138 research outputs found
Finding halo streams with a pencil-beam survey: new wraps in the Sagittarius stream
We use data from two CFHT-MegaCam photometric pencil-beam surveys in the g'
and the r' bands to measure distances to the Sagittarius, the Palomar 5 and the
Orphan stream. We show that, using a cross-correlation algorithm to detect the
turnoff point of the main sequence, it is possible to overcome the main
limitation of a two-bands pencil-beam survey, namely the lack of adjacent
control-fields that can be used to subtract the foreground and background stars
to enhance the signal on the colour-magnitude diagrams (CMDs). We describe the
cross-correlation algorithm and its implementation. We combine the resulting
main sequence turnoff points with theoretical isochrones to derive photometric
distances to the streams. Our results (31 detections on the Sagittarius stream
and one each for the Palomar 5 and the Orphan streams) confirm the findings by
previous studies, expand the distance trend for the Sagittarius faint southern
branch and, for the first time, trace the Sagittarius faint branch of the
northern-leading arm out to 56 kpc. In addition, they show evidence for new
substructure: we argue that these detections trace the continuation of the
Sagittarius northern-leading arm into the southern hemisphere, and find a
nearby branch of the Sagittarius trailing wrap in the northern hemisphere.Comment: 16 pages, 15 figures, 2 table
A skewer survey of the Galactic halo from deep CFHT and INT images
We study the density profile and shape of the Galactic halo using deep
multicolour images from the MENeaCS and CCCP projects, over 33 fields selected
to avoid overlap with the Galactic plane. Using multicolour selection and PSF
homogenization techniques we obtain catalogues of F stars (near-main sequence
turnoff stars) out to Galactocentric distances up to 60kpc. Grouping nearby
lines of sight, we construct the stellar density profiles through the halo in
eight different directions by means of photometric parallaxes. Smooth halo
models are then fitted to these profiles. We find clear evidence for a
steepening of the density profile power law index around R=20 kpc, from -2.50
+- 0.04 to -4.85 +- 0.04, and for a flattening of the halo towards the poles
with best-fit axis ratio 0.63 +- 0.02. Furthermore, we cannot rule out a mild
triaxiality (w>=0.8). We recover the signatures of well-known substructure and
streams that intersect our lines of sight. These results are consistent with
those derived from wider but shallower surveys, and augur well for upcoming,
wide-field surveys of comparable depth to our pencil beam surveys.Comment: 14 pages, 8 figures, 6 table
LEARNING MANAGEMENT SYSTEM (LMS) MICROSOFT TEAMS DAN DRAWING PAD PADA PEMBELAJARAN MATEMATIKA DALAM PENERAPAN PEMBELAJARAN HYBRID LEARNING DI ERA PANDEMIC COVID-19 (STUDI DI SMA KRISTEN IMMANUEL PONTIANAK)
Tujuan dibuatnya tulisan ini yaitu memberikan gambaran mengenai LMS di SMA Kristen Immanuel Pontianak sebagai salah satu solusi dalam menghadapi tantangan pembelajaran daring sehingga dapat dijadikan acuan bagi sekolah lain dalam menerapkannya ditengah pandemic covid-19. Penggunaan LMS dan IT yaitu Microsoft Teams dan Drawing Pad. Dengan adanya penggunaan LMS Microsoft Teams dan Drawing Pad maka pembelajaran online lebih efektif dijalankan sehingga tujuan pembelajaran dapat tercapai dengan baik. Pada artikel ini akan dideskripsikan manfaat dan proses pembelajaran menggunakan LMS Microsoft Teams dan Drawing Pad di SMA Kristen Immanuel Pontiana
Section Extension from Hyperbolic Geometry of Punctured Disk and Holomorphic Family of Flat Bundles
The construction of sections of bundles with prescribed jet values plays a
fundamental role in problems of algebraic and complex geometry. When the jet
values are prescribed on a positive dimensional subvariety, it is handled by
theorems of Ohsawa-Takegoshi type which give extension of line bundle valued
square-integrable top-degree holomorphic forms from the fiber at the origin of
a family of complex manifolds over the open unit 1-disk when the curvature of
the metric of line bundle is semipositive. We prove here an extension result
when the curvature of the line bundle is only semipositive on each fiber with
negativity on the total space assumed bounded from below and the connection of
the metric locally bounded, if a square-integrable extension is known to be
possible over a double point at the origin. It is a Hensel-lemma-type result
analogous to Artin's application of the generalized implicit function theorem
to the theory of obstruction in deformation theory. The motivation is the need
in the abundance conjecture to construct pluricanonical sections from flatly
twisted pluricanonical sections. We also give here a new approach to the
original theorem of Ohsawa-Takegoshi by using the hyperbolic geometry of the
punctured open unit 1-disk to reduce the original theorem of Ohsawa-Takegoshi
to a simple application of the standard method of constructing holomorphic
functions by solving the d-bar equation with cut-off functions and additional
blowup weight functions
Computing L-series of hyperelliptic curves
We discuss the computation of coefficients of the L-series associated to a
hyperelliptic curve over Q of genus at most 3, using point counting, generic
group algorithms, and p-adic methods.Comment: 15 pages, corrected minor typo
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Riding on the Coat-Tails of Traditional Cultural Expressions
Matters related to the protection of traditional cultural expressions (âTCEsâ) or expressions of folklore (âEoFsâ) are sensitive and intricate as a blend of legal, economic, philosophical and anthropological considerations jostle to capture their core features. This results in disparate views surrounding what should qualify as TCEs or EoFs, who should be considered their âownerâ (assuming that ownership per se is conceptually compatible with these items), which is the most appropriate legal protection regime and how broad their scope of protection should be. Drawing from these various accounts on TCEs, this article focuses on the interaction between TCEs and EoFs originating on the European continent and the European Union (âEUâ) trade mark legislation. Specifically, this article examines whether the limitations of the effects of trade mark rights and of the absolute grounds of refusal, as developed by the case law of the Court of Justice of the European Union, are effective in preserving the cohesion of TCEs. This article advances the thesis that registration of TCEs and EoFs as trade marks generates an imbalance between the rights of the trade mark owner and the defences available to others under the EU trade mark law framework. Furthermore, such an imbalance is likely to hinder the unfettered circulation of TCEs and undermine their original meaning. Lastly, in some cases, trade mark registration of TCEs contributes to their appropriation and misappropriation. The article concludes that, de lege ferenda, the direct exclusion of TCEs as eligible subject matter for trade mark registration is preferable to seeking a post factum remedy
Whole genome analysis of a schistosomiasis-transmitting freshwater snail
Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis
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