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Space debris are composed of both natural and human made objects, some in near Earth orbits while others are passing through deep space. Asteroids may represent one form of near Earth and deep space debris. In this article we report on a set of asteroid observations from the southern hemisphere. We indicate that Apollo and Aten class asteroids represent another form of deep space debris of a potentially hazardous nature to orbiting spacecraft and/or Earth based locations. We also show some of the operational challenges, types of facilities and the importance of geographic diversity, that is, necessary for detecting, observing and characterising asteroids, especially PHA’s. For many years, space agencies and institutions have observed and monitored near Earth asteroids and objects (NEO’s) using high gain radio frequency antennas and optical telescopes in the northern hemisphere (GSSR, Arecibo, Catalina, Pan-STARRS, Atlas and Linear) 1) However a regular operational system to monitor the southern skies does not have the same level of maturity and is where a percentage of asteroids and various human made objects are not detected until they pass into northern skies. To fill that gap the Southern Hemisphere Asteroid Radar Program (SHARP) 2) located in Australia uses available antenna time on either a 70 or 34 m beam waveguide antenna located at the Canberra Deep Space Communication Complex (CDSCC) to transmit a Doppler compensated continuous radio wave at 2.114 GHz (14.2 cm) and 7.15945 GHz (4.2 cm) toward the NEO and receive its echoes at the 64 m Parkes or 6 m × 22 m Australia Telescope Compact Array (ATCA) antennas at Narrabri in Australia. This mode of NEO observation is termed a deep space bistatic radar. The southern hemisphere program has also recently been joined by the 12 m University of Tasmania antennas at Hobart (Tasmania) and Katherine (Northern Territory). Combining SHARPS bistatic radar with small optical apertures located at the University of New South Wales (UNSW) and University of Western Australia (UWA) allows combined optical/RF NEO detections. Whilst sub-metre class optical instruments have contributed independently to asteroid detection over decades, the use of coordinated small 0.3–0.5 m instruments synchronized to large asteroid radars offers an observational flexibility and adaptability when larger optical systems 3) are dedicated to other forms of professional optical astronomy. Since 2015, SHARP has illuminated and tracked over 30 NEO’s ranging in diameter from 7 to 5000 m at ranges of 0.1–18 lunar distances (LD) from Australia.

The oscillation continuum in laser-induced fluorescence spectra of bound-free c

The oscillation continuum in laser-induced fluorescence spectra of bound-free $c^3\Sigma^+ \to a^3\Sigma^+$ and (4)$^1\Sigma^+ \to X^1\Sigma^+$ transitions of the KCs molecule were recorded by Fourier-transform spectrometer and modelled under the adiabatic approximation. The required interatomic potentials for ground $a^3\Sigma^+$ and $X^1\Sigma^+$ states were reconstructed in an analytical Chebishev-polynomial-expansion form in the framework of the regularization direct-potential-fit procedure based on the simultaneous consideration of experimental line positions from [R. Ferber et al, Phys. Rev. A, \textbf{80}, 062501 (2009)] and the present \emph{ab initio} calculation of short-range repulsive potential data. It was proved that the repulsive part over dissociation limit of the derived $a^3\Sigma^+$ potential reproduces the experiment better than the potentials reported in literature. It is also shown that all empirical and semi-empirical potentials available for the $X^1\Sigma^+$ state reproduce the bound-free (4)$^1\Sigma^+ \to X^1\Sigma^+$ spectrum with equal quality in the range of observations., Comment: 9 pages, 7 figures

In the coming decades there is going to be a significant increase in the number of spacecrafts, orbiters, landers and rovers that will be launched into deep space on various exploration missions. The ground segment supporting such missions primarily consists of a high gain parabolic reflector antenna, which are legacy systems and represents a single point of failure. Moreover, with the return of humans to moon and the establishment of the lunar gateway, there will be significant increase in data and command traffic between ground control and space segment. Additionally with the entry of commercial parties, there will be a large number of constellations of satellites launched into low earth orbit (LEO), geostationary earth orbit (GEO) and Low lunar orbit (LLO). All of these will place significant stress on existing communications architecture. This paper examines the use of new and emerging technologies to develop innovative planar array tiles for active electronically scanned array (AESA) based deep space communications architecture that is highly modular, scalable and enabling multibeam operations across multiple spacecrafts in space.

