Possible Young Stellar Objects without Detectable CO Emission

We found that at least 18 Young Stellar Object candidates invisible at optical and near-infrared wavelengths, as well as ^12CO emission. They are IRAS point sources with FIR colors similar to those of usual YSOs, and the infrared spectral indices between 2.2 um and 25 um correspond to those of class I YSOs. These peculiar far-infrared objects are highly concentrated around the galactic plane and the distances are estimated to be around 1 kpc. Although their distribution is away from molecular clouds, some of them seem to be associated with large dark clouds or weak radio sources.Comment: 10 pages with 4 figures, LaTeX, accepted for publication in PASJ. Images(fig2) are included in source file as JPEG files. PDF files are avilable at ftp.kusastro.kyoto-u.ac.jp/pub/iwata/preprint

Deriving the Cartography of the Japanese Right Periphery: The Case of Sentence-Final Discourse Particles

The cartographic structure of the Japanese right periphery has been investigated extensively over recent years. (See, for example, Inoue 2007, Ueda 2007, Saito 2009, Endo 2010, and the references cited there.) This paper examines the distributions of the sentence-final discourse particles and presents an account in terms of their lexical properties. We argue, following Endo (2010), that the particles, wa, yo, ne and na, indeed instantiate a cartographic structure in the right periphery. Then, we examine the lexical properties of each of those particles, and show that they explain the observed hierarchy. More specifically, we argue that the selectional requirement of wa and the specific speech acts the four particles are associated with yield the hierarchy wa < yo < ne/na. This conclusion implies that the cartographic structure of the Japanese sentence-final discourse particles can be considered a consequence of the Merge operation that reflects the lexical properties of those particles.La estructura cartográfica de la periferia oracional derecha del japonés ha sido objeto de amplias investigaciones a lo largo de los últimos años (ver, por ejemplo, Inoue 2007, Ueda 2007, Saito 2009, Endo 2010, y las referencias allí citadas). Este artículo examina la distribución de las partículas discursivas en posición final de la oración y presenta una explicación que atiende a sus propiedades léxicas. Argüimos, en la línea de Endo (2010), que las partículas wa, yo, ne y na generan en sí una estructura cartográfica en la periferia oracional derecha. Procedemos seguidamente a examinar las propiedades léxicas de cada una de estas partículas, y demostramos que ilustran la jerarquía mencionada. En particular, argüimos que el requisito de selección para wa y para los actos de habla específicos con los que se vincula a las cuatro partículas producen la jerarquía wa < yo < ne/na. Esta conclusión implica que la estructura cartográfica de las partículas discursivas en posición final en la oración en japonés puede considerarse una consecuencia de la operación de Ensamble (Merge) que refleja las propiedades léxicas de dichas partículas.Nos últimos anos, a estrutura cartográfica da periferia direita em japonês tem sido amplamente investigada. (Veja-se, por exemplo, Inoue 2007, Ueda 2007, Saito 2009, Endo 2010, e as referências aí citadas). Este artigo analisa a distribuição das partículas discursivas em final frase e apresenta uma proposta considerando as suas propriedades lexicais. Argumentamos, seguindo Endo (2010), que as partículas wa, yo, ne e na instanciam uma estrutura cartográfica na periferia direita. Neste sentido, observamos as propriedades lexicais de cada uma destas partículas e mostramos que eles explicam a hierarquia observada. Mais especificamente, argumentamos que a necessidade de seleção de wa e os atos de fala específicos associados a estas quatro partículas geram a hierarquia wa < yo < ne/na. Esta conclusão implica que a estrutura cartográfica das partículas discursivas em final de frase do japonês pode ser considerada como uma consequência da operação Compor (Merge), que reflete as propriedades lexicais destas partículas

