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Related papers: Ram Pressure and Anomalous Shell Formation in HoII

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Ram pressure stripping is an important process in the evolution of both dwarf galaxies and large spirals. Large spirals are severely stripped in rich clusters and may be mildly stripped in groups. Dwarf galaxies can be severely stripped in…

Astrophysics · Physics 2011-02-11 J. A. Hester

FAST HI observations reveal unprecedented internal structures of the high-velocity cloud AC-III, which is found to consist of several coherent subclumps (D1-D6) with nearly constant line widths of $\sim 20~\mathrm{km~s^{-1}}$, while the…

Astrophysics of Galaxies · Physics 2025-10-31 Xunchuan Liu

We present a detailed analysis of the neutral hydrogen kinematics of 12 nearby dwarf irregular galaxies observed as part of the Local Volume HI Survey (LVHIS) conducted at the Australia Telescope Compact Array. For each galaxy we measure…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Emma M. Kirby , Baerbel Koribalski , Helmut Jerjen , Angel Lopez-Sanchez

The spectral characteristics throughout the dwarf irregular galaxy DDO 53 are studied. The results are very similar to those for other irregular galaxies: high excitation and low values of the [SII]/Halpha ratio. The most likely ionization…

Astrophysics · Physics 2008-11-26 A. M. Hidalgo-Gamez

We present new upper limits on the neutral hydrogen (HI) content within the stellar half-light ellipses of 15 Galactic dwarf spheroidal galaxies (dSphs), derived from pointed observations with the Green Bank Telescope (GBT) as well as…

Astrophysics of Galaxies · Physics 2015-06-23 K. Spekkens , N. Urbancic , B. S. Mason , B. Willman , J. E. Aguirre

We investigate the atomic (HI) and molecular (H_2) Hydrogen content of normal galaxies by combining observational studies linking galaxy stellar and gas budgets to their host dark matter (DM) properties, with a physically grounded galaxy…

Astrophysics of Galaxies · Physics 2010-05-25 M. Cook , C. Evoli , E. Barausse , G. L. Granato , A. Lapi

Environments play an important role in galaxy formation and evolution, particularly in regulating the content of neutral gas. However, current HI surveys have limitations in their depth, which prevents them from adequately studying low HI…

Astrophysics of Galaxies · Physics 2023-09-13 Hui-Jie Hu , Qi Guo , Pablo Renard , Hang Yang , Zheng Zheng , Yingjie Jing , Hao Chen , Hui Li

The origin of kpc-scale holes in the atomic hydrogen (H I) distributions of some nearby dwarf irregular galaxies presents an intriguing problem. Star formation histories (SFHs) derived from resolved stars give us the unique opportunity to…

The surface densities of star formation, Sigma_SFR, in 24 dwarf irregular (dIrr) galaxies from the LITTLE THINGS survey are combined with gas surface densities and midplane pressures to examine the correlations found previously for spiral…

Astrophysics of Galaxies · Physics 2025-12-12 Bruce G. Elmegreen , Deidre A. Hunter , Edvige Corbelli

Stellar feedback is often cited as the biggest uncertainty in galaxy formation models today. This uncertainty stems from a dearth of observational constraints as well as the great dynamic range between the small scales (<1 pc) where the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Laura A. Lopez , Mark R. Krumholz , Alberto D. Bolatto , J. Xavier Prochaska , Enrico Ramirez-Ruiz , Daniel Castro

Sensitive 21cm HI observations have been made with the Green Bank Telescope toward the newly-discovered Local Group dwarf galaxy Hydra II, which may lie within the leading arm of the Magellanic Stream. No neutral hydrogen was detected. Our…

HII galaxies are clumpy and their gas kinematics can be mapped to show the global turbulent motions and the effect of massive star evolution. The distribution of their physical conditions is homogeneous and oxygen abundance is uniform. The…

Astrophysics of Galaxies · Physics 2014-02-14 Eduardo Telles

By implementing a dynamic wind-tunnel model in a smoothed-particle chemodynamic/hydrodynamic simulation suite, we have investigated the effects of ram pressure and tidal forces on dwarf galaxies similar to the Magellanic Clouds, within host…

Astrophysics of Galaxies · Physics 2018-11-07 David Williamson , Hugo Martel

We present a detailed analysis of the neutral atomic gas (HI) in the dwarf galaxy UGCA 320, observed with the MeerKAT telescope as part of the MHONGOOSE (MeerKAT HI Observations of Nearby Galactic Objects: Observing Southern Emitters)…

Observations at intermediate redshifts reveal the presence of numerous, compact, weak MgII absorbers with near to super-solar metallicities, often surrounded by more extended regions that produce CIV and/or OVI absorption in the…

Astrophysics of Galaxies · Physics 2021-03-24 Akimi Fujita , Toru Misawa , Jane C. Charlton , Avery Meiksin , Mordecai-Mark Mac Low

The location of HII regions, which indicates the locus of present star formation in galaxies, is analyzed for a large collection of 110 irregular galaxies (Irr) imaged in H$\alpha$ and nearby continuum. The analysis is primarily by visual…

Astrophysics · Physics 2015-06-24 Noah Brosch , Ana Heller , Elchanan Almoznino

We study the IB(s)m galaxy IC 3476 observed in the context of VESTIGE, a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster. The deep narrow-band (NB) image reveals a very pertubed ionised gas distribution, characterised by…

We investigate the interplay between the ionization radiation from massive stars and the turbulence inside the surrounding molecular gas thanks to 3D numerical simulations. We used the 3D hydrodynamical code HERACLES to model an initial…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Tremblin , E. Audit , V. Minier , W. Schmidt , N. Schneider

A group of four compact HII regions associated with the well-known 50 km/s molecular cloud is the closest site of on-going star formation to the dynamical center of the Galaxy, at a projected distance of ~6 pc. We present a study of ionized…

Astrophysics of Galaxies · Physics 2015-05-20 F. Yusef-Zadeh , J. H. Lacy , M. Wardle , B. Whitney , H. Bushouse , D. A. Roberts , R. G. Arendt

We study the neutral hydrogen distribution and kinematics in the Local Group dwarf irregular galaxy IC 1613 and compare them with the ionized gas distribution and stellar content of the galaxy. We discuss several mechanisms which may be…