The limited bandwidth and security provided by radio frequency communications between the ground and space can be overcome with optical communications. The smaller beam divergence and high carrier frequency increase the bandwidth and brings with it the potential of achieving a global communications network with absolute security using quantum states to transmit encryption keys, also known as Quantum Key Distribution (QKD). A drawback of ground-to-satellite optical communications, however, is that clouds provide effectively complete blockage of the beam. This can be mitigated by means of receiver site diversity, in which a network of geographically dispersed receivers provides far higher link availability. We present a proposal for a network of optical ground stations in Australia and New Zealand for optical communications to provide secure satellite links for the growing space-based market. Optical ground station nodes in the Australian Capital Territory and South Australia have been funded and are currently being planned. Partial funding for other nodes in Western Australia and New Zealand has also been achieved. Funding for infrastructure is being sought to tie these stations together to produce a world leading optical communication network. This presents an opportunity for our nations to become a space-to-ground data highway and become a leading provider of secure satellite links for a large and growing market. In order to take advantage of hardware currently in orbit and planned (including quantum communication) each network node will be capable of communications with optical and current radio-frequency methods. This has the added benefit of future proofing optical communications hardware and building industry with the accessibility of an optical ground station network.

The Ti:Saphire laser operated within 13800 - 11800 cm − 1 range was used to excite the c 3 Σ + state of KCs molecule directly from the ground X 1 Σ + state. The laser-induced fluorescence (LIF) spectra of the c 3 Σ + → a 3 Σ + transition were recorded with Fourier-transform spectrometer within 8000 to 10000 cm − 1 range. Overall 673 rovibronic term values belonging to both e / f -components of the c 3 Σ + ( Ω = 1 ± ) state of 39 KCs, covering vibrational levels from v = 0 to about 45, and rotational levels J ∈ [ 11 , 149 ] were determined with the accuracy of about 0.01 cm − 1 ; among them 7 values for 41 KCs. The experimental term values with v ∈ [ 0 , 22 ] were involved in a direct point-wise potential reconstruction for the c 3 Σ + ( Ω = 1 ± ) state, which takes into account the Ω -doubling effect caused by the spin-rotational interaction with the nearby c 3 Σ + ( Ω = 0 − ) state. The analysis and interpretation were facilitated by the fully-relativistic coupled cluster calculation of the potential energy curves for the B 1 Π , c 3 Σ + , and b 3 Π states, as well as of spin-forbidden c − X and spin-allowed c − a transition dipole moments; radiative lifetimes and vibronic branching ratios were calculated. A comparison of relative intensity distributions measured in vibrational c → a LIF progressions with their theoretical counterparts unambiguously confirms the vibrational assignment suggested in [J. Szczepkowski, et al., JQSRT, 204, 133–137 (2018)].

We describe the first demonstration of a southern hemisphere planetary radar system to detect two near-Earth asteroids (NEAs). The demonstration was conducted in a bistatic manner, with the 70 m antenna of the Canberra Deep Space Communications Complex transmitting at 2.1 GHz and reception at the Parkes Radio Telescope, outfitted with multiple receivers, and the Australia Telescope Compact Array. This initial system was used to detect the NEAs (43577) 2005 UL5 and (33342) 1998 WT24 during their close approaches in 2015 November and 2015 December, respectively. We describe the performance of the system and consider future possibilities using other antennas of the Canberra Deep Space Communications Complex as transmitters.

This paper describes a radio astronomy programfor schools, the Goldstone-AppleValley Radio Telescope,GAVRT. The GAVRT program is designed to bring the inspiration and enthusiasm to a younger generation of teachers and children who learn about science by doing real science, just as Iosif Shklovsky brought to an older generation.

