1,167 research outputs found
Phase Field Model for Dynamics of Sweeping Interface
Motivated by the drying pattern experiment by Yamazaki and Mizuguchi[J. Phys.
Soc. Jpn. {\bf 69} (2000) 2387], we propose the dynamics of sweeping interface,
in which material distributed over a region is swept by a moving interface. A
model based on a phase field is constructed and results of numerical
simulations are presented for one and two dimensions. Relevance of the present
model to the drying experiment is discussed.Comment: 4 pages, 7 figure
A Study of Selection Methods for H alpha Emitting Galaxies at z~1.3 for the Subaru/FMOS Galaxy Redshift Survey for Cosmology (FastSound)
The efficient selection of high-redshift emission galaxies is important for
future large galaxy redshift surveys for cosmology. Here we describe the target
selection methods for the FastSound project, a redshift survey for H alpha
emitting galaxies at z=1.2-1.5 using Subaru/FMOS to measure the linear growth
rate f\sigma 8 via Redshift Space Distortion (RSD) and constrain the theory of
gravity. To select ~400 target galaxies in the 0.2 deg^2 FMOS field-of-view
from photometric data of CFHTLS-Wide (u*g'r'i'z'), we test several different
methods based on color-color diagrams or photometric redshift estimates from
spectral energy distribution (SED) fitting. We also test the improvement in
selection efficiency that can be achieved by adding near-infrared data from the
UKIDSS DXS (J). The success rates of H alpha detection with FMOS averaged over
two observed fields using these methods are 11.3% (color-color, optical), 13.6%
(color-color, optical+NIR), 17.3% (photo-z, optical), and 15.1% (photo-z,
optical+NIR). Selection from photometric redshifts tends to give a better
efficiency than color-based methods, although there is no significant
improvement by adding J band data within the statistical scatter. We also
investigate the main limiting factors for the success rate, by using the sample
of the HiZELS H alpha emitters that were selected by narrow-band imaging.
Although the number density of total H alpha emitters having higher H alpha
fluxes than the FMOS sensitivity is comparable with the FMOS fiber density, the
limited accuracy of photometric redshift and H alpha flux estimations have
comparable effects on the success rate of <~20% obtained from SED fitting.Comment: 12 pages, 7 figures, accepted to PAS
Experimental study of energy transport in thin Al and Au foils irradiated with a 263-nm laser
Copyright 1989 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 65(12), 5068-5071, 1989 and may be found at http://dx.doi.org/10.1063/1.34318
Crystal structure of carbonyl{hydridotris[3-phenyl-5-methylpyrazol-1-yl]borato-Îş3N,Nâ˛Nâ˛â˛}copper(I), C31H28BCuN6O
C31H28BCuN6O, monoclinic, P21/n (no. 14), a = 11.506(3) Ă
, b = 16.122(3) Ă
, c = 15.805(3) Ă
, β = 99.433(3)°, V = 2892.2(11) Ă
3, Z = 4, Rgt(F) = 0.0501, wRref(F2) = 0.1260, T = 193(2) K
Metallothionein from wild populations of the African catfish Clarias gariepinus : from sequence, protein expression and metal binding properties to transcriptional biomarker of metal pollution
Anthropogenic pollution with heavy metals is an on-going concern throughout the world, and methods to monitor release and impact of heavy metals are of high importance. With a view to probe its suitability as molecular biomarker of metal pollution, this study has determined a coding sequence for metallothionein of the African sharptooth catfish Clarias gariepinus. The gene product was recombinantly expressed in Escherichia coli in presence of Zn(II), Cd(II), or Cu, and characterised by Electrospray Ionisation Mass Spectrometry and elemental analysis. C. gariepinus MT displays typical features of fish MTs, including 20 conserved cysteines, and seven bound divalent cations (Zn(II) or Cd(II)) when saturated. Livers from wild C. gariepinus fish collected in all three seasons from four different sites on the Kafue River of Zambia were analysed for their metal contents and for MT expression levels by quantitative PCR. Significant correlations were found between Zn and Cu levels and MT expression in livers, with MT expression clearly highest at the most polluted site, Chililabombwe, which is situated in the Copperbelt region. Based on our findings, hepatic expression of MT from C. gariepinus may be further developed as a major molecular biomarker of heavy metal pollution resulting from mining activities in this region
Revisiting the Cosmic Star Formation History: Caution on the Uncertainties in Dust Correction and Star Formation Rate Conversion
The cosmic star formation rate density (CSFRD) has been observationally
investigated out to redshift z~10. However, most of theoretical models for
galaxy formation underpredict the CSFRD at z>1. Since the theoretical models
reproduce the observed luminosity functions (LFs), luminosity densities (LDs),
and stellar mass density at each redshift, this inconsistency does not simply
imply that theoretical models should incorporate some missing unknown physical
processes in galaxy formation. Here, we examine the cause of this inconsistency
in UV wavelengths by using a mock catalog of galaxies generated by a
semi-analytic model of galaxy formation. We find that this inconsistency is due
to two observational uncertainties: dust obscuration correction and conversion
from UV luminosity to star formation rate (SFR). The methods for correction of
