scholarly journals 5.12. High-resolution CO (1-0) observations of the ringed galaxy NGC 4736

1998 ◽  
Vol 184 ◽  
pp. 235-236
Author(s):  
Tony Wong ◽  
Tamara Helfer ◽  
Leo Blitz
Keyword(s):  
Star Formation ◽  
High Resolution ◽  
Spiral Galaxies ◽  
Molecular Gas ◽  
H Ii Regions ◽  
Nearby Galaxies ◽  
Initial Results

It is well known that the radial distributions of atomic and molecular gas differ markedly in spiral galaxies, including our own (e.g. Burton & Gordon 1978, Sofue et al. 1995). We have recently begun a program to obtain multifrequency observations of several nearby galaxies in order to determine whether H I is needed to replenish the H2 consumed by star formation and, if so, how this might be accomplished. Here we present initial results on the nearby RSab galaxy NGC 4736, known for its bright ring of H II regions and recently shown to have a central stellar bar (Möllenhoff et al. 1995). We have mapped the distribution of CO (1-0) emission within r=1′ (1.8 kpc at D=6.2 Mpc) with the BIMA interferometer at ~5″ resolution, and added data from the NRAO 12-m telescope to recover zero-spacing information.

A CCD Hα Survey of Nearby Southern Spiral Galaxies

1991 ◽  
Vol 9 (1) ◽  
pp. 89-90
Author(s):  
Stuart D. Ryder ◽  
Michael A. Dopita
Keyword(s):  
Star Formation ◽  
Observational Data ◽  
Spiral Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
High Mass ◽  
H Ii Regions ◽  
Mass Star ◽  
Reliable Measure ◽  
Initial Results

AbstractSome initial results of a flux-calibrated CCD Hα imaging program of bright, nearby southern spiral galaxies are presented. Very few southern hemisphere spiral galaxies have ever been completely imaged in Hα, let alone with a CCD. This survey (which mainly uses the MSSSO 1.0-m reflector with an f/3.5 focal reducer) will, when combined with spectrophotometry of the H II regions thus revealed, allow us to trace the chemical evolution of each galaxy. Furthermore, since the absolute Hα flux is a reliable measure of the high-mass star formation rate in a galaxy, such observational data will permit us to test the predictions of the various star formation theories.

scholarly journals Molecular gas and dust in spiral galaxies

2012 ◽  
Vol 8 (S292) ◽  
pp. 119-126 ◽  
Author(s):  
Christine D. Wilson
Keyword(s):  
Star Formation ◽  
High Resolution ◽  
Spiral Galaxies ◽  
Dust Content ◽  
Gas Content ◽  
Molecular Gas

AbstractSeveral recent surveys (HERACLES, NGLS, KINGFISH, VNGS) have provided us with sensitive high-resolution observations of the molecular gas and dust content in spiral galaxies within 25 Mpc. I review recent results on the molecular gas content and its relation to star formation, as well as on the gas to dust ratio and the dust heating in spiral galaxies. I also present new results on the effect of environment on the molecular gas content of spiral galaxies.

scholarly journals From Star Formation to Compact Remnants: X-ray Studies of Spiral Galaxies

2004 ◽  
Vol 217 ◽  
pp. 218-219
Author(s):  
Roberto Soria ◽  
Kinwah Wu
Keyword(s):  
Star Formation ◽  
High Resolution ◽  
Spiral Galaxies ◽  
Compact Objects ◽  
X Ray ◽  
Nearby Galaxies ◽  
Gas Recycling

High-resolution multiwavelength studies of nearby galaxies are essential to understand the full cycle of star formation, and the balance between gas recycling and creation of compact objects. In particular, we study this cycle in the environment of ultra-luminous X-ray sources.

scholarly journals The effect of diffuse background on the spatially-resolved Schmidt relation in nearby spiral galaxies

2020 ◽  
Vol 634 ◽  
pp. A24 ◽  
Author(s):  
Nimisha Kumari ◽  
Mike J. Irwin ◽  
Bethan L. James
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Spiral Galaxies ◽  
Formation Rate ◽  
Molecular Gas ◽  
Nearby Galaxy ◽  
Spatially Resolved ◽  
Diffuse Background ◽  
Nearby Galaxies ◽  
Atomic Gas

