For the first time in the history of ground-based x-ray astronomy, the on-axis performance of the dual mirror, aspheric, aplanatic Schwarzschild-Couder optical system has been demonstrated in a 9:7-m aperture imaging atmospheric Cherenkov telescope. The novel design of the prototype Schwarzschild-Couder Telescope (pSCT) is motivated by the need of the next-generation Cherenkov Telescope Array (CTA) observatory to have the ability to perform wide (≥8°) field-of-view observations simultaneously with superior imaging of atmospheric cascades (resolution of 0:067 per pixel or better). The pSCT design, if implemented in the CTA installation, has the potential to improve significantly both the x-ray angular resolution and the off-axis sensitivity of the observatory, reaching nearly the theoretical limit of the technique and thereby making a major impact on the CTA observatory sky survey programs, follow-up observations of multi-messenger transients with poorly known initial localization, as well as on the spatially resolved spectroscopic studies of extended x-ray sources. This contribution reports on the initial alignment procedures and point-spread-function results for the challenging segmented aspheric primary and secondary mirrors of the pSCT.
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 Earth's
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
The Volcano Sierra Negra in Puebla, Mexico was selected to host HAWC (High Altitude Water Cherenkov), a unique observatory of wide field of view (2sr) capable of observing the sky continuously at energies up to 100 TeV. HAWC is proposed as an array of 300 Cherenkov detectors consisting of 5m deep and 7.3 m diameter steel container containing 200,000 liters of purified water, each container with 4 Hamamatsu PMTs. The first construction stage of 7 tanks, VAMOS, was finished this year and it is continuously operating. In this work, the Cherenkov detectors and the electronics of VAMOS are described.
HAWC (High Altitude Water Cherenkov), is a gamma ray (γ) large aperture observatory with high sensitivity that will
be able to continuously monitor the sky for transient sources of photons with energies between 100 GeV and 100 TeV.
HAWC is under construction in Sierra Negra, Puebla, Mexico, which is located at a high altitude of 4100m. HAWC will
be an array of 300 Cherenkov detectors each one with 200,000 liters of highly pure water.
The sensitivity of the instrument depends strongly on the water quality. We present the design and construction of the
HAWC water quality monitoring system. We seek monitor the transparency in violet-blue range to achieve and
maintain the required water transparency quality in each detector. The system is robust and user friendly. The
measurements are reproducible. Also we present some results from the monitoring the water from the VAMOS detector
tanks and of the filtering system.
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.
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
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.
In the last two years the National Observatory at Tonantzintla Puebla, México (OAN Tonantzintla), has been undergoing
several facilities upgrades in order to bring to the observatory suitable conditions to operate as a modern Observational
Astronomy Teaching Laboratory. In this paper, we present the management, requirement definition and project
advances. We made a quantitative diagnosis about of the functionality of the Tonantzintla Observatory (mainly based in
the 1m f/15 telescope) to take aim to educational objectives. Through this project we are taking the steps to correct, to
actualize and to optimize the observatory astronomical instrumentation according to modern techniques of observation.
We present the design and the first actions in order to get a better and efficient use of the main astronomical
instrumentation, as well as, the telescope itself, for the undergraduate, postgraduate levels Observacional Astronomy
students and outreach publics programs for elementary school. The project includes the development of software and
hardware components based in as a common framework for the project management. The Observatory is located at 150
km away from the headquarters at the Instituto de Astronomía, Universidad Nacional Autónoma de México (IAUNAM),
and one of the goals is use this infrastructure for a Remote Observatory System.
