Fernando Quirós

First Light with RATIR: An Automated 6-band Optical/NIR Imaging Camera

The Reionization and Transients InfraRed camera (RATIR) is a simultaneous optical/NIR multi-band imaging camera which is 100% time-dedicated to the followup of Gamma-ray Bursts. The camera is mounted on the 1.5-meter Johnson telescope of the Mexican Observatorio Astronomico Nacional on Sierra San Pedro Martir in Baja California. With rapid slew capability and autonomous interrupt capabilities, the system will image GRBs in 6 bands (i, r, Z, Y, J, and H) within minutes of receiving a satellite position, detecting optically faint afterglows in the NIR and quickly alerting the community to potential GRBs at high redshift (z>6-10). We report here on this Springs first light observing campaign with RATIR. We summarize the instrumental characteristics, capabilities, and observing modes.

Automation of the OAN/SPM 1.5-meter Johnson telescope for operations with RATIR

The Reionization And Transients Infra-Red (RATIR) camera is intended for robotic operation on the 1.5-meter Harold Johnson telescope of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico. This paper describes the work we have carried out to successfully automate the telescope and prepare it for RATIR. One novelty is our use of real-time absolute astrometry from the finder telescopes to point and guide the main telescope.

High order test bench for extreme adaptive optics system optimization

High-contrast imagers dedicated to the search for extrasolar planets are currently being developed for the VLT (SPHERE) and Gemini (GPI) observatories. A vital part of such a high-contrast imager is the extreme adaptive optics (XAO) system that very efficiently removes effects of atmospheric turbulence and instrument aberrations. The high order test bench (HOT) implements an XAO system under realistic telescope conditions reproduced by star and turbulence generators. New technological developments (32x32 actuator micro deformable mirror, read-noise free electron multiplying CCD60, SPARTA real time computer) are used to study and compare two potential XAO wave front sensors: The Pyramid- and the Shack-Hartmann wave front sensors. We will describe the overall design of HOT including the sub-systems. We will present the closed loop study results of the behavior of the Shack-Hartmann wave front sensor in terms of linearity, sensitivity to calibration errors, performance and other specific issues.

Multiframe blind deconvolution for imaging in daylight and strong turbulence conditions

We describe results from new computational techniques to extend the reach of large ground-based optical telescopes, enabling high resolution imaging of space objects under daylight conditions. Current state-of-the-art systems, even those employing adaptive optics, dramatically underperform in such conditions because of strong turbulence generated by diurnal solar heating of the atmosphere, characterized by a ratio of telescope diameter to Fried parameter as high as 70. Our approach extends previous advances in multi-frame blind deconvolution (MFBD) by exploiting measurements from a wavefront sensor recorded simultaneously with high-cadence image data. We describe early results with the new algorithm which may be used with seeing-limited image data or as an adjunct to partial compensation with adaptive optics to restore imaging to the diffraction limit even under the extreme observing conditions found in daylight.

DDOTI: the deca-degree optical transient imager

DDOTI will be a wide-field robotic imager consisting of six 28-cm telescopes with prime focus CCDs mounted on a common equatorial mount. Each telescope will have a field of view of 12 deg2, will have 2 arcsec pixels, and will reach a 10σ limiting magnitude in 60 seconds of r ≈ 18:7 in dark time and r ≈ 18:0 in bright time. The set of six will provide an instantaneous field of view of about 72 deg2. DDOTI uses commercial components almost entirely. The first DDOTI will be installed at the Observatorio Astronómico Nacional in Sierra San Pedro Martír, Baja California, México in early 2017. The main science goals of DDOTI are the localization of the optical transients associated with GRBs detected by the GBM instrument on the Fermi satellite and with gravitational-wave transients. DDOTI will also be used for studies of AGN and YSO variability and to determine the occurrence of hot Jupiters. The principal advantage of DDOTI compared to other similar projects is cost: a single DDOTI installation costs only about US

End-to-end simulations for COLIBRI, ground follow-up telescope for the SVOM mission.

