HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT #5106

 

PERIOD COVERED: 5am May 27 - 5am May 28, 2010 (DOY 147/09:00z-148/09:00z)

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

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

 

HSTARS:

FOR DOY 137

12289 - GSAcq(2,1,2) at 137/17:14:52z failed to Fine Lock backup on FGS2

           with scan step limit exceed on FGS1.

 

           Observations possibly affected, WFC 34 Proposal ID# 11536

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                     SCHEDULED  SUCCESSFUL

FGS GSAcq               08            08       

FGS REAcq               10            10       

OBAD with Maneuver 02            02       

 

SIGNIFICANT EVENTS: (None)

 

 

OBSERVATIONS SCHEDULED:

 

ACS/WFC 11995

 

CCD Daily Monitor (Part 2)

 

This program comprises basic tests for measuring the read noise and dark

current of the ACS WFC and for tracking the growth of hot pixels. The

recorded frames are used to create bias and dark reference images for

science data reduction and calibration. This program will be executed

four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To

facilitate scheduling, this program is split into three proposals. This

proposal covers 320 orbits (20 weeks) from 1 February 2010 to 20 June

2010.

 

COS/FUV/COS/NUV 11598

 

How Galaxies Acquire their Gas: A Map of Multiphase Accretion and

Feedback in Gaseous Galaxy Halos

 

We propose to address two of the biggest open questions in galaxy

formation - how galaxies acquire their gas and how they return it to the

IGM - with a concentrated COS survey of diffuse multiphase gas in the

halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to

establish a basic set of observational facts about the physical state,

metallicity, and kinematics of halo gas, including the sky covering

fraction of hot and cold material, the metallicity of infall and

outflow, and correlations with galaxy stellar mass, type, and color -

all as a function of impact parameter from 10 - 150 kpc. Theory suggests

that the bimodality of galaxy colors, the shape of the luminosity

function, and the mass-metallicity relation are all influenced at a

fundamental level by accretion and feedback, yet these gas processes are

poorly understood and cannot be predicted robustly from first

principles. We lack even a basic observational assessment of the

multiphase gaseous content of galaxy halos on 100 kpc scales, and we do

not know how these processes vary with galaxy properties. This ignorance

is presently one of the key impediments to understanding galaxy

formation in general. We propose to use the high-resolution gratings

G130M and G160M on the Cosmic Origins Spectrograph to obtain sensitive

column density measurements of a comprehensive suite of multiphase ions

in the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from

the Sloan Digital Sky Survey. In aggregate, these sightlines will

constitute a statistically sound map of the physical state and

metallicity of gaseous halos, and subsets of the data with cuts on

galaxy mass, color, and SFR will seek out predicted variations of gas

properties with galaxy properties. Our interpretation of these data will

be aided by state-of-the-art hydrodynamic simulations of accretion and

feedback, in turn providing information to refine and test such models.

We will also use Keck, MMT, and Magellan (as needed) to obtain optical

spectra of the QSOs to measure cold gas with Mg II, and optical spectra

of the galaxies to measure SFRs and to look for outflows. In addition to

our other science goals, these observations will help place the Milky

Way's population of multiphase, accreting High Velocity Clouds (HVCs)

into a global context by identifying analogous structures around other

galaxies. Our program is designed to make optimal use of the unique

capabilities of COS to address our science goals and also generate a

rich dataset of other absorption-line systems along a significant total

pathlength through the IGM (Delta z ~ 20).

 

COS/FUV/COS/NUV 11741

 

Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey

for O VI, Ne VIII, Mg X, and Si XII Absorption Systems

 

Currently we can only account for half of the baryons (or less) expected

to be found in the nearby universe based on D/H and CMB observations.

This "missing baryons problem" is one of the highest-priority challenges

in observational extragalatic astronomy. Cosmological simulations

suggest that the baryons are hidden in low-density, shock-heated

intergalactic gas in the log T = 5 - 7 range, but intensive UV and X-ray

surveys using O VI, O VII, and O VIII absorption lines have not yet

confirmed this prediction. We propose to use COS to carry out a

sensitive survey for Ne VIII and Mg X absorption in the spectra of nine

QSOs at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also

search for Si XII. This survey will provide more robust constraints on

the quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3,

and the data will provide rich constraints on the metal enrichment,

physical conditions, and nature of a wide variety of QSO absorbers in

addition to the warm-hot systems. By comparing the results to other

surveys at lower redshifts (with STIS, FUSE, and from the COS GTO

programs), the project will also enable the first study of how these

absorbers evolve with redshift at z < 1. By combining the program with

follow-up galaxy redshift surveys, we will also push the study of

galaxy-absorber relationships to higher redshifts, with an emphasis on

the distribution of the WHIM with respect to the large-scale matter

distribution of the universe..

