Related papers: The Giant Arc -- Filament or Figment?
We present the serendipitous discovery of a `Giant Arc on the Sky' at $z \sim 0.8$. The Giant Arc (GA) spans $\sim 1$ Gpc (proper size, present epoch), and appears to be almost symmetrical on the sky. It was discovered via intervening MgII…
Recent discoveries of apparent large-scale features in the structure of the universe, extending over many hundreds of megaparsecs, have been claimed to contradict the large-scale isotropy and homogeneity foundational to the standard…
The frequency of giant arcs - highly distorted and strongly gravitationally lensed background galaxies - is a powerful test for cosmological models. Previous comparisons of arc statistics for the currently favored concordance cosmological…
The physical origin of the large-scale conformity in the colours and specific star formation rates of isolated low mass central galaxies and their neighbours on scales in excess of 1 Mpc is still under debate. One possible scenario is that…
Large-scale structure (LSS) studies in cosmology map and analyse matter in the Universe on the largest scales. Understanding the LSS can provide observational support for the Cosmological Principle (CP) and the Standard Cosmological Model…
HI-rich absorbers seen within quasar spectra contain the bulk of neutral gas in the Universe. However, the spatial extent of these reservoirs are not extensively studied due to the pencil beam nature of quasar sightlines. Using two giant…
Throughout the Milky Way, molecular clouds typically appear filamentary, and mounting evidence indicates that this morphology plays an important role in star formation. What is not known is to what extent the dense filaments most closely…
We challenge the conventional view that the majority of MgII/Lyman limit absorbers are extended halos of galaxies comprised of ``clouds'' with near-unity covering factor. The gaseous disks of spiral galaxies are known to extend to large…
We use the latest version of the metal line absorption catalogue of Zhu & M\'enard (2013) to study the clustering of MgII absorbers around massive galaxies (~10^11.5 M_sun), quasars and radio-loud AGN with redshifts between 0.4 and 0.75.…
Filamentary structures are common morphological features of the cold, molecular interstellar medium (ISM). Recent studies have discovered massive, hundred-parsec-scale filaments that may be connected to the large-scale, Galactic spiral arm…
We present initial results from an ongoing large-scale study of the circumgalactic medium in the nearby Universe ($cz \leq 10,000$ km/s), using archival Cosmic Origins Spectrograph spectra of background quasi-stellar objects. This initial…
We study with semi-analytical methods the statistics of pronounced arcs caused by lensing of galaxies by foreground galaxy clusters. For the number density and redshift distribution of rich clusters we use Press-Schechter theory, normalized…
Clowes et al. (2013) have recently reported the discovery of a Large Quasar Group (LQG), dubbed the Huge-LQG, at redshift z~1.3 in the DR7 quasar catalogue of the Sloan Digital Sky Survey. On the basis of its characteristic size ~500 Mpc…
Large-scale gaseous filaments with length up to the order of 100 pc are on the upper end of the filamentary hierarchy of the Galactic interstellar medium. Their association with respect to the Galactic structure and their role in Galactic…
The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is…
We measure the photometric properties of 105 giant arcs that were identified in systematic searches for galaxy-cluster-scale strong lenses in the Second Red-Sequence Cluster Survey (RCS-2) and the Sloan Digital Sky Survey (SDSS). The…
We used the Condor Array Telescope to obtain deep imaging observations through luminance broad-band and He II, [O III], He I, H$\alpha$, [N II], and [S II] narrow-band filters of an extended region of the M81 Group spanning $\approx 8…
According to the cosmological principle, Universal large-scale structure is homogeneous and isotropic. The observable Universe, however, shows complex structures even on very large scales. The recent discoveries of structures significantly…
The interstellar medium has a highly filamentary and hierarchical structure, which may play a significant role in star formation. A systematical study on the large-scale filaments towards their physical parameters, distribution, structures…
The origin of the giant stellar arcs in the LMC remains a controversial issue, discussed since 1966. No other stellar arc is so perfect a segment of a circle, moreover, there is another similar arc nearby. Many hypotheses were advanced to…