NASA Hubble Space Telescope Daily Report #4087
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT #4087
PERIOD COVERED: UT April 06, 2006 (DOY 096)
OBSERVATIONS SCHEDULED
ACS/HRC 10474
Shooting Stars: Looking for Direct Evidence of Massive Central Black Holes in Globular Clusters
We propose to make observations that directly test the proposition that globular clusters contain massive black holes. Our targets are the bulge globular clusters NGC 6388 and NGC 6441. These are probably among the most massive in the galaxy, but are understudied compared to more familiar objects such as M15. Our analysis suggests that these two clusters are the most likely to show unambiguous evidence for a central massive black hole if such things exist in globular clusters. The observations proposed will give us the first thorough kinematic and photometric studies of these two clusters. The combination of the two epochs will give us proper motions good to of order 6 km/s. In addition, they will provide us with the first good, deep, color-magnitude diagrams for these clusters. These diagrams will be used to investigate the make up of the stellar population in the clusters, to more firmly establish their distances, ages, and metallicities, and to search for a binary sequence.
ACS/HRC 10609
Sizes, Shapes, and SEDs: Searching for Mass Segregation in the Super Star Clusters of Nearby Starburst
We propose to investigate mass segregation and star cluster evolution and dissolution processes in Super Star Cluster {SSC} populations in a small sample of nearby starburst galaxies. ACS/HRC and NICMOS images of these nearby {d < 10 Mpc} starbursts can reveal evidence for mass segregation in the form of variations in size, shape, and color of the SSCs as a function of wavelength. The compactness of the cluster light profiles, and hence the stellar mass distributions, is a critical indicator of the likely fate of an SSC: long life and eventual evolution into a globular-like cluster, or dissolution. These observations will allow us to generate spectral energy distributions {SEDs} for a large sample of the SSCs at all ages and extinctions in each system. We will combine the SEDs with population synthesis models and existing ground- based spectra and Spitzer images to estimate ages, reddenings, and masses thus derive a more complete picture of the star-formation histories of the galaxies. For the brightest and most likely virialized among the SSCs we will also constrain their initial mass functions {IMFs} using high- resolution spectroscopy. Conclusions about IMFs from this technique require detailed information about the SSC concentration, light profiles, and virial status, which are only possible via ACS data. The proposed observations will provide an extensive and comprehensive data set for a large number of SSCs. By addressing the issues of mass segregation, evaporation, and destruction of SSC populations, the proposed observations will provide strong constraints on theories regarding the processes involved in the formation and evolution of SSCs and globular clusters. Given the dire predictions for the lifetime of HST, and its tremendous impact on the study of SSCs, we feel that the proposed observations not only are necessary and timely {even urgent} but will also be a fitting { and possibly final} addition to HST's legacy in the study of starburst SSCs.
ACS/HRC 10695
Coronagraphic Search for Disks around Nearby Stars
This is a search for debris disks around nearby G-type stars that have infrared excesses. The ACS coronagraph will be used with filter F606W.
ACS/HRC/WFC 10758
ACS CCDs daily monitor
This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The first half of the program has a different proposal number: 10729.
ACS/WFC 10592
An ACS Survey of a Complete Sample 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 ACS/WFC imaging 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, resolution, and field of view of ACS/WFC on HST enables a unique opportunity to study the detailed structure of galaxies that sample all stages of the merger process. Imaging will be done with the F439W and F814W filters {B and I-band} to examine as a function of both luminosity and merger state {i} the evidence at optical wavelengths of star formation and AGN activity and the manner in which instabilities {bars and bridges} in the galaxies may funnel material to these active regions, {ii} the relationship between star formation and AGN activity, and {iii} the structural properties {AGN, bulge, and disk components} and fundamental parameters {effective radius and surface brightness} of LIRGs and their similarity with putative evolutionary byproducts {elliptical, S0 and classical AGN host galaxies}. This HST survey will also bridge the wavelength gap between a Spitzer imaging survey {covering seven bands in the 3.6-160 micron range} and a GALEX UV imaging survey of these galaxies, but will resolve complexes of star clusters and multiple nuclei at resolutions well beyond the capabilities of either Spitzer or GALEX. The combined datasets will result in the most comprehensive multiwavelength study of interacting and merging galaxies to date.
