Search

We derive limits on any electromagnetic counterpart to the compact binary merger S190814bv, whose parameters are consistent with the merger of a black hole and a neutron star. We present observations with the new wide-field optical imager DDOTI and also consider Swift/BAT observations reported by Palmer et al. (2019). We show that Swift/BAT would have detected a counterpart with similar properties to a typical on-axis short GRB at the 98 per cent confidence level, whereas our DDOTI observations only rule out such a counterpart at the 27 per cent confidence level. Neither have sufficient sensitivity to rule out an off-axis counterpart like GW 170817. We compare the efficiency of Swift/BAT and DDOTI for future observations, and show that DDOTI is likely to be about twice as efficient as Swift/BAT for off-axis events up to about 100 Mpc., Accepted by MNRAS. 6 pages. Fixed typos and references

We present optical photometry of the afterglow of the long GRB 180205A with the COATLI telescope from 217 seconds to about 5 days after the {\itshape Swift}/BAT trigger. We analyse this photometry in the conjunction with the X-ray light curve from {\itshape Swift}/XRT. The late-time light curves and spectra are consistent with the standard forward-shock scenario. However, the early-time optical and X-ray light curves show non-typical behavior; the optical light curve exhibits a flat plateau while the X-ray light curve shows a flare. We explore several scenarios and conclude that the most likely explanation for the early behavior is late activity of the central engine.

We present in this article some of the techniques applied at the Instituto de Astronomia of the Universidad Nacional Autonoma de Mexico (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.

COATLI is a new instrument and telescope that will provide 0.3 arcsec FWHM images from 550 to 920 nm over a large fraction of the sky. It consists of a robotic 50-cm telescope with a diffraction-limited imager. The imager has a steering mirror for fast guiding, a blue channel using an EMCCD from 400 to 550 nm to measure image motion, a red channel using a standard CCD from 550 to 920 nm, and an active optics system based on a deformable mirror to compensate static aberrations in the red channel. Since the telescope is small, fast guiding will provide diffraction-limited image quality in the red channel over a large fraction of the sky, even in relatively poor seeing. The COATLI telescope will be installed at the Observatorio Astronomico Nacional in Sierra San Pedro Martir, Baja California, Mexico, in 2016 and will initially operate with a simple interim imager. The definitive COATLI instrument will be installed in 2017. In this work we present the general optomechanical and control electronics design of COATLI.

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 square degrees, will have 2 arcsec pixels, and will reach a 10-sigma 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 square degrees. DDOTI uses commercial components almost entirely. The first DDOTI will be installed at the Observatorio Astron\'omico Nacional in Sierra San Pedro Mart\'ir, Baja California, M\'exico 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$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., Comment: To appear in the proceedings of SPIE conference 9910 "Observatory Operations: Strategies, Processes, and Systems VI". 12 pages

HH 262 is a group of emitting knots located approximately 35 to the northeast of the L1551 IRS 5 source. We present a detailed study of the kinematic properties of HH 262, based on proper-motion measurements and on high-resolution imaging Fabry-Perot observations in the [S II] 6717 A line. From these observations, we conclude that it indeed appears to be the case that HH 262 is associated with the red lobe of the L1551 IRS 5 outflow.

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 PMT efficiency.

OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy) was the optical Day One instrum ent for the 10.4m Spanish telescope GTC . It is installed at the Observatorio del Roque de Los Muchachos (La Palma, Spain). This instrument has been operational since March -2009 and covers from 360 to 1000 nm. OSIRIS observing modes include direct imaging w ith tunable and conventional filters, long slit and low resolution spectroscopy. OSIRIS wide field of view and high efficiency provide a powerful tool for the scientific exploitation of GTC. OSIRIS was developed by a Consortium formed by the Instituto de A strofisica de Canarias (IAC) and the Instituto de Astronomia de la Universidad Nacional Autonoma de Mexico (IA -UNAM). The latter was in charge of the optical design, the manufacture of the camera and collaboration in the assembly, integration and verificat ion process. The IAC was responsible for the remaining design of the instrument and it was the project leader. The present paper considers the development of the instrument from its design to its present situation in which is in use d by the scientific comm unity. Keywords: Tunable filter s, imaging, spectroscopy, fast spectrophotometry, GTC , camera, optical instruments

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.

