A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Hubble
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Daily Report #4437



 
 
Thread Tools Display Modes
  #1  
Old August 31st 07, 10:50 AM posted to sci.astro.hubble
Cooper, Joe
external usenet poster
 
Posts: 568
Default Daily Report #4437

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science
capability in January, there may be an occasional discrepancy between
a proposal's listed (and correct) instrument usage and the abstract
that follows it.


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT***** # 4437

PERIOD COVERED: UT August 29, 2007 (DOY 241)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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 DARKs. 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 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.

WFPC2 10789

The Role of Environment in the Formation of Dwarf Galaxies

Clusters of galaxies contain an overdensity of dwarfs compared to the
field. Within galaxy clusters there is also a correlation between the
overdensity of dwarfs and local galaxy density, such that areas of
lower galaxy density contain more dwarfs per giant. The origin of
these 'extra' dwarfs is unknown, but a large fraction of them did not
form through standard collapses early in the universe. Some dwarf
ellipticals in clusters have metal rich and young { 6 Gyr} stellar
populations while others contain old metal poor populations,
suggesting multiple formation mechanisms and time scales. We propose
to test the idea that dwarfs descend from galaxies accreted into
clusters during the past 8 Gyr by correlating ages and metallicities
of dwarfs with their internal structures - spiral arms, bars, and
disks. If dwarfs originate from more massive galaxies then these
features should be common in metal rich and young dwarfs. On the other
hand, if no correlation is found it would suggest that dwarfs form
through in-situ collapses of gas in the intragalactic medium after the
universe was reionized.

WFPC2 10818

Very Young Globular Clusters in M31 ?

We propose to use HST's unique high spatial resolution imaging
capabilities to conclusively confirm or refute the presence of alleged
very young globular clusters in M31. Such young globular clusters with
ages 3 Gyr are not present in our galaxy, and, if real, would lead
to a striking difference in the age distribution of the GCs between
M31 and the Milky Way. If the apparent presence of very young globular
clusters in M31 is confirmed through our proposed ACS imaging {now
WFPC2 imaging} with HST, this would suggest major differences in the
history of assembly of the two galaxies, with probable substantial
late accretion into M31 which did not occur in our own galaxy.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi- color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high- resolution imaging to the near-infrared.

WFPC2 11033

Full Moon Earth Flats Closeout

Flat field exposures will be obtained by observing the moonlit Earth
with the broadband WFPC2 filters F606W and F814W, which saturate in
the minimum exposure time on the sunlit Earth. These observations will
be used to improve the flats currently in the pipeline and are part of
the WFPC2 closeout operations. Because CTE effects are large for star
flats and small for full field illumination, Earth flats are the
superior technique.

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************** 05**************** 05
FGS REacq************** 06**************** 06
OBAD with Maneuver **** 24**************** 24

SIGNIFICANT EVENTS: (None)


Ads
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Daily Report #4436 Cooper, Joe Hubble 0 August 29th 07 02:29 PM
Daily Report # 4326 Cooper, Joe Hubble 0 March 26th 07 02:37 PM
Daily Report #3987 Joe Cooper Hubble 0 November 14th 05 04:14 PM
Daily Report [email protected] Hubble 0 October 29th 04 04:59 PM
HST Daily Report 131 George Barbehenn Hubble 0 May 11th 04 02:48 PM


All times are GMT +1. The time now is 05:38 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004-2020 SpaceBanter.com.
The comments are property of their posters.