2,298 research outputs found
Early UV/Optical Emission of The Type Ib SN 2008D
We propose an alternative explanation for the post-breakout emission of SN
2008D associated with the X-ray transient 080109. Observations of this object
show a very small contrast of 0.35 dex between the light-curve minimum
occurring soon after the breakout, and the main luminosity peak that is due to
radioactive heating of the ejecta. Hydrodynamical models show that the cooling
of a shocked Wolf-Rayet star leads to a much greater difference (> 0.9 dex).
Our proposed scenario is that of a jet produced during the explosion which
deposits 56Ni-rich material in the outer layers of the ejecta. The presence of
high-velocity radioactive material allows us to reproduce the complete
luminosity evolution of the object. Without outer 56Ni it could be possible to
reproduce the early emission purely from cooling of the shocked envelope by
assuming a larger progenitor than a Wolf-Rayet star, but that would require an
initial density structure significantly different from what is predicted by
stellar evolution models. Analytic models of the cooling phase have been
proposed reproduce the early emission of SN 2008D with an extended progenitor.
However, we found that the models are valid only until 1.5 days after the
explosion where only two data of SN 2008D are available. We also discuss the
possibility of the interaction of the ejecta with a binary companion, based on
published analytic expressions. However, the binary separation required to fit
the early emission should be < 3 Rsun which is too small for a system
containing two massive stars.Comment: 10 pages, 10 figures, Accepted for publication in Ap
Detection of p73 antibodies in patients with various types of cancer: immunological characterization
p53 antibodies have been found in the sera of patients with various types of cancer. The presence of these antibodies is generally associated with p53 accumulation in the tumour that is believed to trigger this humoral response. The recent discovery of 2 new members of the p53 family, p73 and p63, led us to study the specificity of this immune response towards the 3 proteins. Serum samples from 148 patients with various types of cancer were tested for antibodies against p73 and p63 using immunoprecipitation. 72 patients were previously shown to have p53 antibodies whereas 76 were negative. The control group consisted of 50 blood donors. p73 were detected in 22/148 (14.9%) of the cancer patients (11/72 in the group with p53-antibodies and 11/76 in the negative group). Only two sera from the control (4%) were positive. p63 antibodies were detected in only 4/148 (2.7%) of the cancer patients. Epitope mappings were performed and demonstrate that p73 antibodies are directed toward the central region of the p73 protein whereas p53 antibodies react predominantly toward the amino- and the carboxy-terminus of p53. Our results indicate that there is a specific immune response toward the p73 protein in cancer patients, a finding supported by an increasing number of publications describing p73 accumulation in tumoral cells. © 2001 Cancer Research Campaign http://www.bjcancer.co
On the Light Curve and Spectrum of SN 2003dh Separated from the Optical Afterglow of GRB 030329
The net optical light curves and spectra of the supernova (SN) 2003dh are
obtained from the published spectra of GRB 030329, covering about 6 days before
SN maximum to about 60 days after. The bulk of the U-band flux is subtracted
from the observed spectra using early-time afterglow templates, because strong
line blanketing greatly depresses the UV and U-band SN flux in a metal-rich,
fast-moving SN atmosphere. The blue-end spectra of the gamma-ray burst
(GRB)connected hypernova SN 1998bw is used to determine the amount of
subtraction. The subtraction of a host galaxy template affects the late-time
results. The derived SN 2003dh light curves are narrower than those of SN
1998bw, rising as fast before maximum, reaching a possibly fainter maximum, and
then declining ~ 1.2-1.4 times faster. We then build UVOIR bolometric SN light
curve. Allowing for uncertainties, it can be reproduced with a spherical ejecta
model of Mej ~ 7+/-3 Msun, KE ~ (3.5+/-1.5)E52 ergs, with KE/Mej ~ 5 following
previous spectrum modelling, and M(Ni56) ~ (0.4 +0.15/-0.1) Msun. This suggests
a progenitor main-sequence mass of about 25-40 Msun, lower than SN 1998bw but
significantly higher than normal Type Ic SNe and the GRB-unrelated hypernova SN
2002ap.Comment: 18 pages, 7 figures, published by Ap
The evolution of the peculiar Type Ia supernova SN 2005hk over 400 days
photometry and medium resolution optical spectroscopy of peculiar
Type Ia supernova SN 2005hk are presented and analysed, covering the
pre-maximum phase to around 400 days after explosion. The supernova is found to
be underluminous compared to "normal" Type Ia supernovae. The photometric and
spectroscopic evolution of SN 2005hk is remarkably similar to the peculiar Type
Ia event SN 2002cx. The expansion velocity of the supernova ejecta is found to
be lower than normal Type Ia events. The spectra obtained \gsim 200 days
since explosion do not show the presence of forbidden [\ion{Fe}{ii}],
[\ion{Fe}{iii}] and [\ion{Co}{iii}] lines, but are dominated by narrow,
permitted \ion{Fe}{ii}, NIR \ion{Ca}{ii} and \ion{Na}{i} lines with P-Cygni
profiles. Thermonuclear explosion model with Chandrasekhar mass ejecta and a
kinetic energy smaller (\KE = 0.3 \times 10^{51} {\rm ergs}) than that of
canonical Type Ia supernovae is found to well explain the observed bolometric
light curve. The mass of \Nifs synthesized in this explosion is 0.18 \Msun.
