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29 results on '"Humensky, B."'

1. A Contribution of the HAWC Observatory to the TeV era in the High Energy Gamma-Ray Astrophysics: The case of the TeV-Halos

Author

Torres-Escobedo, Ramiro, Zhou, Hao, de la Fuente, Eduardo, Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Babu, R., Baghmanyan, V., Barber, A. S., Gonzalez, J. Becerra, Belmont-Moreno, E., BenZvi, S. Y., Berley, D., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Chaparro-Amaro, O., Cotti, U., Cotzomi, J., de León, S. Coutiño, de León, C., Diaz-Cruz, L., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., Durocher, M., DuVernois, M. A., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Alonso, M. Fernández, Fick, B., Fleischhack, H., Flores, J. L., Fraija, N. I., Garcia, D., García-González, J. A., García-Torales, G., Garfias, F., Giacinti, G., Goksu, H., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Herzog, I., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hui, C. M., Humensky, B., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Jhee, H., Joshi, V., Kieda, D., Kunde, G J., Kunwar, S., Lara, A., Lee, J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J., Longinotti, A. L., López-Coto, R., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martinez-Castellanos, I., Martínez-Huerta, H., Martínez-Castro, J., Matthews, J. A. J., McEnery, J., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rivière, C., Rosa-Gonzalez, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tanner, M., Tollefson, K., Torres, I., Turner, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Watson, I. J., Weisgarber, T., Werner, F., Willox, E., Wood, J., Yodh, G. B., Zepeda, A., Torres-Escobedo, Ramiro, Zhou, Hao, de la Fuente, Eduardo, Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Camacho, J. R. Angeles, Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Babu, R., Baghmanyan, V., Barber, A. S., Gonzalez, J. Becerra, Belmont-Moreno, E., BenZvi, S. Y., Berley, D., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Chaparro-Amaro, O., Cotti, U., Cotzomi, J., de León, S. Coutiño, de León, C., Diaz-Cruz, L., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., Durocher, M., DuVernois, M. A., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Alonso, M. Fernández, Fick, B., Fleischhack, H., Flores, J. L., Fraija, N. I., Garcia, D., García-González, J. A., García-Torales, G., Garfias, F., Giacinti, G., Goksu, H., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Herzog, I., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hui, C. M., Humensky, B., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Jhee, H., Joshi, V., Kieda, D., Kunde, G J., Kunwar, S., Lara, A., Lee, J., Lee, W. H., Lennarz, D., Vargas, H. León, Linnemann, J., Longinotti, A. L., López-Coto, R., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martinez-Castellanos, I., Martínez-Huerta, H., Martínez-Castro, J., Matthews, J. A. J., McEnery, J., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rivière, C., Rosa-Gonzalez, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tanner, M., Tollefson, K., Torres, I., Turner, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Watson, I. J., Weisgarber, T., Werner, F., Willox, E., Wood, J., Yodh, G. B., and Zepeda, A.

Abstract

We present a short overview of the TeV-Halos objects as a discovery and a relevant contribution of the High Altitude Water \v{C}erenkov (HAWC) observatory to TeV astrophysics. We discuss history, discovery, knowledge, and the next step through a new and more detailed analysis than the original study in 2017. TeV-Halos will contribute to resolving the problem of the local positron excess observed on the Earth. To clarify the latter, understanding the diffusion process is mandatory., Comment: Work presented in the 21st International Symposium on Very High Energy Cosmic Ray Interactions(ISVHECRI 2022) as part of the Ph. D. Thesis of Ramiro Torres-Escobedo (SJTU, Shanghai, China). Accepted for publication in SciPost Physics Proceedings (ISSN 2666-4003). 11 pages, 3 Figures. Short overview of HAWC and TeV Halos objects until 2022

Published
2023

2. Supernova remnants in the very-high-energy sky: prospects for the Cherenkov Telescope Array

Author

Cristofari, P., Zanin, R., Gabici, S., Humensky, B. T., Santander, M., Terrier, R., Cristofari, P., Zanin, R., Gabici, S., Humensky, B. T., Santander, M., and Terrier, R.

Abstract

The Cherenkov Telescope Array is expected to lead to the detection of many new supernova remnants in the TeV and multi-TeV range. In addition to the individual study of each SNR, the study of these objects as a population can help constraining the parameters describing the acceleration of particles and increasing our understanding of the mechanisms involved. We present Monte Carlo simulations of the population of Galactic SNRs emitting TeV gamma rays. We also discuss how the simulated population can be confronted with future observations to provide a novel test for the SNR hypothesis of cosmic ray origins., Comment: All CTA contributions at arXiv:1709.03483

Published
2017

3. Plane-wave impulse approximation extraction of the neutron magnetic form factor from quasielastic 3He(e,e′) at Q2=0.3 to 0.6 (GeV/c)2

