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Related papers: HI Clouds Beyond the Galactic Disk

200 papers

We exploit long-baseline ALMA sub-mm observations of the lensed star-forming galaxy SDP 81 at z=3.042 to investigate the properties of inter-stellar medium on scales of 50-100pc. The kinematics of the CO gas within this system are well…

We analyze the radial distribution of HI gas for 23 disk galaxies with unusually high HI content from the Bluedisk sample, along with a similar-sized sample of "normal" galaxies. We propose an empirical model to fit the radial profile of…

We use a new, improved version of the HI Parkes All-Sky Survey to search for HI emission from nine new, ultra-faint Milky Way satellite galaxy candidates recently discovered in data from the Dark Energy Survey. None of the candidates is…

Astrophysics of Galaxies · Physics 2015-08-19 T. Westmeier , L. Staveley-Smith , M. Calabretta , R. Jurek , B. S. Koribalski , M. Meyer , A. Popping , O. I. Wong

Three-dimensional simulations of the disk-halo interaction show the formation of a thick HI and HII gas disk with different scale heights. The thick HI disk prevents the disk gas from expanding freely upwards, unless some highly energetic…

Astrophysics · Physics 2009-10-31 Miguel A. de Avillez

Interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way provide the majority of the gamma rays observed by the Fermi Gamma Ray Space Telescope. In addition to the gas which is densely concentrated along…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Robert Feldmann , Dan Hooper , Nickolay Y. Gnedin

The high-velocity clouds of atomic hydrogen, discovered about 35 years ago, have velocities inconsistent with simple Galactic rotation models that generally fit the stars and gas in the Milky Way disk. Their origins and role in Galactic…

The HI halo clouds of the Milky Way, and in particular the intermediate-velocity clouds (IVCs), are thought to be connected to Galactic fountain processes. Observations of fountain clouds are important for understanding the role of matter…

Astrophysics of Galaxies · Physics 2016-12-14 T. Röhser , J. Kerp , D. Lenz , B. Winkel

While studying extraplanar neutral hydrogen in the disk-halo transition of the inner Galaxy we have discovered what appears to be a huge superbubble centered around l ~ 30 deg, whose top extends to latitudes > 25 deg at a distance of about…

Astrophysics · Physics 2008-11-26 Yurii Pidopryhora , Felix J. Lockman , Joseph C. Shields

Over the course of its motion through the Galaxy, our solar system has encountered many interstellar environments of varying characteristics. Interstellar medium (ISM) density variations spanning seven orders of magnitude are commonly seen…

Solar and Stellar Astrophysics · Physics 2015-06-16 Katherine Wyman , Seth Redfield

A galactic disk in a spiral galaxy is generally believed to be embedded in an extended dark matter halo, which dominates its dynamics in the outer parts. However, the shape of the halo is not clearly understood. Here we show that the dark…

Astrophysics of Galaxies · Physics 2015-05-27 Arunima Banerjee , Chanda J. Jog

Dwarf irregulars (dIrrs) are among the most common type of galaxy in the Universe. They typically have gas-rich, low surface-brightness, metal-poor, and relatively-thick disks. Here we summarize the current state of our knowledge of the…

Astrophysics of Galaxies · Physics 2024-02-28 Deidre A. Hunter , Bruce G. Elmegreen , Suzanne C. Madden

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…

Astrophysics of Galaxies · Physics 2025-05-06 Colin Holm-Hansen , M. E. Putman , D. A. Kim

High redshift disc galaxies are more gas rich, clumpier, and more turbulent than local Universe galaxies. This early era of galaxy formation imprints the distribution and kinematics of the stars that we observe today, but it is not yet well…

Astrophysics of Galaxies · Physics 2022-03-30 Floor van Donkelaar , Oscar Agertz , Florent Renaud

The discovery of an HI cloud with peculiar properties at equatorial coordinates (J2000) ra=07h49m, dec=04d30m is presented. The HI object was detected at 21cm using the 300-m NAIC Arecibo telescope. Subsequent follow-up high-resolution…

Astrophysics · Physics 2009-11-13 L. Dedes , C. Dedes , P. W. M Kalberla

We report the discovery of two kinematically anomalous atomic hydrogen (HI) clouds in M 100 (NGC 4321), which was observed as part of the Deciphering the Interplay between the Interstellar medium, Stars, and the Circumgalactic medium…

Knowledge of the molecular component of the ISM is fundamental to understand star formation. The H2 component appears to dominate the gas mass in the inner parts of galaxies, while the HI component dominates in the outer parts. Observation…

Astrophysics · Physics 2009-10-31 F. Combes

The gases of the interstellar medium (ISM) possess orders of magnitude more mass than those of all the stars combined and are thus the prime component of the baryonic universe. With L-band surface sensitivity even better than the planned…

Instrumentation and Methods for Astrophysics · Physics 2019-04-05 Carl Heiles , Di Li , Naomi McClure-Griffiths , Lei Qian , Shu Liu

We present a comprehensive investigation of HI (super)clouds, molecular clouds (MCs), and star formation in the Carina spiral arm of the outer Galaxy. Utilizing HI4PI and CfA CO survey data, we identify HI clouds and MCs based on the ($l$,…

Astrophysics of Galaxies · Physics 2023-08-04 Geumsook Park , Bon-Chul Koo , Kee-Tae Kim , Bruce Elmegreen

We discuss HD and MHD compressible turbulence as a cloud-forming and cloud-structuring mechanism in the ISM. Results from a numerical model of the turbulent ISM at large scales suggest that the phase-like appearance of the medium, the…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

Atomic gas in the diffuse interstellar medium (ISM) is organized in filamentary structures. These structures usually host cold and dense molecular clumps. The Galactic magnetic field is considered to play an important role in the formation…

Astrophysics of Galaxies · Physics 2022-09-14 R. Skalidis , K. Tassis , G. V. Panopoulou , J. L. Pineda , Y. Gong , N. Mandarakas , D. Blinov , S. Kiehlmann , J. A. Kypriotakis