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Dimming Betelgeuse likely isn't cold, just dusty, new study shows（图）
Dimming Betelgeuse just dusty
2020/3/11
Late last year, news broke that the star Betelgeuse was fading significantly, ultimately dropping to around 40% of its usual brightness. The activity fueled popular speculation that the red supergiant...
Dark matter is likely ‘cold,’ not ‘fuzzy,’ scientists report after new simulations（图）
Dark matter cold not fuzzy scientists new simulations
2017/7/24
Scientists have never directly detected dark matter. But over decades, they have proposed a variety of theories about what type of material — from new particles to primordial black holes — could compr...
Embryonic cluster galaxy immersed in giant cloud of cold gas
Embryonic cluster galaxy immersed giant cloud of cold gas
2016/12/1
Astronomers studying a cluster of still-forming protogalaxies seen as they were more than 10 billion years ago have found that a giant galaxy in the center of the cluster is forming from a surprisingl...
High-redshift galaxies in cold dark matter models
dark matter large-scale structure of the Universe
2014/12/26
We use hydrodynamic cosmological simulations to predict the star formation properties of high-redshift galaxies (z = 2-6) in five variants of the inflationary cold dark matter scenario, paying particu...
Sensitive limits on the water abundance in cold low-mass molecular cores
formation submil
2014/12/26
We present Submillimeter Wave Astronomy Satellite observations of water vapor in two cold starless clouds, B68 and core D in ρ Ophiuchi. Sensitive nondetections of the 110-101 transition of o-H2O are ...
X-ray absorption by the low-redshift intergalactic medium: A numerical study of the Lambda cold dark matter model
theory intergalactic medium
2014/12/24
Using a hydrodynamic simulation of a cold dark matter universe with a cosmological constant, we investigate the "X-ray forest" absorption imprinted on the spectra of background quasars by the interven...
A Two Micron All Sky Survey view of the Sagittarius dwarf galaxy. II. Swope telescope spectroscopy of M giant stars in the dynamically cold Sagittarius tidal stream
kinematics halo
2014/12/24
We have obtained moderate resolution (~6 km s-1) spectroscopy of several hundred M giant candidates selected from Two Micron All Sky Survey photometry. Radial velocities are presented for stars mainly...
On the origin of cold dark matter halo density profiles
dark matter large-scale structure of the universe
2014/12/24
N-body simulations predict that cold dark matter (CDM) halo-assembly occurs in two phases: (i) a fast-accretion phase with a rapidly deepening potential well; and (ii) a slow-accretion phase character...
The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper we compare two techniques, one based on emission and one on ...
Galaxies in a simulated Lambda CDM Universe - I. Cold mode and hot cores
cooling fl ows feedback cluster
2014/12/23
We study the formation of galaxies in a large volume (50 h−1 Mpc, 2 × 2883 particles) cosmological simulation, evolved using the entropy and energy-conserving smoothed particle hydrodynamics (SP...
The dynamics of satellite disruption in cold dark matter haloes
numerical N-body simulation
2014/12/22
We investigate the physical mechanisms of tidal heating and satellite disruption in cold dark matter host haloes using N-body simulations based on cosmological initial conditions. We show the importan...
DETECTION OF STRONG MILLIMETER EMISSION FROM THE CIRCUMSTELLAR DUST DISK AROUND V1094 SCO: COLD AND MASSIVE DISK AROUND A T TAURI STAR IN A QUIESCENT ACCRETION PHASE?
spectral energy compact dust emission
2014/12/20
We present the discovery of a cold massive dust disk around the T Tauri star V1094 Sco in the Lupus molecular cloud from the 1.1 mm continuum observations with AzTEC on ASTE. A compact (r 320 AU) cont...
Pairwise Velocities of Dark Matter Halos: a Test for the Lambda Cold Dark Matter Model using the Bullet Cluster
method : N-body simulations — galaxies : evolution — galaxies : for-mation — galaxies: clusters — cosmology : theory — cosmology : dark matter
2011/7/26
The existence of a bullet cluster (such as 1E0657-56) poses a challenge to the concordance Lambda cold dark matter model. Here we investigate the velocity distribution of dark matter halo pairs in lar...
Post-Periastron Gamma Ray Flare from PSR~B1259-63/LS 2883 as a Result of Comptonization of the Cold Pulsar Wind
Comptonization Cold Pulsar Wind
2011/7/25
The recent detection of gamma rays with the {\it Fermi} Large Area Telescope (LAT) from the binary system PSR B1259-63/LS2883 provides unique information about the pulsar wind. Although the nature of ...
An HI column density threshold for cold gas formation in the Galaxy
column density threshold cold gas formation Galaxy
2011/7/22
We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ ...