相关论文: High-Velocity Cloud Complex C: Galactic Fuel or ga…
High-velocity clouds (HVC), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total…
We report an accurate distance of d = 10+/-2.5kpc to the high-velocity cloud Complex C. Using high signal-to-noise Keck/HIRES spectra of two horizontal-branch stars, we have detected CaII K absorption lines from the cloud. Significant…
By comparing sensitive Spitzer Space Telescope (SST) infrared and Green Bank Telescope 21 cm observations, we are able to report the first detection of dust emission in Complex C, the largest High Velocity Cloud in the sky. Dust in the…
The high-velocity clouds (HVCs) in the outer Milky Way at $20^{\circ} < l < 190^{\circ}$ have similar spatial locations, metallicities, and kinematics. Moreover, their locations and kinematics are coincident with several extraplanar stellar…
To explore the origin of high-velocity gas in the direction of the Large Magellanic Cloud (LMC) we analyze absorption lines in the ultraviolet spectrum of a Galactic halo star that is located in front of the LMC at d=9.2 kpc distance. We…
We have detected absorption lines from the High Velocity Cloud Complex WB in the spectrum of the star HE1048+0231. This detection sets an upper distance limit to the cloud of 8.8^{+2.3}_{-1.3} kpc. Non-detection (at >4 sigma confidence) in…
We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was…
We present recent results on highly ionized gas in Galactic High-Velocity Clouds (HVCs), originally surveyed in OVI (Sembach et al. 2003). In a new FUSE/HST survey of SiII/III/IV (Shull et al. 2009) toward 37 AGN, we detected SiIII (lambda…
Previous HST and FUSE observations have revealed highly ionized high-velocity clouds (HVCs) or more generally low HI column HVCs along extragalactic sightlines over 70-90% of the sky. The distances of these HVCs have remained largely…
We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) observations of interstellar ultraviolet absorption lines in the Galactic high-velocity cloud Complex C and the Intermediate Velocity…
We characterize the chemical and physical conditions in an outflowing high-velocity cloud in the inner Galaxy. We report a super-solar metallicity of [O/H] = $+0.36\pm0.12$ for the high-velocity cloud at $v_\mathrm{LSR}$ = 125.6 km s$^{-1}$…
Intermediate- and high-velocity clouds (IVCs, HVCs) are a potential source of fuel for star formation in the Milky Way (MW), but their origins and fates depend sensitively on their distances. We search for IVC and HVC in HST high-resolution…
We suggest that the high--velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc and containing 5e7 solar masses of neutral gas and 3e8 solar masses of dark matter, falling onto the Local Group; altogether the HVCs…
We report the detection of extremely broad emission toward two molecular clumps in the Galactic central molecular zone. We have mapped the Sagittarius C complex ($-0^\circ.61 < l < -0^\circ.27$, $-0^\circ.29 < b < 0^\circ.04$) in the HCN…
We use archival UV absorption-line data from HST/STIS to statistically analyse the absorption characteristics of the high-velocity clouds (HVCs) in the Galactic halo towards more than 40 extragalactic background sources. We determine…
We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS E140M) observations of the post-asymptotic giant branch star ZNG 1 in the globular cluster Messier 5 (l=3.9, b=+47.7; d=7.5 kpc, z=+5.3…
We use spectroscopic data from HST and FUSE to study the wide range of ionization states of the "highly ionized high-velocity clouds". Studied extensively in OVI absorption, these clouds are usually assumed to be infalling gas in the…
The high- and intermediate-velocity interstellar clouds (HVCs/IVCs) are tracers of energetic processes in and around the Milky Way. Clouds with near-solar metallicity about one kpc above the disk trace the circulation of material between…
Potential condensed clouds of gas in the Galactic halo are examined in the context of the recent models of cooling, fragmenting clouds building up the baryonic mass of the Galaxy. 582 high-velocity clouds (HVCs) are defined as the potential…
We derived the dust-to-HI ratio of the intermediate-velocity clouds (IVCs), the high-velocity clouds (HVCs), and the local HI gas, by carrying out a multiple-regression analysis of the 21cm HI emission combined with the sub-mm dust optical…