Contribución al conocimiento de Porosagrotis gypaetina (Guen.) (Lep.:Noctuidae)

p.15-22Este trabajo tiene por finalidad brindar una descripcion detallada de los diferentes estados de desarrollo, asi como de los estadios larvales, de Porosagrotis gypaetina (Guen.) y estimar sus principales parametros biologicos. Se trata de una oruga conocida vulgarmente como gusano pardo que frecuenta cultivos de alfalfa, trebol bianco, maiz y girasol y determinadas malezas. Los caracteres considerados para su identificacion fueron, en el huevo: numero y distribucion de costas; en la larva: pigmentacion, distribucion de manchas y cerdas corporales; en la pupa: tamaño, forma y color y caracteristicas del cremaster; y en el adulto: ubicacion y coloracion de maculas y nervaduras alares. La emergencia de imagos alcanzo su maximo en abril y mayo. El periodo embrionario se completo en 22 a 26 dias. Aproximadamente la mitad de las larvas cumplieron su ciclo en 6 estadios y las restantes en 7; la duracion total del periodo larval fue de 134 a 141 dias, sin considerar la forma prepupal e independientemente del numero de estadios. Las orugas permanecieron como prepupas durante la temporada estival (aproximadamente 161 dias). El estado pupal duro 40 a 57 dias. Las observaciones realizadas permiten expresar que, inediante los caracteres descriptos, es factible reconocer la especie a traves no solo de los adultos, sino de sus estados inmaduros. Posee una sola generacion anual; transcurre el inviemo como larva; el daño tipico de corte lo produce a partir del cuarto estadio larval

Long-term monitoring of bright blazars in the multi-GeV to TeV range with FACT

Blazars like Markarian 421 or Markarian 501 are active galactic nuclei (AGN), with their jets orientated towards the observer. They are among the brightest objects in the very high energy (VHE) gamma ray regime (>100 GeV). Their emitted gamma-ray fluxes are extremely variable, with changing activity levels on timescales between minutes, months, and even years. Several questions are part of the current research, such as the question of the emission regions or the engine of the AGN and the particle acceleration. A dedicated longterm monitoring program is necessary to investigate the properties of blazars in detail. A densely sampled and unbiased light curve allows for observation of both high and low states of the sources, and the combination with multi-wavelength observation could contribute to the answer of several questions mentioned above. FACT (First G-APD Cherenkov Telescope) is the first operational telescope using silicon photomultiplier (SiPM, also known as Geigermode—Avalanche Photo Diode, G-APD) as photon detectors. SiPM have a very homogenous and stable longterm performance, and allow operation even during full moon without any filter, leading to a maximal duty cycle for an Imaging Air Cherenkov Telescope (IACT). Hence, FACT is an ideal device for such a longterm monitoring of bright blazars. A small set of sources (e.g., Markarian 421, Markarian 501, 1ES 1959+650, and 1ES 2344+51.4) is currently being monitored. In this contribution, the FACT telescope and the concept of longterm monitoring of bright blazars will be introduced. The results of the monitoring program will be shown, and the advantages of densely sampled and unbiased light curves will be discussed

An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state

Extreme high-frequency BL Lacs (EHBL) feature their synchrotron peak of the broad-band spectral energy distribution (SED) at nu(s) >= 10(17) Hz. The BL Lac object 1ES 2344+514 was included in the EHBL family because of its impressive shift of the synchrotron peak in 1996. During the following years, the source appeared to be in a low state without showing any extreme behaviours. In 2016 August, 1ES 2344+514 was detected with the groundbased gamma-ray telescope FACT during a high gamma-ray state, triggering multiwavelength (MWL) observations. We studied the MWL light curves of 1ES 2344+514 during the 2016 flaring state, using data from radio to very-high-energy (VHE) gamma-rays taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT collaboration at the Teide, Crimean, and St. Petersburg observatories, Swift-UVOT, Swift-XRT, Fermi-LAT, FACT, and MAGIC. With simultaneous observations of the flare, we built the broad-band SED and studied it in the framework of a leptonic and a hadronic model. The VHE gamma-ray observations show a flux level of 55 per cent of the Crab Nebula flux above 300 GeV, similar to the historical maximum of 1995. The combination of MAGIC and Fermi-LAT spectra provides an unprecedented characterization of the inverse-Compton peak for this object during a flaring episode. The Gamma index of the intrinsic spectrum in the VHE gamma-ray band is 2.04 +/- 0.12(stat) +/- 0.15(sys). We find the source in an extreme state with a shift of the position of the synchrotron peak to frequencies above or equal to 1018 Hz

The Great Markarian 421 Flare of 2010 February: Multiwavelength Variability and Correlation Studies

We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsahovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). Light curves are produced spanning multiple days before and after the peak of the VHE flare, including over several flare "decline" epochs. The main flare statistics allow 2 minute time bins to be constructed in both the VHE and optical bands enabling a cross-correlation analysis that shows evidence for an optical lag of ∼25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ⪆ 33) and the size of the emission region (δ-1RB≲ 3.8 × 1013cm) are obtained from the fast variability observed by VERITAS during the main flare. Analysis of 10 minute binned VHE and X-ray data over the decline epochs shows an extraordinary range of behavior in the flux-flux relationship, from linear to quadratic to lack of correlation to anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model.</p

