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Date and Time of the Query: 2019-07-22 T09:10:55 PDT
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For refcode 2001AJ....121.2483U:
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2001AJ....121.2483U SPECTROSCOPIC OBSERVATIONS OF THE STAR FORMATION ACTIVITIES IN THE CENTRAL REGIONS OF EARLY-TYPE SPIRAL GALAXIES TADASHI USUI AND MAMORU SAITO Department of Astronomy, Faculty of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; usui@kusastro.kyoto-u.ac.jp AND AKIHIKO TOMITA Faculty of Education, Wakayama University, Wakayama 640-8510, Japan; atomita@center.wakayama-u.ac.jp Received 2000 November 2; accepted 2001 February 9 ABSTRACT We study the characteristics of central star-forming regions of early- type spiral galaxies by optical spectroscopic observations. The sample consists of 13 galaxies which have ratios of far-infrared (FIR) to optical B-band luminosity, log(L_FIR_/L_B_), larger than the average of this type, -0.5. Strong line emissions are detected around the nucleus, and the line ratios of most regions are H II region-like, except for a few shocked regions. There is no low-ionization nuclear emission-line region (LINER). The [N II] and [S II] lines are somewhat enhanced, compared to the disk H II regions, but the enhancements cannot be attributed to hidden active galactic nuclei (AGNs) and the shock excitation. The median extinction derived from the H{alpha}/H{beta} intensity ratio is 1.0 mag in A_V_, and the median SFR of our sample galaxies, corrected for extinction, is estimated to be 2 M_sun_ yr^-1^. Both values are comparable to those of late-type spiral galaxies. We find a correlation that the radii of the central star-forming regions tend to become larger with the turn-over radii of the rotation curves. Key words: galaxies: abundances-galaxies: spiral-galaxies: starburst- techniques: spectroscopic
Retrieve 13 NED objects in this reference.
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