623 research outputs found
Instability of Magnons in Two-dimensional Antiferromagnet at High Magnetic Fields
Spin dynamics of the square lattice Heisenberg antiferromagnet, \BaMnGeO, is
studied by a combination of bulk measurements, neutron diffraction, and
inelastic neutron scattering techniques. Easy plane type antiferromagnetic
order is identified at K. The exchange interactions are estimated
as = 27.8(3)eV and = 1.0(1) eV, and the saturation
field is 9.75 T. Magnetic excitation measurements with high
experimental resolution setup by triple axis neutron spectrometer reveals the
instability of one magnon excitation in the field range of .Comment: 5 pgase, 5 figuers, to be published in PRB R
V463 Scuti (Nova Sct 2000): Rapidly Evolving Nova with a Prominent Premaximum Halt
We summarize photometric and spectroscopic observations of V463 Sct (Nova Sct
2000), which was originally thought to be a red variable. The spectrum taken on
2000 March 16.81 UT showed prominent emission lines with a FHWM of 990 km/s (H
alpha). The light curve shows a conspicuous premaximum halt lasting at least
for 24 d, and a late-phase flare-like maximum. The nova then started rapidly
fading at a rate corresponding to t2 = 15 +/- 3 d. Long premaximum halts have
been considered as a unique character of the "slowest" novae. The present
observation, however, suggests that the long premaximum halts are not a unique
character of the slowest novae, but a more general phenomenon spreading over a
wider range of nova speed classes than has been previously believed. A recent
interpretation of premaximum halts requires that the conditions of
thermonuclear runaway was only marginally satisfied. Since such conditions are
more difficult to meet in rapidly evolving novae, V463 Sct would provide an
unique opportunity in testing this interpretation. The early post-outburst
spectrum showed co-existence of Fe II lines and some forbidden lines, which
suggests that substantial amount of material may have been ejected before the
observed optical maximum. The impact of the modern global network (VSNET) on
confirmatory processes of transient objects is briefly discussed.Comment: 7 pages, 4 figures, accepted for publication in Publ. Astron. Soc.
Japa
Discovery of a New Deeply Eclipsing SU UMa-Type Dwarf Nova, IY UMa (= TmzV85)
We discovered a new deeply eclipsing SU UMa-type dwarf nova, IY UMa, which
experienced a superoutburst in 2000 January. Our monitoring revealed two
distinct outbursts, which suggest a superoutburst interval of ~800 d, or its
half, and an outburst amplitude of 5.4 mag. From time-series photometry during
the superoutburst, we determined a superhump and orbital period of 0.07588 d
and 0.0739132 d, respectively.Comment: 5 pages, 3 figures, accepted by PASJ lette
An integrated atom-photon junction
Photonic chips that integrate guides, switches, gratings and other
components, process vast amounts of information rapidly on a single device. A
new branch of this technology becomes possible if the light is coupled to cold
atoms in a junction of small enough cross section, so that small numbers of
photons interact appreciably with the atoms. Cold atoms are among the most
sensitive of metrological tools and their quantum nature also provides a basis
for new information processing methods. Here we demonstrate a photonic chip
which provides multiple microscopic junctions between atoms and photons. We use
the absorption of light at a junction to reveal the presence of one atom on
average. Conversely, we use the atoms to probe the intensity and polarisation
of the light. Our device paves the way for a new type of chip with
interconnected circuits of atoms and photons.Comment: 5 pages, 4 figure. Submitted to Nature Photonic
Geriatric Medical Care in the Area of the Regional Association Westphalia-Lippe Dokkyo Medical University 5th grade
Dokkyo Medical University 5th YearDokkyo Medical University 5th YearDokkyo Medical University 5th YearDokkyo Medical University 5th YearDokkyo Medical University 5th YearDokkyo Medical University 5th YearDokkyo MedicalUniversity, Division of Languages and HumanitiesWestphalian Wilhelms University, IfASWestphalian Wilhelms University, General PracticeKlinik Maria Frieden, Abt. f. GeriatrieDokkyo Medical University, Office for German-Japanese CooperationDokkyo Medical University, Office for German-Japanese Cooperatio
Curious Variables Experiment (CURVE). CCD Photometry of QW Serpentis in Superoutburst and Quiescence
We report extensive photometry of the dwarf nova QW Ser throughout its 2003
February superoutburst till quiescence. During the superoutburst the star
displayed clear superhumps with a mean period of Psh = 0.07703(4) days. In the
quiescence we observed a double humped wave characterized by a period of
P=0.07457(2) days. As both periods obey the Stolz-Schoembs relation with a
period excess equal to 3.30+/-0.06% the latter period is interpreted as the
orbital period of the binary system.Comment: accepted for publication in A&A, 5 pages, 7 figure
- …