Author

Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Kent State University, Kent, Ohio 44242, Temple University, Philadelphia, Pennsylvania 19122, College of William and Mary, Williamsburg, Virginia 23187, University of New Hampshire, Durham, New Hampshire 03824, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, Princeton University, Princeton, New Jersey 08544, Duke University, Durham, North Carolina 27708, University of Kentucky, Lexington, Kentucky 40506, LPC, Université Blaise Pascal, F-63177 Aubière, France, Rutgers University, Piscataway, New Jersey 08855, Kharkov Institute of Physics and Technology, Kharkov 310108, Ukraine, Ruhr-Universität Bochum, D-44780 Bochum, Germany, Institute of Physics, Jagellonian University, PL-30059 Cracow, Poland, University of Virginia, Charlottesville, Virginia 22903, Syracuse University, Syracuse, New York 13244, California Institute of Technology, Pasadena, California 91125, Ruhr-Universität Bochum, D-44780 Bochum, Germany (Kyushu institute of Technology, Fukuoka, Japan), INFN, Sezione di Pisa, Pisa, Italy, California State University, Los Angeles, Los Angeles, California 90032, Thomas Jefferson National Accelerator Facility, Newport, INFN, Sezione Tor Vergata, I-00133 Rome, Italy, INFN, Sezione di Roma, I-00185 Rome, Italy, Old Dominion University, Norfolk, Virginia 23508, North Carolina Central University, Durham, North Carolina 27707, Xu, W, Anderson, B, Auberbach, L, Averett, T, Bertozzi, W, Black, T, Calarco, J, Cardman, L, Cates, G.D, Chai, Z.W, Chen, J.P, Choi, S, Chudakov, E, Churchewell, S, Corrado, G.S, Crawford, C, Dale, D, Deur, A, Djawotho, P, Donnelly, T.W, Dutta, D, Finn, J.M., Gao, H, Gilman, R, Glamazdin, A.V, Glashausser, C, Glockle, W, Golak, J, Gomez, J, Gorbenko, V.G, Hansen, J.-O, Hersman, F.W., Higinbotham, D.W., Holmes, R, Howell, C.R., Hughes, E, Humensky, B, Incerti, S, Jager, C.W.de, Jensen, J.S, Jiang, X, Jones, C.E., Jones, M, Kahl, R, Kamada, Hiroyuki, Kievsky, A, Kominis, I, Korsch, W, Kramer, K, Kumbartzki, G, Kuss, M, Lakurigi, E, Liang, M, Liyanage, N, LeRose, J, Malov, S, Margaziotis, D.J, Martin, J.W, McCormick, K, Mckeown, R.D, Mcllhany, K, Meziani, Z.-E, Michaels, R, Miller, G.W, Mitchell, J, Nanda, S, Pace, E, Pavlin, T, Petratos, G.G, Pomatsalyuk, R.I, Pristein, D, Prout, D, Ransome, R.D., Roblin, Y, Rvachev, M, Saha, A, Salme, G, Schnee, M, Shin, T, Slifer, K, Souder, P.A, Strauch, S, Suleiman, R, Sutter, M, Tipton, B, Todor, L, Viviani, M, Vlahovic, B, Watoson, J, Williamson, C.F, Witala, H, Wojtsekhowski, B, Xiong, F, Yeh, J, Zolnierczuk, P, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Kent State University, Kent, Ohio 44242, Temple University, Philadelphia, Pennsylvania 19122, College of William and Mary, Williamsburg, Virginia 23187, University of New Hampshire, Durham, New Hampshire 03824, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, Princeton University, Princeton, New Jersey 08544, Duke University, Durham, North Carolina 27708, University of Kentucky, Lexington, Kentucky 40506, LPC, Université Blaise Pascal, F-63177 Aubière, France, Rutgers University, Piscataway, New Jersey 08855, Kharkov Institute of Physics and Technology, Kharkov 310108, Ukraine, Ruhr-Universität Bochum, D-44780 Bochum, Germany, Institute of Physics, Jagellonian University, PL-30059 Cracow, Poland, University of Virginia, Charlottesville, Virginia 22903, Syracuse University, Syracuse, New York 13244, California Institute of Technology, Pasadena, California 91125, Ruhr-Universität Bochum, D-44780 Bochum, Germany (Kyushu institute of Technology, Fukuoka, Japan), INFN, Sezione di Pisa, Pisa, Italy, California State University, Los Angeles, Los Angeles, California 90032, Thomas Jefferson National Accelerator Facility, Newport, INFN, Sezione Tor Vergata, I-00133 Rome, Italy, INFN, Sezione di Roma, I-00185 Rome, Italy, Old Dominion University, Norfolk, Virginia 23508, North Carolina Central University, Durham, North Carolina 27707, Xu, W, Anderson, B, Auberbach, L, Averett, T, Bertozzi, W, Black, T, Calarco, J, Cardman, L, Cates, G.D, Chai, Z.W, Chen, J.P, Choi, S, Chudakov, E, Churchewell, S, Corrado, G.S, Crawford, C, Dale, D, Deur, A, Djawotho, P, Donnelly, T.W, Dutta, D, Finn, J.M., Gao, H, Gilman, R, Glamazdin, A.V, Glashausser, C, Glockle, W, Golak, J, Gomez, J, Gorbenko, V.G, Hansen, J.-O, Hersman, F.W., Higinbotham, D.W., Holmes, R, Howell, C.R., Hughes, E, Humensky, B, Incerti, S, Jager, C.W.de, Jensen, J.S, Jiang, X, Jones, C.E., Jones, M, Kahl, R, Kamada, Hiroyuki, Kievsky, A, Kominis, I, Korsch, W, Kramer, K, Kumbartzki, G, Kuss, M, Lakurigi, E, Liang, M, Liyanage, N, LeRose, J, Malov, S, Margaziotis, D.J, Martin, J.W, McCormick, K, Mckeown, R.D, Mcllhany, K, Meziani, Z.-E, Michaels, R, Miller, G.W, Mitchell, J, Nanda, S, Pace, E, Pavlin, T, Petratos, G.G, Pomatsalyuk, R.I, Pristein, D, Prout, D, Ransome, R.D., Roblin, Y, Rvachev, M, Saha, A, Salme, G, Schnee, M, Shin, T, Slifer, K, Souder, P.A, Strauch, S, Suleiman, R, Sutter, M, Tipton, B, Todor, L, Viviani, M, Vlahovic, B, Watoson, J, Williamson, C.F, Witala, H, Wojtsekhowski, B, Xiong, F, Yeh, J, and Zolnierczuk, P