A Variation of the Present Star Formation Activity of Spiral Galaxies

The star formation rate in spiral galaxies is considered to be decreasing continuously with time in a time scale of $10^{9}$ yr. The present star formation activity, on the other hand, shows various degrees among galaxies. We make a new data set of 1681 nearby spiral galaxies from available databases and study the statistics of the present star formation activity. We analyze far-infrared and optical B-band surface brightnesses of the H II regions and the non-H II regions in M~31 and show that a far-infrared-to-optical B-band flux ratio, f(FIR)/f(B), is a useful indicator of the present star formation activity of spiral galaxies. For the sample galaxies, we make the distribution diagram of log (f(FIR)/f(B)) versus log L(B) for each morphological type. The distribution of f(FIR)/f(B) has a dispersion of one to two orders of magnitude even within the same morphological type of galaxies, implying that the star formation activities of spiral galaxies changes discontinuously in a short time scale. Analyzing the log (f(FIR)/f(B)) versus log L(B) correlation, we suggest that the most active star formation in galaxies does not continue longer than 10^{8} yr. We also construct a universal distribution histogram of log (f(FIR)/f(B)) for each morphological type. The earlier-type spirals tend to show larger variation of the present star formation activity. We discuss the correlation between the present star formation activity and the structures and environments of galaxies. We suggest that the short-term variation occurs primarily due to internal processes which may change with the morphological type of galaxies.Comment: LaTeX file, 32 pages including tables without figs. 30 figures at ftp://ftp.kusastro.kyoto-u.ac.jp/pub/atomita/preprint/p1489/p1489.tar.gz . To appear in PASJ, Vol. 48, No. 2, April 1996 issu

Some asymmetries in Japanese and their theoretical implications

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND HUMANITIESBibliography: leaves 351-364.by Mamoru Saito.Ph.D

Complementing regional ground GNSS-STEC computerized ionospheric tomography (CIT) with ionosonde data assimilation

A near-real-time computerized ionospheric tomography (CIT) technique was developed over the East Asian sector to specify the 3-D electron density field. The technique is based on a plethora of Global Navigation Satellite System observables within the region of interest which is bounded horizontally 110°–160°E and 10°–60°N and extending from 80 to 25, 000 km in altitude. Prior to deployment, studies validated the CIT results using ionosonde, middle-upper atmosphere radar and occultation data and found the technique to adequately reconstruct the regional ionosphere vertical structure. However, with room for improvement in estimating the peak height and avoiding physically unrealistic negative densities in the final solution, we present preliminary results from a technique that addresses these issues by incorporating CIT results into a data assimilation (DA) technique. The DA technique adds ionosonde bottomside measurements into CIT results, thereby improving the accuracy of the reconstructed bottomside 3-D structure. More specifically, on average CIT NmF2 and hmF2 improve by more than 60%. Further, during analysis, ionospheric electron densities are assumed to be better described by probability log-normal distribution, which introduces the positivity constraint that is mandatory in ionospheric imaging

Characteristics of Kiso Ultra-Violet Excess Galaxies

We examined the general characteristics of the Kiso Ultra-violet Excess Galaxies (KUGs). We present for the first time the quantitative expressions for the criteria of the KUGs; the boundary color separating the KUGs from the non-KUGs is (B-V)_{T} = 0.74 and the KUG degrees of UV strength are found to correlate with the mean (B-V)_{T} colors. We investigate the nature of the KUGs, a sample of blue galaxy population, and show that (1) about a half of the KUGs are spiral galaxies with Sb to Scd, (2) the KUGs are biased to late-type galaxies and include early-type galaxies with young star populations, and (3) the KUGs are preferably found among less luminous galaxies with log L(B) < 10. The KUGs also contain the post-starburst galaxies, many of which are found among the blue galaxy population at intermediate redshifts. The analysis of the far-infrared data shows that a typical present-to-past star formation rate for a KUG is 0.4.Comment: Revised version of astro-ph/9706088, accepted manuscript for AJ; uuencoded gzip'ed tar'ed file containing 25 files; a manuscript (aasms4), 7 tables (aj_pt4), 17 PS figures; To be appeared in The Astronomical Journal, Vol. 114, No. 5 (1997 November issue