This is a resubmission of the Phase II. We implemented the reccomended Y-offset=-4.5'' in the SBC exposures to avoid the area with high dark count rate. The ORIENT constraints have been re-computed accordingly. ----- Submission 1 (Thu May 12 17:09:15 GMT 2005) ----- ----- Submission 2 (Wed Aug 17 23:45:41 GMT 2005) ----- ----- Submission 3 (Sat Apr 15 00:15:31 GMT 2006) ----- Assigned ID: 130 ----- Submission 1 (Fri Jan 21 02:17:06 GMT 2005) ----- Phase I Proposal 130 (0437_new) successfully submitted. PSR J0437-4715 is the nearest and the brightest millisecond (recycled) pulsar, and the only one detected at near-optical wavelengths. We detected it with the HST STIS/FUV-MAMA detector and found that its FUV spectrum is consistent with being emitted from the neutron star surface with a temperature of about 0.1 MK, surprisingly high for such an old object. We also found evidence of an emission line at 1372 A, tentatively interpreted as a Zeeman component of the hydrogen Ly-alpha line in a magnetic field of 700 MG. Unfortunately, the spectrum was imaged in a region of strong detector background, which strongly hampered the spectral analyses. We propose to re-observe the pulsar with the ACS/SBC in FUV and ACS/HRC in NUV to obtain the spectrum of the pulsar in a broad UV range. The spectral analysis will allow us to measure the temperature of the full neutron star surface and probe the heating mechanisms operating in old neutron stars. Confirmation of the spectral line would lead to a first direct measuremnt of the magnetic field and the radius of a spin-powered neutron star and uniquely constrain the equation of state of superdense matter. The NUV spectrum will also probe the magnetospheric emission and the thermal structure of the cool white dwarf companion.

We propose to observe J0437 with the ACS HRC and SBC detectors. The SBC-MAMA will be used to measure the spectrum in the 1250-1800 A range and to confirm the 1372 A line. We will use the PR130L prism to obtain a dispersed low-resolution FUV spectrum with a wavelength-dependent resolution. To obtain a good fit with at least 3 fitting parameters (e.g., temperature, size, and extinction, for the thermal model), the spectrum must be detected in at least 8 wavelength bins with S/N > 8. Because of the lack of a slit, the SBC background over the whole field of view (FOV) will be dominated by emission from the strong geocoronal OI lines at 1304 and 1356 A (hydrogen Ly-alpha line at 1216 A will be cut-off by the prism throughput). Because the bright geocoronal background would severely compromise the observed pulsar spectrum, we request the target to be observed in the Earth shadow to minimize the contribution of the geocoronal background. With the SHADOW requirement the ETC calculations show that we can achieve S/N>8 in 8 spectral bins in a 17.6 ks scientific exposure with SBC/PR130L. This exposure will require 11 HST orbits (1600 ks per orbit), with allowance for the acquisition exposures and instrument overheads. To increase the efficiency of the observation and to better calibrate the wavelength zero-point for the PRISM exposures, we will also take images with SBC/F140LP during the non-SHADOW part of each orbit (850 s scientific exposure per orbit; total 9.35 ks). Using the F140LP filter will allow us to cut off most of the geocoronal emission and detect the pulsar with S/N>13 in a 2 ks exposure (i.e. within one three-orbit visit ) To obtain a low-resolution NUV spectrum (1900-4500 A), we will use the HRC with PR200L prism. The sensitivity of HRC/PR200L is much higher than that of SBC/PR130L, and ETC calculation shows that a sufficiently good spectrum can be obtained with an "average" (default) ETC settings for the sky background. Therefore, we do not need the SHADOW requirement for this part of the observation. To estimate S/N with ETC, we used a three-component source spectral model: NS thermal emission + pulsar magnetospheric emission + WD atmosphere emission. For various combinations of these components, consistent with the previous FUV data, we obtained the distributions of counts over dispersion pixels and calculated the count rates in various wavelength bins. We found that at the lowest reasonable fluxes in the three source components (zero magnetospheric component, lower limit on the thermal NS component, and 4000 K blackbody WD spectrum) we will measure the spectrum with S/N varying from 6 (at the shortest wavelengths) to 100 (at longer wavelengths) in 11 wavelength bins in a 1900-4300 A range in a 7.6 ks exposure (3 orbits, with allowance for overheads). Assuming the strongest magnetospheric component as allowed by the FUV spectrum and the correspondingly fainter thermal NS component, the 7.6 ks exposure will give us a spectrum