1,167 research outputs found
Sub-millimetre galaxies in cosmological hydrodynamic simulations: Source number counts and the spatial clustering
We use large cosmological Smoothed-Particle-Hydrodynamics simulations to
study the formation and evolution of sub-millimetre galaxies (SMGs). In our
previous work, we studied the statistical properties of ultra-violet selected
star-forming galaxies at high redshifts. We populate the same cosmological
simulations with SMGs by calculating the reprocess of stellar light by dust
grains into far-infrared to millimetre wavebands in a self-consistent manner.
We generate light-cone outputs to compare directly the statistical properties
of the simulated SMGs with available observations. Our model reproduces the
submm source number counts and the clustering amplitude. We show that bright
SMGs with flux mJy reside in halos with mass of and have stellar masses greater than .
The angular cross-correlation between the SMGs and Lyman- emitters is
significantly weaker than that between the SMGs and Lyman-break galaxies. The
cross-correlation is also weaker than the auto-correlation of the SMGs. The
redshift distribution of the SMGs shows a broad peak at , where
Bright SMGs contribute significantly to the global cosmic star formation rate
density. Our model predicts that there are hundreds of SMGs with mJy
at per 1 square degree field. Such SMGs can be detected by ALMA.Comment: 11 pages, 13 figures, submitted to MNRA
Physical Properties of UDF12 Galaxies in Cosmological simulations
We have performed a large cosmological hydrodynamics simulation tailored to
the deep survey with the Hubble Space Telescope made in 2012, the so-called
UDF12 campaign. After making a light-cone output, we have applied the same
color selection criteria as the UDF12 campaign to select galaxies from our
simulation, and then, have examined the physical properties of them as a proxy
of the real observed UDF12 galaxies at . As a result, we find that the
halo mass is almost linearly proportional to the observed ultraviolet (UV)
luminosity ( at ). The dust
attenuation and UV slope well correlates with the observed UV
luminosity, which is consistent with observations quantitatively. The star
formation rate (SFR) is also linearly proportional to the stellar mass and the
specific SFR shows only a weak dependency on the mass. We also find an
increasing star formation history with a time-scale of Myr in the
high- galaxies. An average metallicity weighted by the Lyman continuum
luminosity reaches up to Solar even at , suggesting a rapid
metal enrichment. We also expect mJy at 350 GHz of the dust thermal
emission from the galaxies with , which can be detectable with
the Atacama Large Milimetre-submilimetre Array. The galaxies selected by the
UDF12 survey contribute to only of the cosmic SFR density from to , respectively. The James Webb Space Telescope will push
the detection fraction up to .Comment: re-Submitted to MNRAS; 16 pages; 14 figures; 1 tables
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Preliminary study of discrimination of human vocal commands in walrus (Odobenus rosmarus divergens)
Walruses seem to use various acoustic signals in social context. So, the auditory faculty is seems to be important for walruses. Can walruses understand another animals' vocal information using auditory sense? This study tested whether a male walrus could discriminate human vocal words and perform different actions corresponding to each one under various conditions. The subject, a male walrus (Odobenus rosmarus) named Pou, was set on the ground, and the experimenter spoke one of the ten words to the subject under the following conditions; (1) The experimenter stood close to the subject and spoke each vocal stimulus wearing a black cloak and goggles so that the experimenter's eye and body movements would not influence the subject's behavior, (2) A wooden board was placed between the experimenter and the subject so that the subject could not see the experimenter, (3) A wooden board was placed between the experimenter and the subject so that the subject could not to see the experimenter, and the experimenter uttered each vocal stimulus through an audio speaker. Under each condition, when the subject performed the correct action corresponding to the vocal stimulus, he was rewarded with a piece of fish. As a result, the subject responded correctly to almost all the human vocal stimuli in every condition, including when the speaker was not visible. This means that he was indeed responding to the vocal words and not the experimenter's cues. This study demonstrated that walruses can hear and identify human vocal words using their auditory sense and can form correspondence between vocal words and their meanings
Nuclear prolate-shape dominance with the Woods-Saxon potential
We study the prolate-shape predominance of the nuclear ground-state
deformation by calculating the masses of more than two thousand even-even
nuclei using the Strutinsky method, modified by Kruppa, and improved by us. The
influences of the surface thickness of the single-particle potentials, the
strength of the spin-orbit potential, and the pairing correlations are
investigated by varying the parameters of the Woods-Saxon potential and the
pairing interaction. The strong interference between the effects of the surface
thickness and the spin-orbit potential is confirmed to persist for six sets of
the Woods-Saxon potential parameters. The observed behavior of the ratios of
prolate, oblate, and spherical nuclei versus potential parameters are rather
different in different mass regions. It is also found that the ratio of
spherical nuclei increases for weakly bound unstable nuclei. Differences of the
results from the calculations with the Nilsson potential are described in
detail.Comment: 16 pages, 17 figure
Clinical and Arthroscopic Findings of Acute Anterior Cruciate Ligament Tears of the Knee
Clinical, arthrographic, and arthroscopic findings in 53 patients with acutely torn anterior cruciate ligaments (ACLs) were documented. Arthroscopy and instability tests under anesthesia were performed on all patients within 2 weeks after the initial injury. Twenty-three patients complained of extension blocks, and localized tenderness on the medial side was revealed in 26 patients at the initial examination. Aspiration from joints exhibited hemarthrosis in 52 patients. Arthroscopy revealed ACL ruptures in all patients. Four Segond's fractures, 26 meniscus tears (8 medial and 18 lateral), 1 osteochondral fracture, and 19 medial collateral ligament ruptures were revealed. Arthroscopy detected only 1 of the 5 ruptures of the posteromedial corner of the medial meniscus, which were noted on arthrography. Three ACL stumps were protruding among the femorotibial joint, which seemed to be restricting full extension. Statistical analysis showed that tenderness on the medial side was not revealed more frequently in knees with medial collateral ligament injuries than in the others. The volume of aspirated fluids in knees with no leakage in arthrography significantly increased over those with leakages (p < 0.05). Diagnosis of ACL injuries should be completed by clinical, arthrographic, and arthroscopic examinations
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