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Related papers: The Fractal Distribution of HII Regions in Disk Ga…

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We have compared far-ultraviolet (FUV), near-ultraviolet (NUV), and Halpha measurements for star forming regions in 21 galaxies, in order to characterise the properties of their discs at radii beyond the main optical radius (R25). In our…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Q. E. Goddard , R. C. Kennicutt , E. V. Ryan-Weber

We present adaptive optics assisted integral field spectroscopy of nine Halpha-selected galaxies at z=0.84--2.23 selected from the HiZELS narrow-band survey. Our observations map the star-formation and kinematics of these representative…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-12 Mark Swinbank , Ian Smail , David Sobral , Tom Theuns , Philip Best , Jim Geach

A composite map of HI in the LMC using the ATCA interferometer and the Parkes multibeam telescope was analyzed in several ways in an attempt to characterize the structure of the neutral gas and to find an origin for it. Fourier transform…

Astrophysics · Physics 2014-10-13 Bruce G. Elmegreen , Sungeun Kim , Lister Staveley-Smith

We present a study of the diffuse ionized gas (DIG) in three Sculptor group galaxies: NGC 55, NGC 253, and NGC 300. The study is based on narrow band imagery in H-alpha+[NII](6548+6583A) and [SII] (6717+6731A). We find that DIG contributes…

Astrophysics · Physics 2009-10-28 Charles G. Hoopes , Rene A. M. Walterbos , Bruce E. Greenawalt

The results of a three-dimensional model for disk-halo interaction are presented here. The model considers explicitly the input of energy and mass by isolated a nd correlated supernovae in the disk. Once disrupted by the explosions, the…

Astrophysics · Physics 2008-11-26 Miguel A. de Avillez

Using three dimensional Monte Carlo radiation transfer models of photoionisation and dust scattering, we explore different components of the widespread diffuse H$\alpha$ emission observed in the interstellar medium of the Milky Way and…

Astrophysics of Galaxies · Physics 2015-06-23 Joanna E. Barnes , Kenneth Wood , Alex S. Hill , L. Matthew Haffner

The pressures of giant HII regions in 6 dwarf Irregular galaxies are a factor of ~10 larger than the average pressures of the corresponding galaxy disks, obtained from the stellar and gaseous column densities. Either the visible HII regions…

Astrophysics · Physics 2009-10-31 B. G. Elmegreen , D. A. Hunter

We perform a structural decomposition of galaxies identified in three cosmological hydrodynamical simulations by applying Gaussian Mixture Models (GMMs) to the kinematics of their stellar particles. We study the resulting disc, bulge, and…

Astrophysics of Galaxies · Physics 2023-12-08 Katy L. Proctor , Claudia del P. Lagos , Aaron D. Ludlow , Aaron S. G. Robotham

We present new results on the frequency distribution of projected HI column densities f(N,X), total comoving covering fraction, and integrated mass densities rho_HI of high redshift, HI `disks' from a survey of damped Lya systems (DLAs) in…

Astrophysics · Physics 2009-11-13 J. Xavier Prochaska , Arthur M. Wolfe

The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the ``Synthetic Field Method'' from Gonzalez et al (1998) and Holwerda et al. (2005a).…

Astrophysics · Physics 2009-11-11 B. W. Holwerda , R. A. González , Ronald J. Allen , P. C. van der Kruit

We present ALMA observations with a 800 au resolution and radiative-transfer modelling of the inner part ($r\approx6000$ au) of the ionized accretion flow around a compact star cluster in formation at the center of the luminous…

A recent discovery of two stellar clusters associated with the diffuse high-latitude cloud HRK 81.4-77.8 has important implications for star formation in the Galactic halo. We derive a plausible distance estimate to HRK 81.4-77.8 primarily…

Astrophysics of Galaxies · Physics 2016-05-04 J. Kerp , D. Lenz , T. Roehser

Fragmentation and evolution for the molecular shells of the compact HII regions are less explored compared to their evolved counterparts. We map nine compact HII regions with a typical diameter of 0.4 pc that are surrounded by molecular…

The thickness of the neutral hydrogen layer, coupled with the rotation curve, traces the outer dark matter potential. We estimate the amplitude of the flaring in spiral galaxies from a 3D model of the HI gas. Warps in particular are…

Astrophysics · Physics 2007-05-23 J. -F. Becquaert , F. Combes

Ultra-diffuse galaxies (UDGs) are as faint as dwarf galaxies but whose sizes are similar to those of spiral galaxies. A variety of formation mechanisms have been proposed, some of which could result in different disk thicknesses. In this…

Astrophysics of Galaxies · Physics 2022-08-29 Xin Li , Yong Shi , Zhi-Yu Zhang , Jianhang Chen , Xiaoling Yu , Junzhi Wang , Qiusheng Gu , Songlin Li

Observed scaling relations in galaxies between baryons and dark matter global properties are key to shed light on the process of galaxy formation and on the nature of dark matter. Here, we study the scaling relation between the neutral…

The S254-258 star-forming complex is a place of massive star formation where five OB-stars have created HII regions, visible as optical nebulae, and disrupted the parental molecular gas. In this work, we study the 3D structure of these \HII…

Astrophysics of Galaxies · Physics 2024-02-14 Maria S. Kirsanova , Alexei V. Moiseev , Paul A. Boley

We suggest a new method for estimating the fractal dimension of the spatial distribution of galaxies, the method of selected cylinders. We show the capabilities of this method by constructing a two-point conditional column density for…

Astrophysics · Physics 2009-11-10 Yu. V. Baryshev , Yu. L. Bukhmastova

We present newly obtained three-dimensional gaseous maps of the Milky Way Galaxy; HI, H$_2$ and total-gas (HI plus H$_2$) maps, which were derived from the HI and $^{12}$CO($J=1$--0) survey data and rotation curves based on the kinematic…

Astrophysics of Galaxies · Physics 2015-12-01 Hiroyuki Nakanishi , Yoshiaki Sofue

We use the Herschel Hi-GAL survey data to study the spatial distribution in Galactic longitude and latitude of the interstellar medium and of dense, star-forming clumps in the inner Galaxy. The peak position and width of the latitude…