Gordana Tešić
(Penn State University)
07/12/2016, 09:20
The Astrophysical Multimessenger Observatory Network (AMON) will link the world’s leading high-energy neutrino, cosmic-ray, gamma-ray and gravitational wave observatories by performing real-time coincidence searches for multimessenger sources from observatories’ subthreshold data streams. The resulting coincidences will be distributed to interested parties in the form of electronic alerts for...
Dr.
Foteini Oikonomou
(Penn State)
07/12/2016, 09:50
The Pierre Auger Observatory is the world’s largest cosmic-ray detector, sensitive to cosmic rays with energy exceeding $\sim 10^{17}$ eV. In addition to charged cosmic rays that form the bulk of the cosmic-ray flux at ultra-high energies, Auger is sensitive to ultra-high energy neutral messengers (photons, neutrinos, and neutrons). The later are particularly exciting as they are expected to...
Dr.
Azadeh Keivani
(The Pennsylvania State University)
07/12/2016, 10:10
The IceCube high-energy neutrino observatory has reported a 6.5$\sigma$ discovery of the first high-energy astrophysical neutrino candidates. However, the nature of the sources responsible for these neutrinos -- potentially also the sources of the highest-energy cosmic rays -- is still unknown and no high-confidence counterparts to any of the neutrino events have been yet identified. If the...
Elina Lindfors
(Tuorla Observatory, University of Turku)
07/12/2016, 11:15
Long term monitoring of blazars is part of the Key Science Programs of the CTA Consortium. In this talk I will describe the foreseen observing program and the supporting optical monitoring observations.
Abe Falcone
(Penn State University)
07/12/2016, 11:45
Due to its ability to rapidly slew, with relatively minimal loss of observing time, Swift is able to look at many targets per day. This efficient pointing, combined with rapid response and the observatory's suite of sensitive telescopes covering multiple wavebands, make Swift an ideal monitoring observatory for the transient and variable sky. Swift regularly monitors a variety of active...
Dr.
Maria Magdalena Gonzalez
(Universidad Nacional Autonoma de Mexico)
07/12/2016, 12:15
Many multi-wavelength campaigns have been carried out to study high-synchrotron peak BL Lacs (HBL). In particular the activity in the gamma-rays and X-rays seems to be correlated in many observations but, not conclusive results have been achieved yet. In this work we present a robust and comprehensive study of the (VHE) γ-ray/X- ray correlation of Mrk 421 with data taken with different VHE...
Dr.
Amit Shukla
(Institut für Theoretische Physik und Astrophysik, Universität Würzburg)
07/12/2016, 12:35
The nearby TeV Blazar 1ES 1959+650 (z=0. 047) is a high-peaked BL Lacertae object and one of the prime sources which has been monitored at VHE gamma-ray energies by FACT. This source is well known for its orphan flare in June 2002, which makes this an unique source. It was found in a low state of flux since its outburst in 2002 and did not show much of activity during the first three years of...
Dr.
David Thompson
(NASA Goddard Space Flight Center)
07/12/2016, 14:15
For more than eight years, scientists using the two instruments on the Fermi Gamma-ray Space Telescope have gained significant experience with monitoring the high-energy Universe. The Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) have huge fields of view, and Fermi operates in a scanning mode, allowing the entire gamma-ray sky to be viewed about every three hours. Most of the...
Dr.
Robert Lauer
(University of New Mexico)
07/12/2016, 14:45
The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view
gamma-ray detector that performs monitoring of two thirds of the sky
every day at energies between 0.1 and 100 TeV.
Operating in its full configuration since March 2015, with a duty cycle of
approximately 90%, HAWC has already accumulated an unprecedented data set of unbiased and
evenly sampled daily TeV light...
Mr.
Stephan O'Brien
(UCD Dublin)
07/12/2016, 15:15
The Very Energetic Radiation Imaging Telescope Array System (VERITAS), located in southern Arizona USA, is an array of four 12-m diameter imaging atmospheric-Cherenkov telescopes dedicated to studying the very-high-energy (VHE, E > 100 GeV) gamma-ray sky. The investigation of Active Galactic Nuclei (AGN) is a key element of the VERITAS long-term science plan, with 34 detected by VERITAS to...
