Status Report

NASA Hubble Space Telescope Daily Report #3914

By SpaceRef Editor
August 3, 2005
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT         # 3914

PERIOD COVERED:  UT   August 01, 2005 (DOY 213)



Probing the Link between Galactic Bars & Starburst/AGN Activity in

Multi-wavelength data have shown that a substantial fraction of barred
spiral galaxies exhibit enhanced star formation activity in their
central regions. This phenomena is however poorly studied at X-ray
energies. We propose joint Chandra/HST observations of two barred
starburst galaxies NGC1672 and NGC7771. We request Chandra
observations to spatially resolve the X-ray emission into point
sources and diffuse emission, enabling us to trace the star formation
on small spatial scales and search for obscured starburst/AGN
activity. We also request a complimentary optical imaging program with
HST/ACS, permitting us to identify the optical counterparts to X-ray
point sources and map the optical emission from star formation in
their local environments on similar scales to Chandra.

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 10376

ACS Internal Flat Field Stability

The stability of the CCD flat fields will be monitored using the
calibration lamps and a sub-sample of the filter set. High signal
observations will be used to assess the stability of the pixel-to-
pixel flat field structure and to monitor the position of the dust
motes. Only internal exposures with the calibration lamps will be

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.


Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically
hot and cold subpopulations we will be able to answer, with
statistical significance, the question of whether these groups differ
in the abundance of binaries as a result of their particular dynamical
paths into the Kuiper Belt. Today’s Kuiper Belt bears the imprints of
the final stages of giant-planet building and migration; binaries may
offer some of the best preserved evidence of that long-ago era.


Accurate and Robust Calibration of the Extragalactic Distance Scale
with the Maser Galaxy NGC4258 II

The extragalactic distance scale {EDS} is defined by a comparison of
Cepheid Period- Luminosity {PL} relations for nearby galaxies and the
LMC, whose uncertain distance is thereby the SOLE anchor. Studies of
masers orbiting the central black hole in NGC4258 have provided the
most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new
radio data and analysis techniques will reduce the uncertainty to < 3.5% {0.07 mag} by 2005. Since this distance is well determined and based on geometric arguments, NGC4258 can provide a much needed new anchor for the EDS. Ultimately, the combination of an independent measurement of H0 and measurements of CMB fluctuations {e.g., WMAP} can be used to directly constrain cosmological parameters including the equation of state of dark energy. In our Cycle 12 proposal, we defined a program spanning two cycles. The Cycle 12 portion was accepted. We have acquired WFC images and are constructing well sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13 observations is to address systematic sources of error and is crucial for the success of the entire program. To disentangle the effects of reddening and metallicity, and to characterize the effects of blending, we require 50 orbits to obtain H-band photometry {NICMOS/NIC2} and high resolution images {ACS/HRC}.

FGS 10611

Precise Distances to Nearby Planetary Nebulae

We propose to carry out astrometry with the FGS to obtain accurate and
precise distances to four nearby planetary nebulae. In 1992, Cahn et
al. noted that “The distances to Galactic planetary nebulae remain a
serious, if not THE most serious, problem in the field, despite
decades of study.” Twelve years later, the same statement still
applies. Because the distances to planetary nebulae are so uncertain,
our understanding of their masses, luminosities, scale height, birth
rate, and evolutionary state is severely limited. To help remedy this
problem, HST astrometry can guarantee parallaxes with half the error
of any other available approach. These data, when combined with
parallax measurements from the USNO, will improve distance
measurements by more than a factor of two, producing more accurate
distances with uncertainties that are of the order of ~6%. Lastly,
most planetary nebula distance scales in the literature are
statistical. They require several anchor points of known distance in
order to calibrate their zero point. Our program will provide “gold
standard” anchor points by the end of 2006, a decade before any
anticipated results from future space astrometry missions.

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.

NIC3 10406

NICMOS Imaging of Massive Galaxies at z ~ 2

We propose NICMOS F160W imaging of a sample of massive red galaxies
from the Gemini Deep Deep Survey. These galaxies dominate the stellar
mass density at 1.5< z < 2 and are our best link to early galaxy formation. The NICMOS images will be used in conjunction with our ACS images and deep Gemini spectra to examine the formation and early evolution of massive ellpitcal galaxy progenitors. We waive all propretary rights to the data and wil make them available on our web site as we have done with the Gemini Deep Deep Survey spectra, catalogs and ACS images.

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


9906 – U1,2 RD Update Error @ 207/06:06:11z The U1,2 RD Update
scheduled for 2005/207 06:06:11 computed an inaccurate attitude error
due to FHST 2 getting pulled off its star by a brighter moving object
after all 3 error box checks were passed.



                          SCHEDULED     SUCCESSFUL 
 FGS Gsacq              11                     11 
 FGS Reacq              04                     04 
 FHST Update           18                     18 


SpaceRef staff editor.