500,000. This makes it possible to contemplate a global network of DDOTI installations. Such geographic diversity would give earlier access and a higher localization rate. We are actively exploring this option.

Structural design techniques applied in astronomical instruments

We present an overview of the development of the end-to-end simulations programs developed for COLIBRI (Catching OpticaL and Infrared BRIght), a 1.3m robotic follow-up telescope of the forthcoming SVOM (Space Variable Object Monitor) mission dedicated to the detection and study of gamma-ray bursts (GRBs). The overview contains a description of the Exposure Time Calculator, Image Simulator and photometric redshift code developed in order to assess the performance of COLIBRI. They are open source Python packages and were developed to be easily adaptable to any optical/ Near-Infrared imaging telescopes. We present the scientific performances of COLIBRI, which allows detecting about 95% of the current GRB dataset. Based on a sample of 500 simulated GRBs, a new Bayesian photometric redshift code predicts a relative photometric redshift accuracy of about 5% from redshift 3 to 7.

Primary and secondary mirror manufacturing for COLIBRI ground follow-up telescope of the SVOM mission

We present in this article some of the techniques applied at the Instituto de Astronomía of the Universidad Nacional Autónoma de México (IA-UNAM) to the mechanical structural design for astronomical instruments. With this purpose we use two recent projects developed by the Instrumentation Department. The goal of this work is to give guidelines about support structures design for achieving a faster and accurate astronomical instruments design. The main guidelines that lead all the design stages for instrument subsystems are the high-level requirements and the overall specifications. From these, each subsystem needs to get its own requirements, specifications, modes of operation, relative position, tip/tilt angles, and general tolerances. Normally these values are stated in the error budget of the instrument. Nevertheless, the error budget is dynamic, it is changing constantly. Depending on the manufacturing accuracy achieved, the error budget is again distributed. That is why having guidelines for structural design helps to know some of the limits of tolerances in manufacture and assembly. The error budget becomes then a quantified way for the interaction between groups; it is the key for teamwork.

Estimation of the GMT inter-segment piston error from deformable mirror commands

COLIBRI is one of the two robotic ground follow-up telescopes for the SVOM (Space Variable Object Monitor) mission dedicated to the study of gamma-ray bursts, allowing determination of precise celestial coordinates of the detected bursts. COLIBRI telescope is a two-mirror Ritchey-Chrétien telescope whose concave primary and convex secondary mirrors have diameters of 1325mm and 485mm respectively. The mirrors are currently manufactured at LAM (Laboratoire d’Astrophysique de Marseille). In this article, the advancement of the work is presented. We also give a global overview and status of the COLIBRI project.

The spectrograph ESOPO: scientific goals, high-level requirements, and introduction to the design

The Giant Magellan Telescope (GMT) will place seven primary mirror segments of 8.4 m diameter on a common mount to form a single co-phased aperture of 25 m. 1High order adaptive optics (AO) using an adaptive secondary mirror that is segmented in the same way as the primary will correct the telescopes imaging to the diffraction limit in the near infrared. 2Critical to the performance of the telescope will be real-time correction of atmospherically-induced optical path differences between the primary mirror segments. Measuring these errors is challenging because of the large gaps between the segments, where the aberrated wavefront is not explicitly measured by the AO sensors, which are approximately 30 cm even at their narrowest points. In this paper we show that it will be feasible to estimate the path differences between the segments from the commands sent to the adaptive secondary mirror while the AO is running in closed loop. These commands will be an approximate representation of the open-loop atmospheric wavefronts. We have investigated the value of the approach with real-time closed-loop deformable mirror command data from the first-light AO system now running on the Large Binocular Telescope (LBT). 3,4The data are of very high quality and realistically capture the spatio-temporal behavior of the wavefront. We use data from two nights to show that the GMT segment pathlength errors may be recovered to <25 nm accuracy with a simple linear estimator. Additional simulations show similar performance, which, with high-order AO, is quite adequate to maintain high Strehl ratio at near infrared wavelengths.