Dr.
Michael Zacharias
(North-West University)
07/12/2016, 15:35
A key project of the High Energy Stereoscopic System (H.E.S.S.) is the regular monitoring of different types of blazars at very high energies (E>100 GeV). Since the inauguration of H.E.S.S. in 2004 the high-frequency peaked BL Lac object PKS 2155-304 and the radio galaxy M 87 have been observed frequently. The flat spectrum radio quasar PKS 1510-089 has been added to the list of monitored...
Mr.
Paul Morris
(University of Oxford)
07/12/2016, 15:55
Classical Novae were revealed as a surprise source of $\gamma$-rays in *Fermi* LAT observations. During the first 8 years since the LAT was launched, 6 novae in total have been detected to $ > 5\sigma$ in $\gamma$-rays, in contrast to the $69$ discovered optically in the same period. We attempt to resolve this discrepancy by assuming all novae are $\gamma$-ray emitters, and assigning peak...
Dr.
Margo Aller
(University of Michigan)
07/12/2016, 16:45
The University of Michigan 26-m paraboloid (UMRAO) was dedicated to observations of AGN, primarily of the blazar class, for nearly 40 years providing continuous light curves for hundreds of sources. In 1977 the telescope was placed under automatic computer control permitting nearly round-the-clock operation and systematically-obtained measurements of both linear polarization and total flux...
Dr.
Merja Tornikoski
(Aalto University Metsahovi Radio Observatory)
07/12/2016, 17:15
I will present the ongoing blazar monitoring programme and other AGN observing
projects of Aalto University Metsähovi Radio Observatory (MRO) in Finland.
MRO has been operational for more than 40 years now, and even though we
struggle with decreasing funding for basic research just like many other
research units nowadays do, our streamlined operations and flexibility allow
for a...
Dr.
Talvikki Hovatta
(University of Turku)
07/12/2016, 17:45
Since 2008, the 40-m telescope at Owens Valley Radio Observatory in California has been used to monitor a large number of blazars at 15 GHz. The program started with 1158 candidate gamma-ray sources and has been extended now to monitor over 1800 blazars, including all Fermi 1FGL and 2FGL sources and TeV emitters, with twice per week cadence. The data of this program have been used in more than...
Dr.
Daniela Huppenkothen
(New York University)
08/12/2016, 09:00
Virtually all astronomical sources are variable on some time scale, making studies of variability across different wavelengths a major tool in pinning down the underlying physical processes, for example accretion onto compact objects and cataclysmic explosions like gamma-ray bursts. The new telescopes currently starting operations or coming online in the coming years, including the Square...
Mr.
Ioannis Liodakis
(University of Crete, FORTH)
08/12/2016, 09:30
Blazars are known to show periods of quiescence followed by extreme outbursts seen throughout the electromagnetic spectrum. We present a novel maximum likelihood approach to capturing this bimodal behavior by examining blazar radio variability in the flux-density domain. We separate quiescent and flaring components of a source's light curve by modeling its flux-density distribution as a series...
Dr.
Guillaume Belanger
(European Space Agency)
08/12/2016, 09:50
Time domain astronomy and astrophysics are concerned with studying the temporal characteristics of the light from distant astrophysical sources that our instruments detect. Consequently, time domain studies are aimed at the detection and characterisation of variability: periodic variability, aperiodic or stochastic variability, and transient events. In this presentation, I propose to introduce...
Dr.
Arti Goyal
(Astronomical observatory of the Jagiellonian University)
08/12/2016, 10:10
The typical shape of blazar lightcurves' power spectra is a power-law, $P(f) = A f^{-\beta}$, where A is the normalization and $\beta$ is the slope, indicating that the variability is generated by the underlying $\it stochastic$ processes which is of colored noise type (i.e., $\beta \simeq 1-3$). Here we present the results of power spectral analysis of 5 blazars utilizing the $\it Fermi$-LAT...
