Related papers: H_2D^+: a light on baryonic dark matter?
The recent detection of microlensing of stars of LMC by compact objects in the halo of our galaxy suggests that our galaxy is surrounded by a non-luminous halo made of compact objects with mass of about $(0.03-0.5) \msun$. The rate of…
If the Universe has a significant baryonic dark component in the form of compact objects in galaxy halos (machos), then there is a minute chance (about $10^{-7}$) that one of the Galactic machos passes sufficiently close to our line of…
Observed rotational curves of neutral hydrogen clouds strongly support the fact that galactic halo contains huge amount of nonluminous matter, the so called gravitational dark matter. The nature of dark matter is a point of debate among the…
We use cosmological hydrodynamical simulations of the APOSTLE project along with high-quality rotation curve observations to examine the fraction of baryons in {\Lambda}CDM haloes that collect into galaxies. This 'galaxy formation…
Context: Dark cloud chemical models usually predict large amounts of O2, often above observational limits. Aims: We investigate the reason for this discrepancy from a theoretical point of view, inspired by the studies of Jenkins and Whittet…
Galaxy surveys have shown that luminous galaxies are mainly distributed in large filaments and galaxy clusters. The remaining large volumes are virtually devoid of luminous galaxies. This is in concordance with the formation of the…
H$_{\rm I}$ 21-cm and $^{12}$CO 2.6-mm line emissions respectively trace the atomic and molecular gas phases, but they miss most of the opaque H$_{\rm I}$ and diffuse H$_2$ present in the Dark Neutral Medium (DNM) at the transition between…
We present a CSO and BIMA molecular line survey of the dense, quiescent molecular environment ahead of HH2. The molecular gas is cold, 13 K, and moderately dense, 3x10^5 cm^-3. A total of 14 species has been detected (including different…
The presence of dark matter is nowadays widely supported by a large body of astronomical and cosmological observations. A large amount of dark matter is expected to be present in the central region of the Milky Way. Very-high-energy (>100…
Recently, Dixon et al. have re-analyzed the EGRET data, finding a statistically significant diffuse $\gamma$-ray emission from the galactic halo. We show that this emission can naturally be explained within a previously-proposed model for…
Many high velocity HI clouds (HVCs) are now believed to be scattered throughout the Galactic halo on scales of tens of kiloparsecs. Some of these clouds appear to contain substantial HI masses (>10^6 Msun). It has been suggested that these…
Aims. We model a diffuse molecular cloud present along the line of sight to the star HD 102065. We compare our modeling with observations to test our understanding of physical conditions and chemistry in diffuse molecular clouds. Methods.…
The first definite discoveries of extragalactic deuterium are reported. DCO$^+$ has been detected in three and DCN has been measured in one star-forming region of the Large Magellanic Cloud (LMC). While the HCO$^+$/DCO$^+$ abundance ratios…
It has recently been argued that the unidentified SCUBA objects (USOs) are a thick disk population of free-floating dense, compact galactic gas clumps at a temperature of about 7 K. The characteristic mass scale is constrained to be on the…
One of the biggest obstacles to our full understanding of the global dynamics in Milky Way and other spiral galaxies is uncertainty with respect to the form of baryonic dark matter in galactic haloes. Two basic forms discussed recently are…
While the CO(1-0) transition is often used to deduce the total molecular hydrogen in galaxies, it is challenging to detect in low metallicity galaxies, in spite of the star formation taking place. In contrast, the [CII] 158 micron line is…
We report new observations of circumgalactic gas in the halos of early type galaxies obtained by the COS-Halos Survey with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope. We find that detections of HI surrounding early…
The Cold Dark Matter theory of gravitationally-driven hierarchical structure formation has earned its status as a paradigm by explaining the distribution of matter over large spans of cosmic distance and time. However, its central tenet,…
Recent highly sensitive detections of line emission from extended gas in the local universe demonstrate the feasibility of detecting H$\alpha$ emitting galactic halos out to $z\sim1$. We determine the form of the surface brightness vs.…
The concordance cosmological model based on cold dark matter makes definitive predictions for the growth of galaxies in the Universe, which are being actively studied using numerical simulations. These predictions appear to contradict the…