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Title: Nuclear concentration of molecular gas in the late-type spiral galaxy NGC 6946 - 300 parsec scale gaseous disk

Abstract

The CO (J = 1-0) emission in the central 65 arcsec (1.7 kpc) region of the nearby late-type spiral galaxy NGC 6946 has been mapped using the Nobeyama Millimeter Array. The synthesized beam is 7.6 x 4.2 arcsec (HPBW) which corresponds to 200 pc x 110 pc at the distance of 5.5 Mpc. A massive nuclear concentration of molecular gas with a scale of 300 pc and a molecular bar structure elongated more than 1.5 kpc were found. The velocity structure suggests that the molecular gas in the nuclear concentration has a circular rotation and the gas in the molecular bar structure has an infall motion. The total H2 mass in the central 65 arcsec region is (4 + or - 2) x 10 to the 8th solar masses, 75 percent of which was found in the 300 pc scale nuclear concentration. The region of the central concentration coincides with a bright H II region and a radio continuum source. It is suggested that the nuclear concentration is a massive nuclear disk of molecular gas which has been formed by efficient gas inflow in an oval potential field. The high H2 density (found in the nuclear concentration) supports active starmore » formation in the nuclear region. 33 refs.« less

Authors:
; ; ; ;  [1]
  1. Tokyo Univ. (Japan) Nobeyama Radio Observatory, Minamimaki (Japan) Tokyo Univ. (Japan)
Publication Date:
OSTI Identifier:
6690533
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal; (USA)
Additional Journal Information:
Journal Volume: 355; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GALAXIES; SPIRAL CONFIGURATION; GALAXY NUCLEI; COSMIC GASES; CARBON MONOXIDE; COSMIC RADIO SOURCES; EMISSION SPECTRA; GALACTIC EVOLUTION; GAS FLOW; H2 REGIONS; MASS; MORPHOLOGY; STAR EVOLUTION; VELOCITY; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CONFIGURATION; FLUID FLOW; FLUIDS; GASES; OXIDES; OXYGEN COMPOUNDS; SPECTRA; 640105* - Astrophysics & Cosmology- Galaxies

Citation Formats

Ishizuki, S, Kawabe, R, Ishiguro, M, Morita, K I, and Okumura, S K. Nuclear concentration of molecular gas in the late-type spiral galaxy NGC 6946 - 300 parsec scale gaseous disk. United States: N. p., 1990. Web. doi:10.1086/168777.
Ishizuki, S, Kawabe, R, Ishiguro, M, Morita, K I, & Okumura, S K. Nuclear concentration of molecular gas in the late-type spiral galaxy NGC 6946 - 300 parsec scale gaseous disk. United States. https://doi.org/10.1086/168777
Ishizuki, S, Kawabe, R, Ishiguro, M, Morita, K I, and Okumura, S K. 1990. "Nuclear concentration of molecular gas in the late-type spiral galaxy NGC 6946 - 300 parsec scale gaseous disk". United States. https://doi.org/10.1086/168777.
@article{osti_6690533,
title = {Nuclear concentration of molecular gas in the late-type spiral galaxy NGC 6946 - 300 parsec scale gaseous disk},
author = {Ishizuki, S and Kawabe, R and Ishiguro, M and Morita, K I and Okumura, S K},
abstractNote = {The CO (J = 1-0) emission in the central 65 arcsec (1.7 kpc) region of the nearby late-type spiral galaxy NGC 6946 has been mapped using the Nobeyama Millimeter Array. The synthesized beam is 7.6 x 4.2 arcsec (HPBW) which corresponds to 200 pc x 110 pc at the distance of 5.5 Mpc. A massive nuclear concentration of molecular gas with a scale of 300 pc and a molecular bar structure elongated more than 1.5 kpc were found. The velocity structure suggests that the molecular gas in the nuclear concentration has a circular rotation and the gas in the molecular bar structure has an infall motion. The total H2 mass in the central 65 arcsec region is (4 + or - 2) x 10 to the 8th solar masses, 75 percent of which was found in the 300 pc scale nuclear concentration. The region of the central concentration coincides with a bright H II region and a radio continuum source. It is suggested that the nuclear concentration is a massive nuclear disk of molecular gas which has been formed by efficient gas inflow in an oval potential field. The high H2 density (found in the nuclear concentration) supports active star formation in the nuclear region. 33 refs.},
doi = {10.1086/168777},
url = {https://www.osti.gov/biblio/6690533}, journal = {Astrophysical Journal; (USA)},
issn = {0004-637X},
number = ,
volume = 355,
place = {United States},
year = {Fri Jun 01 00:00:00 EDT 1990},
month = {Fri Jun 01 00:00:00 EDT 1990}
}