Unveiling the inner morphology and gas kinematics of NGC 5135 with ALMA

The local Seyfert 2 galaxy NGC5135, thanks to its almost face-on appearance, a bulge overdensity of stars, the presence of a large-scale bar, an AGN and a Supernova Remnant, is an excellent target to investigate the dynamics of inflows, outflows, star formation and AGN feedback. Here we present a reconstruction of the gas morphology and kinematics in the inner regions of this galaxy, based on the analysis of Atacama Large Millimeter Array (ALMA) archival data. To our purpose, we combine the available $\sim$100 pc resolution ALMA 1.3 and 0.45 mm observations of dust continuum emission, the spectroscopic maps of two transitions of the CO molecule (tracer of molecular mass in star forming and nuclear regions), and of the CS molecule (tracer of the dense star forming regions) with the outcome of the SED decomposition. By applying the $^{\rm 3D}$BAROLO software (3D-Based Analysis of Rotating Object via Line Observations), we have been able to fit the galaxy rotation curves reconstructing a 3D tilted-ring model of the disk. Most of the observed emitting features are described by our kinematic model. We also attempt an interpretation for the emission in few regions that the axisymmetric model fails to reproduce. The most relevant of these is a region at the northern edge of the inner bar, where multiple velocity components overlap, as a possible consequence of the expansion of a super-bubble.Comment: 15 pages, 13 figures, resubmitted to MNRAS after moderate revision

The effects of tube deformities on the dynamic calibration of a tubing system

Using the Berge and Tijdemen method for tube calibration is powerful as it allows for tubes of various dimensions to be used in a dynamic pressure data acquisition system by using post-processing methods to calibrate for the tubes natural dynamic response. Knowing the tubes response and using the inverse Fourier transform to calibrate the tube system is accepted however knowing how tube deformities influence this calibration is not known. Small singular deformities caused by pinch, twist and bending, which corresponded to a pinch and internal area ratios less than approximately 5 and 3.57 respectively, do not affect the tubing response of a system. Significant effects on the tubes response only occur at pinch and area ratios above these values. Furthermore, pinching ratios above 5 are extreme and represent a tube that is pinched locally to the point where it is almost blocked. This is testament to the tubes resilience to local and internal diameter changes. It can be safely assumed that unwanted and unexpected dampening of a tubing system could be due to a local tube deformity

Reverse engineering of a fixed wing unmanned aircraft 6-DoF model based on laser scanner measurements

This paper describes a method for deriving sixdegree- of-freedom (6-DoF) aircraft dynamics parameters adopting reverse engineering techniques from three dimensional (3D) laser scanner measurements. In particular, the mass and aerodynamic properties of the JAVELIN Unmanned Aircraft (UA) are determined using accurate measurements from the 3D scanner and successive CAD processing of the geometric data. In order to qualitatively assess the calculated 6-DoF, the trajectory for the spiral mode excited by the engine torque of this UA is simulated and compared to that of a published 6-DoF of the popular AEROSONDE UA which has very similar geometry. Additionally, to further confirm the validity of the approach, the reverse engineering procedure is applied to a published CAD model of the AEROSONDE UA and the associated 6-DoF parameters are calculated. Using these parameters, a spiral descent trajectory is generated using both the published and calculated parameters. The trajectories match closely, providing a good qualitative verification of the reverse engineering method. In future research, the accurate knowledge of the 6-DoF dynamics will enable the development of an Aircraft Dynamics Model (ADM) virtual sensor to augment the UA navigation system in case of primary navigation sensor outages. Additionally, further refinement of the calculated 6-DoF will involve wind tunnel and flight testing activities

Sensing unsteady pressure on MAV Wings: a new method for turbulence alleviation

Experiments at low Reynolds numbers were performed on a pressure tapped NACA2313 wing in a 3 x 2 x 9 meter wind tunnel under nominally smooth (Ti = 1.2%) and turbulent (Ti = 7.2%) flows at a mean flow velocity of 8ms-1 (Re ≈ 120,000). The NACA2313 wing is a replica of a Micro Air Vehicle (MAV) wing of the Flash 3D aircraft used at RMIT University for research purposes. Unsteady surface pressures were measured to understand if the information could be adopted for resolving turbulence-induced perturbations and to furthermore use it in a turbulence mitigation system. Two span-wise locations of chord-wise pressure were acquired when tested under the two different flow conditions. It was discovered that at both span-wise locations, a local Coefficient of Pressure (Cp) held high correlation to the chord-wise Cp integration and allowed for a linear relationship to be formed between the two variables. The defined relationship provided a 95% confidence for angles of attack below stall and was used to estimate the integrated cord-wise pressure coefficient at a particular span wise location. The relationship between a single pressure tap and the integrated Cp of that chord-wise section was valid for the two different span-wise locations with similar defining equations. As one pressure tap is sufficient to adequately estimate the integrated Cp on a chord-wise wing section, a limited amount of pressure taps across the wings span approximates the pressure distribution across the span and eventually approximates the flight perturbations. Being a novel method of sensing aircraft disturbance, applications are not restricted to MAV. The methodology presented could very well be applied to larger aircraft to reduce the effects of turbulence within the terminal area and can provide other means of active stabilization

