Status Report

NASA Hubble Space Telescope Daily Status Report #3856

By SpaceRef Editor
May 11, 2005
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HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT        #3856



ACS/HRC 10133

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled
opportunity to study extragalactic jet phenomena at the highest
resolution. During 2002, HST and Chandra monitoring of the M87 jet
detected a dramatic flare in knot HST-1 located ~1″ from the nucleus.
As of late 2003 its brightness has increased twenty-fold in the
optical band, and continues to increase sharply; the X-rays show a
similarly dramatic outburst. In both bands HST-1 now greatly exceeds
the nucleus in brightness. To our knowledge this is the first
incidence of an optical or X-ray outburst from a jet region which is
spatially distinct from the core source; this presents an
unprecedented opportunity to study the processes responsible for
non-thermal variability and the X-ray emission. We propose seven
epochs of monitoring during Cycle 13, as well as seven epochs of
Chandra/ACIS observation {5ksec each}. We also include a brief HRC/ACS
observations that will be used to gather spectral information and map
the magnetic field structure. This monitoring is continued into Cycles
14 and 15. The results of this investigation are of key importance not
only for understanding the nature of the X-ray emission of the M87
jet, but also for understanding flares in blazar jets, which are
highly variable, but where we have never before been able to resolve
the flaring region in the optical or X-rays. These observations will
allow us to test synchrotron emission models for the X-ray outburst,
constrain particle acceleration and loss timescales, and study the jet
dynamics associated with this flaring component. Revisions 6 Oct 2004:
We are replacing STIS visits 1-7 with ACS/HRC observations in new
visits 31- 37.


The Origin of Gamma-Ray Bursts

The rapid and accurate localization of gamma-ray bursts {GRBs}
promised by a working HETE-2 during the coming year may well
revolutionize our ability to study these enigmatic, highly luminous
transients. We propose a program of HST and Chandra observations to
capitalize on this extraordinary opportunity. We will perform some of
the most stringent tests yet of the standard model, in which GRBs
represent collimated relativistic outflows from collapsing massive
stars. NICMOS imaging will detect broad atomic features of supernovae
underlying GRB optical transients, at luminosities more than three
times fainter than SN 1998bw. UV, optical, and X-ray spectroscopy will
be used to study the local ISM around the GRB. Chandra spectroscopy
will investigate whether the GRB X-ray lines are from metals freshly
ripped from the stellar core by the GRB. HST and CTIO infra-red
imaging of the GRBs and their hosts will be used to determine whether
`dark’ bursts are the product of unusually strong local extinction;
imaging studies may for the first time locate the hosts of `short’
GRBs. Our early polarimetry and late-time broadband imaging will
further test physical models of the relativistic blast wave that
produces the bright GRB afterglow, and will provide unique insight
into the influence of the GRB environment on the afterglow.


The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey — COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I> 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble’s ultimate
legacy for understanding the evolution of both the visible and dark

FGS 10113

Trigonometric Calibration of the Period- Luminosity Relations for
Fundamental and First-Overtone Galactic Cepheids

Cepheids are the primary distance indicators for the extragalactic
distance scale and the Hubble constant. The Hubble Constant Key
Project set the zero-point for their Cepheid distance scale by
adopting a distance to the LMC, averaged over a variety of techniques.
However, different methods give an LMC distance modulus ranging from
18.1 to 18.8, and the uncertainty in the Cepheid zero-point is now the
largest contributor to the error budget for H_0. Moreover, the low
metallicity of the LMC raises additional concerns, since the PL
relation probably depends on metallicity. The zero-point can be
determined from Hipparcos parallaxes of Galactic Cepheids out to
several hundred parsecs, but with a typical parallax error of 0.5-1
mas, the Hipparcos error bars are uncomfortably large for this
demanding application. By contrast, HST’s FGS1R interferometer can
achieve astrometric accuracy of 0.2 mas. We propose to use FGS1R to
determine trigonometric parallaxes for a sample of 9 nearby Cepheids,
including both fundamental {F} and first-overtone {FO} pulsators. We
show that the improvement in the PL relations for F and FO Cepheids
will be dramatic. We will determine the PL slopes from our nearby
solar- metallicity sample alone, without recourse to nearby galaxies
and the issue of [Fe/H] dependence. The zero-point will be determined
robustly to about 0.05 mag, based on accurate, purely geometrical