Walter Max-Moerbeck
(Max-Planck-Institut für Radioastronomie)
08/12/2016, 11:45
I will discuss our efforts to determine the location of the gamma-ray emission site in blazars with the ongoing OVRO 40 meter telescope blazar monitoring program. This program started in 2008 and is currently monitoring about 1800 blazars at 15 GHz with twice a week cadence for a sample including most of the bright blazars north of declination -20 degrees. A summary of previous findings and...
Dr.
Nachiketa Chakraborty
(Max Planck Institute for Nuclear Physics)
08/12/2016, 12:05
Despite intensive research over a few decades facilitated by highly sensitive multiwavelength (MWL) telescopes, fundamental characteristics of active galactic nuclei (AGNs) are still open. With respect to physics of individual AGNs, the location and mechanisms of particle acceleration, their connection to flaring, relative importance of hadronic and leptonic processes in specific sources and...
Dr.
Tim Ruhe
(TU Dortmund)
08/12/2016, 12:25
Obtaining energy spectra of incident particles such as neutrinos or gamma-rays is a common challenge in neutrino- and Air-Cherenkov astronomy, as the particle's energy cannot be observed directly but has to be inferred from other observables e.g. energy losses of secondary particles utilized for detection. The task is further made difficult by the fact that the production of secondaries, e.g....
Dr.
Katsuaki Asano
(Institute for Cosmic Ray Research, The University of Tokyo)
08/12/2016, 14:15
The curved spectra seen in blazar emission can be explained by the curved electron spectra predicted by the stochastic acceleration process via turbulence. In this slow acceleration process, the time-dependent treatment is essential. In this talk I present our results of the time-dependent simulations of the acceleration and emission in blazars. The model naturally explains the hard and curved...
Krzysztof Nalewajko
(Nicolaus Copernicus Astronomical Center)
08/12/2016, 14:45
Magnetic reconnection is one of the most promising mechanisms of dissipation and particle acceleration in relativistic jets of blazars. Magnetic reconnection is a complex physical phenomenon that by nature is very difficult for analytical and experimental studies. Rapid progress in understanding relativistic reconnection has been made over the past several years thanks to numerical kinetic...
Ms.
Stella Boula
(University of Athens)
08/12/2016, 15:15
Adopting the hypothesis that the nonthermal emission of blazars is primarily due to the acceleration of electrons, we construct a simple leptonic model in order to explain the Blazar Sequence. The acceleration process is assumed to be of the first order Fermi type and the injected electrons and photons in the emitting region of the blazar are described by spatially averaged kinetic equations....
Prof.
Markus Boettcher
(North-West University)
08/12/2016, 15:35
We present results of time-dependent flux and polarization calculations in the framework of an internal-shock model for blazars. Both a leptonic and hadronic model are considered. It is shown that polarization-angle swings, accompanied by multi-wavelength flares, are a natural consequence of an internal shock in a jet pervaded by a helical magnetic field, without the need for bent or otherwise...
Prof.
Vasiliki Pavlidou
(University of Crete)
08/12/2016, 16:40
Optical Synchrotron emission from blazars is significantly polarized and the polarization probes the magnetic field structure in the jet. Rotations of the polarization angle in blazars reveal important information about the evolution of disturbances responsible for blazar flares. The RoboPol program for the polarimetric monitoring of statistically complete samples of blazars was developed in...
Dr.
Kosmas Gazeas
(University of Athens)
08/12/2016, 17:10
Blazar Optical Sky Survey (BOSS) Project is a dedicated observational survey with the aim of monitoring known blazars in optical wavelengths. The project was initiated in March 2013 at the University of Athens Observatory (UOAO), performing ground-based optical photometric observations in parallel with orbital (SWIFT/XRT, FERMI/LAT) X-ray observatories. BOSS project has immediately met...
Prof.
