Status Report

NASA Hubble Space Telescope Daily Report #4848

By SpaceRef Editor
May 6, 2009
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science


PERIOD COVERED: 5am May 5 – 5am May 6, 2009 (DOY 125/0900z-126/0900z)

S/C 4974

The Transient Response Test is for the periodic performance monitoring
of the FGS 2R servo A mechanism.

WFPC2 11327
Red Leaks

The aim of this program is to measure the red leaks in the 8 WFPC2 UV??? filters (F122M, F300W, F255W, F218W, F185W, F170W, F160BW, F122M). We will use red crossing filters to isolate and directly measure the leaks. No observations of this kind have ever been performed with WFPC2 to check the red leaks in the UV filters, most of them being extensively used by GO/GTO programs. A previous calibration program has only imaged spectrophotometric standard stars with UV filters (no filter crossing) thus the red leak is hard to measure using this data. The throughput curves for some of the UV filters
(F300W, F255W, F218W, F185W) in synphot have incomplete information, some of them have gaps in the measurements as wide as 3000A.

WFPC2 11603
A Comprehensive Study of Dust Formation in Type II Supernovae with
HST, Spitzer and Gemini

The recent discovery of three extremely bright Type II SNe, (2007it, 2007oc, 2007od) gives us a unique opportunity to combine observations with HST, Spitzer and Gemini to study the little understood dust formation process in Type II SNe. Priority 1 Spitzer Cycle 5 and band 1 Gemini 2008A time has already been approved for this project. Since late-time Type II SNe are faint and tend to be in crowded fields, we need the high sensitivity and high spatial resolution of ACS/HRC and NICMOS/NIC2 for these observations. This project is motivated by the recent detection of large amounts of dust in high redshift galaxies. The dust in these high-z galaxies must come from young, massive stars so Type II SNe could be potential sources. The mechanism and the efficiency of dust condensation in Type II SN ejecta are not well understood, largely due to the lack of observational data. We plan to produce a unique dataset, combining spectroscopy and imaging in the visible, near- and mid-IR covering the key phase, 400-700 days after maximum when dust is known to form in the SN ejecta. Therefore, we are proposing for coordinated HST/NOAO observations (HST ACS/HRC,
NICMOS/NIC2 & Gemini/GMOS and TReCS) which will be combined with our Spitzer Cycle 5 data to study these new bright SNe. The results of this program will place strong constraints on the formation of dust seen in young high redshift (z>5) galaxies.

WFPC2 11793
WFPC2 Cycle 16 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.

WFPC2 11987
The Recent Star Formation History of SINGS Galaxies

The Spitzer Legacy project SINGS provided a unique view of the current state of star formation and dust in a sample of galaxies of all Hubble types. This multi-wavelength view allowed the team to create current star formation diagnostics that are independent of the dust content and increased our understanding of the dust in galaxies. Even so, using the SINGS data alone we can only make rough estimates of the recent star formation history of these galaxies. The lack of U-band observations means that it is impossible to estimate the ages of young
clusters. In addition, the low resolution of the Spitzer and ground-based observations means that what appear to be individual Spitzer sources can actually be composed of many individual clusters with varying ages. In this proposal we plan to address this missing area in SINGS by obtaining high-resolution WFPC2 UBVI observations to accurately find and determine the ages of the young stellar clusters in a subset of the SINGS galaxies. These observations will greatly enhance the legacy value of the SINGS observations while also directly answering questions pertaining to star formation in galaxies.

WFPC2 11988
Searching for Intermediate Mass Black Holes in Globular Clusters via
Proper Motions

The unambiguous detection of an intermediate mas black hole (IMBH) in a globular star cluster would be a major achievement for the Hubble Space Telescope. It is critical to know whether or not IMBHs exist in the centers of clusters in order to understand the dynamical evolution of dense stellar systems. Also, n IMBH detection would prove the existence of BHs in an entirely new mass range. Observationally, the search has been hampered by the low number of stars with known velocities in the central few arcseconds. This limits measurements of the stellar velocity dispersion in the region where the gravitational influence of any IMBH would be felt. Existing IMBH claims in the
literature have all been called into question, and have all been based
on line-of-sight velocities from spectroscopy. In cycle 13, we obtained ACS/HRC observations for 5 nearby Galactic globular clusters for a new proper motion study. Here, we request WFPC2/PC observations of these clusters, all of which are observable in Feb-May 2009. This 4 year baseline will allow us to measure the proper motions of stars into the very center of each cluster, and either detect or place firm constraints on the presence of an IMBH. In addition, we will determine whether or not the clusters rotate or show any anisotropy in their motions. Our small (<75 orbit) program meets the criteria of
addressing high impact science (IMBH detection) using innovative methods (proper motions).


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be


11789 – GSAcq (1,2,2) scheduled at 126/01:42:58 failed due to search
radius limit exceeded. REAcq (1,2,2) scheduled from 126/03:05:51 –
03:13:22, 26/04:47 – 04:54:47 and from 126/06:29:15 – 06:36:46 all
failed to RGA Hold.

Observation affected: WFPC 120 – 123, Proposal ID# 11987


18422-1 – TRTT #22 Execution @ 125/1432z



FGS GSAcq 03 02
FGS REAcq 07 04
OBAD with Maneuver 24 24


The last planned execution of the FGS-2R Transient Response Trending
Test was successfully completed at 125/14:23z via Ops Request 18422.

SpaceRef staff editor.