On the Structure and Morphology of the “Diffuse Ionized Medium” in Star‐forming Galaxies

1999 ◽  
Vol 515 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Jing Wang ◽  
Timothy M. Heckman ◽  
Matthew D. Lehnert
Keyword(s):  
Star Forming ◽  
Structure And Morphology ◽  
Diffuse Ionized Medium

scholarly journals VIS3COS

2019 ◽  
Vol 630 ◽  
pp. A57 ◽  
Author(s):  
Ana Paulino-Afonso ◽  
David Sobral ◽  
Behnam Darvish ◽  
Bruno Ribeiro ◽  
Arjen van der Wel ◽  
...  
Keyword(s):  
Local Density ◽  
Elliptical Galaxies ◽  
Stellar Mass ◽  
High Density ◽  
Low Density ◽  
Star Forming ◽  
Structure And Morphology ◽  
Stellar Masses ◽  
The Impact ◽  
Non Parametric

We study the impact of local density and stellar mass on the structure and morphology of approximately 500 quiescent and star-forming galaxies from the VIMOS Spectroscopic Survey of a Superstructure in COSMOS (VIS3COS). We perform bulge-to-disc decomposition of the surface brightness profiles and find ∼41 ± 3% of > 1010 M⊙ galaxies to be best fitted with two components. We complement our analysis with non-parametric morphological measurements and qualitative visual classifications. We find that both galaxy structure and morphology depend on stellar mass and environment for our sample as a whole. We only find an impact of the environment on galaxy size for galaxies more massive than 1011 M⊙. We find higher Sérsic indices (n) and bulge-to-total ratios (B/T) in high-density regions when compared to low-density counterparts at similar stellar masses. We also find that galaxies with higher stellar mass have steeper light profiles (high n, B/T) compared to galaxies with lower stellar mass. Using visual classifications, we find a morphology–density relation at z ∼ 0.84 for galaxies more massive than 1010 M⊙, with elliptical galaxies being dominant at high-density regions and disc galaxies more common in low-density regions. However, when splitting the sample into colour–colour-selected star-forming and quiescent sub-populations, there are no statistically significant differences between low- and high-density regions. We find that quiescent galaxies are smaller, have higher Sérsic indices (for single profiles, around n ∼ 4), and higher bulge-to-total light ratios (for decomposed profiles, around B/T ∼ 0.5) when compared to star-forming counterparts (n ∼ 1 and B/T ∼ 0.3, for single and double profiles, respectively). We confirm these trends with non-parametric quantities, finding quiescent galaxies to be smoother (lower asymmetry, lower M20) and to have most of their light over smaller areas (higher concentration and Gini coefficient) than star-forming galaxies. Overall, we find a stronger dependence of structure and morphology on stellar mass than on local density and these relations are strongly correlated with the quenching fraction. The change in average structure or morphology corresponds to a change in the relative fractions of blue disc-like galaxies and red elliptical galaxies with stellar mass and environment. We hypothesise that the processes responsible for the quenching of star formation must also affect the galaxy morphology on similar timescales.

Far infrared study of the giant star forming complex W 51

2002 ◽  
Vol 4 ◽  
pp. 333-333
Author(s):  
S. K. Ghosh ◽  
D. K. Ojha ◽  
R. P. Verma
Keyword(s):  
Far Infrared ◽  
Infrared Study ◽  
Giant Star ◽  
Star Forming

The Influence of Structure and Morphology on Ion Permeation Behaviour in Commercial Silicone Hydrogel Contact Lenses

2019 ◽  
Author(s):  
Virginia Saez-Martinez ◽  
Aisling Mann ◽  
Fiona Lydon ◽  
Frank Molock ◽  
Siân A. Layton ◽  
...  
Keyword(s):  
Contact Lenses ◽  
Ion Permeation ◽  
Silicone Hydrogel ◽  
Structure And Morphology

Evolution of the H2O Maser Emission in the Star-Forming Region S252A

2019 ◽  
Vol 63 (12) ◽  
pp. 1022-1034
Author(s):  
N. T. Ashimbaeva ◽  
P. Colom ◽  
E. E. Lekht ◽  
M. I. Pashchenko ◽  
G. M. Rudnitskii ◽  
...  
Keyword(s):  
Maser Emission ◽  
Star Forming

Spectral Indices of Centimeter Continuum Sources in Star-forming Regions: Implications on the Nature of the Outflow Exciting Sources

1998 ◽  
Vol 116 (6) ◽  
pp. 2953-2964 ◽  
Author(s):  
Guillem Anglada ◽  
Eva Villuendas ◽  
Robert Estalella ◽  
Maria T. Beltrán ◽  
Luis F. Rodríguez ◽  
...  
Keyword(s):  
Spectral Indices ◽  
Star Forming ◽  
Star Forming Regions

The Structure and Morphology of the Ionized Gas in Starburst Galaxies: NGC 5253/5236

1999 ◽  
Vol 118 (2) ◽  
pp. 797-816 ◽  
Author(s):  
Daniela Calzetti ◽  
Christopher J. Conselice ◽  
John S. Gallagher III ◽  
Anne L. Kinney
Keyword(s):  
Starburst Galaxies ◽  
Ionized Gas ◽  
Structure And Morphology

A WIYN Lithium Survey for Young Stars in the λ Orionis Star-Forming Region

1999 ◽  
Vol 118 (5) ◽  
pp. 2409-2423 ◽  
Author(s):  
Christopher J. Dolan and Robert D. Mathieu
Keyword(s):  
Young Stars ◽  
Star Forming

Bidimensional Spectroscopic Mapping and Chemical Abundances of the Star‐forming Dwarf Galaxy I Zw 18

1998 ◽  
Vol 508 (1) ◽  
pp. 248-261 ◽  
Author(s):  
José M. Vílchez ◽  
Jorge Iglesias‐Páramo
Keyword(s):  
Dwarf Galaxy ◽  
Chemical Abundances ◽  
Star Forming

scholarly journals Diffuse γ-ray emission toward the massive star-forming region, W40

2020 ◽  
Vol 639 ◽  
pp. A80
Author(s):  
Xiao-Na Sun ◽  
Rui-Zhi Yang ◽  
Yun-Feng Liang ◽  
Fang-Kun Peng ◽  
Hai-Ming Zhang ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Young Star ◽  
Gas Content ◽  
Large Area ◽  
Stellar Cluster ◽  
Production Region ◽  
Star Forming ◽  
Photon Index ◽  
Young Star Clusters

We report the detection of high-energy γ-ray signal towards the young star-forming region, W40. Using 10-yr Pass 8 data from the Fermi Large Area Telescope (Fermi-LAT), we extracted an extended γ-ray excess region with a significance of ~18σ. The radiation has a spectrum with a photon index of 2.49 ± 0.01. The spatial correlation with the ionized gas content favors the hadronic origin of the γ-ray emission. The total cosmic-ray (CR) proton energy in the γ-ray production region is estimated to be the order of 1047 erg. However, this could be a small fraction of the total energy released in cosmic rays (CRs) by local accelerators, presumably by massive stars, over the lifetime of the system. If so, W40, together with earlier detections of γ-rays from Cygnus cocoon, Westerlund 1, Westerlund 2, NGC 3603, and 30 Dor C, supports the hypothesis that young star clusters are effective CR factories. The unique aspect of this result is that the γ-ray emission is detected, for the first time, from a stellar cluster itself, rather than from the surrounding “cocoons”.

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