Optical to Near-IR Spectrum of a Massive Evolved Galaxy at z = 1.26

We present the optical to near-infrared (IR) spectrum of the galaxy TSPS J1329-0957, a red and bright member of the class of extremely red objects (EROs) at z = 1.26. This galaxy was found in the course of the Tokyo-Stromlo Photometry Survey (TSPS) which we are conducting in the southern sky. The spectroscopic observations were carried out with the Gemini Multi-Object Spectrograph (GMOS) and the Gemini Near Infra-Red Spectrograph (GNIRS) mounted on the Gemini-South telescope. The wide wavelength coverage of 0.6 - 2.3 um provides useful clues as to the nature of EROs while most published spectra are limited to a narrower spectral range which is dictated by the need for efficient redshift determination in a large survey. We compare our spectrum with several optical composite spectra obtained in recent large surveys, and with stellar population synthesis models. The effectiveness of using near-IR broad-band data, instead of the spectral data, in deriving the galaxy properties are also investigated. We find that TSPS J1329-0957 formed when the universe was 2 - 3 Gyr old, and subsequently evolved passively to become one of the most massive galaxies found in the z = 1 - 2 universe. Its early type and estimated stellar mass of M* = 10^{11.5} Msun clearly point to this galaxy being a direct ancestor of the brightest elliptical and spheroidal galaxies in the local universe.Comment: 18 pages, 4 figures. Accepted for publication in Ap

Microwave rapid heating system using carbon heating tube

[EN] We report a microwave heating system with a carbon heating tube (CHT) made by a 4-mm diameter quartz tube filled carbon particles and Ar gas at 1400 Pa. 2.45-GHz microwave at 200 W was introduced to a 300-dimameter metal cavity, in which 60-mm-long CHT was set at the central position. The numerical simulation with a finite element moment method resulted in the standing wave of the electric field caused by three dimensional Fresnel interference effect with low high electric field intensity ranging from from 1 to 6 kV/m because of effective absorption of microwave power by the CHT. The lowest average electrical field intensity of 5 kV/m in the cavity space was given by the electrical conductivity of carbon ranging from 10 to 55 S/m. The CHT with 55 S/m heated to 1200oC by microwave irradiation at 200 W. This heating method was applied to activate 1.0x1015-cm-2 boron and phosphorus implanted regions in n-type crystalline silicon substrate to fabricate pn junction and solar cells. The CHT heating at 1200oC realized decrease in the sheet resistivity to 146 Ω/sq, decrease in the density of defect states to 1.3x1011 and 9.2x1010 cm-2 for boron (p+) and phosphorus (n+) implanted surfaces, and solar cell characteristic with a conversion efficiency of 15% under illumination of air mass 1.5 at 0.1 W/cm2.Sameshima, T.; Kikuchi, T.; Uehara, T.; Arima, T.; Hasumi, M.; Miyazaki, T.; Kobayashi, G.... (2019). Microwave rapid heating system using carbon heating tube. En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 318-325. https://doi.org/10.4995/AMPERE2019.2019.9756OCS31832

Supernova dust for the extinction law in a young infrared galaxy at z = 1

We apply the supernova(SN) extinction curves to reproduce the observed properties of SST J1604+4304 which is a young infrared (IR) galaxy at z = 1. The SN extinction curves used in this work were obtained from models of unmixed ejecta of type II supernovae(SNe II) for the Salpeter initial mass function (IMF) with a mass range from 8 to 30 M_sun or 8 to 40 M_sun. The effect of dust distributions on the attenuation of starlight is investigated by performing the chi-square fitting method against various dust distributions. These are the commonly used uniform dust screen, the clumpy dust screen, and the internal dust geometry. We add to these geometries three scattering properties, namely, no-scattering, isotropic scattering, and forward-only scattering. Judging from the chi-square values, we find that the uniform screen models with any scattering property provide good approximations to the real dust geometry. Internal dust is inefficient to attenuate starlight and thus cannot be the dominant source of the extinction. We show that the SN extinction curves reproduce the data of SST J1604+4304 comparable to or better than the Calzetti extinction curve. The Milky Way extinction curve is not in satisfactory agreement with the data unless several dusty clumps are in the line of sight. This trend may be explained by the abundance of SN-origin dust in these galaxies; SN dust is the most abundant in the young IR galaxy at z = 1, abundant in local starbursts, and less abundant in the Galaxy. If dust in SST J1604+4304 is dominated by SN dust, the dust production rate is about 0.1 M_sun per SN.Comment: 12 pages, 8 figures, 1 tabl