Abstract

type:Journal Article, A high precision measurement of the transverse spin-dependent asymmetry AT′ in 3He(e,e′) quasielastic scattering was performed in Hall A at Jefferson Lab at values of the squared four-momentum transfer, Q2, between 0.1 and 0.6 (GeV/c)2. AT′ is sensitive to the neutron magnetic form factor, GMn. Values of GMn at Q2=0.1 and 0.2 (GeV/c)2, extracted using Faddeev calculations, were reported previously. Here, we report the extraction of GMn for the remaining Q2 values in the range from 0.3 to 0.6 (GeV/c)2 using a plane-wave impulse approximation calculation. The results are in good agreement with recent precision data from experiments using a deuterium target., source:http://link.aps.org/abstract/PRC/v67/e012201, source:http://www.aps.org

Published
2017

4. 3He Spin-Dependent Cross Sections and Sum Rules

Author

Temple University, Yarevan Physics Institute, Thomas Jefferson National Accelerator Facility, LPC IN2P3/CNRS, Universite´ Blaise Pascal, Massachusetts Institute of Technology, University of Regina, Kharkov Institute of Physics and Technology, University of New Hampshire, California Institute of Technology, Kent State University, Rutgers, The State University of New Jersey, Old Dominion University, INFN, Sezione di Perugia, INFN, Sezione Roma I, M. Smoluchowski Institute of Physics, Jagiellonian University, Syracuse University, Tohoku University, INFN, Sezione Sanita, CEA Saclay,9INFN, Sezione Tor Vergata, Yerevan Physics Institute, Chungnam National University, Princeton University, University of Kentucky, The College of William and Mary, Hampton University, Institut fu¨r Theoretische Physik II, Ruhr Universita¨t Bochum, Temple UniversityINFNSezione di Perugia, INFN, Sezione Sanita1California Institute of Technology, Department of Physics, Faculty of Engineering, Kyushu Institute of Technology, University of Massachusetts-Amherst, CEA Saclay, Institut fu¨r Kernphysik, INFN, Sezione Tor Vergata, Slifer, K, Amarian, M, Auerbach, L, Averett, T, Berthot, J, Bertin, P, Bertozzi, B, Black, T, Brash, E, Brown, D, Burtin, R, Nogga, A, Pace, E, Papandreou, Z, Pavlin, T, Petratos, G.G, Pripstein, D, Prout, D, Ransome, R, Roblin, Y, Rowntree, D, Saha, A, Rvachev, M, Sabatie´, F, Salme´, G, Scopetta, S, Skibinski, R, Souder, P, Saito, T, Strauch, S, Suleiman, R, Takahashi, K, Teijiro, S, Ueno, H, Todor, L, Tsubota, H, Urciuoli, G, Van, der Meer R, Vernin, P, Voskanian, H, Witala, H, Wojtsekhowski, B, Xiong, F, Xu, W, Yang, J.-C, Calarco, J, Zhang, B, Zolnierczuk, P, Cates, G, Chai, Z, Chen, J.-P, Choi, Seonho, Chudakov, E, Ciofi, degli Atti C, Cisbani, E, deJager, C.W, Deur, A, DiSalvo, R, Dietorich, S, Djawotho, P, Finn, M, Fissum, K, Fonvieille, H, Frullani, S, Gao, H, Gao, J, Garibaldi, F, Gasparian, A, Gilad, S, Gilman, R, Glamadin, A, Glashausser, C, Glo¨ckle, W, Golak, J, Goldberg, E, Gomez, J, Gorbenko, V, Hansen, J.-O, Hersman, B, Holmes, R, Huber, G.M, Hughes, E, Humensky, B, Incerti, S, Iodice, M, Jensen, S, Jiang, X, Jones, C, Jones, G, Jones, M, Jutier, C, Kamada, H, Ketikyan, A, Kominis, I, Korsch, W, Kramer, K, Kumae, K, Kumbartzki, G, Kuss, M, Lakuriqi, E, Laveissier, G, Lerose, J.J, Liang, M, Liyanage, N, Lolos, G, Malov, S, Marroncle, J, McCormick, K, McKeown, R.D, Meziani, Z.-E, Michaels, R, Mitchell, J, Temple University, Yarevan Physics Institute, Thomas Jefferson National Accelerator Facility, LPC IN2P3/CNRS, Universite´ Blaise Pascal, Massachusetts Institute of Technology, University of Regina, Kharkov Institute of Physics and Technology, University of New Hampshire, California Institute of Technology, Kent State University, Rutgers, The State University of New Jersey, Old Dominion University, INFN, Sezione di Perugia, INFN, Sezione Roma I, M. Smoluchowski Institute of Physics, Jagiellonian University, Syracuse University, Tohoku University, INFN, Sezione Sanita, CEA Saclay,9INFN, Sezione Tor Vergata, Yerevan Physics Institute, Chungnam National University, Princeton University, University of Kentucky, The College of William and Mary, Hampton University, Institut fu¨r Theoretische Physik II, Ruhr Universita¨t Bochum, Temple UniversityINFNSezione di Perugia, INFN, Sezione Sanita1California Institute of Technology, Department of Physics, Faculty of Engineering, Kyushu Institute of Technology, University of Massachusetts-Amherst, CEA Saclay, Institut fu¨r Kernphysik, INFN, Sezione Tor Vergata, Slifer, K, Amarian, M, Auerbach, L, Averett, T, Berthot, J, Bertin, P, Bertozzi, B, Black, T, Brash, E, Brown, D, Burtin, R, Nogga, A, Pace, E, Papandreou, Z, Pavlin, T, Petratos, G.G, Pripstein, D, Prout, D, Ransome, R, Roblin, Y, Rowntree, D, Saha, A, Rvachev, M, Sabatie´, F, Salme´, G, Scopetta, S, Skibinski, R, Souder, P, Saito, T, Strauch, S, Suleiman, R, Takahashi, K, Teijiro, S, Ueno, H, Todor, L, Tsubota, H, Urciuoli, G, Van, der Meer R, Vernin, P, Voskanian, H, Witala, H, Wojtsekhowski, B, Xiong, F, Xu, W, Yang, J.-C, Calarco, J, Zhang, B, Zolnierczuk, P, Cates, G, Chai, Z, Chen, J.-P, Choi, Seonho, Chudakov, E, Ciofi, degli Atti C, Cisbani, E, deJager, C.W, Deur, A, DiSalvo, R, Dietorich, S, Djawotho, P, Finn, M, Fissum, K, Fonvieille, H, Frullani, S, Gao, H, Gao, J, Garibaldi, F, Gasparian, A, Gilad, S, Gilman, R, Glamadin, A, Glashausser, C, Glo¨ckle, W, Golak, J, Goldberg, E, Gomez, J, Gorbenko, V, Hansen, J.-O, Hersman, B, Holmes, R, Huber, G.M, Hughes, E, Humensky, B, Incerti, S, Iodice, M, Jensen, S, Jiang, X, Jones, C, Jones, G, Jones, M, Jutier, C, Kamada, H, Ketikyan, A, Kominis, I, Korsch, W, Kramer, K, Kumae, K, Kumbartzki, G, Kuss, M, Lakuriqi, E, Laveissier, G, Lerose, J.J, Liang, M, Liyanage, N, Lolos, G, Malov, S, Marroncle, J, McCormick, K, McKeown, R.D, Meziani, Z.-E, Michaels, R, and Mitchell, J

