Detection of Far Infrared Emission from Galaxies and Quasars in the Galactic Extinction Map by Stacking Analysis

We have performed stacking image analyses of galaxies over the Galactic extinction map constructed by Schlegel, Finkbeiner & Davis (1998). We select ~10^7 galaxies in total from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalog. We detect clear signatures of the enhancement of the extinction in r-band, $\Delta A_r$, around galaxies, indicating that the extinction map is contaminated by their FIR (far infrared) emission. The average amplitude of the contamination per galaxy is well fitted to $\Delta A_r(m_r) = 0.64 \times 10^{0.17(18-m_r)}$ [mmag]. While this value is very small, it is directly associated with galaxies and may have a systematic effect on galaxy statistics. Indeed this correlated contamination leads to a relatively large anomaly of galaxy surface number densities against the SFD extinction A_SFD discovered by Yahata et al. (2007). We model the radial profiles of stacked galaxy images, and find that the FIR signal around each galaxy does not originate from the central galaxy alone, but is dominated by the contributions of nearby galaxies via galaxy angular clustering. The separation of the single galaxy and the clustering terms enables us to infer the statistical relation of the FIR and r-band fluxes of galaxies and also to probe the flux-weighted cross-correlation of galaxies, down to the magnitudes that are difficult to probe directly for individual objects. We repeat the same stacking analysis for SDSS DR6 photometric quasars and discovered the similar signatures but with weaker amplitudes. The implications of the present results for galaxy and quasar statistics and for correction to the Galactic extinction map are briefly discussed.Comment: 11 pages, 19 figures, PASJ, 2013, vol65, No.3, in pres

Modeling the anomaly of surface number densities of galaxies on the Galactic extinction map due to their FIR emission contamination

The most widely used Galactic extinction map (Schlegel, Finkbeiner, & Davis 1998, SFD) is constructed assuming that the observed FIR fluxes entirely come from the Galactic dust. According to the earlier suggestion by Yahata et al. (2007), we consider how far-infrared (FIR) emission of galaxies affects the SFD map. We first compute the surface number density of SDSS DR7 galaxies as a function of the $r$-band extinction, $A_{r,\rm SFD}$. We confirm that the surface densities of those galaxies positively correlate with $A_{r,\rm SFD}$ for $A_{r,\rm SFD}<0.1$, as first discovered by Yahata et al. (2007) for SDSS DR4 galaxies. Next we construct an analytic model to compute the surface density of galaxies taking account of the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of $100\mu {\rm m}$ and $r$-band luminosities of each galaxy, $y \equiv (\nu L)_{100\mu {\rm m}}/(\nu L)_r$. Then we search for the mean and r.m.s values of $y$ that fit the observed anomaly using the analytic model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies (Kashiwagi, Yahata, & Suto 2013). Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. While the corresponding systematic error in the Galactic extinction map is 0.1 to 1mmag, it is directly correlated with galaxy clustering, and thus needs to be carefully examined in precision cosmology.Comment: 20 pages, 12 figures, accepted for publication in Ap

Syntenic analysis of ACCase loci and target-site-resistance mutations in cyhalofop-butyl resistant Echinochloa crus-galli var. crus-galli in Japan

BACKGROUND: Recently, suspected cyhalofop-butyl-resistant populations of allohexaploid weed Echinochloa crus-galli var. crus-galli were discovered in rice fields in Aichi Prefecture, Japan. Analyzing the target-site ACCase genes of cyhalofop-butyl helps understand the resistance mechanism. However, in E. crus-galli, the presence of multiple ACCase genes and the lack of detailed gene investigations have complicated the analysis of target-site genes. Therefore, in this study, we characterized the herbicide response of E. crus-galli lines and thoroughly characterized the ACCase genes, including the evaluation of gene mutations in the ACCase genes of each line. RESULT: Four suspected resistant lines collected from Aichi Prefecture showed varying degrees of resistance to cyhalofop-butyl and other FOP-class ACCase inhibitors but were sensitive to herbicides with other modes of action. Through genomic analysis, six ACCase loci were identified in the E. crus-galli genome. We renamed each gene based on its syntenic relationship with other ACCase genes in the Poaceae species. RNA-sequencing analysis revealed that all ACCase genes, except the pseudogenized copy ACCase2A, were transcribed at a similar level in the shoots of E. crus-galli. Mutations known to confer resistance to FOP-class herbicides, that is W1999C, W2027C/S and I2041N, were found in all resistant lines in either ACCase1A, ACCase1B or ACCase2C. CONCLUSION: In this study, we found that the E. crus-galli lines were resistant exclusively to ACCase-inhibiting herbicides, with a target-site resistance mutation in the ACCase gene. Characterization of ACCase loci in E. crus-galli provides a basis for further research on ACCase herbicide resistance in Echinochloa spp. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry

EVALUATION OF THE BACK-BOMBARDMENT EFFECT IN THE ITC-RF GUN FOR T-ACTS PROJECT AT TOHOKU UNIVERSITY

Abstract An ITC (independently tunable cells) RF gun is currently used to produce sub-picosecond electron pulses as part of the injector for coherent terahertz radiation at Tohoku University. Experiments and simulations of particle tracing by GPT show that the back-bombardment effect on the LaB6 cathode&apos;s surface is serious and should be controlled carefully. To evaluate the temperature increase due to backbombardment a 2D model is created for heat transfer inside the cathode. In the 2D model, the back-streaming electrons are treated as external heat source as well as the cathode heater that heats the cathode from its side along with thermal radiation from its surface. The energy deposit of backbombardment inside the cathode is calculated by EGS5 or Geant4 by use of the information of back-streaming electrons derived from GPT simulation. In addition, we will also compare the simulating results with experimental data on the increase of emission current density of cathode due to back-bombardment

Light source based on a 100 mm-long monolithic undulator magnet with a very short 4 mm-period length

A novel method to fabricate undulator magnets of a-few-millimetre-periodlength is being explored. Plate-type magnets, 100 mm-long with 4 mm-periodlength, have been successfully fabricated. They produce an undulator field ofapproximately 3 kG at a gap of 1.6 mm. Prototype undulators based on thistechnology have been constructed. Field measurements and characterizationshow that the quality of the undulator field of these plate magnets is sufficientfor an undulator light source, and the calculated spectrum shows that thefundamental radiation emitted from this field is quite satisfactory. Testexperiments for light generation using a real electron beam have been carriedout at a test accelerator at the Research Center for Electron Photon Science(ELPH), Tohoku University, Japan, which is able to realize optics conditions toaccept a very short gap of 1.6 mm. First observation and characterization ofblue light was successfully accomplished

Syntheses and X-Ray Crystal Structures of Magnesium- Substituted Polyoxometalates

autho