CATAVIÑA is a near-infrared camera system to be operated in conjunction with the existing multi-purpose nearinfrared
optical bench "CAMALEON" in OAN-SPM. Observing modes include direct imaging, spectroscopy, Fabry-
Perot interferometry and polarimetry. This contribution focuses on the optomechanics and detector controller
description of CATAVIÑA, which is planned to start operating later in 2006. The camera consists of an 8 inch LN2
dewar containing a 10 filter carousel, a radiation baffle and the detector circuit board mount. The system is based on a
Rockwell 1024x1024 HgCdTe (HAWAII-I) FPA, operating in the 1 to 2.5 micron window. The detector
controller/readout system was designed and developed at UNAM Instituto de Astronomia. It is based on five Texas
Instruments DSK digital signal processor (DSP) modules. One module generates the detector and ADC-system control,
while the remaining four are in charge of the acquisition of each of the detector's quadrants. Each DSP has a built-in
expanded memory module in order to store more than one image. The detector read-out and signal driver subsystems
are mounted onto the dewar in a "back-pack" fashion, each containing four independent pre-amplifiers, converters and
signal drivers, that communicate through fiber optics with their respective DSPs. This system has the possibility of
programming the offset input voltage and converter gain. The controller software architecture is based on a client/server
model. The client sends commands through the TCP/IP protocol and acquires the image. The server consists of a
microcomputer with an embedded Linux operating system, which runs the main program that receives the user
commands and interacts with the timing and acquisition DSPs. The observer's interface allows for several readout and
image processing modes.
We present the dual IR camera CID for the 2.12 m telescope of the
Observatorio Astronomico Nacional de Mexico, IA-UNAM. The system
consists of two separate cameras/spectrographs that operate in
different regions of the IR spectrum. In the near IR, CID comprises a direct imaging camera with wide band filters, a CVF, and a low resolution spectrograph employing an InSb 256 x 256 detector. In the mid IR, CID uses a BIB 128 x 128 detector for direct imaging in 10 and 20 microns. Optics and mechanics of CID were developed at IR-Labs
(Tucson). The electronics was developed by R. Leach (S. Diego). General design, construction of auxiliary optics (oscillating
secondary mirror), necessary modifications and optimization of
the electronics, and acquisition software were carried out at OAN/
UNAM. The compact design of the instruments allow them to share
a single dewar and the cryogenics system.
Atmospheric turbulence distorts the wavefront of the incoming light from an astronomical object and so limits the ability of a telescope to form a perfect image. The AO systems for astronomy had come the most powerful tool for infrared observation in the near thermal domain. A conventional AO system requires quite a few reflections that are needed to transfer and correct an image. A typical system would have a collimator, deformable mirror and a camera at the bare minimum. For the thermal region the gains are substantial where one can eliminate extra optical surfaces and their associated thermal background, that occurs when you put the deformable mirror at the secondary. We study the possibility of development an adaptive secondary with the techniques of a Current Bimorph mirror with the necessaries number of actuators for control the edge slope. Also we simulate the performance of a 19 channels curvature adaptive optics system in order to demonstrate the gain achievable with an adaptive secondary. The adaptive secondary for the 2.1 m Telescope at SPM Observatory is designed for a f/50 beam, 100 mm in diameter with 19 actuators necessaries to control the edge slope and curvature.
We describe different works conducing to the adaptive optics system for the TIM 6.5m telescope. We show turbulence profiles result at our San Pedro Martir Observatory in Baja using the Generalized SCIDAR. We can conclude that the turbulence conditions in this site are comparable to the major observatories in the world. From these results and taken in account curvature AO simulations it is possible to predict the performances in limiting magnitude and sky coverage of different AO systems and telescopes in our observatory. We can also define the degree of the AO system for the TIM 6.5m telescope. We made a short description of our LOLA tip-tilt corrector system and the GUIELOA 19 elements curvature AO system. The calculation of the optics quality for the TIM 6.5m is briefly mentioned. Studies about the influence of the finite outerscale on the optical quality of AO corrected images are described.
