Dwarf Elliptical Galaxies
نویسندگان
چکیده
منابع مشابه
Giant Halos in Dwarf Irregular Galaxies vs. Dwarf Elliptical Galaxies
We present a discovery of a giant stellar halo in NGC 6822, a dwarf irregular galaxy in the Local Group. This halo is mostly made of old red giants, showing striking features: 1) it is several times larger than the main body of the galaxy seen in the optical images, and 2) it is elongated in the direction almost perpendicular to the HI disk of NGC 6822. The structure of this stellar halo looks ...
متن کاملDwarf galaxy formation induced by galaxy interactions
Growing evidence has been accumulated for that some gas-rich dwarf galaxies are formed from material liberated by galaxy collisions and/or mergers. Also, gas-poor dwarf elliptical galaxies are often found in the central regions of clusters of galaxies. These observations suggest strongly that the formation of most dwarf galaxies is linked to galaxy interactions. Therefore, now seems like the ri...
متن کاملStellar Populations of Dwarf Elliptical Galaxies: Ubvri Photometry of Dwarf Elliptical Galaxies in the Virgo Cluster
We present UBVRI surface photometry for 16 dwarf elliptical galaxies in the Virgo Cluster with previously measured kinematic properties. The global optical colors are red, with median values for the sample of 0.24 ± 0.03 in (U–B), 0.77 ± 0.02 in (B– V), and 1.02 ± 0.03 in (V–I). We recover the well known color-magnitude relation for cluster galaxies, but find no significant difference in domina...
متن کاملStructural properties of dwarf ellipticals and the connection with (ordinary) elliptical galaxies
This article reviews the popular reasons for the belief that dwarf elliptical galaxies and (ordinary) elliptical galaxies are distinct and separate species. They include: light–profile shape (or similarly image concentration); the magnitude–central surface brightness diagram; the magnitude–effective surface brightness diagram (or similarly the magnitude–effective radius diagram); and the Fundam...
متن کاملGalaxy threshing and the formation of ultra-compact dwarf galaxies
Recent spectroscopic and morphological observational studies of galaxies around NGC 1399 in the Fornax Cluster (Drinkwater et al. 2000b) have discovered several ‘ultra-compact dwarf’ galaxies with intrinsic sizes of ∼ 100 pc and absolute B band magnitudes ranging from −13 to −11 mag. In order to elucidate the origin of these enigmatic objects, we perform numerical simulations on the dynamical e...
متن کاملDissipative Process as a Mechanism of Differentiating Internal Structures between Dwarf and Normal Elliptical Galaxies in a CDM Universe
We simulate the dynamical, chemical, and spectro-photometric evolution of dwarf and normal elliptical galaxies embedded in a dark matter halo, using a three-dimensional N -body/SPH simulation code. For the forming dwarf elliptical galaxies, supernova-driven winds propagating outwards from inside the system collide with the infalling gas and produce the super-shell in which stars are formed. The...
متن کامل