Abstract

type:Journal Article, We present a measurement of the spin-dependent cross sections for the (3)(He) over right arrow((e) over right arrow ,e')X reaction in the quasielastic and resonance regions at a four-momentum transfer 0.1 <= Q(2)<= 0.9 GeV2. The spin-structure functions have been extracted and used to evaluate the nuclear Burkhardt-Cottingham and extended Gerasimov-Drell-Hearn sum rules for the first time. The data are also compared to an impulse approximation calculation and an exact three-body Faddeev calculation in the quasielastic region., source:https://doi.org/10.1103/PhysRevLett.101.022303, source:http://www.aps.org

Published
2017

5. Supernova remnants in the very-high-energy sky: prospects for the Cherenkov Telescope Array

Author

Cristofari, P., Zanin, R., Gabici, S., Humensky, B. T., Santander, M., Terrier, R., Cristofari, P., Zanin, R., Gabici, S., Humensky, B. T., Santander, M., and Terrier, R.

Abstract

The Cherenkov Telescope Array is expected to lead to the detection of many new supernova remnants in the TeV and multi-TeV range. In addition to the individual study of each SNR, the study of these objects as a population can help constraining the parameters describing the acceleration of particles and increasing our understanding of the mechanisms involved. We present Monte Carlo simulations of the population of Galactic SNRs emitting TeV gamma rays. We also discuss how the simulated population can be confronted with future observations to provide a novel test for the SNR hypothesis of cosmic ray origins., Comment: All CTA contributions at arXiv:1709.03483

Published
2017

6. Construction of a medium-sized Schwarzschild-Couder telescope as a candidate for the Cherenkov Telescope Array: development of the optical alignment system

Author

Nieto, D., Griffiths, S., Humensky, B., Kaaret, P., Limon, M., Mognet, I., Peck, A., Petrashyk, A., Ribeiro, D., Rousselle, J., Stevenson, B., Vassiliev, V., Yu, P., Nieto, D., Griffiths, S., Humensky, B., Kaaret, P., Limon, M., Mognet, I., Peck, A., Petrashyk, A., Ribeiro, D., Rousselle, J., Stevenson, B., Vassiliev, V., and Yu, P.

Abstract

The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. The Schwarzschild-Couder (SC) medium-size candidate telescope model features a novel aplanatic two-mirror optical design capable of a wide field-of-view with significantly improved imaging resolution as compared to the traditional Davis-Cotton optics design. Achieving this imaging resolution imposes strict alignment requirements to be accomplished by a dedicated alignment system. In this contribution we present the status of the development of the SC optical alignment system, soon to be materialized in a full-scale prototype SC medium-size telescope at the Fred Lawrence Whipple Observatory in southern Arizona., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

7. Construction of a Medium-Sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array: Implementation of the Cherenkov-Camera Data Acquisition System

Author

Santander, M., Buckley, J., Humensky, B., Mukherjee, R., Santander, M., Buckley, J., Humensky, B., and Mukherjee, R.

Abstract

A medium-sized Schwarzchild-Couder Telescope (SCT) is being developed as a possible extension for the Cherenkov Telescope Array (CTA). The Cherenkov camera of the telescope is designed to have 11328 silicon photomultiplier pixels capable of capturing high-resolution images of air showers in the atmosphere. The combination of the large number of pixels and the high trigger rate (> 5 kHz) expected for this telescope results in a multi-Gbps data throughput. This sets challenging requirements on the design and performance of a data acquisition system for processing and storing this data. A prototype SCT (pSCT) with a partial camera containing 1600 pixels, covering a field of view of 2.5 x 2.5 square degrees, is being assembled at the F.L. Whipple Observatory. We present the design and current status of the SCT data acquisition system., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

8. Layout design studies for medium-sized telescopes within the Cherenkov Telescope Array

Author

Hassan, T., Humensky, B., Nieto, D., Wood, M., Hassan, T., Humensky, B., Nieto, D., and Wood, M.

Abstract

The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. In this study we explore how the medium-sized telescopes layout design and composition impacts the overall CTA performance by analyzing Monte Carlo simulations including Davies-Cotton and Schwarzschild-Couder medium-sized telescopes., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

9. Construction of a Medium-Sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array: Implementation of the Cherenkov-Camera Data Acquisition System

Author

Santander, M., Buckley, J., Humensky, B., Mukherjee, R., Santander, M., Buckley, J., Humensky, B., and Mukherjee, R.

