R. Moderski
University of Colorado Boulder
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by R. Moderski.
The Astrophysical Journal | 2000
Michal Blazejowski; M. H. Sikora; R. Moderski; Greg M. Madejski
We demonstrate the importance of near-infrared radiation from hot dust for Compton cooling of electrons/positrons in quasar jets. In our model, we assume that the nonthermal radiation spectra observed in optically violent variable (OVV) quasars are produced by relativistic electrons/positrons accelerated in thin shells that propagate down the jet with relativistic speeds. We show that the Comptonization of the near-IR flux is likely to dominate the radiative output of OVV quasars in the energy range from tens of keV up to hundreds of MeV, where it exceeds that produced by Comptonization of the UV radiation reprocessed and rescattered in the broad emission line (BEL) region. The main reason for this lies in the fact that the jet encounters the ambient IR radiation over a relatively large distance as compared to the distance where the energy density of the BEL light peaks. In the soft to mid-energy X-ray band, the spectral component resulting from Comptonization of the near-IR radiation joins smoothly with the synchrotron self-Compton component, which may be responsible for the soft X-ray flux. At the highest observed γ-ray energies, in the GeV range, Comptonization of broad emission lines dominates over other components.
The Astrophysical Journal | 1999
Greg M. Madejski; Marek Sikora; Tess Jaffe; MichaŁ BŁażejowski; Keith Jahoda; R. Moderski
This paper reports on the X-ray emission from BL Lacertae during its 1997 July outburst as observed with the Rossi X-Ray Timing Explorer (RXTE), compares the RXTE data with previous measurements, and interprets the overall electromagnetic emission in the context of the currently popular theoretical models. The source is bright and variable, with the 2-10 keV flux approximately 2-3.5 times higher than measured in 1995 November by ASCA. The spectrum is also harder, with power-law energy indices of ~0.4-0.6, compared with ~0.9 in 1995 November. Both in the optical band, where BL Lacertae now shows broad emission lines, and in the X-ray band, where the spectrum is hard, the overall electromagnetic distribution of BL Lacertae is similar to that observed in blazars associated with quasars rather than to that seen in the more common high-energy peaked BL Lac-type objects. We argue that the high-energy (X-ray and γ-ray) emission from BL Lacertae consists of two spectral components: X-rays are produced by Comptonization of synchrotron radiation, while the γ-rays are produced by Comptonization of the broad emission line flux.
arXiv: Instrumentation and Methods for Astrophysics | 2016
J. Niemiec; W. Bilnik; L. Bogacz; J. Borkowski; F. Cadoux; A. Christov; M. Dyrda; Y. Favre; A. Frankowski; M. Grudzi; M. Heller; M. Jamrozy; M. Janiak; J. Kasperek; K. Lalik; E. Lyard; E. Mach; D. Mandat; R. Moderski; T. Montaruli; A. Neronov; M. Ostrowski; M. Pech; A. Porcelli; E. Prandini; P. Rajda; M. Rameez; P. Schovanek; K. Seweryn; K. Skowron
A single-mirror small-size (SST-1M) Davies-Cotton telescope with a dish diameter of 4 m has been built by a consortium of Polish and Swiss institutions as a prototype for one of the proposed small-size telescopes for the southern observatory of the Cherenkov Telescope Array (CTA). The design represents a very simple, reliable, and cheap solution. The mechanical structure prototype with its drive system is now being tested at the Institute of Nuclear Physics PAS in Krakow. Here we present the design of the prototype and results of the performance tests of the structure and the drive and control system.
