相关论文: The warm ionized medium in spiral galaxies
The interstellar medium (ISM) is a key ingredient in galaxy formation and evolution as it provides the molecular gas reservoir which fuels star formation and supermassive black hole accretion. Yet the ISM is one of the least studied aspects…
Hot gaseous halos are predicted around all large galaxies and are critically important for our understanding of galaxy formation, but they have never been detected at distances beyond a few kpc around a spiral galaxy. We used the Chandra…
Aims: We systematically explore a plausible subset of the parameter space involving effective temperatures and metallicities of the ionizing stellar sources, the effects of the hardening of their radiation by surrounding leaky HII regions…
We study the hot and cold circum-galactic medium (CGM) of 86 galaxies of the cosmological, hydrodynamical simulation suite NIHAO. NIHAO allows a study of how the $z=0$ CGM varies across 5 orders of magnitude of stellar mass using OVI and HI…
We investigate models for the photoionization of the widespread diffuse ionized gas in galaxies. In particular we address the long standing question of the penetration of Lyman continuum photons from sources close to the galactic midplane…
The gas surrounding galaxies outside their disks or interstellar medium and inside their virial radii is known as the circumgalactic medium (CGM). In recent years this component of galaxies has assumed an important role in our understanding…
The circumgalactic medium (CGM) is a vital element in galaxies, as it mediates the baryon cycle essential for regulating galaxy activity. It is also highly complex due to the intricate distributions of temperature, density, metallicity, and…
Electrons densities in different locations of our galaxy are obtained in pulsar astronomy by dividing the dispersion measure (DM) by the distance of the pulsar to Earth. The properties of the interstellar plasma are related to its heating.…
Galaxies are part of a vast cosmic ecosystem, embedded in an extensive gaseous reservoir that regulates their growth by providing the necessary fuel for star formation while preserving a fossil record of past interactions, outflows, and…
Recent observations in the 21cm line with the Green Bank Telescope have changed our view of the neutral interstellar medium (ISM) in several ways. The new data show that in the inner parts of the Milky Way the disk-halo interface is…
The galactic gaseous halo is a gas reservoir for the interstellar medium in the galaxy disk, supplying materials for star formation. We developed a gaseous halo model connecting the galaxy disk and the gaseous halo by assuming the star…
We present spectroscopic data of ionized gas in the disk--halo regions of three edge-on galaxies, NGC 891, NGC 4631 and NGC 3079, covering a wavelength range from [\ion{O}{2}] $\lambda$3727\AA to [\ion{S}{2}] $\lambda$6716.4\AA. The…
We present results from an on-going programme to study the dust and ionized gas in E/S0 galaxies with dust lanes. Our data, together with results from previous studies of E/S0 galaxies, are used to demonstrate the tight relationship between…
The intergalactic medium - the cosmic gas that fills the great spaces between the galaxies - is affected by processes ranging from quantum fluctuations in the very early universe to radiative emission from newly-formed stars. This gives the…
We report on observations of several optical emission lines toward a variety of newly revealed faint, large-scale Halpha-emitting regions in the Galaxy. The lines include [NII] 6583, [NII] 5755, [SII] 6716, [OIII] 5007, and HeI 5876…
Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…
We use a series of high-resolution N-body simulations of a `Milky-Way' halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system…
To better understand diffuse ionized gas kinematics and halo rotation in spiral galaxies, we have developed a model in which clouds are ejected from the disk and follow ballistic trajectories through the halo. The behavior of clouds in this…
Most of the visible mass in a typical spiral galaxy is distributed in a thin disk, with a radial extent much larger than its thickness. While the planar disk structure, including non-axisymmetric features such as spiral structure, has been…
As part of a large study to map the distribution of star formation across galactic disks, we have obtained deep Halpha images of the nearby Sculptor Group spirals NGC 247 and NGC 7793. These images are of sufficiently high quality that they…