相关论文: Ionized Gas in the Smith Cloud

Optical emission lines provide an important new window on the HVCs. Recent studies of the H-alpha line reveal that ionized gas is pervasively associated with the neutral hydrogen in HVCs. The Wisconsin H-Alpha Mapper (WHAM) instrument has…

The Large Magellanic Cloud (LMC) has an extensive H$_{\alpha}$ emission halo that traces an extended, warm ionized component of its interstellar medium. Using the Wisconsin H$_{\alpha}$ Mapper (WHAM) telescope, we present the first…

We present direct measures of the ionization fractions of several sulfur ions in the Galactic warm ionized medium (WIM). We obtained high resolution ultraviolet absorption line spectroscopy of post-asymptotic giant branch stars in the the…

The heating and cooling of the interstellar medium allow the gas in the ISM to coexist at very different temperatures in thermal pressure equilibrium. The heating cannot be directly determined, but the cooling can be inferred from…

We mapped a 13 by 22 pc region in emission from 492 GHz [C I] and, for the first time, 551 GHz ^{13}CO(5-4) in the giant molecular cloud M17SW, using the Submillimeter Wave Astronomy Satellite. The morphologies of the [C I] and ^{13}CO…

Using data from the Southern Galactic Plane Survey (SGPS) we analyze an HI self-absorption cloud centered on l = 318.0 deg, b = -0.5 deg, and velocity, v = -1.1 km/s. The cloud was observed with the Australia Telescope Compact Array (ATCA)…

To determine the properties of the ionized gas at the edge of the CMZ near Sgr E we observed a small portion of the edge of the CMZ near Sgr E with spectrally resolved [C II] 158 micron and [N II] 205 micron fine structure lines at six…

The current velocity of the Smith Cloud indicates that it has undergone at least one passage of the Galactic disc. Using hydrodynamic simulations we examine the present day structure of the Smith Cloud. We find that a dark matter supported…

We present new calculations of the photoionization of interstellar matter within ~5 pc of the Sun (which we refer to as the Complex of Local Interstellar Clouds or CLIC) by directly observed radiation sources including nearby hot stars and…

The heliosphere serves as a probe of interstellar material (ISM) close to the Sun. Measurements of ISM inside and outside of the heliosphere show that we reside in typical warm partially ionized ISM that can be successfully modeled using…

The high-velocity cloud (HVC) Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the…

Halpha and Hbeta spectroscopy with the Wisconsin H-Alpha Mapper (WHAM) reveals a strong concentration of high velocity emission in a ~ 5 by 5 deg area centered near (l.b) = (27,-3), known as the Scutum Cloud. The high velocities imply that…

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…

Molecular clouds, which harbor the birthplaces of stars, form out of the atomic phase of the interstellar medium (ISM). We aim to characterize the atomic and molecular phases of the ISM and set their physical properties into the context of…

We present model calculations of ionization fractions for elements in the warm (log T = 4), low-density photoionized interstellar medium (WIM) of the Milky Way. We model the WIM as a combination of overlapping low-excitation H II regions…

We present findings of 3D filamentary structures in the Smith Cloud, a high-velocity cloud (HVC) located at $l=38^{\circ}$, $b=-13^{\circ}$. We use data from the Galactic Arecibo L-Band Feed Array \ion{H}{i} (GALFA-\ion{H}{i}) along with…

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection…

The composition and physical properties of several local clouds, including the Local Interstellar Cloud (LIC) in which the Sun is embedded, are derived from absorption features in the UV spectrum of the star epsilon CMa. We derive…

Motivated by the idea that a subset of HVCs trace dark matter substructure in the Local Group, we search for signs of star formation in the Smith Cloud, a nearby ~2x10^6 Msun HVC currently falling into the Milky Way. Using GALEX NUV and…

We present ISOPHOT observations between 60 and 200 microns and a near-infrared extinction map of LDN 1780. We have used the ISOPHOT data together with the 25, 60 and 100 microns IRIS maps to disentangle the warm and cold components of large…