Josep Martí
(University of Jaén)
08/12/2016, 17:30
The identification of high energy sources in the Galactic Plane is often a difficult but rewarding task as it can lead to the discovery of exotic stellar accelerators, such as gamma-ray binaries and microquasars. Here, we report a multi-wavelength analysis of the unassociated Fermi source 3FGL J0133.3+5930 at low galactic latitude. Two candidate counterparts have been identified inside its 95%...
Mr.
Jens Buß
(Tu Dortmund, Exp. Physik 5b)
09/12/2016, 09:15
The First G-APD Cherenkov Telescope (FACT) is pioneering the usage of solid state photo sensors (G-APD aka SiPM) for measuring the dim flashes of Cherenkov light initiated by the interaction of a high energetic particles or photons with the atmosphere. One advantage of these sensors is that they donot degrade even when exposed to bright light. Therefore, FACT can operate with standard setup...
Dr.
Felicia Krauss
(GRAPPA & API, UvA)
09/12/2016, 11:20
Dr.
Emmanouil Angelakis
(Max-Planck-Institut für Radioastronomie), Dr.
Ioannis Myserlis
(Max Planck Institut für Radioastronomie)
09/12/2016, 11:50
Motivated by the advent of Fermi gamma-ray space telescope and the potential of multi-energy studies of AGN, we initiated in January 2007 a monthly multi-frequency radio monitoring of almost 100 gamma-ray blazars. The observations were being conducted primarily wit the Effelsberg 100-m, the IRAM Pico Veleta 30-m and less regularly the APEX 12-m telescopes in the frequency range from 2.6 to 345...
Dr.
Ioannis Myserlis
(Max Planck Institut für Radioastronomie)
09/12/2016, 12:10
The radio emission of active galactic nuclei (AGN) jets is polarized due to the incoherent synchrotron radiation mechanism. The linear and circular polarization parameters are directly related with the physical conditions (magnetic field strength and topology, particle density and plasma composition) both in the jet as well as any magnetized plasma regions along the line of sight. However,...
Dr.
Amit Shukla
(Institut für Theoretische Physik und Astrophysik, Universität Würzburg)
09/12/2016, 14:00
Blazars are a subclass of Active Galactic Nuclei (AGN) characterized by non-thermal emission extending from radio to high energies. The broadband radiation originates within a relativistic jet that is oriented very close to the line of sight. Radiative processes of Blazars can be studied using ASTROSAT.
ASTROSAT is India's first multi-wavelength astronomy satellite in a 650-km,...
Dr.
Felicia Krauss
(GRAPPA & API, UvA)
09/12/2016, 14:20
Active galactic nuclei often show relativistic outflows of matter, called jets. We study their simultaneous radio to gamma-ray spectral energy distributions (SEDs) from the
TANAMI sample, with over 80 SEDs for 22 sources. The large amount of monitoring data from the TANAMI project allows us to construct dynamic SEDs, highlighting spectral changes in varying flux states. With the data, we can...
Dr.
Volodymyr Savchenko
(APC)
09/12/2016, 15:30
Observations of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) allow us to put upper limits on the gamma-ray and hard X-ray emission associated with the gravitational wave events, reported by LIGO/Virgo collaboration, as well as with exceptional high energy neutrino events detected by IceCube. Large duty cycle of INTEGRAL, stable background, and...
Daniel Kuempel
(RWTH Aachen University)
09/12/2016, 15:50
The Pierre Auger Observatory, located in Argentina, provides an unprecedented integrated aperture for the search of photons with energy above 100 PeV. In this contribution recent results are presented with a focus on directional searches for photon point sources. The derived limits are of considerable astrophysical interest: Diffuse limits place severe constraints on top-down models and start...
Dr.
Azadeh Keivani
(The Pennsylvania State University)
10/12/2016, 09:00
Gordana Tešić
(Penn State University)
10/12/2016, 09:25
Dr.
Foteini Oikonomou
(Penn State)
10/12/2016, 10:15
Dr.
Robert Lauer
(University of New Mexico)
10/12/2016, 11:10
Dr.