 

S/C/WFC3/IR 11929

 

IR Dark Current Monitor

 

Analyses of ground test data showed that dark current signals are more

reliably removed from science data using darks taken with the same

exposure sequences as the science data, than with a single dark current

image scaled by desired exposure time. Therefore, dark current images

must be collected using all sample sequences that will be used in

science observations. These observations will be used to monitor changes

in the dark current of the WFC3-IR channel on a day-to-day basis, and to

build calibration dark current ramps for each of the sample sequences to

be used by GOs in Cycle 17. For each sample sequence/array size

combination, a median ramp will be created and delivered to the

calibration database system (CDBS).

 

STIS/CCD 11845

 

CCD Dark Monitor Part 2

 

Monitor the darks for the STIS CCD.

 

STIS/CCD 11847

 

CCD Bias Monitor-Part 2

 

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,

and 1x1 at gain = 4, to build up high-S/N superbiases and track the

evolution of hot columns.

 

STIS/MA2 11857

 

STIS Cycle 17 MAMA Dark Monitor

 

This proposal monitors the behavior of the dark current in each of the

MAMA detectors.

 

The basic monitor takes two 1380s ACCUM darks each week with each

detector. However, starting Oct 5, pairs are only included for weeks

that the LRP has external MAMA observations planned. The weekly pairs of

exposures for each detector are linked so that they are taken at

opposite ends of the same SAA free interval. This pairing of exposures

will make it easier to separate long and short term temporal variability

from temperature dependent changes.

 

For both detectors, additional blocks of exposures are taken once every

six months. These are groups of five 1314 s FUV-MAMA TIME-TAG darks or

five 3x315 s NUV ACCUM darks distributed over a single SAA free

interval. This will give more information on the brightness of the FUV

MAMA dark current as a function of the amount of time that the HV has

been on, and for the NUV MAMA will give a better measure of the short

term temperature dependence.

 

WFC3/IR 11202

 

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

 

The structure, formation and evolution of early-type galaxies is still

largely an open problem in cosmology: how does the Universe evolve from

large linear scales dominated by dark matter to the highly non-linear

scales of galaxies, where baryons and dark matter both play important,

interacting, roles? To understand the complex physical processes

involved in their formation scenario, and why they have the tight

scaling relations that we observe today (e.g. the Fundamental Plane), it

is critically important not only to undertstand their stellar structure,

but also their dark-matter distribution from the smallest to the largest

scales.

 

Over the last three years the SLACS collaboration has developed a

toolbox to tackle these issues in a unique and encompassing way by

combining new non-parametric strong lensing techniques, stellar

dynamics, and most recently weak gravitational lensing, with

high-quality Hubble Space Telescope imaging and VLT/Keck spectroscopic

data of early-type lens systems. This allows us to break degeneracies

that are inherent to each of these techniques seperately and probe the

mass structure of early-type galaxies from 0.1 to 100 effective radii.

The large dynamic range to which lensing is sentive allows us both to

probe the clumpy substructure of these galaxies, as well as their

low-density outer haloes. These methods have convincingly been

demonstrated, by our team, using smaller pilot-samples of SLACS lens

systems with HST data.

 

In this proposal, we request observing time with WFPC2 and NICMOS to

observe 53 strong lens systems from SLACS, to obtain complete

multi-color imaging for each system. This would bring the total number

of SLACS lens systems to 87 with completed HST imaging and effectively

doubles the known number of galaxy-scale strong lenses. The deep HST

images enable us to fully exploit our new techniques, beat down

low-number statistics, and probe the structure and evolution of

early-type galaxies, not only with a uniform data-set an order of

magnitude larger than what is available now, but also with a fully

coherent and self-consistent methodological approach!

 

WFC3/IR 11219

 

Active Galactic Nuclei in nearby galaxies: a new view of the origin of

the radio-loud radio-quiet dichotomy?