ACS/WFC 10626
A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to z = 0.9
We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy clusters at 0.3 < z < 0.9 from the Red Sequence Cluster Survey {RCS}. An examination of the galaxian light in the brightest cluster galaxies, coupled with a statistical analysis of the strong-lensing properties of the sample, will allow us to contrain the evolution of both the baryonic and dark mass in cluster cores, over an unprecedented redshift range and sample size. In detail, we will use the high- resolution ACS images to measure the metric {10 kpc/h} luminosity and morphological disturbances around the brightest clusters galaxies, in order to calibrate their accretion history in comparison to recent detailed simulations of structure formation in cluster cores. These images will also yield a well-defined sample of arcs formed by strong lensing by these clusters; the frequency and detailed distribution {size, multiplicity, redshifts} of these strong lens systems sets strong constraints on the total mass content {and its structure} in the centers of the clusters. These data will also be invaluable in the study of the morphological evolution and properties of cluster galaxies over a significant redshift range. These analyses will be supported by extensive ongoing optical and near-infrared imaging, and optical spectroscopy at Magellan, VLT and Gemini telescopes, as well as host of smaller facilities.
ACS/WFC 10775
An ACS Survey of Galactic Globular Clusters
We propose to conduct an ACS/WFC imaging survey of Galactic globular clusters. We will construct the most extensive and deepest set of photometry and astrometry to-date for these systems reaching a main sequence mass of ~0.2 solar mass with S/N >= 10. We will combine these data with archival WFPC2 and STIS images to determine proper motions for the stars in our fields. The resultant cleaned cluster CMDs will allow us to study a variety of scientific questions. These include [but are not limited to] 1} the determination of cluster ages and distances 2} the construction of main sequence mass functions and the issue of mass segregation 3} the internal motions and dynamical evolution of globular clusters, and 4} absolute cluster motions, orbits, and the Milky Way gravitational potential. We anticipate that the unique resource provided by the proposed treasury archive will play a central role in the field of globular cluster studies for decades, with a stature comparable to that of the Hubble Deep Field for high redshift studies.
NIC1/NIC2/NIC3 8793
NICMOS Post-SAA calibration – CR Persistence Part 4
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 images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.
NIC2 10527
Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope Around 20 Sun-like Stars
We propose to use the high contrast capability of the NICMOS coronagraph to image a sample of newly discovered circumstellar disks associated with sun-like stars. These systems were identified by their strong thermal infrared emission with the Spitzer Space Telescope as part of the Spitzer Legacy Science program titled, “The Formation and Evolution of Planetary Systems {FEPS}.” Modelling of the thermal excess emission in the form of spectral energy distributions alone cannot distinguish between narrowly confined high opacity disks and broadly distributed, low opacity disks. However, our proposed NICMOS observations can, by imaging the light scattered from this material. Even non- detections will place severe constraints on the disk geometry, ruling out models with high optical depth. Unlike previous disk imaging programs, our program contains a well defined sample of solar mass stars covering a range of ages from ~10Myrs to a few Gyrs, allowing us to study the evolution of disks from primordial to debris for the first time. These results will greatly improve our understanding of debris disks around Sun- like stars at stellar ages nearly 10x older than any previous investigation. Thus we will have fit a crucial piece into the puzzle concerning the formation and evolution of our own solar system.
