84 research outputs found
UBVRI Light Curves of 44 Type Ia Supernovae
We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from
1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence
Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The
data set comprises 2190 observations and is the largest homogeneously observed
and reduced sample of SN Ia to date, nearly doubling the number of
well-observed, nearby SN Ia with published multicolor CCD light curves. The
large sample of U-band photometry is a unique addition, with important
connections to SN Ia observed at high redshift. The decline rate of SN Ia
U-band light curves correlates well with the decline rate in other bands, as
does the U-B color at maximum light. However, the U-band peak magnitudes show
an increased dispersion relative to other bands even after accounting for
extinction and decline rate, amounting to an additional ~40% intrinsic scatter
compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication
in the Astronomical Journal. Version with high-res figures and electronic
data at http://astron.berkeley.edu/~saurabh/cfa2snIa
Observing the Evolution of the Universe
How did the universe evolve? The fine angular scale (l>1000) temperature and
polarization anisotropies in the CMB are a Rosetta stone for understanding the
evolution of the universe. Through detailed measurements one may address
everything from the physics of the birth of the universe to the history of star
formation and the process by which galaxies formed. One may in addition track
the evolution of the dark energy and discover the net neutrino mass.
We are at the dawn of a new era in which hundreds of square degrees of sky
can be mapped with arcminute resolution and sensitivities measured in
microKelvin. Acquiring these data requires the use of special purpose
telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and
the South Pole Telescope (SPT). These new telescopes are outfitted with a new
generation of custom mm-wave kilo-pixel arrays. Additional instruments are in
the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey.
Full list of 177 author available at http://cmbpol.uchicago.ed
Fundamentals of impulsive energy release in the corona
It is essential that there be coordinated and co-optimized observations in
X-rays, gamma-rays, and EUV during the peak of solar cycle 26 (~2036) to
significantly advance our understanding of impulsive energy release in the
corona. The open questions include: What are the physical origins of
space-weather events? How are particles accelerated at the Sun? How is
impulsively released energy transported throughout the solar atmosphere? How is
the solar corona heated? Many of the processes involved in triggering, driving,
and sustaining solar eruptive events -- including magnetic reconnection,
particle acceleration, plasma heating, and energy transport in magnetized
plasmas -- also play important roles in phenomena throughout the Universe. This
set of observations can be achieved through a single flagship mission or, with
foreplanning, through a combination of major missions (e.g., the previously
proposed FIERCE mission concept).Comment: White paper submitted to the Decadal Survey for Solar and Space
Physics (Heliophysics) 2024-2033; 5 pages, 1 figur
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Pharmacokinetics of ss-d-N4-Hydroxycytidine, the Parent Nucleoside of Prodrug Molnupiravir, in Nonplasma Compartments of Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection
ß-d-N4-hydroxycytidine (NHC), the parent nucleoside of molnupiravir, a COVID-19 antiviral, was quantified at sites of SARS-CoV-2 transmission in twelve patients enrolled in AGILE CST-2 (NCT04746183). Saliva, nasal and tear concentrations were 3, 21 and 22% that of plasma. Saliva and nasal NHC concentrations were significantly correlated with plasma (p<0.0001)
CfA4: Light Curves for 94 Type Ia Supernovae
We present multi-band optical photometry of 94 spectroscopically-confirmed
Type Ia supernovae (SN Ia) in the redshift range 0.0055 to 0.073, obtained
between 2006 and 2011. There are a total of 5522 light curve points. We show
that our natural system SN photometry has a precision of roughly 0.03 mag or
better in BVr'i', 0.06 mag in u', and 0.07 mag in U for points brighter than
17.5 mag and estimate that it has a systematic uncertainty of 0.014, 0.010,
0.012, 0.014, 0.046, and 0.073 mag in BVr'i'u'U, respectively. Comparisons of
our standard system photometry with published SN Ia light curves and comparison
stars reveal mean agreement across samples in the range of ~0.00-0.03 mag. We
discuss the recent measurements of our telescope-plus-detector throughput by
direct monochromatic illumination by Cramer et al (in prep.). This technique
measures the whole optical path through the telescope, auxiliary optics,
filters, and detector under the same conditions used to make SN measurements.
Extremely well-characterized natural-system passbands (both in wavelength and
over time) are crucial for the next generation of SN Ia photometry to reach the
0.01 mag accuracy level. The current sample of low-z SN Ia is now sufficiently
large to remove most of the statistical sampling error from the dark energy
error budget. But pursuing the dark-energy systematic errors by determining
highly-accurate detector passbands, combining optical and near-infrared (NIR)
photometry and spectra, using the nearby sample to illuminate the population
properties of SN Ia, and measuring the local departures from the Hubble flow
will benefit from larger, carefully measured nearby samples.Comment: 43 page
A Phase 2a clinical trial of Molnupiravir in patients with COVID-19 shows accelerated SARS-CoV-2 RNA clearance and elimination of infectious virus
Molnupiravir (800 mg dose) accelerated SARS-CoV-2 RNA clearance in patients with COVID-19 compared to placebo
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