Joint analysis of TeV blazar light curves with FACT and HAWC

Probing the high energy emission processes of blazars through their variability relies crucially on long-term monitoring. We present unprecedented light curves from unbiased observations of very high energy fluxes from the blazars Mrk 421 and Mrk 501 based on a joint analysis of data from the First G-APD Cherenkov Telescope (FACT) and the High Altitude Water Cherenkov (HAWC) Observatory. Thanks to an offset of 5.3 hours of the geographic locations, a complementary coverage of up to 12 hours of observation per day allows us to track variability on time scales of hours to days in more detail than with single-instrument analyses. Complementary features, such as better sensitivity thanks to a lower energy threshold with FACT and more regular coverage throughout the year with HAWC, provide valuable cross checks and extensions to the individual analyses. Daily flux comparisons for both Mrk 421 and Mrk 501 show largely correlated variations with a few significant exceptions. These deviations between measurements can be explained through fast variability within a few hours and will be discussed in detail.Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution

M@TE - Monitoring at TeV Energies

Blazars are extremely variable objects emitting radiation across the electromagnetic spectrum and showing variability on time scales from minutes to years. For the understanding of the emission mechanisms, simultaneous multi-wavelength observations are crucial. Various models for flares predict simultaneous flux increases in the X-ray and gamma-ray band or more complex variability patterns, depending on the dominant process responsible for the gamma-ray emission. Monitoring at TeV energies is providing important information to distinguish between different models. To study duty cycle and variability time scales of an object, an unbiased data sample is essential, and good sensitivity and continuous monitoring are needed to resolve smaller time scales. A dedicated long-term monitoring program at TeV energies has been started by the FACT project. Its success clearly illustrated that the usage of silicon based photo sensors (SIPMs) is ideal for long-term monitoring. They provide not only an excellent and stable detector performance, but also allow for observations during bright ambient light minimizing observational gaps and increasing the instrument's duty cycle. The observation time in a single longitude is limited to 6 hours. To study typical variability time scales of few hours to one day, the ultimate goal is 24/7 monitoring with a network of small telescopes around the globe (DWARF project). The installation of an Imaging Air Cherenkov Telescope is planned in San Pedro Martir, Mexico. For the M@TE (Monitoring at TeV energies) telescope, a mount from a previous experiment is being refurbished to be equipped with a camera using the new generation of SiPMs. In the presentation, the status of the M@TE project will be reported outlining the scientific potential, including the possibility to extend monitoring campaigns to 12 hours by coordinated observations together with FACT.Comment: 5 pages, 1 figure. Contribution to the 6th International Symposium on High Energy Gamma-Ray Astronomy (Gamma2016), Heidelberg, Germany. To be published in the AIP Conference Proceeding

Vitalité du francique en Lorraine germanophone ?

Dans notre article nous examinons la vitalité du francique rhénan parlé à Freyming-Merlebach dans le centre du Bassin Houiller de Lorraine. Nous nous intéressons particulièrement aux raisons du déclin de cette langue régionale de France et, afin de répondre à nos questions de recherches, nous avons conjugué méthodes quantitatives et qualitatives. Les résultats montrent que le déclin du francique dans le Bassin Houiller Lorrain est particulièrement marqué, la langue maternelle des jeunes générations dans la plupart des cas étant aujourd’hui le français. C’est la politique linguistique de l’État français qui a joué un rôle décisif dans ce déclin du francique en Lorraine germanophone. Nous limitant à la période de l’après-guerre, nous avons pu constater que les conditions générales étaient favorables à la francisation et que les interventions étaient particulièrement efficaces dans le domaine éducatif.This article examines the issue concerning the vitality of Rhenish Franconian, spoken in Freyming-Merlebach, at the heart of the coal fields in Lorraine, France. We are particularly interested in the reasons behind the decline of this French regional language, and in order to find answers to our research questions, we had recourse to both quantitative and qualitative methods. The results show a marked decline of Franconian in the above-mentioned area. Furthermore, they reveal that the mother tongue of today’s young generation, is in most cases, French. The language policy of the French state played a major role in this language shift in the German-speaking area of Lorraine. Limiting our inquiry to the periode after the Second World War, we discovered that the general conditions for imposing French were not only favourable, but particularly successful in the educational domaine

Vitalité du francique en Lorraine germanophone ?

