Non-comoving cold dark matter in a $$\varLambda $$CDM background

We examine the evolution of peculiar velocities of cold dark matter (CDM) in localized arrays of inhomogeneous cosmic structures in a $$\varLambda $$ Λ CDM background that can be identified as a frame comoving with the Cosmic Microwave (CMB). These arrays are constructed by smoothly matching to this cosmological background regions of Szekeres-II models whose source is an imperfect fluid reinterpreted as non-comoving dust, keeping only first order terms in v/c. Considering a single Szekeres-II region matched along two comoving interfaces to a $$\varLambda $$ Λ CDM background, the magnitudes of peculiar velocities within this region are compatible with values reported in the literature, while the present day Hubble expansion scalar differs from that of the $$\varLambda $$ Λ CDM background value by a 10% factor, a result that might provide useful information to the ongoing debate on the $$H_0$$ H 0 tension. While the models cannot describe the virialization process, we show through a representative example that structures of galactic cluster mass reach the onset of this process at redshifts around $$z\sim 3$$ z ∼ 3 .

Seeding the Solar System with Life: Mars, Venus, Earth, Moon, Protoplanets

In the space of the entire universe, the only conclusive evidence of life, is found on Earth. Although the ultimate source of all life is unknown, many investigators believe Earth, Mars, and Venus may have been seeded with life when these planets, and the sun, were forming in a galactic cluster of thousands of stars and protoplanets. Yet others hypothesize that while and after becoming established members of this solar system, these worlds became contaminated with life during the heavy bombardment phase when struck by millions of life-bearing meteors, asteroids, comets and oceans of ice. Because bolide impacts may eject tons of life-bearing debris into space, and as powerful solar winds may blow upper atmospheric organisms into space, these three planets may have repeatedly exchanged living organisms for billions of years. In support of these hypotheses is evidence suggestive of stromatolites, algae, and lichens on Mars, fungi on Mars and Venus, and formations resembling fossilized acritarchs and metazoans on Mars, and fossilized impressions resembling microbial organisms on the lunar surface, and dormant microbes recovered from the interior of a lunar camera. The evidence reviewed in this report supports the interplanetary transfer hypothesis and that Earth may be seeding this solar system with life.

The effects of dwarf galaxies on the orbital evolution of galactic globular clusters

ABSTRACT We investigate the effect that dwarf galaxies have on the orbits, tidal histories, and assumed formation environment of Milky Way globular clusters. We determine the orbits of the Milky Way’s 150 globular clusters in a gravitational potential both with and without dwarf galaxies. We find that the presence of a small number of satellite galaxies can affect the orbits of many of the globular clusters. Over 12 Gyr, we find that the semimajor axis and orbital eccentricity of individual clusters fluctuate with dispersions of the order of $\sim 10{{\ \rm per\ cent}}$ and $\sim 4{{\ \rm per\ cent}}$, respectively. Outer clusters are more strongly affected by dwarf galaxies than inner clusters, with their semimajor axis and orbital eccentricities fluctuating by more than $\sim 15{{\ \rm per\ cent}}$ and $\sim 5{{\ \rm per\ cent}}$, respectively. Using detailed N-body simulations of select clusters, we find that altering their orbital histories can lead to different mass-loss rates and structural evolution. Furthermore, we caution against using kinematics alone to identify whether a Galactic cluster formed in situ or was accreted during a past merger event as these values are no longer conserved. The presence of dwarf galaxies causes the orbital energies and actions of individual clusters to evolve over time, spanning a wider range than that coming from random uncertainties in a cluster’s proper motions and radial velocity.

Wide Field Photometric Study of Galactic Cluster NGC 6067

We conduct wide field BV photometry of open cluster NGC 6067 using the archive data taken from [email protected] catalogue. The astrophysical parameters of the cluster such as age, cluster center and heliocentric distance using colour magnitude diagrams are calculated. We also calculated the value of interstellar extinction in the direction of this cluster.

Wide Field Photometric Study of Galactic Cluster NGC 6067

We conduct wide field BV photometry of open cluster NGC 6067 using the archive data taken from [email protected] catalogue. The astrophysical parameters of the cluster such as age, cluster center and heliocentric distance using colour magnitude diagrams are calculated. We also calculated the value of interstellar extinction in the direction of this cluster.

Lassaw, Ibram (1913–2003)

A sculptor of the New York School, Ibram Lassaw was born to Russian parents in Alexandria, Egypt. The family immigrated to Brooklyn, NY, in 1921, where Lassaw learned modeling, casting, and carving. He discovered avant-garde art at the Brooklyn Museum in 1926, and continued to study sculpture at the Clay Club from 1927 to 1932. An active participant in New York modernist circles, Lassaw was a founding member of the American Abstract Artists Group (1935), and The Club (1949). Lassaw’s interest in cosmic and religious themes culminated in abstract sculptures for Jewish synagogues, such as Pillar of Fire (1953) at Temple Beth El, Springfield, MA. Known for his web-like structures, Lassaw dripped, fused, and spattered metal, embracing the resulting accidental contours that accrued on his gridded designs, as in Galactic Cluster #1 (1958, Newark Museum). He wielded the oxyacetylene torch like a paintbrush and the intricately structured wires twist, turn, and redouble like skeins of paint by Jackson Pollock. His work was included in the 1959 Kassel Documenta, which showcased American Abstract Expressionism.