Abstract

A medium-sized Schwarzchild-Couder Telescope (SCT) is being developed as a possible extension for the Cherenkov Telescope Array (CTA). The Cherenkov camera of the telescope is designed to have 11328 silicon photomultiplier pixels capable of capturing high-resolution images of air showers in the atmosphere. The combination of the large number of pixels and the high trigger rate (> 5 kHz) expected for this telescope results in a multi-Gbps data throughput. This sets challenging requirements on the design and performance of a data acquisition system for processing and storing this data. A prototype SCT (pSCT) with a partial camera containing 1600 pixels, covering a field of view of 2.5 x 2.5 square degrees, is being assembled at the F.L. Whipple Observatory. We present the design and current status of the SCT data acquisition system., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

10. Construction of a medium-sized Schwarzschild-Couder telescope as a candidate for the Cherenkov Telescope Array: development of the optical alignment system

Author

Nieto, D., Griffiths, S., Humensky, B., Kaaret, P., Limon, M., Mognet, I., Peck, A., Petrashyk, A., Ribeiro, D., Rousselle, J., Stevenson, B., Vassiliev, V., Yu, P., Nieto, D., Griffiths, S., Humensky, B., Kaaret, P., Limon, M., Mognet, I., Peck, A., Petrashyk, A., Ribeiro, D., Rousselle, J., Stevenson, B., Vassiliev, V., and Yu, P.

Abstract

The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. The Schwarzschild-Couder (SC) medium-size candidate telescope model features a novel aplanatic two-mirror optical design capable of a wide field-of-view with significantly improved imaging resolution as compared to the traditional Davis-Cotton optics design. Achieving this imaging resolution imposes strict alignment requirements to be accomplished by a dedicated alignment system. In this contribution we present the status of the development of the SC optical alignment system, soon to be materialized in a full-scale prototype SC medium-size telescope at the Fred Lawrence Whipple Observatory in southern Arizona., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

11. Layout design studies for medium-sized telescopes within the Cherenkov Telescope Array

Author

Hassan, T., Humensky, B., Nieto, D., Wood, M., Hassan, T., Humensky, B., Nieto, D., and Wood, M.

Abstract

The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. In this study we explore how the medium-sized telescopes layout design and composition impacts the overall CTA performance by analyzing Monte Carlo simulations including Davies-Cotton and Schwarzschild-Couder medium-sized telescopes., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.05894

Published
2015

12. First results from NuSTAR observations of Mkn 421

Author

Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, Finn Erland, Forster, K., Furniss, A., Fürst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Humensky, B., Hailey, C. J., Harrison, F. A., Hayashida, M., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Perri, M., Puccetti, S., Reynolds, J. C., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., Zhang, W. W., Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, Finn Erland, Forster, K., Furniss, A., Fürst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Humensky, B., Hailey, C. J., Harrison, F. A., Hayashida, M., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Perri, M., Puccetti, S., Reynolds, J. C., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., and Zhang, W. W.

Abstract

Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad nonthermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in the X-ray and TeV γ-ray bands, where the energy output is dominated by cooling of high-energy electrons in the jet. In order to study the electron distribution and its evolution, we carried out a dedicated multi-wavelength campaign, including extensive observations by the recently launched highly sensitive hard X-ray telescope NuSTAR, between December 2012 and May 2013. Here we present some initial results based on NuSTAR data from January through March 2013, as well as calibration observations conducted in 2012. Although the observations cover some of the faintest hard X-ray flux states ever observed forMkn 421, the sensitivity is high enough to resolve intra-day spectral variability. We find that in this low state the dominant flux variations are smooth on timescales of hours, with typical intra-hour variations of ≠5%. We do not find evidence for either a cutoff in the hard X-ray spectrum, or a rise towards a high-energy component, but rather that at low flux the spectrum assumes a power law shape with a photon index of approximately 3. The spectrum is found to harden with increasing brightness. © Owned by the authors, published by EDP Sciences, 2013.

Published
2013

13. Cosmic Frontier Indirect Dark Matter Detection Working Group Summary

Author

Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., Wood, M., Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., and Wood, M.

Abstract

As part of the Snowmass process, the Cosmic Frontier Indirect-Detection subgroup (CF2) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The purposes of this report are to identify opportunities for dark matter science through indirect detection, to give an overview of the primary scientific drivers for indirect searches for dark matter, and to survey current and planned experiments that have, as a large part of their scientific program, the goal of searching for indirect (or astrophysical) signatures of dark matter. We primarily address existing experiments with a large U.S. role, or future experiments where a U.S. contribution is sought. We also address the limitations of this technique, and answer the tough questions relevant to this subgroup posed by the HEP community through the Snowmass process., Comment: Snowmass Indirect Dark Matter Detection CF2 Working Group Summary, 85 pages, 25 figures; a version with higher-resolution figures can be downloaded at http://scipp.ucsc.edu/~profumo/CF2/driverFile.pdf

Published
2013

14. First Results from NuSTAR Observations of Mkn 421

Author

Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, F. E., Craig, W. W., Forster, K., Furniss, A., Fuerst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Hailey, C. J., Harrison, F. A., Hayashida, M., Humensky, B., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Paneque, D., Perri, M., Puccetti, S., Reynolds, C. S., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., Zhang, W. W., Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, F. E., Craig, W. W., Forster, K., Furniss, A., Fuerst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Hailey, C. J., Harrison, F. A., Hayashida, M., Humensky, B., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Paneque, D., Perri, M., Puccetti, S., Reynolds, C. S., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., and Zhang, W. W.

