Related papers: A low-absorption disk zone at low Galactic latitud…
We report on our search for distant clusters of galaxies based on optical and X-ray follow up observations of X-ray candidates from the SHARC survey. Based on the assumption that the absence of bright optical or radio counterparts to…
A field of 1.013 ster in the ROSAT all-sky survey (RASS), centered on the south galactic pole (SGP), has been searched in a systematic, objective manner for clusters of galaxies. The procedure relied on a correlation of the X-ray positions…
The Galactic Center is the closest galactic nucleus that can be studied with unprecedented angular resolution and sensitivity. We summarize recent basic observational results on Sagittarius A* and the conditions for star formation in the…
We present a high-resolution ($\sim0.''12$, $\sim16$ au, mean sensitivity of $50~\mu$Jy~beam$^{-1}$ at 225 GHz) snapshot survey of 32 protoplanetary disks around young stars with spectral type earlier than M3 in the Taurus star-forming…
The discovery of new clear windows in the Galactic plane using the VVV near-IR extinction maps allows the study of the structure of the Milky Way (MW) disk. The ultimate goal of this work is to map the spiral arms in the far side of the MW,…
It is still unclear whether the Sagittarius spiral arm is a major spiral arm in the Galaxy or whether it just outlines a region of enhanced star formation because of the local compression of gas. The best way to separate these scenarios out…
The Galactic Center (GC) is surrounded by plasma lobes that extend up to ~14 kpc above and below the plane. Until now, UV absorption studies of these lobes have only focused on high-velocity components (|v_LSR| > 100 km/s) because low- and…
Methods. We utilized the combined five SRG/eROSITA All-Sky Survey data (eRASS:5) to perform X-ray imaging and spectral analyses of the Centaurus cluster in various directions to large radii. Surface brightness (SB) profiles out to…
Aims. The main goal of this study is to detect the stellar overdensity associated with the Perseus arm in the anticenter direction. Methods. We used the physical parameters derived from Str\"omgren photometric data to compute the surface…
We have discovered an optically rich galaxy cluster at z=1.7089 with star formation occurring in close proximity to the central galaxy. The system, SpARCS104922.6+564032.5, was detected within the Spitzer Adaptation of the red-sequence…
In this second installment of the series, we look at the internal kinematics of the multiple stellar populations of the globular cluster $\omega$ Centauri in one of the parallel Hubble Space Telescope (HST) fields, located at about 3.5…
We present the results of a CCD imaging survey for gravitational lensing in a sample of 38 X-ray-selected clusters of galaxies. Our sample consists of the most X-ray luminous (Lx>= 2x10^{44} erg s^{-1}) clusters selected from the Einstein…
Since 1996 we have known that the Galactic Center (GC) displays a core-like distribution of red giant branch (RGB) stars starting at ~ 10", which poses a theoretical problem, because the GC should have formed a segregated cusp of old stars.…
We present 850-um observations with the SCUBA submillimetre (sub-mm) camera of the central galaxies in seven concentrated clusters of galaxies at redshifts between 0.19 and 0.41. We detect sub-mm emission from the central galaxies in the…
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have reported an increasing number of metal-deficient stars whose…
We study a sample of ~10^4 galaxy clusters in the redshift range 0.2<z<0.8 with masses M_200 > 5x10^13 h_70^-1 M_sun, discovered in the second Red-sequence Cluster Survey (RCS2). The depth and excellent image quality of the RCS2 enable us…
We present a study of the three-dimensional structure of the molecular clouds in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO…
We analyse color-magnitude diagrams of eight Globular Clusters (GCs) in the outer Galactic Halo. Images were taken with the Wide Field Channel of the Advanced Camera for Survey and the Ultraviolet and Visual Channel of the Wide Field Camera…
The fraction of binary stars is an important ingredient to interpret globular cluster dynamical evolution and their stellar population. We investigate the properties of main-sequence binaries measured in a uniform photometric sample of 59…
The Galactic centre Nuclear Star Cluster is one of the densest stellar clusters in the Galaxy. The stars in its inner portions orbit the supermassive black hole associated with compact radio source Sgr~A* at the orbital speeds of several…