Notice: For the foreseeable future, the daily reports may contain

apparent discrepancies between some proposal descriptions and the listed

instrument usage. This is due to the conversion of previously approved

ACS WFC or HRC observations into WFPC2, or NICMOS observations

subsequent to the loss of ACS CCD science capability in late January.

 

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4322

 

PERIOD COVERED: UT March 19, 2007 (DOY 078)

 

OBSERVATIONS SCHEDULED

 

WFPC2 10563

 

Accurate dark-matter mass profiles in 3 elliptical galaxies as a test of

CDM

 

A critical test of the successful Lambda-CDM picture for structure

formation is the measurement of the power law exponent, gamma, of the

centre of dark matter density profiles, predicted to lie in the range

1.0-1.5. Measurements of gamma derived from rotation curves of LSB

galaxies appear to contradict CDM, but rely on assumptions that are

difficult to verify {e.g. axisymmetry}. We have recently demonstrated,

using our new `semi- linear' inversion method, how strong gravitational

lensing by galaxies can provide a clean and accurate measurement of

gamma, free of such ambiguities. HST images of lensed non-AGN galaxies

provide hundreds of resolution elements, each a constraint on the mass

profile. Such lenses are exceedingly rare, but we have recently

discovered new systems. We propose deep ACS-HRC observations of 3

systems to measure gamma in each, accurate to 0.15 {95% confidence} and

to obtain an indication of its variation between galaxies. To establish

the required number of orbits we have undertaken an end-to-end

simulation of the problem, creating and analysing synthetic ACS images.

Additionally the semi-linear method simultaneously reconstructs the

pixelised source surface brightness distribution. Our simulations

demonstrate that the fine sampling and small pixel scattering of the

HRC, resolves the morphology of the sources with exquisite detail.

 

WFPC2 10833

 

Host Galaxies of Reverberation Mapped AGNs

 

We propose to obtain unsaturated high-resolution images of 17

reverberation-mapped active galactic nuclei in order to remove the

point-like nuclear light from each image, thus yielding a "nucleus-free"

image of the host galaxy. This will allow investigation of host galaxy

properties: our particular interest is determination of the host-galaxy

starlight contribution to the reverberation-mapping observations. This

is necessary {1} for accurate determination of the relationship between

the AGN nuclear continuum flux and the size of the broad Balmer-line

emitting regions of AGNs, which is important in estimating black hole

masses for large samples of QSOs, and {2} for accurate determination of

the bolometric luminosity of the AGN proper. Through observations in

Cycles 12 and 14, we have obtained or will obtain images of 18 of the 35

objects in the reverberation-mapping compilation of Peterson et al.

{2004}. These observations revealed that the host-galaxy contribution,

even in the higher-luminosity AGNs, is higher than expected and that all

of the reverberation- mapped AGNs will have to be observed, not just the

lower-luminosity sources; each source is different, and each source is

important. Therefore we request time to observe the 17 remaining

reverberation-mapped AGNs.

 

WFPC2 10860

 

The largest Kuiper belt object

 

The past year has seen an explosion in the discoveries of Pluto-sized

objects in the Kuiper belt. With the discoveries of the methane-covered

2003 UB313 and 2005 FY9, the multiple satellite system of 2003 EL61, and

the Pluto-Charon analog system of Orcus and its satellite, it is finally

apparent that Pluto is not a unique oddball at the edge of the solar

system, but rather one of a family of similarly large objects in the

Kuiper belt and beyond. HST observations over the past decade have been

critical for understanding the interior, surface, and atmosphere of

Pluto and Charon. We propose here a comprehensive series of observations

designed to similarly expand our knowledge of these recently discovered

Pluto-sized and near-Pluto-sized Kuiper belt objects. These observations

will measure objects' sizes and densities, explore the outcome of

collisions in the outer solar system, and allow the first ever look at

the interior structure of a Kuiper belt object. Our wide field survey

that discovered all of these objects is nearly finished, so after five

years of continuous searching we are finally almost complete in our

tally of these near-Pluto-sized objects. This large HST request is the

culmination of this half-decade search for new planetary-sized objects.

As has been demonstrated repeatedly by the approximately 100 previous

orbits devoted to the study of Pluto, only HST has the resolution and

sensitivity for detailed study of these distant objects.

 

WFPC2 11024

 

WFPC2 CYCLE 15 INTERNAL MONITOR

 

This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays {both gain 7 and

gain 15 -- to test stability of gains and bias levels}, a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.

 

NIC1/NIC2/NIC3 8795

 

NICMOS Post-SAA calibration - CR Persistence Part 6

 

A new proceedure proposed to alleviate the CR-persistence problem of

NICMOS. Dark frames will be obtained immediately upon exiting the SAA

contour 23, and everytime 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 i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

 

NIC2 10802

 

SHOES-Supernovae, HO, for the Equation of State of Dark energy

 

The present uncertainty in the value of the Hubble constant {resulting

in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at

redshifts exceeding 1 are now the leading obstacles to determining the

nature of dark energy. We propose a single, integrated set of

observations for Cycle 15 that will provide a 40% improvement in

constraints on dark energy. This program will observe known Cepheids in

six reliable hosts of Type Ia supernovae with NICMOS, reducing the

uncertainty in H_0 by a factor of two because of the smaller dispersion

along the instability strip, the diminished extinction, and the weaker

metallicity dependence in the infrared. In parallel with ACS, at the

same time the NICMOS observations are underway, we will discover and

follow a sample of Type Ia supernovae at z > 1. Together, these

measurements, along with prior constraints from WMAP, will provide a

great improvement in HST's ability to distinguish between a static,

cosmological constant and dynamical dark energy. The Hubble Space

Telescope is the only instrument in the world that can make these IR

measurements of Cepheids beyond the Local Group, and it is the only

telescope in the world that can be used to find and follow supernovae at

z > 1. Our program exploits both of these unique capabilities of HST to

learn more about one of the greatest mysteries in science.

 

WFPC2 10890

 

Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous Galaxies

 

The formative phase of the most massive galaxies may be extremely

luminous, characterized by intense star- and AGN-formation. Till now,

few such galaxies have been unambiguously identified at high redshift,

restricting us to the study of low-redshift ultraluminous infrared

galaxies as possible analogs. We have recently discovered a sample of

objects which may indeed represent this early phase in galaxy formation,

and are undertaking an extensive multiwavelength study of this

population. These objects are bright at mid-IR wavelengths

{F[24um]>0.8mJy}, but deep ground based imaging suggests extremely faint

{and in some cases extended} optical counterparts {R~24-27}. Deep K-band

images show barely resolved galaxies. Mid-infrared spectroscopy with

Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting

bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS

F814W and NIC2 F160W images of these sources and their environs in order

to determine kpc-scale morphologies and surface photometry for these

galaxies. The proposed observations will help us determine whether these

extreme objects are merging systems, massive obscured starbursts {with

obscuration on kpc scales!} or very reddened {locally obscured} AGN

hosted by intrinsically low-luminosity galaxies.

 

WFPC2 11023

 

WFPC2 CYCLE 15 Standard Darks - part 1

 

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.

 

Notice: For the foreseeable future, the daily reports may contain

apparent discrepancies between some proposal descriptions and the listed

instrument usage. This is due to the conversion of previously approved

ACS WFC or HRC observations into WFPC2, or NICMOS observations

subsequent to the loss of ACS CCD science capability in late January.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS: (None)

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                        SCHEDULED      SUCCESSFUL 

FGS GSacq                07                 07             

FGS REacq               05                  05              

OBAD with Maneuver 25                  25                                  

 

SIGNIFICANT EVENTS: (None)