Daniela Dorner
(Universität Würzburg)
10/12/2016, 11:30
Dr.
Fabian Schüssler
(IRFU / CEA-Saclay)
10/12/2016, 11:50
In this contribution I will present the H.E.S.S. programs to follow up on multi-wavelength and multi-messenger observations and alerts.
I will show first results from searches for high-energy gamma-ray emission in spatial coincidence with neutrino events detected by the IceCube and ANTARES neutrino telescopes and discuss recent extensions towards a fully integrated real-time alert system...
Konstancja Satalecka
(DESY Zeuthen)
10/12/2016, 12:10
Dr.
Chris Copperwheat
(Astrophysics Research Institute, Liverpool John Moores University)
10/12/2016, 14:00
The Liverpool Telescope is a 2-metre clear aperture, fully robotic telescope based at the Observatorio Del Roque De Los Muchachos on the Canary island of La Palma. Robotic telescopes are powerful tools for the exploration of the time variable sky, and their rapid reaction and flexible scheduling capabilities provide them with an important role in the multimessenger era. In this talk I will...
Prof.
Vladimir Lipunov
(Lomonosov Moscow State University)
10/12/2016, 14:20
Dr.
Felicia Krauss
(GRAPPA & API, UvA)
10/12/2016, 15:30
The IceCube Collaboration has published results on a neutrino flux significantly in excess of the atmospheric background. Due to low atmospheric background at PeV energies, the highest energy events are the most likely ones to be of extraterrestrial origin. We use broadband spectra in the IceCube integration period to calculate the maximum expected number of neutrinos assuming a pion...
Mr.
armin vahdat motlagh
(Istanbul Technical University)
HAP Workshop
Poster
To be able to fully describe the emission properties of a
black hole binary
system multi-wavelength observations are required as the inner parts
of the accretion disk and the corona emit X- and Gamma-
rays, outer parts of the accretion disk and the companion star emit
optical and infrared emission and jets emit radiation from
radio all the way to soft X-rays. In this matter i will model...
Prof.
Pedro Luis Luque-Escamilla
(University of Jaén)
HAP Workshop
Oral
GRS 1758-258 is a prototypical microquasar near the Galactic Center whose non-degenerate
optical counterpart was believed to be a late-type giant star. The system has remained poorly studied at optical wavelengths because it is very faint and strongly absorbed. In this work, we present the results of long-slit spectroscopy at low resolution with a 10 m class telescope (GRANTECAN). Details...
Mr.
Bernd Schleicher
(Universität Würzburg)
HAP Workshop
Poster
The First G-APD Cherenkov Telescope (FACT) is observing bright blazars at TeV energies. One main goal of the project is the long-term monitoring of the brightest TeV-sources in the sky. To obtain a continuous and unbiased data sample, a small sample of sources is observed as much as possible. For data at the beginning and end of the observation window and for sources with large declination,...
Mr.
Tobias Herbst
(Universität Würzburg)
HAP Workshop
Poster
The First G-APD Cherenkov Telescope (FACT) has been monitoring the blazar 1ES 1959+650 since 2012.
While the source was found in a low state in the first three years,
a major flaring activity was detected in 2016 with several outbursts.
In total there are more than 1000 hours of observations on this source.
It has been observed at high zenith angles and also during bright moon.
The...
Johannes Schumacher
(RWTH Aachen University)
AMON Workshop
Poster
The FAMOUS telescope is a prove-of-concept study for the application of silicon photomultipliers (SiPMs) in fluorescence telescopes. Such telescopes detect the fluorescence light emitted by molecules in the Earth’s atmosphere when excited by secondary particles of an extended air shower. Today’s instruments are using photomultiplier tubes for photon detection. The 61-pixel FAMOUS camera makes...
Dr.
Narek Sahakyan
(ICRANet-Armenia)
HAP Workshop
Oral
Detection of high energy gamma-ray emissions from non-blazar active galactic nuclei (AGN) with Fermi LAT shows, that these are different and potentially very interesting classes of gamma-ray emitters. This provides an alternative approach for studying the high energy emission processes compared to blazars where the emission is strongly Doppler boosted. Up to now there are 27 non-blazar AGNs...
