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Title: The far-infrared morphology of the double-ringed galaxy NGC 4736 (M94) - A ring surrounding an extended nucleus

Abstract

High spatial resolution 100-micron observations of the central region of the double-ringed spiral galaxy NGC 4736 (M94) were obtained using the Kuiper Airborne Observatory. The data show a strong central peak with secondary peaks at the radius of the inner ring (50 arcsec = 1.6 kpc). The nuclear emission is extended at 100 microns, with a radius of 15 arcsec (500 pc). The far-infrared morphology is similar to that of the molecular gas, while the H I distribution shows a pronounced central depression. Since most of the hydrogen gas in the inner regions of NGC 4736 is in molecular form, it is concluded that the far-infrared emission from NGC 4736 arises mainly from dust associated with molecular gas. The H-alpha distribution differs dramatically from the far-infrared and molecular gas distributions. The ring dominates the H-alpha emission, while the total 100-micron ring emission is only slightly larger than that of the nucleus, yielding an L(FIR)/L(H-alpha) for the nucleus about 100 times that of the ring. The bolometric luminosity of the stars in the inner 1 kpc of NGC 4736 is sufficient to power the far-infrared from this region, which suggests that a significant fraction of the far-infrared emission in the nuclearmore » region of NGC 4736 is powered by non-OB stars rather than by star formation. 61 refs.« less

Authors:
; ; ;  [1]
  1. Texas, University, Austin Ohio State University, Columbus (USA)
Publication Date:
Research Org.:
Texas Univ., Austin, TX (United States)
OSTI Identifier:
5549317
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal; (United States)
Additional Journal Information:
Journal Volume: 373; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GALAXIES; FAR INFRARED RADIATION; MORPHOLOGY; COSMIC DUST; COSMIC GASES; GALAXY NUCLEI; INFRARED SPECTRA; INTERSTELLAR SPACE; RESOLUTION; SPATIAL DISTRIBUTION; SPATIAL RESOLUTION; SPIRAL CONFIGURATION; VISIBLE SPECTRA; CONFIGURATION; DISTRIBUTION; DUSTS; ELECTROMAGNETIC RADIATION; FLUIDS; GASES; INFRARED RADIATION; RADIATIONS; SPACE; SPECTRA; 640105* - Astrophysics & Cosmology- Galaxies

Citation Formats

Smith, B J, Lester, D F, Harvey, P M, and Pogge, R W. The far-infrared morphology of the double-ringed galaxy NGC 4736 (M94) - A ring surrounding an extended nucleus. United States: N. p., 1991. Web. doi:10.1086/170023.
Smith, B J, Lester, D F, Harvey, P M, & Pogge, R W. The far-infrared morphology of the double-ringed galaxy NGC 4736 (M94) - A ring surrounding an extended nucleus. United States. https://doi.org/10.1086/170023
Smith, B J, Lester, D F, Harvey, P M, and Pogge, R W. 1991. "The far-infrared morphology of the double-ringed galaxy NGC 4736 (M94) - A ring surrounding an extended nucleus". United States. https://doi.org/10.1086/170023.
@article{osti_5549317,
title = {The far-infrared morphology of the double-ringed galaxy NGC 4736 (M94) - A ring surrounding an extended nucleus},
author = {Smith, B J and Lester, D F and Harvey, P M and Pogge, R W},
abstractNote = {High spatial resolution 100-micron observations of the central region of the double-ringed spiral galaxy NGC 4736 (M94) were obtained using the Kuiper Airborne Observatory. The data show a strong central peak with secondary peaks at the radius of the inner ring (50 arcsec = 1.6 kpc). The nuclear emission is extended at 100 microns, with a radius of 15 arcsec (500 pc). The far-infrared morphology is similar to that of the molecular gas, while the H I distribution shows a pronounced central depression. Since most of the hydrogen gas in the inner regions of NGC 4736 is in molecular form, it is concluded that the far-infrared emission from NGC 4736 arises mainly from dust associated with molecular gas. The H-alpha distribution differs dramatically from the far-infrared and molecular gas distributions. The ring dominates the H-alpha emission, while the total 100-micron ring emission is only slightly larger than that of the nucleus, yielding an L(FIR)/L(H-alpha) for the nucleus about 100 times that of the ring. The bolometric luminosity of the stars in the inner 1 kpc of NGC 4736 is sufficient to power the far-infrared from this region, which suggests that a significant fraction of the far-infrared emission in the nuclear region of NGC 4736 is powered by non-OB stars rather than by star formation. 61 refs.},
doi = {10.1086/170023},
url = {https://www.osti.gov/biblio/5549317}, journal = {Astrophysical Journal; (United States)},
issn = {0004-637X},
number = ,
volume = 373,
place = {United States},
year = {Wed May 01 00:00:00 EDT 1991},
month = {Wed May 01 00:00:00 EDT 1991}
}