English
Related papers

Related papers: High-resolution imaging of compact high-velocity c…

200 papers

Cold dark matter haloes are populated by high-density structures with sharply-peaked profiles known as caustics which have not yet been resolved by 3-dimensional numerical simulations. Here, we derive semi-analytic expressions for the…

Astrophysics · Physics 2009-11-10 Roya Mohayaee , Sergei Shandarin

The transition from the diffuse warm neutral medium (WNM) to the dense cold neutral medium (CNM) is what set the initial conditions to the formation of molecular clouds. The properties of the turbulent cascade in the WNM, essential to…

Astrophysics of Galaxies · Physics 2021-03-03 Antoine Marchal , Marc-Antoine Miville-Deschênes

We report on the detection of low-column density neutral hydrogen clumps in the halo of the Milky Way. Using high-resolution (FWHM~7 km/s) optical spectra obtained with the VLT/UVES spectrograph we detect narrow interstellar absorption by…

Astrophysics · Physics 2009-11-11 Philipp Richter , Tobias Westmeier , Christian Bruens

We confirm and discuss recently discovered cold HI clouds with column densities among the lowest ever detected. The column densities of Cold Neutral Medium (CNM) towards 3C286 and 3C287 are ~10^18 cm^-2, below an observational lower limit,…

Astrophysics · Physics 2009-11-11 Snezana Stanimirovic , Carl Heiles

High Velocity Clouds (HVCs) have recently attracted renewed attention as being long lived, massive dark matter dominated clouds of primordial composition distributed throughout the Local Group. In this picture the HVCs would contain a few…

Astrophysics · Physics 2007-05-23 Martin A. Zwaan

We report an accurate distance of d = 10+/-2.5kpc to the high-velocity cloud Complex C. Using high signal-to-noise Keck/HIRES spectra of two horizontal-branch stars, we have detected CaII K absorption lines from the cloud. Significant…

Astrophysics · Physics 2009-11-13 C. Thom , J. E. G. Peek , M. E. Putman , Carl Heiles , K. M. G. Peek , R. Wilhelm

We present a precise estimate of the bulk virial scaling relation of halos formed via hierarchical clustering in an ensemble of simulated cold dark matter cosmologies. The result is insensitive to cosmological parameters, the presence of a…

We report the detection of a peculiar molecular cloud, CO 0.02-0.02, lying about 5' Galactic-east from the center of the Galaxy. (12)CO images taken with NRO 45 m telescope showed that it is relatively compact (about 3x4 pc^2) as well as…

Astrophysics · Physics 2009-10-31 T. Oka , G. J. White , T. Hasegawa , F. Sato , M. Tsuboi , A. Miyazaki

We use the rotation curves of more than 100 disk galaxies to examine whether the structure of their surrounding dark halos is consistent with the universal density profile proposed by Navarro, Frenk & White (NFW profiles). Rotation curve…

Astrophysics · Physics 2007-05-23 Julio F. Navarro

We report Submillimeter Array dust continuum and molecular spectral line observations toward the Orion Bar photon-dominated region (PDR). The 1.2 mm continuum map reveals, for the first time, a total of 9 compact (r < 0.01pc) dust…

Solar and Stellar Astrophysics · Physics 2018-03-08 Keping Qiu , Zeqiang Xie , Qizhou Zhang

We have observed the NGC 2403 group of galaxies using the Robert C. Byrd Green Bank Telescope (GBT) in a search for faint, extended neutral hydrogen clouds similar to the clouds found around the M81/M82 group, which is located approximately…

Astrophysics of Galaxies · Physics 2015-05-13 Katie M. Chynoweth , Glen I. Langston , Kelly Holley-Bockelmann , Felix J. Lockman

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

Within the framework of the cold dark matter (CDM) cosmogony, a central cusp in the density profiles of virialized dark haloes is predicted. This prediction disagrees with the soft inner halo mass distribution inferred from observations of…

Astrophysics · Physics 2009-10-31 C. Firmani , E. D'Onghia , V. Avila-Reese , G. Chincarini , X. Hernandez

The smallest dark matter haloes are the first objects to form in the hierarchical structure formation of cold dark matter (CDM) cosmology and are expected to be the densest and most fundamental building blocks of CDM structures in our…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-06 Chiamaka Okoli , Niayesh Afshordi

High velocity gas that does not conform to Galactic rotation is observed throughout the Galaxy's halo. One component of this gas, HI high velocity clouds (HVCs), have attracted attention since their discovery in the 1960s and remain…

Astrophysics of Galaxies · Physics 2017-08-24 Asger Grønnow , Thor Tepper-García , Joss Bland-Hawthorn , Naomi McClure-Griffiths

We model the kinematics of the high- and intermediate- velocity clouds (HVCs and IVCs) observed in absorption towards a sample of 55 Galactic halo stars with accurate distance measurements. We employ a simple model of a thick disc whose…

Astrophysics of Galaxies · Physics 2022-05-25 A. Marasco , F. Fraternali , N. Lehner , J. C. Howk

The evolution of halos consisting of weakly self-interacting dark matter particles is investigated using a new numerical Monte-Carlo N-body method. The halos initially contain kinematically cold, dense 1/r-power-law cores. For interaction…

Astrophysics · Physics 2009-10-31 Andreas Burkert

Using a Fourier-plane technique, we have merged HI ATCA and Parkes data sets providing an accurate set of images of the LMC sensitive to structure on scales of 15 pc (for an LMC distance of 55 kpc) upwards. The spatial dynamic range (2.8…

Astrophysics · Physics 2008-11-26 S. Kim , L. Staveley-Smith , M. A. Dopita , R. J. Sault , K. C. Freeman , Y. Lee , Y. -H. Chu

We use the Gaussian-fit results of Paper I to investigate the properties of interstellar HI in the Solar neighborhood. The Warm and Cold Neutral Media (WNM and CNM) are physically distinct components. The CNM spin temperature histogram…

Astrophysics · Physics 2010-04-06 Carl Heiles , T. H. Troland

(ABRIDGED) We present a Far-Ultraviolet Spectroscopic Explorer survey of highly ionized high-velocity clouds (HVCs) in 66 extragalactic sight lines. We find a total of 63 high-velocity O VI absorbers, 16 with 21 cm-emitting H I counterparts…

Astrophysics · Physics 2009-11-11 Andrew J. Fox , Blair D. Savage , Bart P. Wakker