Synthetic emmprin peptides with chitobiose substitution stimulate MMP-2 production by fibroblasts

<p>Abstract</p> <p>Background</p> <p>Emmprin, a glycoprotein containing two Ig domains, is enriched on tumor cell surfaces and stimulates matrix metalloproteinase (MMP) production by adjacent stromal cells. Its first Ig domain (ECI) contains the biologically active site. The dependence of emmprin activity on N-glycosylation is controversial. We investigated whether synthetic ECI with the shortest sugar is functionally active.</p> <p>Methods</p> <p>The whole ECI peptides carrying sugar chains, a chitobiose unit or N-linked core pentasaccharide, were synthesized by the thioester method and added to fibroblasts to examine whether they stimulate MMP-2 production.</p> <p>Results</p> <p>ECI carrying a chitobiose unit, ECI-(GlcNAc) ₂, but not ECI without a chitobiose unit or the chitobiose unit alone, dose-dependently stimulated MMP-2 production by fibroblasts. ECI with longer chitobiose units, ECI-[(Man)₃(GlcNAc)₂], also stimulated MMP-2 production, but the extent of its stimulation was lower than that of ECI-(GlcNAc)₂.</p> <p>Conclusions</p> <p>Our results indicate that ECI can mimic emmprin activity when substituted with chitobiose, the disaccharide with which N-glycosylation starts.</p

Stellar population and dust extinction in an ultraluminous infrared galaxy at z=1.135

We present the detailed optical to far-infrared observations of SST J1604+4304, an ULIRG at z = 1.135. Analyzing the stellar absorption lines, namely, the CaII H & K and Balmer H lines in the optical spectrum, we derive the upper limits of an age for the stellar population. Given this constraint, the minimum {chi}^2 method is used to fit the stellar population models to the observed SED from 0.44 to 5.8um. We find the following properties. The stellar population has an age 40 - 200 Myr with a metallicity 2.5 Z_{sun}. The starlight is reddened by E(B-V) = 0.8. The reddening is caused by the foreground dust screen, indicating that dust is depleted in the starburst site and the starburst site is surrounded by a dust shell. The infrared (8-1000um) luminosity is L_{ir} = 1.78 +/- 0.63 * 10^{12} L_{sun}. This is two times greater than that expected from the observed starlight, suggesting either that 1/2 of the starburst site is completely obscured at UV-optical wavelengths, or that 1/2 of L_{ir} comes from AGN emission. The inferred dust mass is 2.0 +/- 1.0 * 10^8 M_{sun}. This is sufficient to form a shell surrounding the galaxy with an optical depth E(B-V) = 0.8. From our best stellar population model - an instantaneous starburst with an age 40 Myr, we infer the rate of 19 supernovae(SNe) per year. Simply analytical models imply that 2.5 Z_{sun} in stars was reached when the gas mass reduced to 30% of the galaxy mass. The gas metallcity is 4.8 Z_{sun} at this point. The gas-to-dust mass ratio is then 120 +/- 73. The inferred dust production rate is 0.24 +/- 0.12 M_{sun} per SN. If 1/2 of L_{ir} comes from AGN emission, the rate is 0.48 +/- 0.24 M_{sun} per SN. We discuss the evolutionary link of SST J1604+4304 to other galaxy populations in terms of the stellar masses and the galactic winds.Comment: 11 pages, 9 figures, accepted for publication in MNRA