7,452 research outputs found
CO Observations of Luminous IR Galaxies at Intermediate Redshift
We present new measurement of CO() emission from 16 luminous
infrared galaxies (LIGs) at intermediate redshift (). These new data were selected by isolated and normal
morphology. The CO observations were performed using the NRO 45-m telescope.
Comparison of the CO and dust properties of the new result with those from
other CO measurements revealed characteristics of this sample: (1) It is the
deepest CO observations of IRAS galaxies at intermediate redshift without
strong interaction features. (2) It has typical properties of normal IRAS
galaxies in terms of star-formation efficiency, color-color diagrams and
galactic nuclear activity. (3) It has smaller gas-to-dust ratio than normal
IRAS galaxies. This can be explained by two-component dust model, and our
sample consists of most of warm dust.Comment: To appear in PASJ, text 9 pages, 5 tables, and 12 figure
Heavy Fermion Bound States for Diphoton Excess at 750GeV Collider and Cosmological Constraints
A colored heavy particle with sufficiently small width may form
non-relativistic bound states when they are produced at the large hadron
collider\,(LHC), and they can annihilate into a diphoton final state. The
invariant mass of the diphoton would be around twice of the colored particle
mass. In this paper, we study if such bound state can be responsible for the
750 GeV diphoton excess reported by ATLAS and CMS. We found that the best-fit
signal cross section is obtained for the SU(2) singlet colored fermion
with . Having such an exotic hypercharge, the particle is expected to
decay through some higher dimensional operators, consistent with the small
width assumption. The decay of may involve a stable particle , if
both and are odd under some conserved symmetry. In that case,
the particle suffers from the constraints of jets + missing searches
by ATLAS and CMS at 8 TeV and 13 TeV. We found that such a scenario still
survives if the mass difference between and is above 30 GeV
for GeV. Even assuming pair annihilation of is small, the
relic density of is small enough if the mass difference between and
is smaller than 40 GeV
Excellent daytime seeing at Dome Fuji on the Antarctic plateau
Context. Dome Fuji, the second highest region on the Antarctic plateau, is
expected to have some of the best astronomical seeing on Earth. However, site
testing at Dome Fuji is still in its very early stages.
Aims. To investigate the astronomical seeing in the free atmosphere above
Dome Fuji, and to determine the height of the surface boundary layer.
Methods. A Differential Image Motion Monitor was used to measure the seeing
in the visible (472 nm) at a height of 11 m above the snow surface at Dome Fuji
during the austral summer of 2012/2013.
Results. Seeing below 0.2'' has been observed. The seeing often has a local
minimum of ~0.3'' near 18 h local time. Some periods of excellent seeing, 0.3''
or smaller, were also observed, sometimes extending for several hours at local
midnight. The median seeing is higher, at 0.52''---this large value is believed
to be caused by periods when the telescope was within the turbulent boundary
layer.
Conclusions. The diurnal variation of the daytime seeing at Dome Fuji is
similar to that reported for Dome C, and the height of the surface boundary
layer is consistent with previous simulations for Dome Fuji. The free
atmosphere seeing is ~0.2'', and the height of the surface boundary layer can
be as low as ~11 m.Comment: 4 pages, 6 figures, Submitted to Astronomy & Astrophysics (letter
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