Airborne laser sensors and integrated systems

The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the development of such requirements, useful guidelines are provided for test and evaluation of airborne laser systems including laboratory, ground and flight test activities

Advanced flight management system for an unmanned reusable space vehicle

The innovative architecture of an advanced Flight Management System (FMS) for Unmanned Reusable Space Vehicle (URSV) applications is presented with the associated re-entry trajectory computation algorithm. The SL-12 unmanned space vehicle, developed by Cranfield University as a part of the 2012-2013 Aerospace Vehicle Design (AVD) Group Design Project (GDP) is used as the reference platform. The overall avionics architecture of the future space transportation vehicle is described. A detailed architecture is developed for the FMS and the core functions of such an FMS are described. A dedicated computation algorithm is presented for re-entry trajectory planning, which involves determination of the path of re-entry vehicle by means of angle of attack and bank angle modulation. Simulation case studies are performed in a realistic re-entry operational scenario resulting in the generation of efficient and feasible trajectories, without violating any of the defined constraints

Extension of the rigid‐constraint method for the heuristic suboptimal parameter tuning to ten sensor fusion algorithms using inertial and magnetic sensing

The orientation of a magneto‐inertial measurement unit can be estimated using a sensor fusion algorithm (SFA). However, orientation accuracy is greatly affected by the choice of the SFA parameter values which represents one of the most critical steps. A commonly adopted approach is to fine‐tune parameter values to minimize the difference between estimated and true orientation. However, this can only be implemented within the laboratory setting by requiring the use of a concurrent gold‐standard technology. To overcome this limitation, a Rigid‐Constraint Method (RCM) was proposed to estimate suboptimal parameter values without relying on any orientation reference. The RCM method effectiveness was successfully tested on a single‐parameter SFA, with an average error increase with respect to the optimal of 1.5 deg. In this work, the applicability of the RCM was evaluated on 10 popular SFAs with multiple parameters under different experimental scenarios. The average residual between the optimal and suboptimal errors amounted to 0.6 deg with a maximum of 3.7 deg. These encouraging results suggest the possibility to properly tune a generic SFA on different scenarios without using any reference. The synchronized dataset also including the optical data and the SFA codes are available online

Simultaneous multi-band detection of Low Surface Brightness galaxies with Markovian modelling

We present an algorithm for the detection of Low Surface Brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. To assess the robustness of our method, the method was applied to a set of 18 B and I band images (covering 1.3 square degrees in total) of the Virgo cluster. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (i) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (ii) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered ~20% more mock LSB galaxies and ~40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is reached for sources with r_e > 3" at a mean surface brightness level of mu_g=27.7 mag/arcsec^2 and a central surface brightness of mu^0 g=26.7 mag/arcsec^2. About 10% of the false positives are artifacts, the rest being background galaxies. We have found our method to be complementary to the application of matched filters and an optimized use of SExtractor, and to have the following advantages: it is scale-free, can be applied simultaneously to several bands, and is well adapted for crowded regions on the sky.Comment: 39 pages, 18 figures, accepted for publication in A

Revealing the organic dye and mordant composition of Paracas textiles by a combined analytical approach

The object of this study is a wide selection of dyed cotton and camelid samples from an important collection of 2000-year-old Paracas textiles, now at the Museo Nacional de Arqueología, Antropología e Historia del Perú (MNAAHP; Lima; Peru) and at the National Museum of World Culture (NMWC; Gothenburg; Sweden). The threads, chosen as representative of the whole palette, were selected from eighteen different textiles. A combined spectroscopic and spectrometric analytical approach was selected to characterize the organic and inorganic composition of this wide set of samples. In particular, technical photography was used to gain a general overview of the samples, X-ray fluorescence (XRF) was employed for identifying the mordants and mapping the elemental distribution in the threads, while liquid chromatography coupled with diode array detector and with high-resolution mass spectrometry (HPLC–DAD, HPLC–HRMS) were used for characterizing organic dye composition. This study provides fundamental information on the mordants or other inorganic auxiliaries used in the dyeing processes, rarely investigated up to now, and to the varieties of vegetal sources employed in Paracas textiles. The widening of the Andean dyestuff database is highly important not only to acquire knowledge on Paracas culture, but also to ease the dye characterization of archaeological textiles from the Peruvian region and South American area in general.[Figure not available: see fulltext.]

Temperature Chaos in Two-Dimensional Ising Spin Glasses with Binary Couplings: a Further Case for Universality

We study temperature chaos in a two-dimensional Ising spin glass with random quenched bimodal couplings, by an exact computation of the partition functions on large systems. We study two temperature correlators from the total free energy and from the domain wall free energy: in the second case we detect a chaotic behavior. We determine and discuss the chaos exponent and the fractal dimension of the domain walls.Comment: 5 pages, 6 postscript figures; added reference