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| STScI Analysis Newsletter (STAN)
| Cosmic Origins Spectrograph (COS)
| Space Telescope Imaging Spectrograph (STIS)
| March 2016
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In this Newsletter we provide updates of interest to
COS and STIS users who will be drafting and submitting Phase I
HST programs over the next weeks:
Contents:
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The Hubble Spectroscopic Legacy Archive: Data Products
available on MAST
Cycle 24 proposers can now mine the new Hubble Spectroscopic
Legacy Archive (HSLA) for high-level data products from COS.
The HSLA includes coadded spectra of all public COS FUV
observations, combining exposures for each target from across
visits, programs, and cycles. These data are organized into
archives by target type (such as "early type stars”, “white
dwarfs”, "starburst galaxies") so that samples can be readily
constructed and downloaded. The HSLA products are available on
MAST at: https://archive.stsci.edu/hst/spectral_legacy/ together
with a description of their contents. These products are being
released now to assist in the preparation of GO and AR proposals.
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COS/FUV Lifetime Position 3 Line Spread Functions and Cross-dispersion
Spread Functions now available on the COS website
Line Spread Functions (LSF) and Cross-dispersion Spread
Functions (CDSF) for lifetime position 3 (LP3) of COS/FUV are
now available on the COS website, at
http://www.stsci.edu/hst/cos/performance/spectral_resolution.
The LSFs have been validated with on-orbit data taken as part
of program 13931 ("Third COS FUV Lifetime Position: Wavelength
and Resolution Calibration (LCAL2)", PI Roman-Duval). Updated
LSF and CDSF models for LP2 are also available.
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Reminder: Calibration of COS Observations of Extended Targets
With the move to Lifetime Position 3 (LP3) of the COS/FUV
detector, which occurred in February 2015, the calibration of
COS/FUV observations of extended objects, and of COS/FUV
observations using the Bright Object Aperture (BOA), has become
more complex. In these cases, the standard pipeline calibration
will not always produce the flux accuracy achieved for point
sources observed with the Primary Science Aperture (PSA), and
it is the responsibility of the user to evaluate the adequacy
of the spectral extraction and, if necessary, undertake any
customized extractions. For more details about changes to the
spectral extraction with the move to LP3 please see COS ISR 2015-03.
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Achieving 10-6 Contrast Visible Light Coronagraphy with BAR5
The BAR5 coronagraphic position in the 50CORON aperture is now
a supported mode in APT 24.0. Additionally, a recent calibration
program that utilizes an optimized observing strategy has
demonstrated contrast levels for point sources with 10-6
or better contrast down to 0.6” and 10-5 or better contrasts
down to 0.25”. This new approach rivals the capabilities of
modern ground-based extreme AO-fed corongraphs, such as GPI and
VLT/SPHERE, in a complementary wavelength regime to these
instruments.
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| http://www.stsci.edu/hst/stis/faqs/help
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| The Space Telescope Science Institute is operated by the
| Association of Universities for Research in Astronomy,
| Inc., under NASA contract NAS5-26555.
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