Abstract

Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad non-thermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in the X-ray and TeV gamma-ray bands, where the energy output is dominated by cooling of high-energy electrons in the jet. In order to study the electron distribution and its evolution, we carried out a dedicated multi-wavelength campaign, including extensive observations by the recently launched highly sensitive hard X-ray telescope NuSTAR, between December 2012 and May 2013. Here we present some initial results based on NuSTAR data from January through March 2013, as well as calibration observations conducted in 2012. Although the observations cover some of the faintest hard X-ray flux states ever observed for Mkn 421, the sensitivity is high enough to resolve intra-day spectral variability. We find that in this low state the dominant flux variations are smooth on timescales of hours, with typical intra-hour variations of less than 5%. We do not find evidence for either a cutoff in the hard X-ray spectrum, or a rise towards a high-energy component, but rather that at low flux the spectrum assumes a power law shape with a photon index of approximately 3. The spectrum is found to harden with increasing brightness., Comment: 4 pages, 4 figures; to appear in "The Innermost Regions of Relativistic Jets and Their Magnetic Fields" conference proceedings; updated with minor corrections

Published
2013
Full Text
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15. The Real-Time Analysis of the Cherenkov Telescope Array Observatory

Author

Bulgarelli, A., Fioretti, V., Contreras, J. L., Lorca, A., Aboudan, A., Rodríguez-Vázquez, J. J., Lombardi, S., Maier, G., Antonelli, L. A., Bastieri, D., Boisson, C., Borkowski, J., Buson, S., Carosi, A., Conforti, V., Djannati-Ataï, A., Dumm, J., Evans, P., Fortson, L., Gianotti, F., Graciani, R., Grandi, P., Hinton, J., Humensky, B., Kosack, K., Lamanna, G., Malaguti, G., Marisaldi, M., Nicastro, L., Ohm, S., Osborne, J., Rosen, S., Trifoglio, M., Tosti, G., Bulgarelli, A., Fioretti, V., Contreras, J. L., Lorca, A., Aboudan, A., Rodríguez-Vázquez, J. J., Lombardi, S., Maier, G., Antonelli, L. A., Bastieri, D., Boisson, C., Borkowski, J., Buson, S., Carosi, A., Conforti, V., Djannati-Ataï, A., Dumm, J., Evans, P., Fortson, L., Gianotti, F., Graciani, R., Grandi, P., Hinton, J., Humensky, B., Kosack, K., Lamanna, G., Malaguti, G., Marisaldi, M., Nicastro, L., Ohm, S., Osborne, J., Rosen, S., Trifoglio, M., and Tosti, G.

Abstract

The Cherenkov Telescope Array (CTA) Observatory must be capable of issuing fast alerts on variable and transient sources to maximize the scientific return. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a key system of the CTA observatory. The latency and sensitivity requirements of the alarm system impose a challenge because of the large foreseen data flow rate, between 0.5 and 8 GB/s. As a consequence, substantial efforts toward the optimization of this high-throughput computing service are envisaged, with the additional constraint that the RTA should be performed on-site (as part of the auxiliary infrastructure of the telescopes). In this work, the functional design of the RTA pipeline is presented., Comment: In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.2232

Published
2013

16. Fundamental Physics with Charged Particle Measurements at the Cherenkov Telescope Array

Author

Vandenbroucke, J., Humensky, B., Holder, J., Ong, R. A., Vandenbroucke, J., Humensky, B., Holder, J., and Ong, R. A.

Abstract

Cosmic electrons, positrons, protons, and antiprotons carry essential information about both astrophysical processes and fundamental physics. Charged particles provide signatures of dark matter annihilation or decay, \emph{in situ} in the universe, that are complementary to the other messengers of indirect dark matter detection, gamma rays and neutrinos. We discuss the science potential for measurements of charged particles by the Cherenkov Telescope Array (CTA), an instrument under development primarily for the study of cosmic gamma rays with energies $30\ \textrm{GeV} - 200\ \textrm{TeV}$., Comment: White paper prepared for the 2013 Snowmass Community Summer Study. Work groups: Cosmic Frontier 2 (WIMP Dark Matter Indirect Detection), Cosmic Frontier 6 (Cosmic Particles and Fundamental Physics)

Published
2013

17. Cosmic Frontier Indirect Dark Matter Detection Working Group Summary

Author

Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., Wood, M., Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., and Wood, M.

Abstract

As part of the Snowmass process, the Cosmic Frontier Indirect-Detection subgroup (CF2) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The purposes of this report are to identify opportunities for dark matter science through indirect detection, to give an overview of the primary scientific drivers for indirect searches for dark matter, and to survey current and planned experiments that have, as a large part of their scientific program, the goal of searching for indirect (or astrophysical) signatures of dark matter. We primarily address existing experiments with a large U.S. role, or future experiments where a U.S. contribution is sought. We also address the limitations of this technique, and answer the tough questions relevant to this subgroup posed by the HEP community through the Snowmass process., Comment: Snowmass Indirect Dark Matter Detection CF2 Working Group Summary, 85 pages, 25 figures; a version with higher-resolution figures can be downloaded at http://scipp.ucsc.edu/~profumo/CF2/driverFile.pdf

Published
2013

18. Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics

Author

Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., Zitzer, B., Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., and Zitzer, B.

Abstract

Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime., Comment: Snowmass 2013 CF6 Working Group Report; author list corrected

Published
2013

19. Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics

Author

Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., Zitzer, B., Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., and Zitzer, B.

Abstract

Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime., Comment: Snowmass 2013 CF6 Working Group Report; author list corrected

Published
2013

20. Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics

Author

Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., Zitzer, B., Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., and Zitzer, B.

Abstract

Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime., Comment: Snowmass 2013 CF6 Working Group Report; author list corrected

Published
2013

21. Cosmic Frontier Indirect Dark Matter Detection Working Group Summary

Author

Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., Wood, M., Buckley, J., Cowen, D. F., Profumo, S., Archer, A., Cahill-Rowley, M., Cotta, R., Digel, S., Drlica-Wagner, A., Ferrer, F., Funk, S., Hewett, J., Holder, J., Humensky, B., Ismail, A., Israel, M., Jeltema, T., Olinto, A., Peter, A., Pretz, J., Rizzo, T., Siegal-Gaskins, J., Smith, A., Staszak, D., Vandenbroucke, J., and Wood, M.