Astronomische Nachrichten | 2016
Luisa Ostorero; Raffaella Morganti; Aneta Siemiginowska; R. Moderski; Alvaro Labiano
With the Westerbork Synthesis Radio Telescope, we performed H I observations of a sample of known X-ray emitting Gigahertz-peaked-spectrum galaxies with compact-symmetric-object morphology (GPS/CSOs) that lacked an H I absorption detection. We combined radio and X-ray data of the full sample of X-ray emitting GPS/CSOs and found a significant, positive correlation between the column densities of the total and neutral hydrogen (NH and NHI, respectively). Using a Bayesian approach, we simultaneously quantified the parameters of the NH-NHI relation and the intrinsic spread of the data set. For a specific subset of our sample, we found NH ∝ NHI b, with b=0.93+0.49-0.33, and σ_int(NH)= 1.27+1.30-0.40. The NH-NHI correlation suggests a connection between the physical properties of the radio and X-ray absorbing gas. Data from the Westerbork Synthesis Radio Telescope
arXiv: Instrumentation and Methods for Astrophysics | 2016
S. Toscano; E. Prandini; W. Bilnik; F. Cadoux; A. Christov; M. Dyrda; Y. Favre; A. Frankowski; M. Heller; M. Jamrozy; M. Janiak; J. Kasperek; K. Lalik; E. Lyard; E. Mach; D. Mandat; R. Moderski; T. Montaruli; A. Neronov; J. Niemiec; M. Ostrowski; M. Pech; A. Porcelli; P. Rajda; M. Rameez; P. Schovanek; K. Seweryn; K. Skowron; V. Sliusar; M. Stodulska
S. Toscano∗ a,n, E. Prandinia E-mail: [email protected] W. Bilnikk, J. Blockic, L. .Bogaczm, T .Bulikd , F. Cadouxb, A. Christovb, M. Curyloc, D. della Volpeb, M. Dyrdac, Y. Favreb, A. Frankowskig, Ł. Grudnikic, M. Grudzinskad , M. Hellerb, B. Idźkowskie, M. Jamrozye, M. Janiakg, J. Kasperekk, K. Lalikk, E. Lyarda, E. Machc, D. Mandatl , A. Marszalekc,e, J. Michalowskic, R. Moderskig, T. Montarulib, A. Neronova, J. Niemiecc, M. Ostrowskie, P. Paśko f , M. Pechl , A. Porcellib, P. Rajdak, M. Rameezb, E. Jr. Schioppab, P. Schovanekl , K. Seweryn f , K. Skowronc, V. Sliusar j, M. Sowinskic, Ł. Stawarze, M. Stodulskae, M. Stodulskic, I. Troyano Pujadasb, R. Waltera, M. Wiȩcekk, A. Zagdanskie, K. Ziȩtarae, P. Żychowskic for the CTA Consortium† a. ISDC, Observatoire de Geneve, Universite de Geneve, 1290 Versoix, Switzerland. b. Department de physique nucleaire et corpusculaire, Universite de Geneve, CH-1205 Switzerland. c. Instytut Fizyki Jadrowej im. H. Niewodniczanskiego Polskiej Akademii Nauk, 31-342 Krakow, Poland. d. Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw, Poland e. Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244, Krakow, Poland. f. Centrum Badan Kosmicznych Polskiej Akademii Nauk, 18a Bartycka str., 00-716 Warsaw, Poland. g. Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland. j. Astronomical Observatory, Taras Shevchenko Nat. University of Kyiv, Observatorna str., 3, Kyiv, Ukraine. k. AGH University of Science and Technology, al.Mickiewicza 30, Krakow, Poland, l. Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic. m. Department of Information Technologies, Jagiellonian University, 30-348 Krakow, Poland. n. Vrije Universiteit Brussels, Pleinlaan 2 1050 Brussels, Belgium.
arXiv: Instrumentation and Methods for Astrophysics | 2016
Michael Ostrowski; R. Moderski; E. Mach; A. Neronov; M. Sowiński; D. Mandat; J. Niemiec; Y. Favre; E. Schioppa; A. Frankowski; W. Bilnik; M. Wiȩcek; S. Toscano; M. Jamrozy; Roman Wawrzaszek; J. Błocki; P. Paśko; J. Michałowski; M. Janiak; K. Ziȩtara; A. Porcelli; Ł. Grudnik; Ł. Stawarz; F. Cadoux; M. Curyło; L. Bogacz; A. Marszałek; M. Grudzińska; M. Rataj; M. Pech
The prototype of a Davies-Cotton small size telescope (SST-1M) has been designed and developed by a consortium of Polish and Swiss institutions and proposed for the Cherenkov Telescope Array (CTA) observatory. The main purpose of the optical system is to focus the Cherenkov light emitted by extensive air showers in the atmosphere onto the focal plane detectors. The main component of the system is a dish consisting of 18 hexagonal mirrors with a total effective collection area of 6.47 m 2 (including the shadowing and estimated mirror reflectivity). Such a solution was chosen taking into account the analysis of the Cherenkov light propagation and based on optical simulations. The proper curvature and stability of the dish is ensured by the mirror alignment system and the isostatic interface to the telescope structure. Here we present the design of the optical subsystem together with the performance measurements of its components.
Proceedings of SPIE | 2016
J. A. Aguilar; W. Bilnik; J. Borkowski; F. Cadoux; A. Christov; D. della Volpe; Y. Favre; Mathieu Heller; J. Kasperek; E. Lyard; A. Marszałek; R. Moderski; T. Montaruli; A. Porcelli; E. Prandini; P. Rajda; M. Rameez; E.jr Schioppa; I. Troyano Pujadas; K. Zietara; J. Błocki; L. Bogacz; T. Bulik; A. Frankowski; M. Grudzińska; B. Idźkowski; M. Jamrozy; M. Janiak; K. Lalik; E. Mach
The Small Size Telescope with Single Mirror (SST-1M) is one of the proposed types of Small Size Telescopes (SST) for the Cherenkov Telescope Array (CTA). The CTA south array will be composed of about 100 telescopes, out of which about 70 are of SST class, which are optimized for the detection of gamma rays in the energy range from 5 TeV to 300 TeV. The SST-1M implements a Davies-Cotton optics with a 4 m dish diameter with a field of view of 9°. The Cherenkov light produced in atmospheric showers is focused onto a 88 cm wide hexagonal photo-detection plane, composed of 1296 custom designed large area hexagonal silicon photomultipliers (SiPM) and a fully digital readout and trigger system. The SST-1M camera has been designed to provide high performance in a robust as well as compact and lightweight design. In this contribution, we review the different steps that led to the realization of the telescope prototype and its innovative camera.
