HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT       # 4602

PERIOD COVERED: 5am May 01 - 5am May 02, 2008 (DOY 122/0900z - 123/0900z) 

OBSERVATIONS SCHEDULED

ACS/SBC 11200

An Ultraluminous EUV Source?

Ultraluminous X-ray sources (ULXs) are bright, irregularly variable,

non-nuclear, X- ray sources with apparent luminosities exceeding the

Eddington limit for stellar- mass black holes. There is great interest

in ULXs because they may represent a new class of black holes with

masses intermediate between stellar-mass and supermassive black holes.

Recently, it has been found that X-ray emission from the nebula MF 16 in

the galaxy NGC 6946, previously thought to be an usually luminous

supernova remnant, actually arises from an accreting compact object.

Optical spectroscopy of nebula shows that it is powered via

photoionization by an extreme ultraviolet (EUV) source with a luminosity

exceeding that measured from the X-ray source. If correct this would be

the first ultraluminous UV source and may be a 10, 000 solar mass black

hole. We propose an FUV observation with the ACS/SBC to determine if a

highly luminous EUV source is indeed, present within MF 16.

NIC1 11136

Resolving Ultracool Astrophysics with Brown Dwarf Binaries

We propose to obtain resolved far-red and near-IR photometry of 13 brown

dwarf binaries with HST/NICMOS in order to study one of the

long-standing puzzles in ultracool astrophysics, namely the rapid change

in spectra from L dwarfs to T dwarfs at nearly constant effective

temperature (a.k.a. the "L/T transition''). While many nearby brown

dwarfs have been studied, use of such samples is inevitably hindered by

the unknown ages, masses, and metallicities of the field population.

Characterization of resolved ultracool binaries is a promising avenue

for addressing this problem, by providing coeval systems of the same

composition with comparable masses and temperatures. Our proposed

HST/NICMOS (0.9-1.6 micron) observations will be combined with longer

wavelength ground-based photometry and spectroscopy from Keck laser

guide star adaptive optics. The resulting multiband (0.9-2.5 micron)

dataset will be a unique resource for measuring the evolution of

spectral energy distributions across the L/T transition, to test

state-of-the-art atmospheric models, and to determine the physical

process(es) that dominate the L/T transition. Understanding the L/T

transition is important not only for testing brown dwarf atmospheres,

but also provides a key pathway for understanding the same physical

effects, namely the formation and removal of clouds, in the atmospheres

of the extrasolar planets.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA calibration - CR Persistence Part 6

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 i

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

passages leave different imprints on the NICMOS detectors.

NIC2/NIC1/NIC3 11159

The True Galactic Bulge Luminosity Function

We propose to obtain second epoch imaging of the deep Galactic bulge

field observed using NICMOS by Zoccali et al. (2000). The bulge

luminosity and mass function suffered from 30-50% contamination by

foreground disk stars, which was impossible to correct for in the

original study. Revisiting the field after 9 years, we propose to

segregate the foreground disk stars because they have large transverse

velocities, thus revealing the luminosity function of Galactic bulge low

mass stars to near the hydrogen burning limit. The slope of the mass

function has implications for galaxy formation and for understanding the

nature of microlensing in the Galactic bulge.

NIC3 11332

NICMOS Cycle 16 Time Dependent Flat Fields

This proposal obtains sequences of NICMOS narrow, medium and broad band

filter flat fields for camera 1. In cameras 2 and 3, parallel

observations will allow us to obtain high S/N flats for all spectral

elements.

WEPC2 11196

An Ultraviolet Survey of Luminous Infrared Galaxies in the Local

Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared

selected galaxies exceeds that of optically selected galaxies. These

Luminous Infrared Galaxies {LIRGs} are primarily interacting or merging

disk galaxies undergoing starbursts and creating/fueling central AGN. We

propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a

sample of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy

Sample {RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS

imaging observations, to have significant numbers of bright {23 < B < 21

mag} star clusters in the central 30 arcsec. The HST UV data will be

combined with previously obtained HST, Spitzer, and GALEX images to {i}

calculate the ages of the clusters as function of merger stage, {ii}

measure the amount of UV light in massive star clusters relative to

diffuse regions of star formation, {iii} assess the feasibility of using

the UV slope to predict the far-IR luminosity {and thus the star

formation rate} both among and within IR-luminous galaxies, and {iv}

provide a much needed catalog of rest- frame UV morphologies for

comparison with rest-frame UV images of high-z LIRGs and Lyman Break

Galaxies. These observations will achieve the resolution required to

perform both detailed photometry of compact structures and spatial

correlations between UV and redder wavelengths for a physical

interpretation our IRX-Beta results. The HST UV data, combined with the

HST ACS, Spitzer, Chandra, and GALEX observations of this sample, will

result in the most comprehensive study of luminous starburst galaxies to

date.

