Luis A. Martínez

San Pedro Mártir: astronomical site evaluation

The Observatorio Astronomico Nacional at San Pedro Martir is situated on the summit of the San Pedro Martir Sierra in the Baja California peninsula of Mexico, at 2800m above sea level. For as long as three decades, a number of groups and individuals have gathered extremely valuable data leading to the site characterization for astronomical observations. Here we present a summary of the most important results obtained so far. The aspects covered are: weather, cloud coverage, local meteorology, atmospheric optical extinction, millimetric opacity, geotechnical studies, seeing, optical turbulence profiles, wind profiles and 3D simulations of atmospheric turbulence. The results place San Pedro Martir among the most favorable sites in the world for astronomical observations. It seems to be particularly well-suited for extremely large telescopes because of the excellent turbulence and local wind conditions, to mention but two characteristics. Long-term monitoring of some parameters still have to be undertaken. The National University of Mexico (UNAM) and other international institutions are putting a considerable effort in that sense.

Monitoring at TeV Energies with M@TE

Blazars are extremely variable objects emitting radiation across the electromagnetic spectrum and showing variability on time scales from minutes to years. Simultaneous multi-wavelength observations are crucial for understanding the emission mechanisms. In particular the study of their TeV emission is relevant to test the dominant radiative process at such energies (e.g. leptonic models predict a correlation between X-ray and TeV emission). As well, the correlation with the bump at low energy or the possible common detection with a neutrino signal can be relevant to constrain the physical model. From radio via optical and from X-ray to gamma rays, a variety of instruments, as OVRO and Fermi, are already monitoring blazars. At TeV energies, long-term monitoring is currently carried out by HAWC and FACT. Towards 24/7 continuous observations, the goal is to have similar monitoring telescopes at locations around the globe in order to close temporal gaps and compile light curves with homogeneous sensitivity. With the M@TE (Monitoring at TeV energies) project, we are planning to install an Imaging Air Cherenkov Telescope equipped with an improved version of the FACT camera and the mechanical structure of one of the mounts of the HEGRA experiment at the site of San Pedro Martir in Mexico. Featuring excellent observation conditions, this location provides a variety of instruments from radio to optical wavelength allowing for coordinated multi-wavelength blazar studies. In this work, we will present the status of the project.

A system for the characterization of the HAWC PMTs sensitivity

The HAWC Project is a very high-energy gamma-ray observatory under construction at the Sierra Negra volcano (4100 meters above sea level) in the Pico de Orizaba National Park located in central Mexico. HAWC will reuse the 900 Hamamatsu R5912 photomultipliers (PMTs) from Milagro Observatory for the 300 Water Cherenkov Detectors. In order to characterize their present performance it is necessary to scan the active area of the photocathode by measuring its efficiency and gain. A characterization system was designed and manufactured to achieve an automated measurement of over 100 points distributed on the PMT active spherical surface. Preliminary results show the variation of QE of PMTs with respect of the position of incoming photons, as well as the changes in the PMTs response due to the Earths magnetic field and gain vs. high voltage. The system allows automated PMT characterization improving its performance, reliability, precision and repeatability. In this work we present the characterization system and preliminary results on the PMT efficiency.

Virtual reality and project management for astronomy

Over the years astronomical instrumentation projects are becoming increasingly complex making necessary to find efficient ways for project communication management. While all projects share the need to communicate project information, the required information and the methods of distribution vary widely between projects and project staff. A particular problem experienced on many projects regardless of their size, is related to the amount of design, planning information and how that is distributed among the project stakeholders. One way to improve project communications management is to use a workflow that offers a predefined way to share information in a project. Virtual Reality (VR) offers the possibility to get a visual feedback of designed components without the expenses of prototype building, giving an experience that mimics real life situations using a computer. In this contribution we explore VR as a communication technology that helps to manage instrumentation projects by means of a workflow implemented on a software package called Discut designed at Universidad Nacional Autónoma de Mexico (UNAM). The workflow can integrate VR environments generated as CAD models.