Abstract

As part of the Snowmass process, the Cosmic Frontier Indirect-Detection subgroup (CF2) has drawn on input from the Cosmic Frontier and the broader Particle Physics community to produce this document. The purposes of this report are to identify opportunities for dark matter science through indirect detection, to give an overview of the primary scientific drivers for indirect searches for dark matter, and to survey current and planned experiments that have, as a large part of their scientific program, the goal of searching for indirect (or astrophysical) signatures of dark matter. We primarily address existing experiments with a large U.S. role, or future experiments where a U.S. contribution is sought. We also address the limitations of this technique, and answer the tough questions relevant to this subgroup posed by the HEP community through the Snowmass process., Comment: Snowmass Indirect Dark Matter Detection CF2 Working Group Summary, 85 pages, 25 figures; a version with higher-resolution figures can be downloaded at http://scipp.ucsc.edu/~profumo/CF2/driverFile.pdf

Published
2013

22. Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics

Author

Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., Zitzer, B., Beatty, J. J., Nelson, A. E., Olinto, A., Sinnis, G., Abeysekara, A. U., Anchordoqui, L. A., Aramaki, T., Belz, J., Buckley, J. H., Byrum, K., Cameron, R., Chen, M-C., Clark, K., Connolly, A., Cowen, D., DeYoung, T., Dumm, P. von Doetinchem J., Errando, M., Farrar, G., Ferrer, F., Fortson, L., Funk, S., Grant, D., Griffiths, S., Groß, A., Hailey, C., Hogan, C., Holder, J., Humensky, B., Kaaret, P., Klein, S. R., Krawczynski, H., Krennrich, F., Krings, K., Krizmanic, J., Kusenko, A., Linnemann, J. T., MacGibbon, J. H., Matthews, J., McCann, A., Mitchell, J., Mukherjee, R., Nitz, D., Ong, R. A., Orr, M., Otte, N., Paul, T., Resconi, E., Sanchez-Conde, M. A., Sokolsky, P., Stecker, F., Stump, D., Taboada, I., Thomson, G. B., Tollefson, K., von Doetinchem, P., Ukwatta, T., Vandenbroucke, J., Vasileiou, V., Vassileiv, V. V., Weiler, T. J., Williams, D. A., Weinstein, A., Wood, M., and Zitzer, B.

Abstract

Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime., Comment: Snowmass 2013 CF6 Working Group Report; author list corrected

Published
2013

23. First Results from NuSTAR Observations of Mkn 421

Author

Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, F. E., Craig, W. W., Forster, K., Furniss, A., Fuerst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Hailey, C. J., Harrison, F. A., Hayashida, M., Humensky, B., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Paneque, D., Perri, M., Puccetti, S., Reynolds, C. S., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., Zhang, W. W., Baloković, M., Ajello, M., Blandford, R. D., Boggs, S. E., Borracci, F., Chiang, J., Christensen, F. E., Craig, W. W., Forster, K., Furniss, A., Fuerst, F., Ghisellini, G., Giebels, B., Giommi, P., Grefenstette, B. W., Hailey, C. J., Harrison, F. A., Hayashida, M., Humensky, B., Inoue, Y., Koglin, J. E., Krawczynski, H., Madejski, G. M., Madsen, K. K., Meier, D. L., Nelson, T., Ogle, P., Paneque, D., Perri, M., Puccetti, S., Reynolds, C. S., Sbarrato, T., Stern, D., Tagliaferri, G., Urry, C. M., Wehrle, A. E., and Zhang, W. W.

Abstract

Mkn 421 is a nearby active galactic nucleus dominated at all wavelengths by a very broad non-thermal continuum thought to arise from a relativistic jet seen at a small angle to the line of sight. Its spectral energy distribution peaks in the X-ray and TeV gamma-ray bands, where the energy output is dominated by cooling of high-energy electrons in the jet. In order to study the electron distribution and its evolution, we carried out a dedicated multi-wavelength campaign, including extensive observations by the recently launched highly sensitive hard X-ray telescope NuSTAR, between December 2012 and May 2013. Here we present some initial results based on NuSTAR data from January through March 2013, as well as calibration observations conducted in 2012. Although the observations cover some of the faintest hard X-ray flux states ever observed for Mkn 421, the sensitivity is high enough to resolve intra-day spectral variability. We find that in this low state the dominant flux variations are smooth on timescales of hours, with typical intra-hour variations of less than 5%. We do not find evidence for either a cutoff in the hard X-ray spectrum, or a rise towards a high-energy component, but rather that at low flux the spectrum assumes a power law shape with a photon index of approximately 3. The spectrum is found to harden with increasing brightness., Comment: 4 pages, 4 figures; to appear in "The Innermost Regions of Relativistic Jets and Their Magnetic Fields" conference proceedings; updated with minor corrections

Published
2013
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24. The Real-Time Analysis of the Cherenkov Telescope Array Observatory

Author

Bulgarelli, A., Fioretti, V., Contreras, J. L., Lorca, A., Aboudan, A., Rodríguez-Vázquez, J. J., Lombardi, S., Maier, G., Antonelli, L. A., Bastieri, D., Boisson, C., Borkowski, J., Buson, S., Carosi, A., Conforti, V., Djannati-Ataï, A., Dumm, J., Evans, P., Fortson, L., Gianotti, F., Graciani, R., Grandi, P., Hinton, J., Humensky, B., Kosack, K., Lamanna, G., Malaguti, G., Marisaldi, M., Nicastro, L., Ohm, S., Osborne, J., Rosen, S., Trifoglio, M., Tosti, G., Bulgarelli, A., Fioretti, V., Contreras, J. L., Lorca, A., Aboudan, A., Rodríguez-Vázquez, J. J., Lombardi, S., Maier, G., Antonelli, L. A., Bastieri, D., Boisson, C., Borkowski, J., Buson, S., Carosi, A., Conforti, V., Djannati-Ataï, A., Dumm, J., Evans, P., Fortson, L., Gianotti, F., Graciani, R., Grandi, P., Hinton, J., Humensky, B., Kosack, K., Lamanna, G., Malaguti, G., Marisaldi, M., Nicastro, L., Ohm, S., Osborne, J., Rosen, S., Trifoglio, M., and Tosti, G.