The early spectra are successfully modeled with this less energetic model with
some modifications of the abundance distribution. The late spectrum is
explained as a combination of a photospheric component and a nebular component.Comment: Accepted for publication in The Astrophysical Journal. Minor
revision, discussion section adde
Dynamical Susceptibility in KDP-type Crysals above and below Tc II
The path probability method (PPM) in the tetrahedron-cactus approximation is
applied to the Slater-Takagi model with dipole-dipole interaction for
KH2PO4-type hydrogen-bonded ferroelectric crystals in order to derive a small
dip structure in the real part of dynamical susceptibility observed at the
transition temperature Tc. The dip structure can be ascribed to finite
relaxation times of electric dipole moments responsible for the first order
transition with contrast to the critical slowing down in the second order
transition. The light scattering intensity which is related to the imaginary
part of dynamical susceptibility is also calculated above and below the
transition temperature and the obtained central peak structure is consistent
with polarization fluctuation modes in Raman scattering experiments.Comment: 8 pages, 11 figure
Thermal Diffusion of a Two Layer System
In this paper thermal conductivity and thermal diffusivity of a two layer
system is examined from the theoretical point of view. We use the one
dimensional heat diffusion equation with the appropriate solution in each layer
and boundary conditions at the interfaces to calculate the heat transport in
this bounded system. We also consider the heat flux at the surface of the samle
as boundary condition instead of using a fixed tempertaure. From this, we
obtain an expression for the efective thermal diffusivity of the composite
sample in terms of the thermal diffusivity of its constituent materials
whithout any approximations.Comment: 16 pages, 1 figure, RevTeX v. 3.0 macro packag
SN 2016jhj at redshift 0.34: extending the Type II supernova Hubble diagram using the standard candle method
Although Type Ia supernova cosmology has now reached a mature state, it is important to develop as many independent methods as possible to understand the true nature of dark energy. Recent studies have shown that Type II supernovae (SNe II) offer such a path and could be used as alternative distance indicators. However, the majority of these studies were unable to extend the Hubble diagram above redshift z = 0.3 because of observational limitations. Here, we show that we are now ready to move beyond low redshifts and attempt high-redshift (z ≳ 0.3) SN II cosmology as a result of new-generation deep surveys such as the Subaru/Hyper Suprime-Cam survey. Applying the ´standard candle method´ to SN 2016jhj (z = 0.3398 ± 0.0002; discovered by HSC) together with a low-redshift sample, we are able to construct the highest-redshift SN II Hubble diagram to date with an observed dispersion of 0.27 mag (i.e. 12-13 per cent in distance). This work demonstrates the bright future of SN II cosmology in the coming era of large, wide-field surveys like that of the Large Synoptic Survey Telescope.Fil: de Jaeger, T.. University of California at Berkeley; Estados UnidosFil: Galbany, L.. University of Pittsburgh at Johnstown; Estados UnidosFil: Filippenko, A. V.. University of California at Berkeley; Estados UnidosFil: González Gaitán, S.. Universidad de Chile; ChileFil: Yasuda, N.. University of Tokio; JapónFil: Maeda, K.. University of Tokio; JapónFil: Tanaka, M.. University of Tokio; JapónFil: Morokuma, T.. University of Tokio; JapónFil: Moriya, T. J.. National Astronomical Observatory of Japan; JapónFil: Tominaga, N.. University of Tokyo; JapónFil: Nomoto, Ken’ichi. University of Tokyo; JapónFil: Komiyama, Y.. National Astronomical Observatory of Japan; JapónFil: Anderson, J. P.. European Southern Observatory; ChileFil: Brink, T. G.. University of California at Berkeley; Estados UnidosFil: Carlberg, R. G.. University of Toronto; CanadáFil: Folatelli, Gaston. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y GeofÃsicas; Argentina. University of Tokyo; JapónFil: Hamuy, M.. Universidad de Chile; ChileFil: Pignata, G.. Universidad Andrés Bello; ChileFil: Zheng, W.. University of California at Berkeley; Estados Unido
Molecular characterization of the β chain of the murine interleukin 5 receptor
Interleukin 5 (IL-5) is a multifunctional cytokine that regulates the proliferation and differentiation of hematopoietlc cells Including B cells and eosinophlls. The murine IL-5 acts on target cells via an IL-5 specific high-affinity receptor (Kd ≃ 150 pM) that has been proposed to be composed of at least two membrane polypeptide chains. The p60 component recognized by anti-murine IL-5 receptor mAbs H7 and T21 binds IL-5 with low affinity (Kd ≃ 10 nM). The other component is p130, detectable by following cross-linking experiments with IL-5. Using H7, T21, and R52.120 mAbs specific to murine IL-5 receptor, we characterized the molecular nature of the p130 of the high affinity receptor for murine IL-5. R52.120 mAb did not recognize the IL-5 binding recombinant p60 expressed on COS7 cells, but reacted with p130/140 on IL-5-dependent cell lines. R52.120 mAb showed partial inhibition of the IL-5-induced proliferation of the IL-5-dependent early B cell line Y16 at high IL-5 concentrations. Addition of R52.120 mAb together with H7 or T21 mAb caused more striking inhibition of the IL-5-dependent proliferation than that caused by either of them alone. R52.120 mAb down-regulated the number and dissociation constant of IL-5 binding sites with high affinity without affecting the levels of these with low-affinity. It also preferentially inhibited the formation of the cross-linked complex of p130 with radlolabeledIL-5. These results Indicate that p130/p140, recognized by R52.120 mAb, Is indispensable, together with p60, for the formation of high affinity IL-5 receptor. We propose to designate p60 and p130/p140 as the α and β chain of IL-5 receptor, respectivel
Scattering of particles by neutron stars: Time-evolutions for axial perturbations
The excitation of the axial quasi-normal modes of a relativistic star by
scattered particles is studied by evolving the time dependent perturbation
equations. This work is the first step towards the understanding of more
complicated perturbative processes, like the capture or the scattering of
particles by rotating stars. In addition, it may serve as a test for the
results of the full nonlinear evolution of binary systems.Comment: 7 pages, 5 figures, Phys. Rev. D in pres
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