NEFER: a high-resolution scanning Fabry-Perot Spectrograph II scanning Fabry-Perot testing

NEFER (Nuevo Espectrómetro Fabry-Perot de Extrema Resolución) is a high spectral resolution, scanning Fabry-Perot Spectrometer. It will be installed in the OSIRIS instrument at the GTC 10 m telescope. This 3D instrument uses a high order scanning Fabry-Perot to obtain highly accurate kinematical information of extended cosmic sources such as galaxies or nebulae. Astronomical data obtained with this instrument lead to a 3D spectroscopic data cubes composed of several images, each one at different gaps of the scanning Fabry-Perot Interferometer. In this work we present laboratory testing of some characteristics of the ICOS Fabry-Perot acquired for this instrument such Finesse, free spectral range, and peak transmission. We also present software design and development for the 3D data reduction standalone package of this high resolution 3D instrument.

A virtual reality environment for telescope operation

Astronomical observatories and telescopes are becoming increasingly large and complex systems, demanding to any potential user the acquirement of great amount of information previous to access them. At present, the most common way to overcome that information is through the implementation of larger graphical user interfaces and computer monitors to increase the display area. Tonantzintla Observatory has a 1-m telescope with a remote observing system. As a step forward in the improvement of the telescope software, we have designed a Virtual Reality (VR) environment that works as an extension of the remote system and allows us to operate the telescope. In this work we explore this alternative technology that is being suggested here as a software platform for the operation of the 1-m telescope.

GUIELOA, the Mexican adaptive optics system: expected performance and operation

We describe progress in the construction of an adaptive optics system for the 2.1 meter telescope of the Observatorio Astronomico Nacional on Sierra San Pedro Martir, in Baja California, Mexico. The system will use a 19 element bimorph deformable mirror mounted on an articulated platform and a curvature wavefront sensor with natural guide stars. It will have two modes of operation. In adaptive optics mode, it is expected to give excellent correction above 1.0 μm and good correction down to 0.6-0.9 μm, depending on the seeing, although the sky coverage will be limited. In fast guiding mode, the system should give images at or better than the excellent natural seeing of the site and have much greater sky coverage. The system is currently undergoing laboratory testing.

NEFER: a high resolution scanning Fabry-Perot spectrograph

The scanning Fabry-Perot spectrograph could give highly accurate, kinematical information of star forming regions (HH objects, protoplanetary disks and large scale flows) and the dynamics of isolated and interacting galaxies (resonances, galaxy pairs, compact groups). In this project we are developing a high spectral resolution scanning Fabry-Perot interferometer for the GTC 10 m telescope and the OSIRIS instrument. The system will provide the following characteristics: high spectral resolution data (R up to 20000) over a whole field of view of approximate 8 × 8 arcmin, 0.125 arcsec pixel size in two spectral ranges; 6300 to 7000 Å (galactic projects) and 8000 to 9500 Å (OTELO objects kinematics). ICOS ET100 Fabry-Perot will be used and installed within the OSIRIS collimated beam in the filter wheel hosting the tunable filters. Several acquisition software features have been defined like: synchronizing Fabry-Perot scanning with image acquisition, data cube assembly; single frame or data cube files would be provided according to the observer data reduction process. Fabry-Perot plates parallelism is extremely important to improve Finesse. Our team has developed an algorithm to accomplish this task.

Virtualization as an alternative for astronomical software integration

The integration of software which requires different operating system platforms to run, is a common challenge that has to be overcome by astronomical software developers. In recent years, the possibility to execute different operating systems (OS) and programs at the same time, on a single computer by means of virtual machines, known as virtualization, has emerged as a novel tool to integrate software from different platforms. In this paper, we share our virtualization experiences and how virtualization has improved the software integration of two astronomical software projects developed at the Instituto de Astronomía, Universidad Nacional Autónoma de Mexico (IAUNAM).

A DSP-based infrared and optical bidimensional detectors controller

The Institute of Astronomy at the Universidad Nacional Autonoma de México have developed and tested a CCD controller based on Texas Instruments Digital Signal Processor (DSP) TMS30C31@50MHz. Images are temporally stored in a 2MB static RAM attached to the DSP and transferred to the host computer running under Linux. Both tasks, acquisition and timing, are programmable so it can be conditioned to control any bidimensional detector. Analog voltage for bias, offsets and gains are fully programmable also. The system has been tested on an infrared Hawaii detector and fast Marconi 80x80 pixels CCD.