WFPC2 11022

WFPC2 Cycle 15 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument

monitors tied to decons: photometric stability check, focus monitor,

pre- and post-decon internals {bias, intflats, kspots, & darks}, UV

throughput check, VISFLAT sweep, and internal UV flat check.

WFPC2 11027

Visible Earth Flats

This proposal monitors flatfield stability. This proposal obtains

sequences of Earth streak flats to construct high quality flat fields

for the WFPC2 filter set. These flat fields will allow mapping of the

OTA illumination pattern and will be used in conjunction with previous

internal and external flats to generate new pipeline superflats. These

Earth flats will complement the Earth flat data obtained during cycles

4-14.

WFPC2 11029

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly

Monitor

Intflat observations will be taken to provide a linearity check: the

linearity test consists of a series of intflats in F555W, in each gain

and each shutter. A combination of intflats, visflats, and earthflats

will be used to check the repeatability of filter wheel motions.

{Intflat sequences tied to decons, visits 1-18 in prop 10363, have been

moved to the cycle 15 decon proposal xxxx for easier scheduling.} Note:

long-exposure WFPC2 intflats must be scheduled during ACS anneals to

prevent stray light from the WFPC2 lamps from contaminating long ACS

external exposures.

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge

Paradigm, Part II

The recent progress in the study of central black holes in galactic

nuclei has led to a general consensus that supermassive {10^6-10^9 solar

mass} black holes are closely connected with the formation and

evolutionary history of large galaxies, especially their bulge

component. Two outstanding issues, however, remain unresolved. Can

central black holes form in the absence of a bulge? And does the mass

function of central black holes extend below 10^6 solar masses?

Intermediate-mass black holes {<10^6 solar masses}, if they exist, may

offer important clues to the nature of the seeds of supermassive black

holes. Using the SDSS, our group has successfully uncovered a new

population of AGNs with intermediate-mass black holes that reside in

low-luminosity galaxies. However, very little is known about the

detailed morphologies or structural parameters of the host galaxies

themselves, including the crucial question of whether they have bulges

or not. Surprisingly, the majority of the targets of our Cycle 14 pilot

program have structural properties similar to dwarf elliptical galaxies.

The statistics from this initial study, however, are really too sparse

to reach definitive conclusions on this important new class of black

holes. We wish to extend this study to a larger sample, by using the

Snapshot mode to obtain WFPC2 F814W images from a parent sample of 175

AGNs with intermediate- mass black holes selected from our final SDSS

search. We are particularly keen to determine whether the hosts contain

bulges, and if so, how the fundamental plane properties of the host

depend on the mass of their central black holes. We will also

investigate the environment of this unique class of AGNs.

WFPC2 11178

Probing Solar System History with Orbits, Masses, and Colors of

Transneptunian Binaries

The recent discovery of numerous transneptunian binaries {TNBs} opens a

window into dynamical conditions in the protoplanetary disk where they

formed as well as the history of subsequent events which sculpted the

outer Solar System and emplaced them onto their present day heliocentric

orbits. To date, at least 47 TNBs have been discovered, but only about a

dozen have had their mutual orbits and separate colors determined,

frustrating their use to investigate numerous important scientific

questions. The current shortage of data especially cripples scientific

investigations requiring statistical comparisons among the ensemble

characteristics. We propose to obtain sufficient astrometry and

photometry of 23 TNBs to compute their mutual orbits and system masses

and to determine separate primary and secondary colors, roughly tripling

the sample for which this information is known, as well as extending it

to include systems of two near-equal size bodies. To make the most

efficient possible use of HST, we will use a Monte Carlo technique to

optimally schedule our observations.

WFPC2 11316

HST Cycle 16 & pre-SM4 Optical Monitor

This is a continuation of the Cycle 15 & pre-SM4 Optical Monitor, 11020.

Please see that proposal for a more complete description of the

observing strategy. The 6 visits comprising this proposal observe two

single standard stars with WFPC2/PC in order to establish overall OTA

focal length for the purposes of focus maintenance. The goal of this

monitoring before SM4 is to establish a best estimate of the OTA focus

entering SMOV.

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                09                  09                  

FGS REacq                06                  06                  

OBAD with Maneuver  30                  30                

SIGNIFICANT EVENTS: (None)