We report results of Canberra-ATCA Doppler-only continuous wave (CW) radar observations of near-Earth asteroid (163899) 2003 SD220 at a receiving frequency of 7159 MHz (4.19 cm) on 2018 December 20, 21, and 22 during its close approach within 0.019 au (7.4 lunar distances). Echo power spectra provide evidence that the shape is significantly elongated, asymmetric, and has at least one relatively large concavity. An average spectrum per track yields an OC (opposite sense of circular polarisation) radar cross section of 0.39, 0.27, and 0.25 km$^{2}$, respectively, with an uncertainty of 35 \%. Variations by roughly a factor of two in the limb-to-limb bandwidth over the three days indicate rotation of an elongated object. We obtain a circular polarization ratio of 0.21 $\pm$ 0.07 that is consistent with, but somewhat lower than, the average among other S-class near-Earth asteroids observed by radar., Comment: 15 pages, 4 figures, accepted for publication in Icarus

The 4503 rovibronic term values belonging to the mutually perturbed $A^1\Sigma^+_u$ and $b^3\Pi_u$ states of Cs$_2$ were extracted from laser induced fluorescence (LIF) $A\sim b\rightarrow X^1\Sigma^+_g$ Fourier transform spectra with the 0.01 cm$^{-1}$ uncertainty. The experimental term values of the $A^1\Sigma^+_u\sim b^3\Pi_u$ complex covering the rotational levels $J\in [4,395]$ in the excitation energy range $[9655,13630]$ cm$^{-1}$ were involved into coupled-channel (CC) deperturbation analysis. The deperturbation model takes explicitly into account spin-orbit coupling of the $A^1\Sigma^+_u(A0^+_u)$ and $b^3\Pi^+_{0_u}(b0^+_u)$ states as well as spin-rotational interaction between the $\Omega=0$, $1$ and $2$ components of the $b^3\Pi^+_{\Omega_u}$ state. The \emph{ab initio} relativistic calculations on the low-lying electronic states of Cs$_2$ were accomplished in the framework of Fock space relativistic coupled cluster (FSRCC) approach to provide the interatomic potentials of the interacting $A0^+_u$ and $b0^+_u$ states as well as the relevant $A\sim b$ spin-orbit coupling function. To validate the present CC deperturbation analysis solely obtained by energy-based data, the $A\sim b \to X(v^{\prime\prime}_X)$ LIF intensity distributions were measured and compared with their theoretical counterparts obtained by means of the non-adiabatic vibrational wave functions of the $A\sim b$ complex and the FSRCC $A\sim b \to X$ transition dipole moments calculated by the finite-field method.

We observed the A 1 Σ + ∼ b 3 Π → a 3 Σ + / X 1 Σ + laser-induced fluorescence (LIF) of the RbCs molecule excited from the ground X 1 Σ + state by the Ti:Sapphire laser. The LIF spectra from the common perturbed levels of the singlet-triplet A ∼ b complex was recorded by the Fourier-transform (FT) spectrometer with the instrumental resolution of 0.03 cm − 1 . The relative intensity distribution in the rotationally resolved A ∼ b → a 3 Σ + ( v a ) / X 1 Σ + ( v X ) progressions was measured, and their branching ratio was found to be about of 1 ÷ 5 × 10 − 4 in the bound region of the a 3 Σ + and X 1 Σ + states. The experiment was complemented with the scalar- and full-relativistic calculations of the A / b − X / a transition dipole moments (TDMs) as functions of internuclear distance. The relative systematic error in the resulting ab initio TDM functions evaluated for the strong A − X transition was estimated as few percent in the energy region, where the experimental LIF intensities are relevant. The relative spectral sensitivity of the FT registration system, operated with the InGaAs diode detector and CaF beam-splitter, was calibrated in the range [6 500, 12 000] cm − 1 by a comparison of experimental intensities in the long A ∼ b → X(vX) LIF progressions of the K2 and KCs molecules with their theoretical counterparts evaluated using the ab initio A − X TDMs. Both experimental and theoretical transition probabilities can be employed to improve the stimulated Raman adiabatic passage process, a → A ∼ b → X, which is exploited for a laser assembling of ultracold RbCs molecules.