Dr.
David Hiriart
(Landessternwarte Königstuhl (LSW), Heidelberg University)
AMON Workshop
Poster
We carried out a long-term (2007-2016) polarimetric monitoring in the
optical R-band of 37 bright blazars (12 mag < m(R) <18 mag) using the
84-cm telescope at San Pedro Martir Observatory in Mexico. Data were
obtained using an optical single beam polarimeter as part of the GASP-WEBT
collaboration. Some of the photometric data and few polarization data points
were previously...
Ms.
Eda Vurgun
(Istanbul University)
HAP Workshop
Poster
In this work, we study the long-term spectral evolution of the first transient anomalous X-ray pulsar XTE J1810−197 which was discovered in 2003, when its X-ray luminosity increased ≈100 fold. We fit the spectral data from all archival X-ray observations using a two-component blackbody model, where the cool component is most likely originating from the whole surface of the neutron star and the...
Dr.
Maria Magdalena Gonzalez
(Universidad Nacional Autonoma de Mexico)
Poster
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 in the gamma-ray band or more complex
variability...
Dr.
Amit Shukla
(Institut für Theoretische Physik und Astrophysik, Universität Würzburg), Dr.
Jayashree Roy
(UM-DAE Center for Excellence in Basic Sciences)
HAP Workshop
Poster
A multiwavelength study of the Flat Spectrum Radio Quasar (FSRQ) B3 1708+433 (z=1.027), also known as CGRaBS J1709+4318, has been performed using 7 years of Fermi-LAT observations. A few GeV gamma ray flares are observed during this period . These flares are analyzed and compared to understand their emission mechanisms. An energy dependent flux variability of the source is studied. The...
Prof.
Josep Martí
(University of Jaén)
HAP Workshop
Poster
We present a technical description of the Astronomical Observatory of the University of Jaén (UJA). Equipped with a 41 cm Schmidt-Cassegrain telescope on a robotic equatorial mount, this instrument is mainly devoted to educational tasks for Astronomy students and long-term photometric monitoring for research purposes. Outreach activities are also occasionally carried out, and a live all-sky...
Mr.
Omar Kurtanidze
(Abastumani Observatory)
HAP Workshop
Oral
To study optical variability of extragalactic objects since 1997 we are conducting in Abastumani Observatory a long-term campaign using dedicated telescopes, which allowed to collect ~300 000 CCD frames during ~2 900 nights. This extensive monitoring campaign over 100 blazars during first five years was carried out in BVRI bands and later on from 2002 mainly in R band using the 70-cm meniscus...
Dr.
Robert Lauer
(University of New Mexico)
Poster
Astrophysical sources are now observed by many different instruments at
different wavelengths, from radio to high-energy gamma-rays, with an
unprecedented quality. Putting all these data together to form a
coherent view, however, is a very difficult task, for example when
performing a broadband fit of the energy spectrum of the source. Each
instrument has its own data format, software and...
Dr.
Daniela Dorner
(Universität Würzburg)
HAP Workshop
Poster
The nearby TeV-detected blazar 1ES 1959+650 is one of the bright sources in the X-ray sky and a frequent target of X-ray Telescope onboard the Swift satellite. It has shown two exceptionally two strong and prolonged X-ray flaring activities during the one year period since 2015 August compared to those observed in previous years. During these flares, long lasting X-ray states was...
Mr.
Julian Kemp
(RWTH Aachen University)
AMON Workshop
Poster
The Pierre Auger Observatory successfully measures cosmic-ray air-showers at the highest energies and sets the best limits for the photon flux in the EeV range. Currently, the Pierre Auger Observatory is a hybrid detector consisting of 1660 water-Cherenkov detectors deployed over an area of 3000 km$^2$ and four fluorescence detector sites where the atmosphere above the surface detector is...