with S/N > 8 in 11 bins in a 1900-4300 A range. At the intermediate wavelengths, 2800-3800 A, expected S/N values are 20-50, regardless of the magnetospheric component strength. The number of spectral bins and/or S/N will be further increased if the WD atmosphere flux exceeds the 4000 K blackbody flux in the NUV range. To better calibrate the wavelength zero-point in the spectroscopic exposures with PR200L prism, we will also take 3 short imaging exposures. The first one is the default AUTOIMAGE exposure (360 s with HRC/F330W). It will be taken during the first orbit and should detect the pulsar's WD companion with S/N>13. The second and third imaging exposures (100 s long each; both with HRC/F555W filter) will be taken during the 2nd and 3rd orbits, respectively. In each of this exposures the WD will be detected with S/N>30 (the WD is brighter in the V band). During the second and third orbits no AUTOIMAGE (360 s with FHRC/F330W) should be taken. HOT STARS 12 false 0.0 false false false false false AVAILABLE STAR PULSAR This binary pulsar has a proper motion (+121,-71) mas/yr. The position has been measured from the HST STIS/CCD image of 2001.65 and computed for 2006.0. This observation does not require on-board aquisition. A pointing accuracy of 2'' is sufficient. B-V=1.2+/-0.1, R=20.1+/-0.1, I=19.4+/-0.1 J2000 04 37 15.7200 -47 15 8.30 J2000 ACS/SBC Spectroscopic No No PR130L ACS/HRC Spectroscopic No No PR200L C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v01.xml 1144970666630 NUV spectroscopy with PR200L prism. (Tic-Visit :proposal-id 10568 :visit-id "01" :proposal-version -1 :trans-version "20050323" :date "13-Apr-2006 19:24:26.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 165616 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "01" :orbit-number 1 :pcs-time 367 :si-vis-utilization 3029 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "01" :orbit-number 2 :pcs-time 367 :si-vis-utilization 3030 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "01" :orbit-number 3 :pcs-time 367 :si-vis-utilization 3030 :al-overhead-at-end 0 :internal-dur-at-end 219 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 3 0 C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v01.xml 1144970666630 First orbit. The default AUTOIMAGE is taken during this orbit. Second orbit, 100 s V-band imaging exposure is taken for wavelength calibraration instead of the default AUTOIMAGE. We require the direct image to be centered at the same position on the detector as the prism image. We request AUTOIMAGE=NO for this exposure since the 100 s F555W image is taken instead. Third orbit, 100 s V-band imaging exposure taken for wavelength calibraration instead of the default AUTOIMAGE. We require the direct image to be centered at the same position on the detector as the prism image. We request AUTOIMAGE=NO for this exposure since the 100 s F555W image is taken instead. C:\Documents and Settings\Oleg\Local Settings\Temp\OPVisit52677.xml 1145060114815 FUV spectroscopy with SBC and PR1300L. The ORIENT is restricted to avoid a potentially bright nearby galaxy. (Tic-Visit :proposal-id 10568 :visit-id "02" :proposal-version -1 :trans-version "20050323" :date "14-Apr-2006 20:15:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 111088 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "02" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "02" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "02" :orbit-number 3 :pcs-time 367 :si-vis-utilization 2635 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 3 0 1124305255618 This is 1st spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 1st imaging exposure taken outside the SHADOW. It should follow (or precede) the 1st spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 2nd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 2nd imaging exposure taken outside the SHADOW. It should follow (or precede) the 2nd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 3rd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 3rd imaging exposure taken outside the SHADOW. It should follow (or precede) the 3rd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v52.xml 1145059760576 FUV spectroscopy with SBC and PR1300L. The ORIENT is restricted to avoid a potentially bright nearby galaxy. We apply POS TARG Y-OFFSET=-4.5'' to reduce the impact of the SBC thermal glow. (Tic-Visit :proposal-id 10568 :visit-id "52" :proposal-version -1 :trans-version "20050323" :date "14-Apr-2006 20:09:20.