Context. The global Schmidt law of star formation provides a power-law relation between the surface densities of star-formation rate (SFR) and gas, and successfully explains plausible scenarios of galaxy formation and evolution. However, star formation being a multi-scale process, requires spatially-resolved analysis for a better understanding of the physics of star formation. Aims. It has been shown that the removal of a diffuse background from SFR tracers, such as Hα, far-ultraviolet (FUV), infrared, leads to an increase in the slope of the sub-galactic Schmidt relation. We reinvestigate the local Schmidt relations in nine nearby spiral galaxies taking into account the effect of inclusion and removal of diffuse background in SFR tracers as well as in the atomic gas. Methods. We used multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey, Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel, The H I Nearby Galaxy Survey, and HERA CO-Line Extragalactic Survey. Making use of a novel split of the overall light distribution as a function of spatial scale, we subtracted the diffuse background in the SFR tracers as well as the atomic gas. Using aperture photometry, we study the Schmidt relations on background subtracted and unsubtracted data at physical scales varying between 0.5–2 kpc. Results. The fraction of diffuse background varies from galaxy to galaxy and accounts to ∼34% in Hα, ∼43% in FUV, ∼37% in 24 μm, and ∼75% in H I on average. We find that the inclusion of diffuse background in SFR tracers leads to a linear molecular gas Schmidt relation and a bimodal total gas Schmidt relation. However, the removal of diffuse background in SFR tracers leads to a super-linear molecular gas Schmidt relation. A further removal of the diffuse background from atomic gas results in a slope ∼1.4 ± 0.1, which agrees with dynamical models of star formation accounting for flaring effects in the outer regions of galaxies.

scholarly journals THE JAMES CLERK MAXWELL TELESCOPE NEARBY GALAXIES LEGACY SURVEY. II. WARM MOLECULAR GAS AND STAR FORMATION IN THREE FIELD SPIRAL GALAXIES

2010 ◽  
Vol 714 (1) ◽  
pp. 571-588 ◽  
Author(s):  
B. E. Warren ◽  
C. D. Wilson ◽  
F. P. Israel ◽  
S. Serjeant ◽  
G. J. Bendo ◽  
...  
Keyword(s):  
Star Formation ◽  
Spiral Galaxies ◽  
Molecular Gas ◽  
James Clerk Maxwell ◽  
Nearby Galaxies

scholarly journals Molecules as tracers of galaxy evolution

2012 ◽  
Vol 8 (S292) ◽  
pp. 199-208 ◽  
Author(s):  
Susanne Aalto
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
High Resolution ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Short Review ◽  
Stimulated Emission ◽  
Molecular Gas ◽  
Infrared Galaxies ◽  
Luminous Infrared Galaxies

AbstractStudying the molecular phase of the interstellar medium in galaxies is fundamental for the understanding of the onset and evolution of star formation and the growth of supermassive black holes. We can use molecules as observational tools exploiting them as tracers of chemical, physical and dynamical conditions. In this short review, key molecules (e.g. HCN, HCO+, HNC, HC3N, CN, H3O+) in identifying the nature of buried activity and its evolution are discussed including some standard astrochemical scenarios. Furthermore, we can use IR excited molecular emission to probe the very inner regions of luminous infrared galaxies (LIRGs) allowing us to get past the optically thick dust barrier of the compact obscured nuclei, e.g. in the dusty LIRG NGC4418. High resolution studies are often necessary to separate effects of excitation and radiative transport from those of chemistry - one example is absorption and effects of stimulated emission in the ULIRG Arp220. Finally, molecular gas in large scale galactic outflows is briefly discussed.

scholarly journals 5.17. The NRO CO survey of nearby spiral galaxies

1998 ◽  
Vol 184 ◽  
pp. 245-246 ◽  
Author(s):  
K. Nishiyama ◽  
N. Nakai
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Spiral Galaxies ◽  
High Spatial Resolution ◽  
Molecular Gas ◽  
Characteristic Structure

Our survey observation is high spatial resolution (16″) by NRO observatory 45 m antenna and have many galaxies of sample. This high resolution observations (16″ = 1.6 kpc at 20 Mpc) could be to resolve the some characteristic structure, typical molecular gas disk, arm - interarm and optical bar.

scholarly journals The JCMT Nearby Galaxies Legacy Survey – XI. Environmental variations in the atomic and molecular gas radial profiles of nearby spiral galaxies

2017 ◽  
Vol 467 (4) ◽  
pp. 4282-4292 ◽  
Author(s):  
Angus Mok ◽  
C. D. Wilson ◽  
J. H. Knapen ◽  
J. R. Sánchez-Gallego ◽  
E. Brinks ◽  
...  
Keyword(s):  
Spiral Galaxies ◽  
Molecular Gas ◽  
Radial Profiles ◽  
Environmental Variations ◽  
Nearby Galaxies

scholarly journals SKA studies of nearby galaxies: star-formation, accretion processes and molecular gas across all environments

2015 ◽  
Author(s):  
Rob J. Beswick ◽  
Elias Brinks ◽  
Miguel Perez-Torres ◽  
Anita Richards ◽  
Susanne Aalto ◽  
...  
Keyword(s):  
Star Formation ◽  
Molecular Gas ◽  
Nearby Galaxies
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