Probing Halos of Galaxies at Very Large Radii using Background QSOs
نویسنده
چکیده
Gaseous halos of nine nearby galaxies (with redshifts cz < 6000 km s) were probed at large galactocentric radii using background quasars observed with HST GHRS and STIS. The projected quasar-galaxy separations range from 55 to 387 h 75 kpc. Lyα absorption lines were successfully detected in the spectra
منابع مشابه
Probing the Nature of Dark Matter through QSO Distribution in the Fields of Galactic Halos
The amplification caused by gravitational light bending by compact objects in a foreground galaxy can affect the apparent number density of background QSOs, as well as their distribution in the fields of galactic halos. In this work we investigate the distribution of QSOs in the fields of galactic halos caused by point mass lensing effect and singular isothermal lensing effect, and apply the mi...
متن کاملProbing the Large Scale Structure with QSOs and radio-galaxies
QSOs and radio-galaxies, together with the CMB, “normal” galaxies and clusters, represent the main source of information about the origin and evolution of the Large Scale Structure. They can be used either directly, as tracers of the density peaks, or as cosmic lighthouses, probing the Universe along the line of sight with their conspicuous flow of photons. Observations of the QSO and radio-gal...
متن کاملGalaxy-galaxy Lensing as a Probe of Galaxy Dark Matter Halos
Gravitational lensing has now become a popular tool to measure the mass distribution of structures in the Universe on various scales. Here we focus on the study of galaxy’s scale dark matter halos with galaxy-galaxy lensing techniques: observing the shapes of distant background galaxies which have been lensed by foreground galaxies allows us to map the mass distribution of the foreground galaxi...
متن کاملProbing Baryons in Galactic Halos and Gas Near Galaxies
We describe an extensive FUSE survey of highly ionized oxygen in the vicinity of the Milky Way that serves as an example of the type of study that would be desirable for other galactic systems. Understanding the origin of hot gas in the vicinity of galaxies and its relationship to the intergalactic medium presents a major observational challenge. Ultraviolet absorption-line spectroscopy is curr...
متن کاملWhat Is a Halo? Observations of Faint Starlight around Disk Galaxies
Early observations of the stellar halos of nearby disk galaxies are discussed. Since most of the currently available data come from deep CCD surface photometry, and it can be diicult to discriminate between spatially overlapping populations with this technique, all non-thin-disk populations (bulges, halos, thick disks, and any component with low surface brightness) are considered. The sample of...
متن کامل