HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT       #4654

 

PERIOD COVERED: 5am July 16 - 5am July 17, 2008 (DOY 198/0900z-199/0900z)

 

OBSERVATIONS SCHEDULED

 

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 11237

 

The Origin of the Break in the AGN Luminosity Function

 

We propose to use NICMOS imaging to measure rest-frame optical

luminosities and morphological properties of a complete sample of faint

AGN host galaxies at redshifts z ~ 1.4. The targets are drawn from the

VLT-VIMOS Deep Survey, and they constitute a sample of the lowest

luminosity type 1 AGN known at z > 1. The spectroscopically estimated

black hole masses are up to an order of magnitude higher than expected

given their nuclear luminosities, implying highly sub-Eddington

accretion rates. This exactly matches the prediction made by recent

theoretical models of AGN evolution, according to which the faint end of

the AGN luminosity function is populated mainly by big black holes that

have already exhausted a good part of their fuel. In this proposal we

want to test further predictions of that hypothesis, by focusing on the

host galaxy properties of our low-luminosity, low- accretion AGN. If the

local ratio between black hole and bulge masses holds at least

approximately at these redshifts, one expects most of these

low-luminosity AGN to reside in fairly big ellipticals with stellar

masses around and above 10^11 solar masses (in contrast to the Seyfert

phenomenon in the local universe). With NICMOS imaging we will find out

whether that is true, implying also a sensitive test for the validity of

the M_BH/M_bulge relation at z ~ 1.4.

 

NIC2 11547

 

Characterizing Pre-Main Sequence Populations in Stellar Associations of

the Large Magellanic Cloud

 

The Large Magellanic Cloud (LMC) offers an extremely rich sample of

resolved low-mass stars (below 1 Solar Mass) in the act of formation

that has not been explored sufficiently yet. These pre-main sequence

(PMS) stars provide a unique snapshot of the star formation process, as

it is being recorded for the last ~20 Myr, and they give important

information on the low-mass Initial Mass Function (IMF) of their host

stellar systems. Studies of young, rich LMC clusters like 30 Doradus are

crowding limited, even at the angular resolution facilitated by HST in

the optical. To learn more about low-mass PMS stars in the LMC, one has

to study less crowded regions like young stellar associations. We propose

to employ WFPC2 to obtain deep photometry (V ~ 25.5 mag) of four

selected LMC stellar associations in order to perform an original

optical analysis of their red PMS and blue bright MS stellar

populations. With these observations we aim at a comprehensive study,

which will add substantial information on the most recent star formation

and the IMF in the LMC. The data reduction and analysis will be

performed with a 2D photometry software package especially developed by

us for WFPC2 imaging of extended stellar associations with variable

background. Our targets have been selected optimizing a combination of

criteria, namely spatial resolution, crowding, low extinction, nebular

contamination, and background confusion in comparison to other regions

in the Local Group. Parallel NICMOS imaging will provide additional

information on near-infrared properties of the stellar population in the

regions surrounding these systems.

 

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 11113

 

Binaries in the Kuiper Belt: Probes of Solar System Formation and

Evolution

 

The discovery of binaries in the Kuiper Belt and related small body

populations is powering a revolutionary step forward in the study of

this remote region. Three quarters of the known binaries in the Kuiper

Belt have been discovered with HST, most by our snapshot surveys. The

statistics derived from this work are beginning to yield surprising and

unexpected results. We have found a strong concentration of binaries

among low-inclination Classicals, a possible size cutoff to binaries

among the Centaurs, an apparent preference for nearly equal mass

binaries, and a strong increase in the number of binaries at small

separations. We propose to continue this successful program in Cycle 16;

we expect to discover at least 13 new binary systems, targeted to

subgroups where these discoveries can have the greatest impact.

 

WFPC2 11122

 

Expanding PNe: Distances and Hydro Models

 

We propose to obtain repeat narrowband images of a sample of eighteen

planetary nebulae {PNe} which have HST/WFPC2 archival data spanning time

baselines of a decade. All of these targets have previous high

signal-to-noise WFPC2/PC observations and are sufficiently nearby to

have readily detectable expansion signatures after a few years. Our main

scientific objectives are {a} to determine precise distances to these

PNe based on their angular expansions, {b} to test detailed and highly

successful hydrodynamic models that predict nebular morphologies and

expansions for subsamples of round/elliptical and axisymmetric PNe, and

{c} to monitor the proper motions of nebular microstructures in an

effort to learn more about their physical nature and formation

mechanisms. The proposed observations will result in high-precision

distances to a healthy subsample of PNe, and from this their expansion

ages, luminosities, CSPN properties, and masses of their ionized cores.

With good distances and our hydro models, we will be able to determine

fundamental parameters {such as nebular and central star masses,

luminosity, age}. The same images allow us to monitor the changing

overall ionization state and to search for the surprisingly

non-homologous growth patterns to bright elliptical PNe of the same sort

seen by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is a sure

sign of active pressure imbalances within the nebula that require

careful hydro models to understand.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

11396 - GSAcq (1,2,1) failed due to Search Radius Limit Exceeded on FGS 2

           At 198/17:07:41, GSAcq (1,2,1) scheduled from 17:04:07 - 17:11:19 failed

           to RGA control due to Search Radius Limit Exceeded on FGS 2. Received

           flags QF2SRLEX and QF2STOPF on FGS 2. Received 486 ESB message a07

           "Exceeded SRL". FGS 1 achieved Fine Lock at 17:06:49.

 

           Observations affected: NICMOS 72 - 77, WFPC #88 to 108.

 

           REACQ(1,2,1) at 18:37:41, 20:13:31 and 21:49:21 alos failed.

 

11398 - OBAD Failed Quaternion (ESB 1903)

           At 199/06:12:54 OBAD2 scheduled at 199/06:10:05 using FHST Trackers 1

           and 3 failed. OBAD Flag mnemonic GOBSTAT posted "AttDtErr" status. One

           486 ESB 1903 "OBAD Failed Quaternion" was received at 199/06:12:54.

           Additional 486 ESB 1806 (T2G Open Loop Timeout) received at

           199/06:12:15. The subsequent guide star did not attempt.

 

 

11399 - GSAcq (1,2,1) not attempted, open loop timer expired

           GSAcq (1,2,1) scheduled at 199/06:16:42 - 06:24:47 was not attempted due

           to open loop timer expiration. The acquistion failure resulted in unplanned

           transition to M2G.

 

           The subsequent REAcq(1,2,1) scheduled at 199/07:52:19 was not attempted.

           One 486 ESB 1903 "OBAD Failed Quaternion" was received. Additional ESB

           1806 (T2G Open Loop Timeout)was received. HST transitioned to unplanned M2G.

 

           Possible Observations affected: NICMOS #84-93  Proposal #08795 & 11545.

 

 

COMPLETED OPS REQUEST:

17543-2 - Dump OBAD tables after failed OBAD (Generic) @ 199/08:02z

 

COMPLETED OPS NOTES: (None)

 

                         SCHEDULED      SUCCESSFUL 

FGS GSacq                 07                  05      

FGS REacq                 07                  03                         

OBAD with Maneuver  28                   27      

 

SIGNIFICANT EVENTS: (None)