Optical testing of the 2.1-m telescope in San Pedro Martir, Observatorio Astronomico Nacional de Mexico, by the methods of wavefront curvature sensing and bi-Ronchi analysis, has shown that the telescope suffered of large amounts of astigmatism. We identified these as due to improper primary mirror support and developed an active control system to correct for it. The number and position of the actuators were decided in accordance to the flexural modes that needed to be corrected, resulting in a system of 18 pressure controlled pneumatic actuators, with an outer loop that verifies the load at three hard points. A PID algorithm and matrix inversion are fundamental parts of this outer loop, that guarantees that the M1 mirror is tilted as a rigid body to maintain it properly aligned. The successful performance of the system to correct low order aberrations is reported.
We present the Mexican Infrared-Optical New Technology Telescope Project (TIM). The design and construction of a 7.8 m telescope, which will operate at the Observatorio Astronomico Nacional in San Pedro Martir, B.C. (Mexico), are described. The site has been selected based on seeing and sky condition measurements taken for several years. The f/1.5 primary mirror consists of 19 hexagonal off-axis parabolic Zerodur segments. The telescope structure will be alt-az, lightweight, low cost, and high stiffness. It will be supported by hydrostatic bearings. The single secondary will complement a Ritchey-Chretien f/15 design, delivering to Cassegrain focus instrumentation. The telescope will be infrared optimized to allow observations ranging from 0.3 to 20 microns. The TIM mirror cell provides an independent and full active support system for each segment, in order to achieve both, phasing capability and very high quality imaging (0.25 arcsec).
We describe the configuration and operation modes of the IR camera/spectrograph: TEQUILA based on a 1024 X 1024 HgCdTe FPA. The optical system will allow three possible modes of operation: direct imaging, low and medium resolution spectroscopy and polarimetry. The basic system is being designed to consist of the following: 1) A LN2 dewar that allocates the FPA together with the preamplifiers and a 24 filter position cylinder. 2) Control and readout electronics based on DSP modules linked to a workstation through fiber optics. 3) An opto-mechanical assembly cooled to -30 degrees that provides an efficient operation of the instrument in its various modes. 4) A control module for the moving parts of the instrument. The opto-mechanical assembly will have the necessary provision to install a scanning Fabry-Perot interferometer and an adaptive optics correction system. The final image acquisition and control of the whole instrument is carried out in a workstation to provide the observer with a friendly environment. The system will operate at the 2.1 m telescope at the Observatorio Astronomico Nacional in San Pedro Martir, B.C. (Mexico), and is intended to be a first-light instrument for the new 7.8m Mexican IR-Optical Telescope.
The Observatorio Astronomico Nacional, located at Tonantzintla, Puebla, Mexico, has a 1 m equatorial mount telescope of excellent quality. In order to increase its potential for research, teaching and outreach programs, the Astronomy Institute has generated a project for the remote operation of the telescope and acquisition of astronomical data from the university site in Mexico City. The telescope has computerized control, whose programs are recently optimized for remote control handling. The dome was optoelectronic codified in order to have its movements coordinated with the telescope. The Ethernet type fiber optics network is the communication channel for the remote control of the telescope. This will allow to carry out a significant number of projects for the acquisition and processing of astronomical data. The status of the 1 m telescope remote control system is presented.
The development of the IR camera and spectrograph (CAMILA) is described. It is based on a NICMOS 3 HgCdTe detector developed by Rockwell with a spectral response of 1 to 2.5 micrometers . The initial configuration of the system was recently concluded and consists of the following components: detector cryostat, detector control electronics, low noise preamplifiers, detector-PC interface, operating system and optics. The characterization of the electronics and the science grade chip are presented. The complete optical configuration allows the following modes of operation: direct imaging (12 filter positions), polarimetry and spectroscopy on three dispersion modes (low, medium, and high resolution). Preliminary spectroscopic results at the H band with R equals 1500 are presented. The project is a collaborative effort of groups from IAUNAM and UMASS (Amherst) and will be used mainly at the 2.1-m telescope of San Pedro Martir, B.C. (Mexico).