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Related papers: HI shells in the outer Milky Way

200 papers

There is evidence in 21cm HI emission for voids several kpc in size centered approximately on the Galactic centre, both above and below the Galactic plane. These appear to map the boundaries of the Galactic nuclear wind. An analysis of HI…

Astrophysics of Galaxies · Physics 2016-08-17 Felix J. Lockman , N. M. McClure-Griffiths

During the formation of the Milky Way, > 100 central black holes (BHs) may have been ejected from their small host galaxies as a result of asymmetric gravitational wave emission. We previously showed that many of these BHs are surrounded by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Ryan M. O'Leary , Abraham Loeb

As part of a survey of HI 21-cm emission in the Southern Milky Way, we have detected two large shells in the interstellar neutral hydrogen near l=279 deg. The center velocities are +36 and +59 km/s, which puts the shells at kinematic…

Star-formation in the outer Galaxy is thought to be different from the inner Galaxy, as it is subject to different environmental parameters such as metallicity, interstellar radiation field, or mass surface density that all change with…

Astrophysics of Galaxies · Physics 2021-01-27 Carsten König , James S. Urquhart , Friedrich Wyrowski , Dario Colombo , Karl M. Menten

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3-D HI volume density distribution…

Astrophysics · Physics 2009-11-13 P. M. W. Kalberla , L. Dedes , J. Kerp , U. Haud

The recent data collected by {\it Herschel} have confirmed that interstellar structures with filamentary shape are ubiquitously present in the Milky Way. Filaments are thought to be formed by several physical mechanisms acting from the…

About 25% of the optical extragalactic sky is obscured by the dust and stars of our Milky Way. Dynamically important structures might still lie hidden in this zone. Various approaches are presently being employed to uncover the galaxy…

Astrophysics · Physics 2016-01-27 R. C. Kraan-Korteweg , A. Schroeder , G. A. Mamon , S. Ruphy

We report the results of a systematic photometric survey of the peripheral regions of a sample of fourteen globular clusters in the outer halo of the Milky Way at distances d_GC>25 kpc from the Galactic centre. The survey is aimed at…

We introduce a new maximum likelihood method to model the density profile of Blue Horizontal Branch and Blue Straggler stars and apply it to the Sloan Digital Sky Survey Data Release 8 (DR8) photometric catalogue. There are a large number…

Astrophysics of Galaxies · Physics 2015-05-27 A. J. Deason , V. Belokurov , N. W. Evans

A set of diffuse interstellar clouds in the inner Galaxy within a few hundred pc of the Galactic plane has been observed at an angular resolution of ~1 arcmin combining data from the NRAO Green Bank Telescope and the Very Large Array. At…

Astrophysics of Galaxies · Physics 2015-06-15 Yurii Pidopryhora , Felix J. Lockman , John M. Dickey , Michael P. Rupen

We describe HI observations of a 4 x 4 degrees field in the Milky Way centered on l=61 deg, b=0 deg made by the Effelsberg radiotelescope. The field contains one previously identified HI supershell, GS061+00+51 (Heiles, 1979); apart from it…

Astrophysics · Physics 2009-11-06 S. Ehlerova , J. Palous , W. K. Huchtmeier

Data from the Canadian Galactic Plane Survey reveal an abundance of HI shells and arcs in the disk of our galaxy. While their shape is suggestive of stellar winds or supernovae influence, very few of these structures have been examined in…

Astrophysics · Physics 2015-06-24 Magdalen Normandeau , A. R. Taylor , P. E. Dewdney , Shantanu Basu

We examine the HI content and environment of all of the Local Group dwarf galaxies (M_tot < 10^10 M_solar), including the numerous newly discovered satellites of the Milky Way and M31. All of the new dwarfs, with the exception of Leo T,…

Astrophysics of Galaxies · Physics 2016-06-02 Jana Grcevich , Mary E Putman

We leverage recent numerical simulations of highly resolved star-forming regions in a Milky Way-like Galaxy to explore the nature of extended gaseous envelopes around molecular clouds. We extract a sample of two dozen star-forming clouds…

Astrophysics of Galaxies · Physics 2024-03-06 Elijah Mullens , Catherine Zucker , Claire E. Murray , Rowan Smith

Using 21cm HI observations from the Parkes Radio Telescope's Galactic All-Sky Survey, we measure 255 HI clouds in the lower Galactic halo that are located near the tangent points at 16.9 < l < 35.3 degrees and |b| < 20 degrees. The clouds…

Astrophysics of Galaxies · Physics 2015-05-19 H. Alyson Ford , Felix J. Lockman , N. M. McClure-Griffiths

About 25% of the optical extragalactic sky is obscured by the dust and stars of our Milky Way. Dynamically important structures might still lie hidden in this zone. Various approaches are presently being employed to uncover the galaxy…

Astrophysics · Physics 2007-05-23 Renee C. Kraan-Korteweg , Baerbel Koribalski , Sebastian Juraszek

Stellar shells are low surface brightness features, created during nearly head-on galaxy mergers from the debris of the tidally disrupted satellite. Here, we investigate the formation and evolution mechanism of shells in six dimensions (3d…

Astrophysics of Galaxies · Physics 2022-02-25 C. A. Dong-Páez , E. Vasiliev , N. W. Evans

Based on the \textit{Gaia} DR3 RR Lyrae catalog, we use two methods to fit the density profiles with an improved broken power law, and find that there are two break radii coinciding with the two apocenter pile-ups of high-eccentricity…

Astrophysics of Galaxies · Physics 2023-08-09 Dashuang Ye , Cuihua Du , Jianrong Shi , Jun Ma

Neutral atomic hydrogen (HI) gas in interstellar space is largely organized into filaments, loops, and shells, the most prominent of which are "supershells". These gigantic structures requiring $\gtrsim 3 \times 10^{52}$ erg to form are…

We present a study of the filamentary structure in the atomic hydrogen (HI) emission at the 21 cm wavelength toward the Galactic plane using the observations in the HI4PI survey. Using the Hessian matrix method across radial velocity…