HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4605

 

PERIOD COVERED: 5am May 06 - 5am May 07, 2008 (DOY 127/0900z - 128/0900z)

 

OBSERVATIONS SCHEDULED

 

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.

 

FGS 11210

 

The Architecture of Exoplanetary Systems

 

Are all planetary systems coplanar? Concordance cosmogony makes that

prediction. It is, however, a prediction of extrasolar planetary system

architecture as yet untested by direct observation for main sequence

stars other than the Sun. To provide such a test, we propose to carry

out FGS astrometric studies on four stars hosting seven companions. Our

understanding of the planet formation process will grow as we match not

only system architecture, but formed planet mass and true distance from

the primary with host star characteristics for a wide variety of host

stars and exoplanet masses. We propose that a series of FGS astrometric

observations with demonstrated 1 millisecond of arc per-observation

precision can establish the degree of coplanarity and component true

masses for four extrasolar systems: HD 202206 {brown dwarf+planet}; HD

128311 {planet+planet}, HD 160691 = mu Arae {planet+planet}, and HD

222404AB = gamma Cephei {planet+star}. In each case the companion is

identified as such by assuming that the minimum mass is the actual mass.

For the last target, a known stellar binary system, the companion orbit

is stable only if coplanar with the AB binary orbit.

 

FGS 11299

 

Calibrating the Mass-Luminosity Relation at the End of the Main Sequence

 

We propose to use HST-FGS1R to finish calibrating the mass-luminosity

relation for stars less massive than 0.5 Msun, with special emphasis on

objects near the stellar/substellar border. Our goals are to determine

Mv values to 0.05 magnitude and masses to 5%, and thereby build the

fundamental database of stellar masses that we will use to test

theoretical models as never before. This program uses the combination of

HST-FGS3/FGS1R at optical wavelengths, historical infrared speckle data,

ground-based parallax work, metallicity studies, and radial velocity

monitoring to examine nearby, subarcsecond binary systems. The high

precision separation and position angle measurements with HST-FGS3/FGS1R

{to 1 mas in the separations} for these faint {V = 10-15} targets simply

cannot be equaled by any ground-based technique. As a result of these

measurements, we are deriving high quality luminosities and masses for

the components in the systems, and characterizing their spectral energy

distributions from 0.5 to 2.2 microns. One of the objects, GJ 1245 C

with mass 0.074 +/- 0.002 Msun, is the only object known with an

accurate dynamical mass less than 0.10 Msun. The payoff of this proposal

is high because the six systems selected for final observations in

Cycles 15 and 16 have already been resolved during Cycles 5-13 with HST

FGS3/FGS1R and contain most of the reddest objects for which accurate

dynamical masses can be determined.

 

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 11341

 

Lower Luminosity AGNs at Cosmologically Interesting Redshifts: SEDs and

Accretion Rates of z~0.36 Seyferts

 

We propose a multiwavelength campaign to constrain the SEDs of Seyferts

at z~0.36. This epoch, corresponding to a look back time of 4 Gyrs, is

cosmologically interesting for studies of the coeval development of

black holes and their host galaxy bulges. Our sample, comprising 24

Seyferts, has unprecedented high quality Keck spectroscopy and HST

imaging already invested to extract host galaxy bulge properties,

estimate black hole masses, and separate nuclear and host optical

luminosities. To supplement and extend this successful program, we

request 93 ks of Chandra time (to measure the shape and power of the

AGN-only X-ray continuum), 11 hrs each of Spitzer and Gemini (to

constrain the dust temperature), and 7 orbits of HST (to determine the

nuclear luminosity for the final 7 objects).

 

NIC2/WFPC2 11142

 

Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7

Using HST and Spitzer

 

We aim to determine physical properties of IR luminous galaxies at

0.3<z<2.7 by requesting coordinated HST/NIC2 and MIPS 70um observations

of a unique, 24um flux-limited sample with complete Spitzer mid-IR

spectroscopy. The 150 sources investigated in this program have S{24um}

> 0.8mJy and their mid-IR spectra have already provided the majority

targets with spectroscopic redshifts {0.3<z<2.7}. The proposed

150~orbits of NIC2 and 66~hours of MIPS 70um will provide the physical

measurements of the light distribution at the rest-frame ~8000A and

better estimates of the bolometric luminosity. Combining these

parameters together with the rich suite of spectral diagnostics from the

mid-IR spectra, we will {1} measure how common mergers are among LIRGs

and ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers

of z>1 ULIRGs, as in the local Universe. {2} study the co-evolution of

star formation and blackhole accretion by investigating the relations

between the fraction of starburst/AGN measured from mid-IR spectra vs.

HST morphologies, L{bol} and z. {3} obtain the current best estimates of

the far-IR emission, thus L{bol} for this sample, and establish if the

relative contribution of mid-to-far IR dust emission is correlated with

morphology {resolved vs. unresolved}.

 

NIC3 11334

 

NICMOS Cycle 16 Spectrophotometry

 

Observation of the three primary WD flux standards must be repeated to

refine the NICMOS absolute calibration and monitor for sensitivity

degradation. So far, NICMOS grism spectrophotometry is available for

only ~16 stars with good STIS spectra at shorter wavelengths. There are

more in the HST CALSPEC standard star data base with good STIS spectra

that would also become precise IR standards with NICMOS absolute SED

measurements. Monitoring the crucial three very red stars (M, L, T) for

variability and better S/N in the IR. Apparent variability was

discovered at shorter wavelengths during the ACS cross-calibration work

that revealed a ~2% discrepancy of the cool star fluxes with respect to

the hot primary WD standards. About a third of these stars are bright

enough to do in one orbit, the rest require 2 orbits.

