Radio continuum observations of early- and late-type spiral galaxies

1987 ◽  
Vol 63 ◽  
pp. 771 ◽  
Author(s):  
Isabella M. Gioia ◽  
Giuseppina Fabbiano
Keyword(s):  
Spiral Galaxies ◽  
Radio Continuum ◽  
Late Type

scholarly journals The inner mass distribution of late-type spiral galaxies fromSAURONstellar kinematic maps

2016 ◽  
Vol 464 (2) ◽  
pp. 1903-1922 ◽  
Author(s):  
Veselina Kalinova ◽  
Glenn van de Ven ◽  
Mariya Lyubenova ◽  
Jesús Falcón-Barroso ◽  
Dario Colombo ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Spiral Galaxies ◽  
Late Type

AHubble Space TelescopeCensus of Nuclear Star Clusters in Late-Type Spiral Galaxies. II. Cluster Sizes and Structural Parameter Correlations

2004 ◽  
Vol 127 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Torsten Bker ◽  
Marc Sarzi ◽  
Dean E. McLaughlin ◽  
Roeland P. van der Marel ◽  
Hans-Walter Rix ◽  
...  
Keyword(s):  
Spiral Galaxies ◽  
Star Clusters ◽  
Structural Parameter ◽  
Late Type

scholarly journals CHANG-ES

2018 ◽  
Vol 611 ◽  
pp. A72 ◽  
Author(s):  
Marita Krause ◽  
Judith Irwin ◽  
Theresa Wiegert ◽  
Arpad Miskolczi ◽  
Ancor Damas-Segovia ◽  
...  
Keyword(s):  
Star Formation ◽  
Wind Velocity ◽  
Surface Density ◽  
Spiral Galaxies ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Cosmic Ray ◽  
Scale Height ◽  
Radio Continuum ◽  
Frequency Bands

Aim. The vertical halo scale height is a crucial parameter to understand the transport of cosmic-ray electrons (CRE) and their energy loss mechanisms in spiral galaxies. Until now, the radio scale height could only be determined for a few edge-on galaxies because of missing sensitivity at high resolution.Methods. We developed a sophisticated method for the scale height determination of edge-on galaxies. With this we determined the scale heights and radial scale lengths for a sample of 13 galaxies from the CHANG-ES radio continuum survey in two frequency bands.Results. The sample average values for the radio scale heights of the halo are 1.1 ± 0.3 kpc in C-band and 1.4 ± 0.7 kpc in L-band. From the frequency dependence analysis of the halo scale heights we found that the wind velocities (estimated using the adiabatic loss time) are above the escape velocity. We found that the halo scale heights increase linearly with the radio diameters. In order to exclude the diameter dependence, we defined a normalized scale height h˜ which is quite similar for all sample galaxies at both frequency bands and does not depend on the star formation rate or the magnetic field strength. However, h˜ shows a tight anticorrelation with the mass surface density.Conclusions. The sample galaxies with smaller scale lengths are more spherical in the radio emission, while those with larger scale lengths are flatter. The radio scale height depends mainly on the radio diameter of the galaxy. The sample galaxies are consistent with an escape-dominated radio halo with convective cosmic ray propagation, indicating that galactic winds are a widespread phenomenon in spiral galaxies. While a higher star formation rate or star formation surface density does not lead to a higher wind velocity, we found for the first time observational evidence of a gravitational deceleration of CRE outflow, e.g. a lowering of the wind velocity from the galactic disk.

scholarly journals Hubble Sequence as a Temporal Evolution Sequence

1999 ◽  
Vol 186 ◽  
pp. 491-491
Author(s):  
Xiaolei Zhang
Keyword(s):  
Spiral Galaxies ◽  
Temporal Evolution ◽  
Natural Question ◽  
Late Type ◽  
Present Epoch ◽  
Hubble Sequence ◽  
Deep Survey ◽  
Deep Fields ◽  
The Universe ◽  
Evolution Sequence

The results from Hubble Space Telescope's Medium Deep Survey and Deep Fields indicate that there exists far more blue spiral galaxies at the intermediate and high redshifts than at the present epoch. A natural question therefore is: what have become of these excess late type galaxies as the Universe aged?

Near-infrared disk parameters in late-type spiral galaxies

1988 ◽  
Vol 95 ◽  
pp. 408 ◽  
Author(s):  
C. Giovanardi ◽  
L. K. Hunt
Keyword(s):  
Near Infrared ◽  
Spiral Galaxies ◽  
Late Type

scholarly journals Spatial Distribution of Far Infrared and Radio Continuum Emission in Spiral Galaxies

1996 ◽  
Vol 171 ◽  
pp. 415-415
Author(s):  
Y.D. Mayya ◽  
T.N. Rengarajan
Keyword(s):  
Spiral Galaxies ◽  
Far Infrared ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Emission Profile ◽  
Exponential Component ◽  
Dust Temperature ◽  
Order Of Magnitude ◽  
Disk Component ◽  
Exponential Disk

A study of 8 nearby spiral galaxies (NGC 2903, 3079, 3198, 3628, 4303, 4321, 4656 and 6946) is carried out using the radio continuum (RC) and far infrared (FIR) images at 1′ resolution. These images are used to study the radial gradients in the ratios of FIR to RC (Q60 and Q100), warm dust temperature (Td(60/100)) etc. The main results are illustrated with NGC 2903 as an example in Fig. 1, where azimuthally averaged quantities are plotted. Td(60/100) decreases away from the center (45–25 K), increasing again by ∼ 5 K in outer galaxies. Typically Q60 decreases by a factor of three away from the center in a given galaxy, but has an order of magnitude spread in the pixel values over all the galaxies. In contrast, Q100 shows flatter gradient, which is expected from the observed temperature gradient. 20 cm RC emission profile is also shown in Fig. 1. The RC and FIR profiles can be fitted by a combination of central gaussian and exponential disk components. In general RC and FIR have about the same fraction of exponential component with the exception of NGC 3628, in which the FIR is dominated by the gaussian while the RC is mostly disk component (see Fig. 2). In 5 of the remaining 7 galaxies, the exponential component contributes > 50% of the total. In general RC scale lengths are larger than the FIR.

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