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

Nuclear Rotation Curves of Galaxies in the CO Line Emission

We have obtained high-resolution position-velocity (PV) diagrams along the major axes of the central regions of nearby galaxies in the CO-line emission using the Nobeyama 45-m telescope and the Millimeter Array. Nuclear rotation curves for 14 galaxies have been derived based on the PV diagrams using the envelope-tracing method. The nuclear rotation curves for most of the galaxies show a steep rise within a few hundred pc, which indicates a high-density concentration of mass. Keywords: Galaxies: general - Galaxies: structure - ISM: molecular lineComment: To appear in AJ, Plain TeX, Figures on reques

The Central Gas Systems of Early-Type Galaxies Traced by Dust Feature: Based on the HST WFPC2 Archival Images

We investigated the central gas systems of E/S0 galaxies by making use of the WFPC2 images of the Hubble Space Telescope archive. We searched the gas systems that were traced by the dust with a new method of making color excess images in F555W - F814W (V-I). Out of 25 sample galaxies, we detected gas system in 14 galaxies. The dust was newly detected in two galaxies that were thought to contain no dust based on single band, pre-refurbishment data. The full extents of the gas systems are 0.1 to 3.5 kpc, and the masses of the gas, log M(gas) [M(solar)], are 4.2 to 7.2. The AGN activity is well correlated with existence of the gas systems. None of galaxies without the gas systems show the AGN activity. On the other hand, some galaxies with the gas systems show the AGN activity; optical AGN activities are shown in 5 out of 11 galaxies of which AGNs are optically studied, and radio activities are shown in 6 out of 14 galaxies. This shows that the AGN activity is driven with the gas system.Comment: gzipped tarred file containing 7 files: Tomita.tex (main text, needs aaspp4.sty), Tomita.tab[1,2].tex (tables, need aj_pt4.sty), Tomita.fig [1a,1b,1c,2].ps (PS figures). To be appeared in AJ, Vol.120, No.1 (July 2000

Screwballquestions seen in classes by teacher's training students

TesisLa presente investigación tuvo como problema: ¿Cuál es la calidad de las sentencias de primera y segunda instancia sobre, Divorcio por Causal de Violencia Psicológica, según los parámetros normativos, doctrinarios y jurisprudenciales pertinentes, en el expediente N° 00036-2014-0-3102-JR-FC-01, del Distrito Judicial del Sullana; 2019?; el objetivo fue: determinar la calidad de las sentencias en estudio. Por lo tanto, es de tipo, cuantitativo - cualitativo, nivel exploratorio - descriptivo, y diseño no experimental, retrospectivo y transversal. La unidad muestra fue un expediente judicial, seleccionado mediante muestreo por conveniencia; para recolectar los datos se utilizó las técnicas de la observación y el análisis de contenido; y como instrumento una lista de cotejo, validado mediante juicio de expertos. Los resultados revelaron que la calidad de la parte expositiva, considerativa y resolutiva, pertenecientes a: la sentencia de primera instancia fue de rango: alta, mediana y alta; mientras que, de la sentencia de segunda instancia: muy alta, muy alta y alta. En conclusión, la calidad de las sentencias de primera y segunda instancia, fueron de rango alta y muy alta, respectivamente