Related papers: Improved distances to several Galactic OB associat…
The main objective of this study is the characterization of the velocity field in the Cygnus OB1 association using the radial velocity data currently available in the literature. This association is part of a larger star-forming complex…
The color-magnitude diagrams of $\sim 1 \times 10^6$ stars obtained for 19 fields towards the Galactic bulge with the OGLE project reveal a well-defined population of bulge red clump stars. We found that the distributions of the…
(Abridged) We present the first results from our spectroscopic survey of the environments of strong gravitational lenses. The lens galaxy belongs to a poor group of galaxies in six of the eight systems in our sample. We discover three new…
We present the first intermediate-resolution (lambda / 3000) spectrum of the bright quasi-stellar object 3C273 at wavelengths between 900 and 1200 A. Observations were performed with the Berkeley spectrograph aboard the ORFEUS-SPAS II…
Massive OB stars are critical to the ecology of galaxies, and yet our knowledge of OB stars in the Milky Way, fainter than $V \sim 12$, remains patchy. Data from the VST Photometric H$\alpha$ Survey (VPHAS+) permit the construction of the…
We present a study of the ionized gas kinematics and feedback properties in a sample of 14 low-mass, UV-luminous Lyman Break Analogs (LBAs) at redshifts z~0.1-0.3. These compact, strongly star-forming galaxies serve as local analogs of…
OB associations are unbound groups of young stars made prominent by their bright OB members, and have long been thought to be the expanded remnants of dense star clusters. They have been important in astrophysics for over a century thanks…
Photometric CCD {\it UBVI}$_C$ photometry obtained for 4860 stars surrounding the embedded southern cluster SAI~113 (Skiff~8) is used to examine the reddening in the field and derive the distance to the cluster and nearby van~Genderen~1.…
In the hierarchical theory of galaxy formation, a galaxy overdensity is a hallmark of a massive cosmic structure. However, it is less well understood how different types of galaxies trace the underlying large-scale structure. Motivated by…
Halpha and UBV photometry of the inner kpc of M33 are used to study the distribution of OB stars and HII regions in the galaxy and to determine whether individual regions of the galaxy are in a state of ionization balance. Based on the…
The spiral structure of the Milky Way is nowadays receiving renewed attention thanks to the combined efforts of observational campaigns in different wavelength regimes, from the optical to the radio. We start in the paper the exploration of…
Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. In many cases, these studies only concentrated on the central region or were not homogeneous. This latter…
OB associations play an important role in Galactic evolution, though their origins and dynamics remain poorly studied, with only a small number of systems analysed in detail. In this paper we revisit the existence and membership of the…
In a programme of observations of local luminous blue compact galaxies (BCGs), we are investigating kinematics by using tracers of both stars and ionized gas. Here we summarise our program and present new data on the local Lyman break…
We discuss the state of the assembly of the Hubble Sequence in the mix of bright galaxies at redshift 1.4< z \le 2.5 with a large sample of 1,671 galaxies down to H_{AB}~26, selected from the HST/ACS and WFC3 images of the GOODS--South…
This paper begins a series in which we examine the structures of distant galaxies to directly determine the history of their formation modes. We start this series by examining the structures of z_F850LP < 27 galaxies in the Hubble…
The problem of (non-)existence of a typical size of the stellar associations is revisited by use of deep UBVRI stellar CCD photometry in M 33 from the Local Group Survey (Massey et al. 2006). We compare the outlines of the `classical OB…
Loop I is a nearby giant radio loop spanning over 100 degrees and centered on the Sco-Cen OB association. It may correspond to a superbubble formed by the joint action of stellar winds and supernova remnants. ROSAT observations revealed…
We present results of the second planetary and low-luminosity object transit campaign conducted by the OGLE-III survey. Three fields (35'x35' each) located in the Carina regions of the Galactic disk (l~290) were monitored continuously in…
Core collapse supernovae of massive (> 8 Mo) stars are formed primarily in OB associations and help blow giant superbubbles, where their collective shocks accelerate most of the Galactic cosmic rays. The spatial distribution of these stars…