 

WFPC2 11028

 

WFPC2 Cycle 15 UV Earth Flats

 

Monitor flat field stability. This proposal obtains sequences of earth

streak flats to improve the quality of pipeline flat fields for the

WFPC2 UV filter set. These Earth flats will complement the UV earth flat

data obtained during cycles 8-14.

 

WFPC2 11070

 

WFPC2 CYCLE 15 Standard Darks - part II

 

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.

 

WFPC2 11124

 

The Origin of QSO Absorption Lines from QSOs

 

We propose using WFPC2 to image the fields of 10 redshift z ~ 0.7

foreground {FG} QSOs which lie within ~29-151 kpc of the sightlines to

high-z background {BG} QSOs. A surprisingly high fraction of the BG QSO

spectra show strong MgII {2796,2803} absorption lines at precisely the

same redshifts as the FG QSOs. The high resolution capabilities of WFPC2

are needed to understand the origin of these absorption systems, in two

ways. First, we wish to explore the FG QSO environment as close as

possible to the position of the BG QSO, to search for interloping group

or cluster galaxies which might be responsible for the absorption, or

irregularly shaped post-merger debris between the FG and BG QSO which

may indicate the presence of large amount of disrupted gas along a

sightline. Similarly, high resolution images are needed to search for

signs of tidal interactions between any galaxies which might be found

close to the FG QSO. Such features might provide evidence of young

merging events causing the start of QSO duty cycles and producing

outflows from the central AGN. Such winds may be responsible for the

observed absorption lines. Second, we seek to measure the intrinsic

parameters of the FG QSO host galaxy, such as luminosity and morphology,

to correlate with the properties of the MgII absorption lines. We wish

to observe each field through the F814W filter, close to the rest- frame

B-band of the FG QSO. These blue data can reveal enhanced star formation

regions close to the nucleus of the host galaxy, which may be indicative

of galaxy mergers with the FG QSO host. The FG QSO environment offers

quite a different set of phenomena which might be responsible for MgII

absorption, providing an important comparison to studies of MgII

absorption from regular field galaxies.

 

WFPC2 11232

 

Determination of Angular Expansion Velocities in the Ring Nebula

 

The Ring Nebula (NGC 6720) represents an important stage in the

evolution of planetary nebulae, being large enough that it has entered

the post fast-wind stage yet has not reached the late ballistic phase of

objects like the Helix Nebula. Understanding this nebula well presents

the opportunity to determine how nebulae transition from their creation

phase into the form they have as their material enters the interstellar

medium. A recent study based on ground-based spectroscopy has derived a

new and accurate model for the Ring Nebula. A well defined

characteristic of this model is that it predicts a tangential velocity

of 20 km/s whereas the application of its quite uncertain trigonometric

parallax distance of 700 (+450/-200) pc with the angular expansion

velocity determined from HST observations with a 2 year time base

indicates a tangential velocity of 69 (+45/-20) km/s. This disagreement

indicates that either the distance is even more uncertain than thought

or that the earlier angular velocity is incorrect. We propose to make a

new set of observations of the Ring Nebula in the diagnostic emission

line filters F469N (HeII), F502N ([OIII]), and F658N ([NII]) that will

produce much more accurate angular velocities than the previous study by

having a time base of 8.8 years and imaging the nebula entirely within a

single CCD of the WFPC2. The primary result from this study will be an

accurate distance to this important nebula and from this to be able to

use this object to refine our picture of how planetary nebulae evolve

during middle-age.

 

WFPC2 11235

 

HST NICMOS Survey of the Nuclear Regions 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 enhanced star formation and Active

Galactic Nuclei {AGN} activity, possibly triggered as the objects

transform into massive S0 and elliptical merger remnants. We propose

NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88

L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised

Bright Galaxy Sample {RBGS: i.e., 60 micron flux density > 5.24 Jy}.

This sample is ideal not only in its completeness and sample size, but

also in the proximity and brightness of the galaxies. The superb

sensitivity and resolution of NICMOS NIC2 on HST enables a unique

opportunity to study the detailed structure of the nuclear regions,

where dust obscuration may mask star clusters, AGN and additional nuclei

from optical view, with a resolution significantly higher than possible

with Spitzer IRAC. This survey thus provides a crucial component to our

study of the dynamics and evolution of IR galaxies presently underway

with Wide-Field, HST ACS/WFC and Spitzer IRAC observations of these 88

galaxies. Imaging will be done with the F160W filter {H-band} to examine

as a function of both luminosity and merger stage {i} the luminosity and

distribution of embedded star clusters, {ii} the presence of optically

obscured AGN and nuclei, {iii} the correlation between the distribution

of 1.6 micron emission and the mid- IR emission as detected by Spitzer

IRAC, {iv} the evidence of bars or bridges that may funnel fuel into the

nuclear region, and {v} the ages of star clusters for which photometry

is available via ACS/WFC observations. The NICMOS data, combined with

the HST ACS, Spitzer, and GALEX observations of this sample, will result

in the most comprehensive study of merging and interacting galaxies to

date.

 

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               06                 06                  

FGS REacq               07                 07                  

OBAD with Maneuver 26                 26      

 

SIGNIFICANT EVENTS: (None)