NIC2 10540
Imaging Nearby Dusty Disks
Images of circumstellar debris disks around young stars display complex structures that suggest they harbor forming planets. Disks around stars of nearly the same age and mass show dramatically different morphologies including rings with brightness asymmetries and multiple warps. The reasons for this heterogeneity are not understood, nor given the small sample of imaged disks, can we be sure we have yet observed all possible outcomes of the planet formation process. Disk imaging programs have demonstrated that the Hubble Space Telescope is the only excellent platform for the high-contrast detection of scattered light disks in the presence of their bright parent stars. Therefore, we propose a NICMOS imaging survey of the nearest, youngest, stars to Earth with substantial disks known from infrared excess emission.
WFPC2 10749
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 conjuction with previous internal and external flats to generate new pipeline superflats. These Earth flats will complement the Earth flat data obtained during cycles 4-13.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS:
10204 – GSAcq (2,1,2) failed due to search radius limit exceeded on FGS-2 @ 096/12:13:06z
GSAcq(2,1,2)scheduled for 096/12:08:48-12:16:05 failed due to search radius limit exceeded on FGS-2. Received three (3) ESB 1805’s “FHST Moving Target Detected”. Received ESB a05 “Exceeded SRL”. OBAD #1: V1 -858.58, V2 992.82, V3 -155.20, RSS 1321.72 OBAD #2: V1 -10.81, V2 3.52, V3 -9.66, RSS 14.92 No OBAD MAP scheduled after acquisition.
10205 – GSAcq (2,1,2) and its two Reacquisitions failed @ 096/18:32:35z
The GSacq(2,1,2) at 096/18:32:35 and its reacqusitions at 20:07:04 and 21:42:59 failed due to search radius limit exceeded on FGS 1.
These acquisitions used the same guide star that caused the failures documented in HSTAR 10196. The guide star does not really exist.
COMPLETED OPS REQUEST:
- 17695-2 – Monitor VehConLaw.Integral Path Data via TMDIAG Slot 0 @ 096/2036z
- 17692-0 – CONTINGENCY: Disable ROC test for Battery 6 capacity test @ 097/0020z
- 17686-0 – Continuous Engineering Recording for Battery # 6 BCT @ 096/1122z, 096/1304z, 096/1344z, 096/2055z
- 17689-0 – Battery 6 Capacity Test Script & Battery Pressure Limit COP (thru Step 30)
- 17696-0 – Genslew for proposal 10487 – slot 9 @ 096/1618z
- 17697-0 – Genslew for proposal 10487 – slot 11 @ 096/1620z
- 17698-0 – Genslew for proposal 10487 – slot 10 @ 096/1622z
- 17699-0 – Genslew for proposal 10487 – slot 14 @ 096/1624z
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS
GSacq 06 04 096/12:13:06z
(HSTAR 10204)
096/18:32:35z
(HSTAR 10205)
FGS
REacq 09 07 096/20:07:04z
(HSTAR 10205)
096/21:42:59z
(HSTAR 10205)
OBAD with Maneuver 30 30
SIGNIFICANT EVENTS:
1. Flash Report- Battery 6 Discharge Termination – (EPS SE, Thurs, 06 Apr 2006 20:01:18) – Battery 6 low-rate discharge was completed on Thursday afternoon. Following approximately 53 hours of total discharge time, the target low voltage was reached and the reconditioning resistor was autonomously turned off by HST486 FSW at 096/1853 GMT. EPS hardware reconfiguration was completed during the orbit night period, with the reconnection of solar array section 6 to battery 6 occurring at 096/1854 GMT.
2. Flash Report- Battery 6 Capacity Flash Report – Elev VT – (Fri, 7 Apr 2006 00:00:44) – Battery Capacity Flash Report – The Battery 6 Capacity test recovery period began at approximately 2006/096 18:56 GMT with the batteries charging at the K1L4 equivalent. EPS SEs monitored the system for 3 orbits following termination of the 2 orbit elevated VT and observed nominal system performance. Battery 6 is recovering as expected and battery temperatures did not exceed 1.75 DegC during this part of the recovery. Battery 6 is scheduled to be placed back on-line in a 6-Battery FSW configuration on 097/15:25 GMT (Friday at 11:25 am).