Proceedings of SPIE | 2014
R. Moderski; J. A. Aguilar; W. Bilnik; L. Bogacz; T. Bulik; A. Christov; D. della Volpe; M. Dyrda; A. Frankowski; M. Grudzińska; Jerzy Grygorczuk; M. Heller; B. Idźkowski; M. Janiak; M. Jamrozy; M. Karczewski; J. Kasperek; E. Lyard; A. Marszałek; J. Michałowski; R. Mohamed; T. Montaruli; A. Neronov; J. Nicolau-Kukliński; J. Niemiec; M. Ostrowski; P. Paśko; Ł. Płatos; E. Prandini; R. Pruchniewicz
The southern part of the Cherenkov Telescope Array (CTA) observatory will consist of at least three types of telescopes: large size, medium size and small size telescopes. Massive Monte Carlo simulations have been performed using the European Grid Infrastructure to analyze the performance of this array. We present the results of these simulations for a sub-array of small size telescopes of the Davies-Cotton type. Such a telescope, called SST-1M, is currently being proposed for the CTA observatory by a group of Polish and Swiss institutions. SST-1M will have a mirror of 4m diameter and it will be equipped with a fully digital camera based on silicon photodetectors. We present the analysis of the sub-array sensitivity, angular resolution, and energy resolution to demonstrate the fulfillment of the requirements of the CTA Consortium. To verify the results obtained in numerical simulations a construction of a mini array of five SST-1M telescopes is planned. We also present the performance of such a mini array and discuss the prospects of its scientific program.
Proceedings of SPIE | 2014
J. A. Aguilar; W. Bilnik; L. Bogacz; T. Bulik; A. Christov; D. della Volpe; M. Dyrda; A. Frankowski; M. Grudzińska; Jerzy Grygorczuk; M. Heller; B. Idźkowski; M. Janiak; M. Jamrozy; M. Karczewski; J. Kasperek; E. Lyard; A. Marszałek; J. Michałowski; R. Moderski; T. Montaruli; A. Neronov; J. Nicolau-Kukliński; J. Niemiec; M. Ostrowski; P. Paśko; Ł. Płatos; E. Prandini; R. Pruchniewicz; J. Rafalski
The single mirror Small Size Telescopes (SST-1M), being built by a sub-consortium of Polish and Swiss Institutions of the CTA Consortium, will be equipped with a fully digital camera with a compact photodetector plane based on silicon photomultipliers. The internal trigger signal transmission overhead will be kept at low level by introducing a high level of integration. It will be achieved by massively deploying state-of-the-art multi-gigabit transceivers, beginning from the ADC flash converters, through the internal data and trigger signals transmission over backplanes and cables, to the camera’s server 10Gb/s Ethernet links. Such approach will allow fitting the size and weight of the camera exactly to the SST-1M needs, still retaining the flexibility of a fully digital design. Such solution has low power consumption, high reliability and long lifetime. The concept of the camera will be described, along with some construction details and performance results.
arXiv: Instrumentation and Methods for Astrophysics | 2017
Mathieu Heller; E.jr Schioppa; A. Porcelli; I. Troyano Pujadas; K. Ziȩtara; D. della Volpe; T. Montaruli; F. Cadoux; Y. Favre; J. A. Aguilar; A. Christov; E. Prandini; P. Rajda; M. Rameez; W. Bilnik; J. Błocki; L. Bogacz; J. Borkowski; T. Bulik; A. Frankowski; M. Grudzińska; B. Idźkowski; M. Jamrozy; M. Janiak; J. Kasperek; K. Lalik; E. Lyard; E. Mach; D. Mandat; A. Marszałek
The Small Size Telescope with Single Mirror (SST-1M) is one of the proposed types of Small Size Telescopes (SST) for the Cherenkov Telescope Array (CTA). About 70 SST telescopes will be part the CTA southern array which will also include Medium Sized Telescopes (MST) in its threshold configuration. Optimized for the detection of gamma rays in the energy range from 5 TeV to 300 TeV, the SST-1M uses a Davies-Cotton optics with a 4 m dish diameter with a field of view of 9 degrees. The Cherenkov light resulting from the interaction of the gamma-rays in the atmosphere is focused onto a 88 cm side-to-side hexagonal photo-detection plane. The latter is composed of 1296 hollow light guides coupled to large area hexagonal silicon photomultipliers (SiPM). The SiPM readout is fully digital readout as for the trigger system. The compact and lightweight design of the SST-1M camera offers very high performance ideal for gamma-ray observation requirement. In this contribution, the concept, design, performance and status of the first telescope prototype are presented.