Status Report

NASA Hubble Space Telescope Daily Report # 3887

By SpaceRef Editor
June 23, 2005
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT        # 3887

PERIOD COVERED: UT June 22, 2005 (DOY 173)


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.

ACS/HRC 10182

Towards a Comprehensive Understanding of Type Ia Supernovae: The
Necessity of UV Observations

Type Ia supernovae {SNe Ia} are very important to many diverse areas
of astrophysics, from the chemical evolution of galaxies to
observational cosmology which led to the discovery of dark energy and
the accelerating Universe. However, the utility of SNe Ia as
cosmological probes depends on the degree of our understanding of SN
Ia physics, and various systematic effects such as cosmic chemical
evolution. At present, the progenitors of SNe Ia and the exact
explosion mechanisms are still poorly understood, as are evolutionary
effects on SN Ia peak luminosities. Since early-time UV spectra and
light curves of nearby SNe Ia can directly address these questions, we
propose an approach consisting of two observational components: {1}
Detailed studies of two very bright, young, nearby SNe Ia with HST UV
spectroscopy at 13 epochs within the first 1.5 months after discovery;
and {2} studies of correlations with luminosity for five somewhat more
distant Hubble-flow SNe Ia, for which relative luminosities can be
determined with precision, using 8 epochs of HST UV spectroscopy
and/or broad-band imaging. The HST data, along with extensive
ground-based optical to near-IR observations, will be analyzed with
state-of-the-art models to probe SN Ia explosion physics and constrain
the nature of the progenitors. The results will form the basis for the
next phase of precision cosmology measurements using SNe Ia, allowing
us to more fully capitalize on the substantial past {and future}
investments of time made with HST in observations of high-redshift SNe

ACS/HRC 10259

Planetary nebulae in the SMC: a study of stellar evolution and
populations in an extremely low- metallicity environment

The final phase of the evolution of low- and intermediate-mass stars,
the planetary nebula {PN} ejection, is thought to largely contribute
to the carbon and nitrogen enrichment in galaxies, in particular in
old stellar populations. Stellar generations forming from a carbon-
and nitrogen- enriched medium are a necessary condition for planetary
and life formation. It is essential to understand how stars go through
the process of shedding their chemically-enriched shells, and to test
the predictions of stellar evolution theory on the relationship
between stellar mass and elemental enrichment. Magellanic Cloud PNs
are ideal probes for this study. Their abundances can be directly
related to the mass of the central stars and to that of the stellar
progenitor, without the great {distance and reddening} uncertainties
that affect Galactic PNs. The UV lines are essential for calculating
the abundances of the element related to stellar evolution {C, N, O}
and to progenitor populations {e.g., Ne}. We propose to acquire UV
spectroscopy of the SMC PNs whose morphology and central star
properties has been previously determined by us with HST. We will
derive the {C, N, O} abundance-to-mass relation, and determine the
extent to which the mass of the progenitors of asymmetric PNs exceed
that of symmetric PNs. We will also test the PN luminosity function,
and probe cosmic recycling, in a very low-metallicity environment.

ACS/HRC 10377

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.


ACS CCDs daily monitor – Cycle 13 – Part 2

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This program will be
for the entire lifetime of ACS.


Environmental drivers of galaxy evolution: an HST survey of dwarf
galaxy morphologies in the Abell

Galaxies in dense environments are subject to numerous physical
processes that leave a lasting impact, yet studies of galaxy evolution
to date have been limited to the most luminous galaxies — those least
sensitive to environmental influence. We propose to explore the
environmental drivers of DWARF galaxy evolution: with a mosaic of 9×9
ACS pointings in F606W we will determine morphologies for ~1200
galaxies down to M_V=-14 in the A901/902 supercluster, spanning 3×3
Mpc at z=0.16. The deep ACS data will allow us to probe their surface
brightness profiles, shapes, sizes, asymmetry and fine structure such
as tidal features. With the addition of extensive existing
multi-wavelength data, we will probe the dependence of these important
parameters on dark matter content {from weak lensing maps}, the hot
intercluster medium {from deep XMM-Newton imaging}, and local galaxy
density {from hyper-accurate COMBO-17 photometric redshifts with delta
z=0.02 to m_R=24}, thus disentangling the various environmental
processes shaping dwarf galaxy evolution. Furthermore, the 8000+
background galaxies at 0.2

NIC1 10143

Ultracool companions to the nearest L dwarfs

We propose to conduct the most sensitive survey to date for low mass
companions to nearby L dwarfs. We will use NICMOS to image targets
drawn from a volume-complete sample of 70 L dwarfs within 20 parsecs.
The combination of infrared imaging and proximity will allow us to
search for T dwarf companions at separations as small as 1.6 AU. This
is crucial, since no ultracool binaries are currently known with
separations exceeding 15 AU. Only 10 dwarfs in this sample have
previous HST observations primarily at optical wavelengths. With the
increased sensitivity of our survey, we will provide the most
stringent test to date of brown dwarf models which envisage formation
as ejected stellar embryos. In addition, our observations will be
capable of detecting binaries with mass ratios as low as 0.3, and will
therefore also test the apparent preference for equal-mass ultracool
binaries. Finally, our observations offer the best prospect to date of
detecting companions significantly cooler than the coolest t dwarf
currently known.

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration – CR Persistence Part 3

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 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.


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


9858 – GSAcq(1,2,1) requires three attempts to achieve CT-DV @
165/16:53:45z GSAcq(1,2,1) required three attempts before achieving
CT-DV. The acquisition was successful.

9859 – GSAcq(1,2,1) returns to SSM control @ 169/16:02:32z OTA SE
review of PTAS processing reveals that GSAcq(1,2,1) at 169/16:02:32,
achieved FL-DV on both FGS 1 and 2 by 16:07:44, but both FGSs returned
to SSM control at 16:09:29. Both FGSs successfully recovered to FL-DV
at 16:10:27.

9860 – ReAcq(2,1,2) returns to SSM control @ 170/17:43:04z OTA SE
review of PTAS processing reveals that ReAcq(2,1,2) at 17:43:04
achieve fine lock on both FGS’s at 17:45:28. It then returned to SSM
control 17:46:44. Both FGS’s returned to Fine Lock at 17:47:39.


17455-0 Genslew For Proposal 10147- slot 2 @174/07:10z

17456-0 Genslew For Proposal 10147- slot 3 @ 174/07:11z


                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
 FGS Gsacq              14                      14 
 FGS Reacq               05                      05 
 FHST Update            18                      18 


SpaceRef staff editor.