrument of XMM as part of the guaranteed time observing programme (P.I. Becker). In addition, contemporaneous radio observations of PSR1929+10 will be performed through a collaboration with MPIfR in Bonn, which will provide us the radio ephemeris of all the pulsars accepted in the XMM guaranteed time programme. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR- STAR, NEUTRON STAR RA=19H 32M 13.89S +/- 0.0006S, J2000 V = 27 1932+1059 DEC=10D 59' 31.99" +/- 0.1" B-V = 0. Coordinate Source: OTHER_SOURCE Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.34 0.007 0.039 0.0 8710( 5) - 09/04/01 09:37 - [ 4] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 5] Visit: 02 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 6] Visit: 03 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 7] Visit: 04 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 8] Visit: 05 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 9] Visit: 54 Visit Priority: Visit Requirements: PCS MODE FINE On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 2 STAR-1932+1 STIS/N TIME-TA F25QTZ MIRROR BUFFER-TIME=600 1 1200 S 059 UV-MAM G A ------------------------------------------------------------------------------------------------------------------------------------ 8710( 5) - 09/04/01 09:37 - [ 10] Summary Form for Proposal 8710 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25QTZ ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=600 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names STAR-1932+1059 ------------------------------------------------------------------------------------------------------------------------------------