相关论文: M31 and Local Group QSO's

Normal galaxies begin to arise from the shadows at high energies, as can be seen with the discovery of high-energy gamma-ray emission from the Andromeda galaxy (M 31) by the Fermi /LAT collaboration. We present a study on the search for…

We report on the discovery of a z=1.58 mature cluster around the high-redshift radio galaxy 7C1753+6311, first identified in the Clusters Around Radio-Loud AGN survey. Two-thirds of the excess galaxies within the central 1Mpc lie on a red…

We present ALMA band 3 observations of the CO(6-5), CO(7-6), and [CI] 369micron emission lines in three of the highest redshift quasar host galaxies at 6.6<z<6.9. These measurements constitute the highest-redshift CO detections to date. The…

There is a growing consensus that the emergence of quasars at high redshifts is related to the onset of galaxy formation, suggesting that the detection of concentrations of gas accompanying such quasars should provide clues about the early…

We present observations of a remarkable compact group of galaxies at $z = 2.48$. Four galaxies, all within 40 kpc of each other, surround a powerful high redshift radio source. This group comprises two compact red passive galaxies and a…

Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds. While many M31 GCs have been detected and studied from ground-based images, the high spatial resolution of HST allows much more robust detection and…

We present new data on several z=1.54 radio-loud quasar fields from a sample of 31 at z=1-2 in which we have previously identified an excess population of predominantly red galaxies. Narrow-band H-alpha observations detect five candidate…

The Local Group offers an excellent laboratory for near-field cosmology by permitting us to use the resolved stellar content of its constituent galaxies as probes of galaxy formation and evolution, which in turn is an important means for…

We discuss broad- and narrow-band imaging of 7 arcmin fields of 14 QSOs with redshift ~1.1. The narrow-band filters were chosen to detect redshifted [O II] 3727A, and the broad bands are R and I, which correspond to rest wavelengths…

2 micron broad- and narrow-band imaging with the Gemini-N telescope of five z~4.7 QSOs, has resolved both the host galaxies and [O II] emission-line gas. The resolved fluxes of the host galaxies fall within the extrapolated spread of the…

New HI observations of Messier 31 (M31) obtained with the Effelsberg and Green Bank 100-m telescopes make it possible to measure the rotation curve of that galaxy out to ~35 kpc. Between 20 and 35 kpc, the rotation curve is nearly flat at a…

037-B327 is of interest because it is both the most luminous and the most highly reddened cluster known in M31. Deep observations with the Advanced Camera for Surveys on the Hubble Space Telescope provide photometric data in the F606W band,…

We gathered two complete samples of $M_{AB}(r)<-18$ ($M_{star} > 10^{9} M_{\odot}$) galaxies, which are representative of the present-day galaxies and their counterparts at 5 Gyr ago. We analysed their 2D luminosity profiles and carefully…

The Local Group compact elliptical galaxy M32 hosts one of the nearest candidate super-massive black holes (SMBHs), which has a previously suggested X-ray counterpart. Based on sensitive observations taken with the {\it Karl G. Jansky} Very…

The properties of a stellar grouping that is ~ 3.5 kpc to the north east of the center of M31 is examined. This structure has (1) a surface brightness that is lower than the surrounding disk, (2) a more-or-less round appearance, (3) a size…

We report here the spectroscopic identification of galaxies in the neighborhood of the radio-galaxy MRC0316-257, at a redshift $z\sim3.14$. Candidate cluster galaxies were selected from deep V and I images combined with narrow band imaging…

The deep homogeneous survey of the large Local-Group spiral galaxy M 31 is a milestone project for X-ray astronomy, as it allows a detailed X-ray inventory of an archetypal low-star-formation-rate galaxy like our own. We present first…

Our current knowledge of M31's dwarf spheroidal companions is reviewed. Two topics of recent interest constitute the bulk of this review. First, color-magnitude diagrams reaching below the horizontal branch have been constructed for two M31…

In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180 micron. Each pair was selected such that both the…

Using the MegaCam imager on the Canada-France-Hawaii Telescope, we have resolved individual stars in the outskirts of the nearby large spiral galaxy M81 (NGC 3031) well below the tip of the red giant branch of metal-poor stellar populations…