相关论文: NGC5719/13: interacting spirals forming a counter-…

Though S0 galaxies are usually thought to be `red and dead', they demonstrate often star formation organized in ring structures. We try to clarify the nature of this phenomenon and its difference from star formation in spiral galaxies. The…

We present a comprehensive multi-wavelength study of the nearby interacting dwarf galaxy NGC3077 (member of the M81 triplet). High resolution VLA HI observations show that most of the atomic gas (~90%) around NGC3077 is situated in a…

Star-forming galaxies like the Milky Way are surrounded by a hot gaseous halo at the virial temperature - the so-called galactic corona - that plays a fundamental role in their evolution. The interaction between the disc and the corona has…

ATCA HI and radio continuum observations of the peculiar southern galaxy IC2554 and its surroundings reveal typical signatures of an interacting galaxy group. We detected a large HI cloud between IC2554 and the elliptical galaxy NGC3136B.…

We report the discovery of a giant stellar tidal stream in the halo of NGC 4631, a nearby edge-on spiral galaxy interacting with the spiral NGC 4656, in deep images taken with a 40-cm aperture robotic telescope. The stream has two…

Tidal encounters are believed to be one of the key drivers of galactic spiral structure in the Universe. Such spirals are expected to produce different morphological and kinematic features compared to density wave and dynamic spiral arms.…

We have obtained and analyzed long-slit spectral data for the lenticular galaxy IC 719. In this gas-rich S0 galaxy, its large-scale gaseous disk counterrotates the global stellar disk. Moreover in the IC 719 disk we have detected a…

Studies of the HI in galaxies have clearly shown that subtle details of the HI distribution and kinematics often harbour key information for understanding the structure and evolution of galaxies. Evidence for the accretion of material has…

Star formation (SF) takes place in unusual places such as way out in the intergalactic medium out of material expelled from parent galaxies. We wish to answer whether SF proceeds in this specific environment in a similar way than in…

Results from new HI synthesis observations of the nearby blue compact dwarf galaxy, NGC 2915, carried out on the Australian Telescope Compact Array are presented. High resolution HI moment maps for the galaxy reveal complex HI distributions…

Models of disk galaxy formation commonly predict the existence of an extended reservoir of accreted hot gas surrounding massive spirals at low redshift. As a test of these models, we use X-ray and H-alpha data of the two massive, quiescent…

We report the discovery of active star formation in the HI cloud associated with the interacting Seyfert system NGC 3227/NGC 3226 that was originally identified as a candidate tidal dwarf galaxy (TDG) by Mundell et al. and that we name…

Aims: To gain insight into the expected gas dynamics at the interface of the Galactic bar and spiral arms in our own Milky Way galaxy, we examine as an extragalactic counterpart the evidence for multiple distinct velocity components in the…

(abridged) Several N-body methods were combined in order to develop a method for the determination of the parameters of interacting galaxies. This method has been applied to the HI distribution of NGC4449. In a first step the fast…

Counter-rotating components in galaxies are one of the most direct forms of evidence for past gas accretion or merging. We discovered ten edge-on disk gaseous counter-rotators in a sample of 523 edge-on galaxies identified in the final…

We present high-quality aperture synthesis observations of the neutral hydrogen distribution in a sample of five galactic systems believed to be involved in progressive stages of merging: Arp295, NGC4676, NGC520, NGC3921, and NGC7252. These…

We investigate, by means of numerical simulations, the possibility of forming counter-rotating old stellar components by major mergers between an elliptical and a spiral galaxy. We show that counter-rotation can appear both in dissipative…

Many spiral galaxy haloes show stellar streams with various morphologies when observed with deep images. The origin of these tidal features is discussed, either coming from a satellite infall or caused by residuals of an ancient, gas-rich…

(abridged) We combined several N-body methods in order to investigate the interaction scenario between NGC 4449 and DDO 125, a close companion in projected space. In a first step fast restricted N-body models are used to confine a region in…

We present results from GMRT HI 21 cm line observations of the interacting galaxy pair Arp 181 (NGC 3212 and NGC 3215) at z =0.032. We find almost all of the detected HI (90%) displaced well beyond the optical disks of the pair with the…