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 37040 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "52" :obset-id "52" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "52" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2635 :al-overhead-at-end 0 :internal-dur-at-end 79 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 1 0 C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v52.xml 1144970429939 This is 2nd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 2nd imaging exposure taken outside the SHADOW. It should follow (or precede) the 2nd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v03.xml 1145059768597 FUV spectroscopy with SBC and PR1300L. The ORIENT is restricted to avoid a potentially bright nearby galaxy. We apply POS TARG Y-OFFSET=-4.5'' to reduce the impact of the SBC thermal glow. (Tic-Visit :proposal-id 10568 :visit-id "03" :proposal-version -1 :trans-version "20050323" :date "14-Apr-2006 20:09:28.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 111088 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "03" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "03" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "03" :orbit-number 3 :pcs-time 367 :si-vis-utilization 2635 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 3 0 C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v03.xml 1144970551664 This is 1st spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 1st imaging exposure taken outside the SHADOW. It should follow (or precede) the 1st spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 2nd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 2nd imaging exposure taken outside the SHADOW. It should follow (or precede) the 2nd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 3rd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 3rd imaging exposure taken outside the SHADOW. It should follow (or precede) the 3rd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v04.xml 1145059776969 FUV spectroscopy with SBC and PR1300L. The ORIENT is restricted to avoid a potentially bright nearby galaxy. We apply POS TARG Y-OFFSET=-4.5'' to reduce the impact of the SBC thermal glow. (Tic-Visit :proposal-id 10568 :visit-id "04" :proposal-version -1 :trans-version "20050323" :date "14-Apr-2006 20:09:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 111088 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "04" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "04" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "04" :orbit-number 3 :pcs-time 367 :si-vis-utilization 2635 :al-overhead-at-end 0 :internal-dur-at-end 160 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 3 0 C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v04.xml 1144970595888 This is 1st spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 1st imaging exposure taken outside the SHADOW. It should follow (or precede) the 1st spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 2nd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 2nd imaging exposure taken outside the SHADOW. It should follow (or precede) the 2nd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 3rd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 3rd imaging exposure taken outside the SHADOW. It should follow (or precede) the 3rd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v05.xml 1145059783659 FUV spectroscopy with SBC and PR1300L. The ORIENT is restricted to avoid a potentially bright nearby galaxy. We apply POS TARG Y-OFFSET=-4.5'' to reduce the impact of the SBC thermal glow. (Tic-Visit :proposal-id 10568 :visit-id "05" :proposal-version -1 :trans-version "20050323" :date "14-Apr-2006 20:09:43.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 74064 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10568 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10568 :visit-id "05" :orbit-number 1 :pcs-time 367 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10568 :visit-id "05" :orbit-number 2 :pcs-time 367 :si-vis-utilization 2635 :al-overhead-at-end 0 :internal-dur-at-end 119 :dark-offset 0 :dark-utilization 1681 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3398 :pcs-gap 0 ) true 2 0 C:\Documents and Settings\Oleg\Desktop\Desktop on kr2 (Bobr)\Proposals2\HST_AO14\0437\PhaseII_new\OP-cache\10568_modified-v05.xml 1144970610739 This is 1st spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 1st imaging exposure taken outside the SHADOW. It should follow (or precede) the 1st spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image. This is 2nd spectroscopic exposure taken with the SHADOW requirement. It should be followed (or preceded) by the imaging exposure taken outside the SHADOW during the same orbit. This is 2nd imaging exposure taken outside the SHADOW. It should follow (or precede) the 2nd spectroscopic exposure taken within the SHADOW during the same orbit. We require the direct image to be centered at the same position on the detector as the prism image.