相关论文: Local tadpole galaxies: dynamics and metallicity

We report multi-wavelength observations of the far-infrared source IRAS 20324+4057, including high-resolution optical imaging with HST, and ground-based near-infrared, millimeter-wave and radio observations. These data show an extended,…

Gas inflow feeds galaxies with low metallicity gas from the cosmic web, sustaining star formation across the Hubble time. We make a connection between these inflows and metallicity inhomogeneities in star-forming galaxies, by using…

After summarizing the characteristics of different types of dwarf galaxies I briefly review our current state of knowledge of dwarf galaxy evolution in the Local Group, for which we now have a fairly detailed although by no means…

Nearly 400 Tycho-2 stars have been observed in a 720 square degree field in the direction of the North Galactic Pole with the high resolution echelle spectrograph ELODIE. Absolute magnitudes, effective temperatures, gravities and…

We present here far-infrared photometry of galaxies in a sample that is relatively unexplored at these wavelengths: low-metallicity dwarf galaxies with moderate star formation rates. Four dwarf irregular galaxies from the…

The analysis of the chemical composition of galaxies provides fundamental insights into their evolution. This holds true also in the case of the outer regions of spiral galaxies. This Chapter presents the observational data, accumulated in…

The extremely metal-poor (XMP) galaxies analyzed in a previous paper have large star-forming regions with a metallicity lower than the rest of the galaxy. Such a chemical inhomogeneity reveals the external origin of the metal-poor gas…

Prompted by a new catalogue of M31 globular clusters, we have collected together individual metallicity values for globular clusters in the Local Group. Although we briefly describe the globular cluster systems of the individual Local Group…

Colors and magnitudes were determined for 69 chain galaxies, 58 other linear structures, 32 normal edge-on galaxies, and all of their large star formation clumps in the HST ACS field of the Tadpole galaxy. Redshifts of 0.5 to 2 are inferred…

In order to study early type galaxies in their simplest environments, we have constructed a well-defined sample of 30 isolated galaxies. The sample contains all RC3 early-type galaxies with no other cataloged galaxy with known redshift…

In order to recognize environmental effects on the evolution of dwarf galaxies in clusters of galaxies, it is first necessary to quantify the properties of objects which have evolved in relative isolation. With oxygen abundance as the gauge…

Thanks to recent advances in integral field spectroscopy (IFS), modern surveys of nearby galaxies are capable of resolving metallicity maps of Hii regions down to scales of ~50pc. However, statistical analysis of these metallicity maps has…

We present a statistical analysis of the properties of a large sample of dynamically hot old stellar systems, from globular clusters to giant ellipticals, which was performed in order to investigate the origin of ultra-compact dwarf…

The metal content of a galaxy's interstellar medium reflects the interplay between different evolutionary processes such as feedback from massive stars and the accretion of gas from the intergalactic medium. Despite the expected abundance…

We present a statistical study of the presence of galaxy warps in the Hubble deep fields. Among a complete sample of 45 edge-on galaxies above a diameter of 1.''3, we find 5 galaxies to be certainly warped and 6 galaxies as good candidates.…

Galaxies in the Hubble Ultra Deep Field (UDF) larger than 10 pixels (0.3 arcsec) have been classified according to morphology and their photometric properties are presented. There are 269 spirals, 100 ellipticals, 114 chains, 126…

The extreme outer regions of disk galaxies, lying at or beyond the classical optical radius defined by R25, present an opportunity to study star formation and chemical evolution under unique physical conditions, possibly reminscent of those…

The light distribution in the disks of many galaxies is non-axisymmetric or `lopsided' with a spatial extent much larger along one half of a galaxy than the other, as in M101. Recent near-IR observations show that lopsidedness is common.…

We used the $H\alpha$ images from a large sample of nearby late-type dwarf galaxies to investigate properties of their emission structure. The sample consists of three hundred galaxies of the irregular (Irr), Magellanic irregular (Im), blue…

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…