Related papers: Density Distribution of the Warm Ionized Medium
Optical emission lines are used to categorize galaxies into three groups according to their dominant central radiation source: active galactic nuclei, star formation, or low-ionization (nuclear) emission regions [LI(N)ERs] that may trace…
One of the keys to interpreting the character and evolution of interstellar matter in the galaxy is understanding the distribution of the low density hot (10^5 K -10^6 K) phase of the interstellar medium (ISM). This phase is much more…
In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies…
Determining the properties of the warm ionized medium (WIM) at the leading edge of spiral arms is important for understanding its dynamics and cloud formation. The inner edge of the Scutum arm tangency is a unique location in which to…
Recent observations have found the ratio of H-alpha to free-free radio continuum to be surprisingly high in the diffuse ionized ISM (the so-called WIM), corresponding to an electron temperature of only ~3000K. Such low temperatures were…
We present an analysis of the Lyman alpha forests of five quasar spectra in the near UV. Properties of the intergalactic medium (IGM) at an intermediate redshift interval (0.9 < z < 1.9) are studied. The amount of baryons in the diffuse…
We develop a kinematical model for the Milky Way Si IV-bearing gas to determine its density distribution and kinematics. This model is constrained by a column density line shape sample extracted from the {\it HST}/COS archival data, which…
At present, 30-40 per cent of the baryons in the local Universe is still undetected. According to theoretical predictions, this gas should reside in filaments filling the large-scale structure (LSS) in the form of a Warm-Hot Intergalactic…
Most of cosmic baryons predicted by the big-bang nucleosynthesis has evaded the direct detection. Recent numerical simulations indicate that approximately 30 to 50 percent of the total baryons in the present universe is supposed to take a…
The submillimeter opacity of dust in the diffuse Galactic interstellar medium (ISM) has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used three BLAST bands at 250,…
We combine observations of spiral galaxies in the [CII] line at 158 micron, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main…
We combine parallax distances to nearby O stars with parsec-scale resolution three-dimensional dust maps of the local region of the Milky Way (within 1.25 kpc of the Sun) to simulate the transfer of Lyman continuum photons through the…
Observations of far-infrared (FIR) and submillimeter (SMM) polarized emission are used to study magnetic fields and dust grains in dense regions of the interstellar medium (ISM). These observations place constraints on models of molecular…
A simple analytic model is presented to predict the near-IR H2 fluorescent line intensities emitted by diffuse interstellar clouds with a Plummer density profile. It is applicable to sightlines where (1) the column densities of H and H2…
We use the Herschel Hi-GAL survey data to study the spatial distribution in Galactic longitude and latitude of the interstellar medium and of dense, star-forming clumps in the inner Galaxy. The peak position and width of the latitude…
Context. A large fraction of the interstellar medium can be characterized as a multiphase medium. The neutral hydrogen gas is bistable with a cold and warm neutral medium (CNM and WNM respectively) but there is evidence for an additional…
Observations of ionised H$\alpha$ gas in high-redshift disc galaxies have ubiquitously found significant line broadening, $\sigma_{\rm H\alpha}\sim10-100$ km s$^{-1}$. To understand whether this broadening reflects gas turbulence within the…
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…
As the Universe evolves, it develops a web of filamentary structure of matter. This cosmic web is filled with gas, with the most diffuse gas lying in the intergalactic regions. At low redshift, the gas is predominantly warm-hot, and one of…
The diffuse high-energy gamma-ray emission of the Milky Way arises from interactions of cosmic-rays (CRs) with interstellar gas and radiation field in the Galaxy. The neutral hydrogen (H I) gas component is by far the most massive and…