English
Related papers

Related papers: Present-day Galactic Evolution: Low-metallicity, W…

200 papers

We report the results of observations toward the center of the molecular cloud CO 0.02-0.02 made using the Atacama Large Millimeter/Submillimeter Array. The successfully obtained 1 arcsec resolution images of CO $J$=3-2, H$^{13}$CN $J$=4-3,…

Astrophysics of Galaxies · Physics 2023-06-14 Yuhei Iwata , Tomoharu Oka , Shunya Takekawa , Shiho Tsujimoto , Rei Enokiya

We analyze an adaptive mesh refinement hydrodynamic cosmological simulation of a Milky Way-sized galaxy to study the cold gas in the halo. HI observations of the Milky Way and other nearby spirals have revealed the presence of such gas in…

Astrophysics of Galaxies · Physics 2015-06-04 Ximena Fernández , M. Ryan Joung , Mary E. Putman

Six examples of the compact, isolated high-velocity HI clouds (CHVCs) identified by Braun and Burton (1999) have been imaged with the WSRT. The 65 confirmed objects in this class define a dynamically cold system, with a global minimum for…

Astrophysics · Physics 2007-05-23 Robert Braun , Butler Burton

I examine some of the evidence relevant to the idea that high-velocity clouds (HVCs) are gas clouds distributed throughout the Local Group, as proposed by Blitz et al. (1999) and Braun & Burton (1999). This model makes several predictions:…

Astrophysics · Physics 2007-05-23 B. P. Wakker

This study developed an automated identification procedure for compact clouds with broad velocity widths in the spectral line data cubes of highly crowded regions. The procedure was applied to the CO J=3-2 line data, obtained using the…

Astrophysics of Galaxies · Physics 2022-09-27 Tomoharu Oka , Asaka Uruno , Rei Enokiya , Taichi Nakamura , Yuto Yamasaki , Yuto Watanabe , Sekito Tokuyama , Yuhei Iwata

We present a census of neutral gas in the Milky Way disk and halo down to limiting column densities of $N$(HI)$\sim10^{14}$ cm$^{-2}$ using measurements of HI Lyman-series absorption from the Far Ultraviolet Spectroscopic Explorer (FUSE).…

This study presents a catalog of 8107 molecular clouds that covers the entire Galactic plane and includes 98% of the $^{12}$CO emission observed within $b\pm5^\circ$. The catalog was produced using a hierarchical cluster identification…

Astrophysics of Galaxies · Physics 2017-01-11 Marc-Antoine Miville-Deschênes , Norman Murray , Eve J. Lee

The nucleus of the Milky Way is known to drive a large-scale, multiphase galactic outflow, with gas phases ranging from the hot highly-ionized to the cold molecular component. In this work, we present the first systematic search for…

(ABRIDGED) We present a Far-Ultraviolet Spectroscopic Explorer survey of highly ionized high-velocity clouds (HVCs) in 66 extragalactic sight lines. We find a total of 63 high-velocity O VI absorbers, 16 with 21 cm-emitting H I counterparts…

Astrophysics · Physics 2009-11-11 Andrew J. Fox , Blair D. Savage , Bart P. Wakker

The accretion of metal-poor gas sustains galactic star formation. In the Milky Way, this process is fueled by high-velocity clouds (HVCs), yet their fundamental properties have remained elusive in the absence of stellar tracers. Here we…

Astrophysics of Galaxies · Physics 2026-03-12 Zhihong He , Wenkang Pang , Kun Wang , Yangping Luo , Qian Cui

The standard treatment of cooling in Cold Dark Matter halos assumes that all of the gas within a ``cooling radius'' cools and contracts monolithically to fuel galaxy formation. Here we take into account the expectation that the hot gas in…

Astrophysics · Physics 2010-04-06 Ariyeh H. Maller , James S. Bullock

We present evidence that the accretion of warm gas onto the Galaxy today is at least as important as cold gas accretion. For more than a decade, the source of the bright H-alpha emission (up to 750 mR) along the Magellanic Stream has…

Astrophysics · Physics 2015-05-13 J. Bland-Hawthorn

The Wisconsin H-Alpha Mapper (WHAM) has surveyed the distribution and kinematics of ionized gas in the Galaxy above declination -30 degrees. The WHAM Northern Sky Survey (WHAM-NSS) has an angular resolution of one degree and provides the…

Astrophysics · Physics 2009-11-10 L. M. Haffner , R. J. Reynolds , S. L. Tufte , G. J. Madsen , K. P. Jaehnig , J. W. Percival

The diffuse gas in and nearby the Milky Way plays an important role in the evolution of the entire Galaxy. It has a complex structure characterized by neutral, weakly and highly ionized gas, dust, and molecules. We probe this gas through…

Astrophysics of Galaxies · Physics 2013-02-19 C. Pinto , G. A. Kriss , J. S. Kaastra , E. Costantini , J. Ebrero , K. C. Steenbrugge , M. Mehdipour , G. Ponti

We report the discovery of eleven high-velocity HI clouds at Galactic latitudes of 25-30 degrees, likely embedded in the Milky Way's nuclear wind. The clouds are detected with deep Green Bank Telescope 21 cm observations of a $3.2^\circ…

Astrophysics of Galaxies · Physics 2025-07-08 Rongmon Bordoloi , Andrew J. Fox , Felix J. Lockman

High quality data are presented of neutral hydrogen emission and absorption in the fields of eleven of the nearest spiral galaxies. Multi-configuration VLA observations have provided angular resolution of 6~arcsec (corresponding to about…

Astrophysics · Physics 2007-05-23 Robert Braun

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…

Astrophysics of Galaxies · Physics 2015-05-14 N. Lehner , J. C. Howk

We present results on gas flows in the halo of a Milky Way-like galaxy at z=0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution towards an extended…

Using Milky Way data of the new Effelsberg-Bonn HI Survey (EBHIS) and the Galactic All-Sky Survey (GASS), we present a revised picture of the high-velocity cloud (HVC) complex Galactic Center Negative (GCN). Owing to the higher angular…

Astrophysics of Galaxies · Physics 2015-05-28 Benjamin Winkel , Nadya Ben Bekhti , Verena Darmstädter , Lars Flöer , Jürgen Kerp , Philipp Richter

We present observations of an HI cloud complex most likely located in the Virgo galaxy cluster, first reported by Kent et al. (2007). The complex consists of five clouds, detected in the data set of the ALFALFA extragalactic HI survey at…