English
Related papers

Related papers: Distances to Galactic high-velocity clouds. Comple…

200 papers

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…

Astrophysics · Physics 2009-11-13 C. Thom , J. E. G. Peek , M. E. Putman , Carl Heiles , K. M. G. Peek , R. Wilhelm

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…

Astrophysics · Physics 2009-11-11 C. Thom , M. E. Putman , B. K. Gibson , N. Christlieb , C. Flynn , T. C. Beers , R. Wilhelm , Y. S. Lee

We present HST GHRS and STIS observations of five QSOs that probe the prominent high-velocity cloud (HVC) Complex C, covering 10% of the northern sky. Based upon a single sightline measurement (Mrk 290), a metallicity [S/H]=-1.05+/-0.12 has…

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…

Astrophysics · Physics 2009-06-23 B. P. Wakker , D. G. York , R. Wilhelm , J. C. Barentine , P. Richter , T. C. Beers , Z. Ivezic , J. C. Howk

We present observations of the (field of the) Seyfert galaxy Mark290, which probes the high-velocity cloud (HVC) complex C, one of the largest HVCs. We find that this object has a metallicity of 0.094pm0.020(+0.022-0.019) times solar. We…

High-velocity clouds (HVCs) are composed of neutral hydrogen (HI) moving at velocities that deviate from the general rotational motion of the Milky Way. Currently, the origins of the HVCs remain poorly known due to the difficulty in…

Astrophysics of Galaxies · Physics 2025-04-15 Xiao-Lan Liu , Jin-Long Xu , Peng Jiang , Ming Zhu , Chuan-Peng Zhang , Naiping Yu , Ye Xu , Xin Guan , Jun-Jie Wang

We present a new measurement, 0.85-3.5 Z_solar, of the metallicity of high velocity cloud (HVC) Complex M by analyzing ultraviolet spectroscopic observations of the blazar Mrk 421 taken with the Cosmic Origins Spectrograph on the Hubble…

Astrophysics of Galaxies · Physics 2015-05-27 Yangsen Yao , J. Michael Shull , Charles W. Danforth

There is a fortuitous coincidence in the positions of the quasar TonS210 and the compact H I high velocity cloud CHVC224.0-83.4-197 on the sky. Using Far Ultraviolet Spectroscopic Explorer observations of the metal-line absorption in this…

Astrophysics · Physics 2009-11-07 Kenneth R. Sembach , Brad K. Gibson , Yeshe Fenner , Mary E. Putman

(Abridged) We present a new high-resolution (7 km/s FWHM) echelle spectrum of 3C 351 obtained with STIS. 3C 351 lies behind the low-latitude edge of high-velocity cloud Complex C, and the new spectrum provides accurate measurements of O I,…

We have recently identified several high velocity (V < -100 km/s) clouds in the directions of Mrk 509 and PKS 2155-304 that have unusual ionization properties. The clouds exhibit strong C IV absorption with little or no detectable low ion…

Astrophysics · Physics 2009-10-30 Kenneth R. Sembach , Blair D. Savage , Limin Lu , Edward M. Murphy

A table is presented that summarizes published absorption line measurements for the high- and intermediate velocity clouds (HVCs and IVCs). New values are derived for N(HI) in the direction of observed probes, in order to arrive at reliable…

Astrophysics · Physics 2009-11-06 B. P. Wakker

We report ultraviolet spectra of Galactic high-velocity clouds (HVCs) in Complex C, taken by the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), together with new 21-cm spectra from the Green Bank Telescope. The wide…

Astrophysics of Galaxies · Physics 2015-05-28 Michael Shull , Matthew Stevans , Charles Danforth , Steven Penton , Felix J. Lockman , Nahum Arav

High-velocity clouds (HVCs) are interstellar gas clouds whose velocities are incompatible with Galactic rotation. Since the first discovery of HVCs in 1963, their origins have been debated for decades but are still not settled down, because…

Astrophysics of Galaxies · Physics 2025-06-19 Yu-Ting Wang , Chao Liu , Zhi-Yu Zhang

We compare existing high spectral resolution (R=40,000) CaII K observations towards 88 mainly B-type stars, and new observations at R=10,000 towards 3 stars, with 21-cm HI emission-line profiles, in order to search for optical absorption…

We have used infrared and radio observations to search for a dwarf galaxy associated with the high-velocity cloud (HVC) known as Complex H. Complex H is a large (> 400 deg^2) and probably nearby (d = 27 kpc) HVC whose location in the…

Astrophysics · Physics 2009-11-13 Joshua D. Simon , Leo Blitz , Andrew A. Cole , Martin D. Weinberg , Martin Cohen

Using Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of the QSO PG1259+593, we detect D I Lyman-series absorption in high velocity cloud Complex C, a low-metallicity gas cloud falling onto the Milky Way. This…

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…

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…

Astrophysics · Physics 2009-11-11 M. -A. Miville-Deschenes , F. Boulanger , W. T. Reach , A. Noreiga-Crespo

We present the detection of dust depletion in Complex C, a massive, infalling, low-metallicity high-velocity cloud in the northern Galactic hemisphere that traces the ongoing accretion of gas onto the Milky Way. We analyze a very high…

We present Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of high, intermediate, and low ion absorption in high-velocity cloud Complex C along the lines of sight toward five active galaxies. Our purpose is to…

‹ Prev 1 2 3 10 Next ›