 

Using archival HST and Chandra observations of 34 nearby early-type

galaxies (drawn from a complete radio selected sample) we have found

evidence that the radio-loud/radio-quiet dichotomy is directly connected

to the structure of the inner regions of their host galaxies in the

following sense: [1] Radio-loud AGN are associated with galaxies with

shallow cores in their light profiles [2] Radio-quiet AGN are only

hosted by galaxies with steep cusps. Since the brightness profile is

determined by the galaxy's evolution, through its merger history, our

results suggest that the same process sets the AGN flavour. This

provides us with a novel tool to explore the co-evolution of galaxies

and supermassive black holes, and it opens a new path to understand the

origin of the radio-loud/radio-quiet AGN dichotomy. Currently our

analysis is statistically incomplete as the brightness profile is not

available for 82 of the 116 targets. Most galaxies were not observed

with HST, while in some cases the study is obstructed by the presence of

dust features. We here propose to perform an infrared NICMOS snapshot

survey of these 82 galaxies. This will enable us to i) test the reality

of the dichotomic behaviour in a substantially larger sample; ii) extend

the comparison between radio-loud and radio-quiet AGN to a larger range

of luminosities.

 

WFC3/IR 11696

 

Infrared Survey of Star Formation Across Cosmic Time

 

We propose to use the unique power of WFC3 slitless spectroscopy to

measure the evolution of cosmic star formation from the end of the

reionization epoch at z>6 to the close of the galaxy-building era at

z~0.3.Pure parallel observations with the grisms have proven to be

efficient for identifying line emission from galaxies across a broad

range of redshifts. The G102 grism on WFC3 was designed to extend this

capability to search for Ly-alpha emission from the first galaxies.

Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will

observe about 40 deep (4-5 orbit) fields with the combination of G102

and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.

 

Our primary science goals at the highest redshifts are: (1) Detect Lya

in ~100 galaxies with z>5.6 and measure the evolution of the Lya

luminosity function, independent of of cosmic variance; 2) Determine the

connection between emission-line selected and continuum-break selected

galaxies at these high redshifts, and 3) Search for the proposed

signature of neutral hydrogen absorption at re-ionization. At

intermediate redshifts we will (4) Detect more than 1000 galaxies in

Halpha at 0.5<z<1.8 to measure the evolution of the extinction-corrected

star formation density across the peak epoch of star formation. This is

over an order-of-magnitude improvement in the current statistics, from

the NICMOS Parallel grism survey. (5) Trace ``cosmic downsizing" from

0.5<z<2.2; and (6) Estimate the evolution in reddening and metallicty in

star-forming galaxies and measure the evolution of the Seyfert

population. For hundreds of spectra we will be able to measure one or

even two line pair ratios -- in particular, the Balmer decrement and

[OII]/[OIII] are sensitive to gas reddening and metallicity. As a bonus,

the G102 grism offers the possiblity of detecting Lya emission at

z=7-8.8.

 

To identify single-line Lya emitters, we will exploit the wide

0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All

[OII] and [OIII] interlopers detected in G102 will be reliably separated

from true LAEs by the detection of at least one strong line in the G141

spectrum, without the need for any ancillary data. We waive all

proprietary rights to our data and will make high-level data products

available through the ST/ECF.

 

WFC3/IR 11700

 

Bright Galaxies at z>7.5 with a WFC3 Pure Parallel Survey

 

The epoch of reionization represents a special moment in the history of

the Universe as it is during this era that the first galaxies and star

clusters are formed. Reionization also profoundly affects the

environment where subsequent generations of galaxies evolve. Our

overarching goal is to test the hypothesis that galaxies are responsible

for reionizing neutral hydrogen. To do so we propose to carry out a pure

parallel WFC3 survey to constrain the bright end of the redshift z>7.5

galaxy luminosity function on a total area of 176 arcmin^2 of sky.