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

A new procedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour 23, and every time a NICMOS exposure is scheduled within 50
minutes of coming out of the SAA. The darks will be obtained in
parallel in all three NICMOS Cameras. The POST-SAA darks will be
non-standard reference files available to users with a USEAFTER
date/time mark. The keyword ‘USEAFTER=date/time’ will also be added to
the header of each POST-SAA DARK frame. The keyword must be populated
with the time, in addition to the date, because HST crosses the SAA ~8
times per day so each POST-SAA DARK will need to have the appropriate
time specified, for users to identify the ones they need. Both the raw
and processed images will be archived as POST-SAA DARKSs. Generally we
expect that all NICMOS science/calibration observations started within
50 minutes of leaving an SAA will need such maps to remove the CR
persistence from the science images. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.

NIC2 10167

Imaging of Ices in Circumstellar Disks

The link between the material of the interstellar medium and the
ultimate composition of planets lies in the way gas and dust are
processed in circumstellar disks. Planet formation models rely upon a
knowledge of the disk constituents and temperature profiles to
simulate how small grains eventually combine into terrestrial planets
and gas giant cores. Disks around other stars may be analogs for our
own early Solar System and thus allow the direct measurement of such
phenomena. Only recently, however, have well-resolved images of dust
disks around several late T Tauri or main sequence stars been secured.
HST provides a uniquely stable platform for making such sensitive high
dynamic range images. Now, for those handful of disks already
resolved, we are able to go beyond the discovery phase and begin
making astrophysical measurements to deepen our understanding of the
course of disk evolution. We therefore propose a multi-wavelength
study with NICMOS designed to discover the spatial distribution of two
common Solar System materials — methane and water ices — in other

NIC2 10173

Infrared Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they
are one of the most energetic astrophysical phenomena and they provide
an exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of
the structure, contents and evolution of these important objects.
Amongst the results, we discovered new optical jets, dust lanes,
face-on disks with optical jets, and revealed point-like nuclei whose
properties support FR-I/BL Lac unified schemes. Here, we propose to
obtain NICMOS infrared images of 3CR sources with z<0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying “young stars near
Earth”. For most of the proposed young {<~ 30 Myrs} and nearby {<~ 60 pc} targets, we can detect a few Jupiter-mass planets as close as a few tens of AUs from the primary stars. This represents the first time that potential analogs of our solar system - that is planetary systems with giant planets having semi-major axes comparable to those of the four giant planets of the Solar System - come within the grasp of existing instrumentation. Our proposed targets have not been observed for planets with the Hubble Space Telescope previously. Considering the very successful earlier NICMOS observations of low mass brown dwarfs and planetary disks among members of the TW Hydrae Association, a fair fraction of our targets should also turn out to posses low mass brown dwarfs, giant planets, or dusty planetary disks because our targets are similar to {or even better than} the TW Hydrae stars in terms of youth and proximity to Earth. Should HST time be awarded and planetary mass candidates be found, proper motion follow-up of candidate planets will be done with ground-based AOs.

NIC3 10337

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 10092.

WFPC2 10359

WFPC2 CYCLE 13 Standard Darks

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be


9804 – NICMOS Cooling System MNDRDT2 broke limit for one sample @
129/23:29:02z On day 129/23:29:02 mnemonic MNDRDT2 (Nicmos Cooling
System – Capillary Pumped Loop Reservoir Delta-T) broke lower limit
for 60 seconds, with a value of 5.88875 Degrees C. PRD lower limit is
7.0 Degrees C.

9805 – GSACQ(1,2,2) fine lock backup, scan step limit exceeded on FGS
1 @ 130/02:41:31z GSACQ(1,2,2) at 130/02:38:32 ended in fine lock
backup on FGS 1 due to scan step limit exceeded on FGS 1 at 02:41:31.
 REACQ(1,2,2) at 04:15:14 also ended up in fine lock backup on FGS 1.


0942-0 – Detecting and Reporting of Loss of Locks @130/05:05:43z (HSTAR #

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES 
 FGS Gsacq               15                       15 
 FGS Reacq                03                       03 
 FHST Update             17                       17 
 LOSS of 
 LOCK                                                    130/05:05:43z 
 (HSTAR # 9805) 


SpaceRef staff editor.