Commissioning and improvements of the instrumentation and launch of the scientific exploitation of OARPAF, the Regional Astronomical Observatory of the Antola Park

The OARPAF telescope is an 80-cm-diameter optical telescope installed in the Antola Mount Regional Reserve, in Northern Italy. We present the results of the characterization of the site, as well as developments and interventions that have been implemented, with the goal of exploiting the facility for scientific and educational purposes. During the characterization of the site, an average background brightness of 22.40mAB (B filter) to 21.14mAB (I) per arcsecond squared, and a 1.5″ to 3.0″ seeing, have been measured. An estimate of the magnitude zero points for photometry is also reported. The material under commissioning includes three CCD detectors for which we provide the linearity range, gain, and dark current; a 31-orders échelle spectrograph with R ∼ 8500 to 15,000 and a dispersion of n = 1.39 × 10 − 6 px − 1λ + 1.45 × 10 − 4 nm / px, where λ is expressed in nm. The scientific and outreach potential of the facility is proven in different science cases, such as exoplanetary transits and active galactic nuclei variability. The determination of time delays of gravitationally lensed quasars, the microlensing phenomenon, and the tracking and the study of asteroids are also discussed as prospective science cases

Photo-controlled deformable mirror for wavefront shaping

International audienceWavefront shaping is of main interest in the field of Adaptive Optics for Astronomy, wide-field imaging in Microscopy and live cells/tissues imaging in Biology. We propose an innovative technology for a new type of membrane deformable mirror, made by coupling a reflective polymeric membrane with a monolithic non-pixelated photoconductive substrate. The device is called continuous photocontrolled deformable mirror (PCDM), actuated by sending a light flux with given shape and intensity distribution, on the back side of the photoconductor, opposite to the reflective side. Unlike the other actuation mechanisms, this allows to obtain a continuous actuation field, without the typical segmented actuators pattern. Furthermore, it leads to a strong simplification to the driving electronics, for example by eliminating hundreds of cables used for the deformation control. Fundamental is the role played by the photo-excitation dynamics of the photoconductive material, in fact the deformation is obtained through the electrostatic pressure exerted by the photo-generated charge carriers, on the thin reflective membrane. We have developed a device with a single crystalline semiconductor photoconductor wafer, either Silicon or Cadmium Sulfide. The actuation is controlled by a light pattern modulated by a DMD (Digital Micromirror Device) chip, generating a reprogrammable actuator pattern projected on the photoconductor. In order to test the performance of the PCDM, we are addressing two deformation regimes: static behavior and dynamical response. We are then able to measure the response with light actuation, as the influence function matrix with respect to the number of projected virtual actuators; the response with frequency, including response time, resonance frequency, with respect to the different applied patterns, and with respect to the number of virtual actuators; finally, the response in open/close loop

Silicon based photo-controlled deformable mirror

International audienceThe fabrication and characterization of a Silicon based photo-controlled deformable mirror (PCDM) for spatial light modulation and wavefront control is reported. The device is a membrane mirror based on a 1-inch monolithic non-pixelated Silicon photoconductive substrate with a transparent ITO electrode on one side coupled with a 5 μm thick nitrocellulose membrane. The device is driven applying an AC voltage and it is characterized by measuring the generated wavefront using a Shack-Hartmann wavefront sensor. Upon uniform illumination with a NIR LED, the deformation increases with the voltage applied, its frequency and the light intensity. The maximum deformation achieved is approximately 2 μm PtV (wavefront). The repeatability of the induced deformation is also evaluated together with its time stability, proving that the device is reliable in the working conditions. The response time is evaluated and it is in the range of 10 ms. The device is suitable for an efficient adaptable focusing element with an important focus control

Cerberus: A three-headed instrument for the OARPAF telescope

We present the preliminary design of Cerberus, a new scientific instrument for the alt-az, 80cm OARPAF telescope in the Ligurian mountains above Genoa, Italy. Cerberus will provide three focal stations at the Nasmyth focus, allowing: imaging and photometry with standard Johnson-Cousins UBV RI+H\u3b1+Free filters, an on-axis guiding camera, and a tip-tilt lens for image stabilization up to 10Hz; long slit spectroscopy at R 3c 5900 thanks to a LHIRES III spectrograph provided with a 1200l/mm grism; \ue9chelle spectroscopy at R 3c 9300 using a FLECHAS spectrograph with optical fiber

Effect of RNS60 in amyotrophic lateral sclerosis: a phase II multicentre, randomized, double-blind, placebo-controlled trial

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with limited treatment options. RNS60 is an immunomodulatory and neuroprotective investigational product that has shown efficacy in animal models of ALS and other neurodegenerative diseases. Its administration has been safe and well-tolerated in ALS subjects in previous early phase trials