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相关论文: The distribution of HI velocity profiles in a $\La…

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We use 85 pairs of high resolution LCDM cosmological simulations from the NIHAO project to investigate why in dwarf galaxies neutral hydrogen (HI) linewidths measured at 50% of the peak flux W_50 /2 (from the hydrodynamical simulations)…

星系天体物理 · 物理学 2018-11-28 Aaron A. Dutton , Aura Obreja , Andrea V. Macciò

We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of…

星系天体物理 · 物理学 2017-09-20 Ericson López , Jairo Armijos , Mario Llerena , Franklin Aldás

We investigate the nature of objects in a complete sample of 28 galaxies selected from the first sky area fully covered by ALFALFA, being well-detected and having HI profiles wider than 550 km/s. The selection does not use brightness,…

星系天体物理 · 物理学 2017-03-22 Noah Brosch , Oded Spector , Adi Zitrin

Accurately predicting the shape of the HI velocity function of galaxies is regarded widely as a fundamental test of any viable dark matter model. Straightforward analyses of cosmological $N$-body simulations imply that the $\Lambda$CDM…

星系天体物理 · 物理学 2019-08-14 G. Chauhan , C. D. P. Lagos , D. Obreschkow , C. Power , K. Oman , P. J. Elahi

We use the high-resolution Aquarius cosmological dark matter simulations coupled to the semi-analytic model by Starkenburg et al. (2013) to study the HI content and velocity width properties of field galaxies at the low mass end in the…

星系天体物理 · 物理学 2016-02-17 C. Y. Yaryura , A. Helmi , M. G. Abadi , E. Starkenburg

We analyze the shapes of the HI velocity profiles of The HI Nearby Galaxy Survey (THINGS) to study the phase structure of the neutral interstellar medium (ISM) and its relation to global galaxy properties. We use a method analogous to the…

宇宙学与河外天体物理 · 物理学 2015-06-05 R. Ianjamasimanana , W. J. G. de Blok , Fabian Walter , George H. Heald

We use a sample of 83 high-resolution cosmological zoom-in simulations and a semi-analytic model (SAM) to study the stochasticity of galaxy formation in haloes ranging from dwarf to Milky Way masses. Our simulated galaxies reproduce the…

We detect the neutral hydrogen (HI) radial brightness temperature profile in large-scale haloes by stacking 48,430 galaxies selected from the 2dFGRS catalogue onto a set of 21-cm intensity maps obtained with the Parkes radio telescope,…

宇宙学与河外天体物理 · 物理学 2020-10-14 Denis Tramonte , Yin-Zhe Ma

Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of NHI ~ 10^19 cm-2, the…

宇宙学与河外天体物理 · 物理学 2015-05-13 Attila Popping , Romeel Dave , Robert Braun , Benjamin D. Oppenheimer

The ongoing Arecibo Legacy Fast ALFA (ALFALFA) survey is a wide-area, extragalactic HI-line survey conducted at the Arecibo Observatory. Sources have so far been extracted over ~3,000 sq.deg of sky (40% of its final area), resulting in the…

宇宙学与河外天体物理 · 物理学 2011-10-06 Emmanouil Papastergis , Ann M. Martin , Riccardo Giovanelli , Martha P. Haynes

Context: To investigate the properties of the 21-cm radio-lines of galactic neutral hydrogen, the profiles of "The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI" are decomposed into Gaussian components. Aims: The width distribution of…

天体物理学 · 物理学 2008-11-26 Urmas Haud , Peter M. W. Kalberla

We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…

Upcoming 21 cm intensity mapping experiments like the Square Kilometer Array (SKA) hold significant potential to constrain the properties of dark matter. In this work, we model neutral hydrogen (HI) distributions using high-resolution…

宇宙学与河外天体物理 · 物理学 2024-01-02 Tibor Dome , Rumail Azhar , Anastasia Fialkov

In this paper, we use the outer-galactic HI scale height data as well as the observed rotation curve as constraints to determine the halo density distribution of the Andromeda galaxy (M31). We model the galaxy as a gravitationally-coupled…

天体物理学 · 物理学 2009-11-13 Arunima Banerjee , Chanda J. Jog

We use numerical simulations in a Lambda CDM cosmology to model density profiles in a set of 16 dark matter haloes with resolutions of up to 7 million particles within the virial radius. These simulations allow us to follow robustly the…

We present a spectroscopic sample of 910 distant halo stars from the Hypervelocity Star survey from which we derive the velocity dispersion profile of the Milky Way halo. The sample is a mix of 74% evolved horizontal branch stars and 26%…

星系天体物理 · 物理学 2010-07-22 Warren R. Brown , Margaret J. Geller , Scott J. Kenyon , Antonaldo Diaferio

We use N-body simulations of dark matter haloes in cold dark matter (CDM) and a large set of different warm dark matter (WDM) cosmologies to demonstrate that the spherically averaged density profile of dark matter haloes has a shape that…

星系天体物理 · 物理学 2015-05-20 E. Polisensky , M. Ricotti

Resolved rotation curves (RCs) are our best probe of the dark matter distribution around individual galaxies. However their acquisition is resource-intensive, rendering them impractical for large-scale surveys and studies at higher…

星系天体物理 · 物理学 2024-09-02 Tariq Yasin , Harry Desmond

We have used the WSRT to carry out an unbiased wide-field survey of HI emission features, achieving an RMS sensitivity of about 18 mJy/Beam at a velocity resolution of 17 km/s over 1800 deg^2. In this paper we present our HI detections at…

天体物理学 · 物理学 2009-11-10 Robert Braun , David Thilker

We introduce a new methodology to robustly determine the mass profile, as well as the overall distribution, of Local Group satellite galaxies. Specifically we employ a statistical multilevel modelling technique, Bayesian hierarchical…

星系天体物理 · 物理学 2015-06-23 Gregory D. Martinez
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