English
Related papers

Related papers: HI scale height in spiral galaxies

200 papers

We present 21-cm HI line and optical R-band observations for a sample of 26 edge-on galaxies. The HI observations were obtained with the Westerbork Synthesis Radio Telescope, and are part of the WHISP database (Westerbork HI Survey of…

Astrophysics · Physics 2016-08-30 I. Garcia-Ruiz , R. Sancisi , K. Kuijken

We present an analysis of the photometric parallaxes of stars in 21 BATC fields carried out with the National Astronomical Observatories (NAOC) 60/90 cm Schmidt Telescope in 15 intermediate-band filters from 3000 to 10000 {\AA}. In this…

Astrophysics · Physics 2009-11-11 Cuihua Du , Jun Ma , Zhenyu Wu , Xu Zhou

Observations of turbulent velocity dispersions in the HI component of galactic disks show a characteristic floor in galaxies with low star formation rates and within individual galaxies the dispersion profiles decline with radius. We carry…

Astrophysics · Physics 2009-11-13 Oscar Agertz , George Lake , Romain Teyssier , Ben Moore , Lucio Mayer , Alessandro B. Romeo

We analyze the velocity dispersions of individual HI and CO profiles in a number of nearby galaxies from the high-resolution HERACLES CO and THINGS HI surveys. Focusing on regions with bright CO emission, we find a CO dispersion value: 7.3…

Astrophysics of Galaxies · Physics 2016-01-13 K. M. Mogotsi , W. J. G. de Blok , A. Caldu-Primo , F. Walter , R. Ianjamasimanana , A. K. Leroy

We combine new VLA D array HI data of NGC 2613 with previous high resolution data to show new disk-halo features in this galaxy. The global HI distribution is modeled in detail using a technique which can disentangle the effects of…

Astrophysics · Physics 2009-11-07 Judith A. Irwin , Tara Chaves

Context. Understanding the dwarf galaxy population in low density environments is crucial for testing the LCDM cosmological model. The increase in diversity towards low mass galaxies is seen as an increase in the scatter of scaling…

A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) to deduce details about star formation in nearby disk galaxies selected with no bias to optical surface brightness…

Astrophysics · Physics 2009-11-11 J. F. Helmboldt , R. A. M. Walterbos , G. D. Bothun , K. O'Neil

We present a census of neutral gas in the Milky Way disk and halo down to limiting column densities of $N$(HI)$\sim10^{14}$ cm$^{-2}$ using measurements of HI Lyman-series absorption from the Far Ultraviolet Spectroscopic Explorer (FUSE).…

Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size and axial-ratio distribution of galaxies as a function of redshift at lookback times t > 8 Gyr. These…

We examine the dependence between hydrogen total mass $M_{HI}$ and rotation speed $V_{rot}$, optical size $D_{25}$ or disc radial scale $R_0$ for two samples of late-type galaxies: a) isolated galaxy (AMIGA sample), and b) the edge-on…

Astrophysics of Galaxies · Physics 2017-07-26 Analoty V. Zasov , Natalia A. Zaitseva

We have developed an automated cross-correlation technique to detect 21cm emission in sample spectra obtained from the HI Parkes All Sky Survey. The initial sample selection was the nearest spectra to 2435 low surface brightness galaxies in…

The decomposition of the rotation curve of galaxies into contribution from the disc and dark halo remains uncertain and depends on the adopted mass to light ratio (M/L) of the disc. Given the vertical velocity dispersion of stars and disc…

Astrophysics of Galaxies · Physics 2018-02-13 S. Aniyan , K. C. Freeman , M. Arnaboldi , O. E. Gerhard , L. Coccato , M. Fabricius , K. Kuijken , M. Merrifield , A. A. Ponomareva

The oxygen gradient of four dS galaxies has been determined using abundances for several HII regions determined with four different methods. The gradient slopes of the three non-barred galaxies in the sample are quite steep, larger than…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-05 A. M. Hidalgo-Gamez , D. Ramirez-Fuentes , J. J. Gonzalez

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

Neutral hydrogen (HI) is the primary component of the cool interstellar medium (ISM) and is the reservoir of fuel for star formation. Owing to the sensitivity of existing radio telescopes, our understanding of the evolution of the ISM in…

We use the Stripe 82 proper motion catalogue of Bramich et al. (2008) to study the kinematics of Galactic disk stars in the solar neighborhood. We select samples of dwarf stars with reliable spectra and proper motions. They have cylindrical…

Astrophysics of Galaxies · Physics 2012-02-08 Martin C. Smith , S. Hannah Whiteoak , N. W. Evans

We present a kinematic model of the neutral-hydrogen in the spiral galaxy of the lens system PKS1830-211, based on a Multi Element Radio-Linked Interferometer (MERLIN) 1.4-GHz radio map and the integrated and redshifted 21-cm hydrogen…

Astrophysics · Physics 2007-05-23 L. V. E. Koopmans , A. G. de Bruyn

Much of our understanding of dark matter halos comes from the assumption that the mass-to-light ratio (M/L) of spiral disks is constant. The best way to test this hypothesis is to measure the disk surface mass density directly via the…

Astrophysics of Galaxies · Physics 2014-11-20 Kimberly A. Herrmann , Robin Ciardullo

Using 21cm HI observations from the Parkes Radio Telescope's Galactic All-Sky Survey, we measure 255 HI clouds in the lower Galactic halo that are located near the tangent points at 16.9 < l < 35.3 degrees and |b| < 20 degrees. The clouds…

Astrophysics of Galaxies · Physics 2015-05-19 H. Alyson Ford , Felix J. Lockman , N. M. McClure-Griffiths

The spatial distribution of the gaseous components of the Milky Way is of great importance for a number of different fields, for example, Galactic structure, star formation, and cosmic rays. However, obtaining distance information to…