Dans notre article nous examinons la vitalité du francique rhénan parlé à Freyming-Merlebach dans le centre du Bassin Houiller de Lorraine. Nous nous intéressons particulièrement aux raisons du déclin de cette langue régionale de France et, afin de répondre à nos questions de recherches, nous avons conjugué méthodes quantitatives et qualitatives. Les résultats montrent que le déclin du francique dans le Bassin Houiller Lorrain est particulièrement marqué, la langue maternelle des jeunes générations dans la plupart des cas étant aujourd’hui le français. C’est la politique linguistique de l’État français qui a joué un rôle décisif dans ce déclin du francique en Lorraine germanophone. Nous limitant à la période de l’après-guerre, nous avons pu constater que les conditions générales étaient favorables à la francisation et que les interventions étaient particulièrement efficaces dans le domaine éducatif.This article examines the issue concerning the vitality of Rhenish Franconian, spoken in Freyming-Merlebach, at the heart of the coal fields in Lorraine, France. We are particularly interested in the reasons behind the decline of this French regional language, and in order to find answers to our research questions, we had recourse to both quantitative and qualitative methods. The results show a marked decline of Franconian in the above-mentioned area. Furthermore, they reveal that the mother tongue of today’s young generation, is in most cases, French. The language policy of the French state played a major role in this language shift in the German-speaking area of Lorraine. Limiting our inquiry to the periode after the Second World War, we discovered that the general conditions for imposing French were not only favourable, but particularly successful in the educational domaine

Detection of Very-High Energy Gamma-Rays from the BL Lac Object PG 1553+113 with the MAGIC Telescope

The MAGIC telescope has observed very-high energy gamma-ray emission from the BL Lac object PG 1553+113 in 2005 and 2006 at an overall significance is 8.8 sigma. The light curve shows no significant flux variations on a daily timescale. The flux level during 2005 was, however, significantly higher as compared to 2006. The differential energy spectrum between approx. 90 GeV and 500 GeV is well described by a power law with a spectral index of -4.2+-0.3. The photon energy spectrum and spectral modeling allow to pose upper limits of z=0.74 and z=0.56, respectively, on the yet undetermined redshift of PG 1553+113. Recent VLT observations of this blazar show featureless spectra in the near-IR, thus no direct redshift could be determined from these measurements.Comment: 4 pages, 4 figures, to appear in the proceedings of the 30th International Cosmic Ray Conference, Merida, July 200

Pentaplexed quantitative real-time PCR assay for the simultaneous detection and quantification of botulinum neurotoxin-producing clostridia in food and clinical samples

Botulinum neurotoxins are produced by the anaerobic bacterium Clostridium botulinum and are divided into seven distinct serotypes (A to G) known to cause botulism in animals and humans. In this study, a multiplexed quantitative real-time PCR assay for the simultaneous detection of the human pathogenic C. botulinum serotypes A, B, E, and F was developed. Based on the TaqMan chemistry, we used five individual primer-probe sets within one PCR, combining both minor groove binder- and locked nucleic acid-containing probes. Each hydrolysis probe was individually labeled with distinguishable fluorochromes, thus enabling discrimination between the serotypes A, B, E, and F. To avoid false-negative results, we designed an internal amplification control, which was simultaneously amplified with the four target genes, thus yielding a pentaplexed PCR approach with 95% detection probabilities between 7 and 287 genome equivalents per PCR. In addition, we developed six individual singleplex real-time PCR assays based on the TaqMan chemistry for the detection of the C. botulinum serotypes A, B, C, D, E, and F. Upon analysis of 42 C. botulinum and 57 non-C. botulinum strains, the singleplex and multiplex PCR assays showed an excellent specificity. Using spiked food samples we were able to detect between 10(3) and 10(5) CFU/ml, respectively. Furthermore, we were able to detect C. botulinum in samples from several cases of botulism in Germany. Overall, the pentaplexed assay showed high sensitivity and specificity and allowed for the simultaneous screening and differentiation of specimens for C. botulinum A, B, E, and F

Mrk 421 after the Giant X-Ray Outburst in 2013

We present the results of the Swift observations of the nearby BL Lac object Mrk 421 during 2013 November-2015 June. The source exhibited a strong long-term variability in the 0.3-10 keV band, with a maximum-to-minimum flux ratio of 13, and underwent X-ray flares by a factor of 1.8-5.2 on timescales of a few weeks or shorter. The source showed 48 instances of intraday flux variability in this period, which sometimes was observed within the 1 ks observational run. It was characterized by fractional amplitudes of 1.5(0.3)%-38.6(0.4)% and flux doubling/halving times of 2.6-20.1 hr. The X-ray flux showed a lack of correlation with the TeV flux on some occasions (strong TeV flares were not accompanied by comparable X-ray activity and vice versa), indicating that the high-energy emission in Mrk 421 was generated from an emission region more complex than a single zone. The best fits of the 0.3-10 keV spectra were mainly obtained using the log-parabola model, showing a strong spectral variability that generally followed a “harder-when-brighter” trend. The position of the synchrotron spectral energy distribution peak showed an extreme range from a few eV to ∼10 keV that happens rarely in blazars