© 2019 Marsh-Wakefield, Kruzins, McGuire, Yang, Bryant, Fazekas de St. Groth, Nassif, Byrne, Gibson, Brown, Larsen, McCulloch, Boyle, Clark, Joshua, Ho and Vuckovic. Multiple Myeloma (MM) is preceded by the clinically stable condition monoclonal gammopathy of undetermined significance (MGUS). Critical immune events that discriminate MGUS from newly diagnosed MM (ND)MM patients remain unknown, but may involve changes in the regulatory T cell (Treg) compartment that favor myeloma growth. To address this possibility, we used mass cytometry and the unsupervised clustering algorithm Flow self-organizing map (FlowSOM) to interrogate the distribution of multiple subsets within CD25+ CD127low/neg Treg in matched bone marrow (BM) and peripheral blood (PB) of MGUS and NDMM patients. Both mass cytometry and flow cytometry confirmed a trend toward prevalence of CD39− Treg within the Treg compartment in BM and PB of NDMM patients compared to CD39− Treg in MGUS patients. FlowSOM clustering displayed a phenotypic organization of Treg into 25 metaclusters that confirmed Treg heterogeneity. It identified two subsets which emerged within CD39− Treg of NDMM patients that were negligible or absent in CD39− Treg of MGUS patients. One subset was found in both BM and PB which phenotypically resembled activated Treg based on CD45RO, CD49d, and CD62L expression; another subset resembled BM-resident Treg based on its tissue-resident CD69+ CD62L− CD49d− phenotype and restricted location within the BM. Both subsets co-expressed PD-1 and TIGIT, but PD-1 was expressed at higher levels on BM-resident Treg than on activated Treg. Within BM, both subsets had limited Perforin and Granzyme B production, whilst activated Treg in PB acquired high Perforin and Granzyme B production. In conclusion, the use of mass cytometry and FlowSOM clustering discovered two discrete subsets of CD39− Treg which are discordant in MGUS and NDMM patients and may be permissive of myeloma growth which warrants further study. Understanding the regulatory properties of these subsets may also advance MGUS and MM diagnosis, prognosis, and therapeutic implications for MM patients.

We performed a high-resolution Fourier-transform spectroscopic study of the (4)1Π state of the RbCs molecule by applying two-step (4)1Π ← A1Σ+ ∼ b3Π ← X1Σ+ optical excitation followed by observation of the (4)1Π → X1Σ+ laser induced fluorescence (LIF) spectra. In many LIF progressions the collision-induced satellite rotational lines were observed thus increasing the amount of term values and allowing to estimate the Λ-doubling effect in the (4)1Π state. The Direct-Potential-Fit (DPF) of experimental term values of 777 rovibronic levels of both 85RbCs and 87RbCs isotopologues has been performed by means of the robust weighted non-linear least squares method. The PFanalysis based on adiabatic approximation and analytical Expanded Morse Oscillator potential revealed numerous regular shifts in the measured level positions. The spectroscopic studies of the (4)1Π state were supported by the electronic structure calculations including the potential energy curves of the singlet and triplet states manifold and spin-allowed transition dipole moments. The subsequent estimates of radiative lifetimes and corresponding vibronic branching ratios elucidated a dominant contribution of the (4)1Π → A ∼ b channel into the total radiative decay of the (4)1Π state. The relative intensity distributions simulated for (4)1Π → X1Σ+ LIF progressions agree well with their observed counterparts even for the profoundly shifted levels of the entirely perturbed (4)1Π state. To get an insight into the origin of the intramolecular perturbations the relevant spin-orbit and L-uncoupling electronic matrix elements were evaluated, Latvian Science Council Project No. lzp-2018/1-0020 (LZP2018/5): ”Determination of structural and dynamic properties of alkali diatomic molecules for quantum technology applications”; the University of Latvia Base Funding No A5-AZ27; Post-doctoral Grant No 1.1.1.2/16/I/001, proposal No 1.1.1.2/I/16/068; Russian Foundation for Basic Research (RFBR) Grant No. 1603-00529a