Extrapolating the evolution of the luminosity function from z~6, we

expect to detect about 20 Lyman Break Galaxies brighter than M_* at z~8

significantly improving the current sample of only a few galaxies known

at these redshifts. Finding significantly fewer objects than predicted

on the basis of extrapolation from z=6 would set strong limits to the

brightness of M_*, highlighting a fast evolution of the luminosity

function with the possible implication that galaxies alone cannot

reionize the Universe. Our observations will find the best candidates

for spectroscopic confirmation, that is bright z>7.5 objects, which

would be missed by small area deeper surveys. The random pointing nature

of the program is ideal to beat cosmic variance, especially severe for

luminous massive galaxies, which are strongly clustered. In fact our

survey geometry of 38 independent fields will constrain the luminosity

function like a contiguous single field survey with two times more area

at the same depth. Lyman Break Galaxies at z>7.5 down to m_AB=26.85 (5

sigma) in F125W will be selected as F098M dropouts, using three to five

orbits visits that include a total of four filters (F606W, F098M, F125W,

F160W) optimized to remove low-redshift interlopers and cool stars. Our

data will be highly complementary to a deep field search for high-z

galaxies aimed at probing the faint end of the luminosity function,

allowing us to disentangle the degeneracy between faint end slope and

M_* in a Schechter function fit of the luminosity function. We waive

proprietary rights for the data. In addition, we commit to release the

coordinates and properties of our z>7.5 candidates within one month from

the acquisition of each field.

 

WFC3/IR 11909

 

UVIS Hot Pixel Anneal

 

The on-orbit radiation environment of WFC3 will continually generate new

hot pixels. This proposal performs the procedure required for repairing

those hot pixels in the UVIS CCDs. During an anneal, the two-stage

thermo-electric cooler (TEC) is turned off and the four-stage TEC is

used as a heater to bring the UVIS CCDs up to ~20C. As a result of the

CCD warmup, a majority of the hot pixels will be fixed; previous

instruments such as WFPC2 and ACS have seen repair rates of about 80%.

Internal UVIS exposures are taken before and after each anneal, to allow

an assessment of the procedure's effectiveness in WFC3, provide a check

of bias, global dark current, and hot pixel levels, as well as support

hysteresis (bowtie) monitoring and CDBS reference file generation. One

IR dark is taken after each anneal, to provide a check of the IR

detector.

 

WFC3/UVI 11903

 

UVIS Photometric Zero Points

 

This proposal obtains the photometric zero points in 53 of the 62

UVIS/WFC3 filters: the 18 broad-band filters, 8 medium-band filters, 16

narrow-band filters, and 11 of the 20 quad filters (those being used in

cycle 17). The observations will be primary obtained by observing the

hot DA white dwarf standards GD153 and G191-B2B. A redder secondary

standard, P330E, will be observed in a subset of the filters to provide

color corrections. Repeat observations in 16 of the most widely used

cycle 17 filters will be obtained once per month for the first three

months, and then once every second month for the duration of cycle 17,

alternating and depending on target availability. These observations

will enable monitoring of the stability of the photometric system.

Photometric transformation equations will be calculated by comparing the

photometry of stars in two globular clusters, 47 Tuc and NGC 2419, to

previous measurements with other telescopes/instruments.

 

WFC3/UVI 11905

 

WFC3 UVIS CCD Daily Monitor

 

The behavior of the WFC3 UVIS CCD will be monitored daily with a set of

full-frame, four-amp bias<BR>and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals<BR>throughout

the cycle to support subarray science observations. The internals from

this proposal,<BR>along with those from the anneal procedure (11909),

will be used to generate the necessary superbias<BR>and superdark

reference files for the calibration pipeline (CDBS).

 

WFC3/UVI 11907

 

UVIS Cycle 17 Contamination Monitor

 

The UV throughput of WFC3 during Cycle 17 is monitored via weekly

standard star observations in a subset of key filters covering 200-600nm

and F606W, F814W as controls on the red end. The data will provide a

measure of throughput levels as a function of time and wavelength,

allowing for detection of the presence of possible contaminants.

 

 

WFC3/UV/COS/FUV/WFC 11536

 

COS-GTO: Sleuthing the Source of Distant Cometary Activity

 

Distant comets and Centaurs often show cometary activity and outbursts

well beyond 3 AU, the boundary of the sublimation zone of water.

Super-volatiles (most likely CO, but possibly CH4, N2, or S2) are

suspected to be responsible, but have never been detected in distant

comets in the UV. We will obtain FUV spectra of active bodies to cover

important CO emission bands. We plan two sets of observations: comet

29P/Schwassmann-Wachmann at 6 AU, whose outbursts are too short to

capture as a Target of Opportunity, but which also shows persistent

cometary activity in quiescence; and Target of Opportunity observations

of the Centaur 2060 Chiron (at ~15.5 AU) in outburst.