Cloud Detection and Prediction with All Sky Cameras

Atmospheric monitoring is a field of special importance for astroparticle physics, especially for Imaging Atmospheric Cherenkov Telescopes (IACTs) as clouds will absorb and scatter the Cherenkov photons of air showers. Conventional tools used for atmospheric monitoring (e.g. LIDAR) are very expensive and monitor only a small part of the sky at once. Therefore, they are not suitable to perform a wide scan of the sky which is necessary to detect clouds in advance. This article gives a short overview about a method that uses an all sky camera with a 180 ° field of view to identify the cloud distribution by measuring the absorption of star light. It can be used to assign a sky quality rating to single spots, arbitrary regions or the whole sky at once within a 1 min exposure time. A cloud map can be created from the available data that can be used to determine shape and dimension of clouds and to predict their movement. The resulting data can be used by a scheduling algorithm or the operating crew to point the telescope to a different source before the current source gets covered by clouds. The all sky cameras used so far are located on La Palma at the observatory Roque de los Muchachos close to the telescopes FACT and MAGIC and the planned northern CTA site

FACT - Status and experience from three years operation of the first SiPM camera

The First G-APD Cherenkov Telescope (FACT) is pioneering the usage of solid state photosensors (G-APD, also known as SiPM). The 1440 pixel camera is installed in a 9.5 m2 refurbished HEGRA telescope on the Canary Island La Palma. Physics data-taking with FACT started in October 2011, a few hours after installation of the camera. Since Summer 2012, FACT is operated remotely without the need of a data-taking crew on site. During more than three years of operation of FACT, G-APDs have proven to be very reliable. Despite operating them regularly also under very strong moonlight conditions, the GAPDs show no change in their properties or any indication for aging. This allows FACT to have a successful monitoring program of the brightest TeV blazars in the Northern hemisphere and several flare-alerts have been sent to the community. This proceeding summarizes the history and status of FACT as well as reporting the lessons learned about the usage of SiPM in a Cherenkov telescope from the construction and operation of FACT.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

FACT - Novel mirror alignment using bokeh and enhancement of the VERITAS SCCAN alignment method

Imaging Air Cherenkov Telescopes, including the First G-APD Cherenkov Telescope (FACT), use segmented reflectors. These offer large and fast apertures for little resources. However, one challenge is the alignment of the mirrors to gain a sharp image. For Cherenkov telescopes, high spatial and temporal resolution is crucial to reconstruct air shower events. Therefore one has to align the individual mirror positions and orientations precisely. Alignment is difficult due to the large number of degrees of freedom and, because most techniques involve a star, has to be done during good weather nights which overlaps with observation time. We present the mirror alignment of FACT, done using two methods. Firstly, we show a new method which we call Bokeh alignment. This method is simple, cheap and can even be done during daytime. Secondly, we demonstrate an enhancement of the SCCAN method by F. Arqueros et al. and first implemented by the McGill VERITAS group. Using a second camera, our enhanced SCCAN is optimized for changing weather, changing zenith distance, and changing reference stars. Developed off site in the lab on a 1/10th scale model of FACT, both our methods resulted in a highly telescope independent procedure, e.g. both our methods run without communication to the telescope's drive. We compare alignment results by using the point spread function of star images, ray tracing simulations, and overall muon rates before and after the alignment.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

FACT - TeV flare alerts triggering multi-wavelength observations

Active galactic nuclei show variability on time scales ranging from minutes to decades. The radiation from these extreme objects spans many orders of magnitude along the whole electromagnetic spectrum. The spectral energy distribution shows two peaks, where for the subgroup of blazars the first peak is in the radio to X-ray regime, while the second peak is in the gamma-ray regime. Due to the extreme variability and the wide spectral range, simultaneous multi-wavelength observations are vital to understand the underlying physics. Furthermore, long-term monitoring is crucial to obtain an unbiased data sample. While for the measurements of the low-energy peak, many instruments are available, the data at TeV energies are sparse. The First G-APD Cherenkov Telescope (FACT) is a gamma-ray telescope dedicated to the long-term monitoring of bright TeV blazars. Operational since October 2011, it has collected more than three years of data from a dedicated sample of sources. The results of an automatic quick look analysis are publicly available on a website the same night. Based on this, other instruments are informed in case of a high flux state and target-of-opportunity observations are carried out. In the previous year, seven flare alerts have been sent to the community and several periods of strong variability have been observed for the blazars Mrk 421 and Mrk 501.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

FACT - First energy spectrum from a SiPM cherenkov telescope

The First G-APD Cherenkov Telescope (FACT) is an Imaging Air Cherenkov Telescope located on the Canary Island of La Palma. It is the first of its kind which uses Geiger-mode Avalanche Photo Diodes (G-APDs) as photosensors to detect the Cherenkov radiation emitted from secondary particles in a high-energy gamma-ray air shower. A new analysis chain has been developed using modern data mining methods and unfolding techniques to obtain the energy spectrum of an observed source. This analysis chain has been applied to data of the Crab Nebula, the so called 'standard candle' in Cherenkov astronomy. Here, the individual steps are described and results of this application are reported providing the energy spectrum and light curve.SCOPUS: cp.pinfo:eu-repo/semantics/publishe