obscuration and SFR conversion used in observational studies result in the
overestimation of CSFRD by ~ 0.1-0.3 dex and ~ 0.1-0.2 dex, respectively,
compared to the results obtained directly from our mock catalog. We present new
empirical calibrations for dust attenuation and conversion from observed UV LFs
and LDs into CSFRD.Comment: 12 pages including 11 figures. matches the published version (ApJ
2013 Jan. 20 issue
SXDF-UDS-CANDELS-ALMA 1.5 arcmin deep survey
We have conducted 1.1 mm ALMA observations of a contiguous or 1.5 arcmin window in the SXDF-UDS-CANDELS. We achieved a 5
sensitivity of 0.28 mJy, providing a flat sensus of dusty star-forming galaxies
with (for =40K) up to
thanks to the negative K-correction at this wavelength. We detected 5
brightest sources (S/N6) and 18 low-significance sources (5S/N4; these
may contain spurious detections, though). One of the 5 brightest ALMA sources
( mJy) is extremely faint in the WFC3 and
VLT/HAWK-I images, demonstrating that a contiguous ALMA imaging survey is able
to uncover a faint dust-obscured population that is invisible in deep
optical/near-infrared surveys. We found a possible [CII]-line emitter at
or a low- CO emitting galaxy within the field, which may allow us
to constrain the [CII] and/or the CO luminosity functions across the history of
the universe.Comment: 4 pages, 2 figures, 1 table, to appear in the proceedings of IAU
Symposium 319 "Galaxies at High Redshift and Their Evolution over Cosmic
Time", eds. S. Kaviraj & H. Ferguso
Treadmill Experience Alters Treadmill Effects on Perceived Visual Motion
Information on ongoing body movements can affect the perception of ambiguous visual motion. Previous studies on âtreadmill captureâ have shown that treadmill walking biases the perception of ambiguous apparent motion in backward direction in accordance with the optic flow during normal walking, and that long-term treadmill experience changes the effect of treadmill capture. To understand the underlying mechanisms for these phenomena, we conducted Experiment 1 with non-treadmill runners and Experiment 2 with treadmill runners. The participants judged the motion direction of the apparent motion stimuli of horizontal gratings in front of their feet under three conditions: walking on a treadmill, standing on a treadmill, and standing on the floor. The non-treadmill runners showed the presence of downward bias only under the walking condition, indicating that ongoing treadmill walking but not the awareness of being on a treadmill biased the visual directional discrimination. In contrast, the treadmill runners showed no downward bias under any of the conditions, indicating that neither ongoing activity nor the awareness of spatial context produced perception bias. This suggests that the long-term repetitive experience of treadmill walking without optic flow induced the formation of a treadmill-specific locomotor-visual linkage to perceive the complex relationship between self and the environment
Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies
We report the study of far-IR sizes of submillimeter galaxies (SMGs) in
relation to their dust-obscured star formation rate (SFR) and active galactic
nuclei (AGN) presence, determined using mid-IR photometry. We determined the
millimeter-wave (m) sizes of 69 ALMA-identified
SMGs, selected with confidence on ALMA images (--7.4 mJy). We found that all the SMGs are located above an
avoidance region in the millimeter size-flux plane, as expected by the
Eddington limit for star formation. In order to understand what drives the
different millimeter-wave sizes in SMGs, we investigated the relation between
millimeter-wave size and AGN fraction for 25 of our SMGs at --3. We found
that the SMGs for which the mid-IR emission is dominated by star formation or
AGN have extended millimeter-sizes, with respective median and 1.5 kpc. Instead, the SMGs for which
the mid-IR emission corresponds to star-forming/AGN composites have more
compact millimeter-wave sizes, with median
kpc. The relation between millimeter-wave size and AGN fraction suggests that
this size may be related to the evolutionary stage of the SMG. The very compact
sizes for composite star-forming/AGN systems could be explained by supermassive
black holes growing rapidly during the SMG coalescing, star-formation phase.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in ApJ Lette
Stellar properties of z ~ 1 Lyman-break galaxies from ACS slitless grism spectra
Lyman-break galaxies are now regularly found in the high redshift Universe by
searching for the break in the galaxy spectrum caused by the Lyman-limit
redshifted into the optical or even near-IR. At lower redshift, this break is
covered by the GALEX UV channels and small samples of z ~ 1 LBGs have been
presented in the literature. Here we give results from fitting the spectral
energy distributions of a small sub-set of low redshift LBGs and demonstrate
the advantage of including photometric points derived from HST ACS slitless
grism observations. The results show these galaxies to have very young, star
forming populations, while still being massive and dusty. LBGs at low and high
redshift show remarkable similarities in their properties, indicating that the
LBG selection method picks similar galaxies throughout the Universe.Comment: 7 pages, 3 figures, 2 tables, accepted in A&
- âŚ