In the last two years the National Observatory at Tonantzintla Puebla, Mexico (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 Astronomia, Universidad Nacional Autonoma de Mexico (IAUNAM), and one of the goals is use this infrastructure for a Remote Observatory System.

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.

We are developing an instrument to study the morphology and kinematics of the molecular gas and its interrelationship with the ionized gas in star forming regions, planetary nebulae and supernova remnants in our Galaxy and other galaxies, as well as the kinematics of the IR emitting gas in starburst and interacting galaxies. This instrument consists of a water-free fused silica scanning Fabry-Perot interferometer optimized in the spectral range from 1.5 to 2.4 micrometers with high spectral resolution. It will be installed in the collimated beam of a nearly 2:1 focal reducer, designed for the Cassegrain focus of the 2.1 m telescope of the San Pedro Martir National Astronomical Observatory. Mexico, in its f/7.5 configuration, yielding a field of view of 11.6 arc-min. It will provide direct images as well as interferograms to be focused on a 1024 X 1024 HAWAII array, covering a spectral range from 0.9 to 2.5 micrometers .

The kinematics of the interstellar medium may be studied by means of a scanning Fabry-Perot interferometer (SFPI). This allows the coverage of a wider field of view with higher spatial and spectral resolution than when a high-dispersion classical spectrograph is used. The system called PUMA consists of a focal reducer and a SFPI installed in the 2.1 m telescope of the San Pedro Martir National Astronomical Observatory (SPM), Mexico, in its f/7.5 configuration. It covers a field of view of 10 arcmin providing direct images as well as interferograms which are focused on a 1024 X 1024 Tektronix CCD, covering a wide spectral range. It is considered the integration of other optical elements for further developments. The optomechanical system and the developed software allow exact, remote positioning of all movable parts and control the FPI scanning and data acquisition. The parallelism of the interferometer plates is automatically achieved by a custom method. The PUMA provides spectral resolutions of 0.414 Angstrom and a free spectral range of 19.8 Angstrom. Results of high quality that compete with those obtained by similar systems in bigger telescopes, are presented.

Differential speckle interferometry is based on the cross analysis of series of speckle patterns produced in different wavelengths. The study of the position differences between these speckles provides angular information on objects much smaller than the diffraction limit. In order to make the measurements of the photocenter displacement, we have built an instrument which behaves like a spectrograph in one direction and a speckle interferometer in the perpendicular direction. A mirror anamorphoser permits us to meet the different sampling requirements. The dispersed speckle pattern is recorded by a photon counting camera. The measurements of the photocenter displacements are very sensitive to differences of aberration between spectral channels and temporal variations of the detector's distorsion. Our instrument provides images with a quality equal to the diffraction limit plus residual aberrations of the order of one hundreth of the wavelength used. The distorsion of the optics is much smaller than the size of the temporal variations of the detector's distorsion. In order to correct this variable distorsion, spatial and spectral modulations are made in a fully automated instrument.

The system called PUMA is an instrument consisting of a focal reducer coupled to a scanning Fabry-Perot interferometer (SFPI), which is being developed for the Observatorio Astronomicao Nacional at San Pedro Martir, B.C. It will be installed at the 2.0 m Ritchey-Chretien telescope with a focal ratio of F/7.9. It has interference filters, a calibration system, and field diaphragms. The SFPI can be moved out of the optical path in order to acquire direct images. The images produced by this instrument will be focused on an optoelectronic detector, a CCD, or a Mepsicron, depending on the spectral range used.

We describe recent advances in the development of a scanning Fabry-Perot interferometer applied to the study of the kinematics of the interstellar medium at the Observatorio Astronómico Nacional at San Pedro Mártir, B.C. México.

COATLI will provide 0.3 arcsec FWHM images from 550 to 900 nm over a large fraction of the sky. It consists of a robotic 50-cm telescope with a diffraction-limited fast-guiding imager. Since the telescope is small, fast guiding will provide diffraction-limited image quality over a field of at least 1 arcmin and with coverage of a large fraction of the sky, even in relatively poor seeing. The COATLI telescope will be installed at the at the Observatorio Astron\'omico Nacional in Sierra San Pedro M\'artir, M\'exico, during 2016 and the diffraction-limited imager will follow in 2017., Comment: To appear in the proceedings of SPIE conference 9908 "Ground-based and Airborne Instrumentation for Astronomy VI". 9 pages