Abstract

The Cherenkov Telescope Array (CTA) Observatory must be capable of issuing fast alerts on variable and transient sources to maximize the scientific return. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a key system of the CTA observatory. The latency and sensitivity requirements of the alarm system impose a challenge because of the large foreseen data flow rate, between 0.5 and 8 GB/s. As a consequence, substantial efforts toward the optimization of this high-throughput computing service are envisaged, with the additional constraint that the RTA should be performed on-site (as part of the auxiliary infrastructure of the telescopes). In this work, the functional design of the RTA pipeline is presented., Comment: In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.2232

Published
2013

25. Fundamental Physics with Charged Particle Measurements at the Cherenkov Telescope Array

Author

Vandenbroucke, J., Humensky, B., Holder, J., Ong, R. A., Vandenbroucke, J., Humensky, B., Holder, J., and Ong, R. A.

Abstract

Cosmic electrons, positrons, protons, and antiprotons carry essential information about both astrophysical processes and fundamental physics. Charged particles provide signatures of dark matter annihilation or decay, \emph{in situ} in the universe, that are complementary to the other messengers of indirect dark matter detection, gamma rays and neutrinos. We discuss the science potential for measurements of charged particles by the Cherenkov Telescope Array (CTA), an instrument under development primarily for the study of cosmic gamma rays with energies $30\ \textrm{GeV} - 200\ \textrm{TeV}$., Comment: White paper prepared for the 2013 Snowmass Community Summer Study. Work groups: Cosmic Frontier 2 (WIMP Dark Matter Indirect Detection), Cosmic Frontier 6 (Cosmic Particles and Fundamental Physics)

Published
2013

26. Section on Supernova remnants and cosmic rays of the White Paper on the Status and Future of Ground-based Gamma-ray Astronomy

Author

Pohl, M., Abdo, A., Atoyan, A., Baring, M., Beacom, J., Blandford, R., Butt, Y., Bykov, A., Ellison, D., Funk, S., Halzen, F., Hays, E., Humensky, B., Jones, T., Kaaret, P., Kieda, D., LeBohec, S., Meszaros, P., Moskalenko, I., Slane, P., Strong, A., Wakely, S., Pohl, M., Abdo, A., Atoyan, A., Baring, M., Beacom, J., Blandford, R., Butt, Y., Bykov, A., Ellison, D., Funk, S., Halzen, F., Hays, E., Humensky, B., Jones, T., Kaaret, P., Kieda, D., LeBohec, S., Meszaros, P., Moskalenko, I., Slane, P., Strong, A., and Wakely, S.

Abstract

This is a report on the findings of the SNR/cosmic-ray working group for the white paper on the status and future of ground-based gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses the status of past and current attempts to observe shell-type supernova remnants and diffuse emission from cosmic rays at GeV-TeV energies. We concentrate on the potential of future ground-based gamma-ray experiments to study the acceleration of relativistic charged particles which is one of the main unsolved, yet fundamental, problems in modern astrophysics. The acceleration of particles relies on interactions between energetic particles and magnetic turbulence. In the case of SNRs we can perform spatially resolved studies in systems with known geometry, and the plasma physics deduced from these observations will help us to understand other systems where rapid particle acceleration is believed to occur and where observations as detailed as those of SNRs are not possible., Comment: Report from the SNR/CR Working group of the APS-commissioned White paper on ground-based gamma ray astronomy. More information available at http://cherenkov.physics.iastate.edu/wp

Published
2008

27. Section on Supernova remnants and cosmic rays of the White Paper on the Status and Future of Ground-based Gamma-ray Astronomy

Author

Pohl, M., Abdo, A., Atoyan, A., Baring, M., Beacom, J., Blandford, R., Butt, Y., Bykov, A., Ellison, D., Funk, S., Halzen, F., Hays, E., Humensky, B., Jones, T., Kaaret, P., Kieda, D., LeBohec, S., Meszaros, P., Moskalenko, I., Slane, P., Strong, A., Wakely, S., Pohl, M., Abdo, A., Atoyan, A., Baring, M., Beacom, J., Blandford, R., Butt, Y., Bykov, A., Ellison, D., Funk, S., Halzen, F., Hays, E., Humensky, B., Jones, T., Kaaret, P., Kieda, D., LeBohec, S., Meszaros, P., Moskalenko, I., Slane, P., Strong, A., and Wakely, S.

Abstract

This is a report on the findings of the SNR/cosmic-ray working group for the white paper on the status and future of ground-based gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses the status of past and current attempts to observe shell-type supernova remnants and diffuse emission from cosmic rays at GeV-TeV energies. We concentrate on the potential of future ground-based gamma-ray experiments to study the acceleration of relativistic charged particles which is one of the main unsolved, yet fundamental, problems in modern astrophysics. The acceleration of particles relies on interactions between energetic particles and magnetic turbulence. In the case of SNRs we can perform spatially resolved studies in systems with known geometry, and the plasma physics deduced from these observations will help us to understand other systems where rapid particle acceleration is believed to occur and where observations as detailed as those of SNRs are not possible., Comment: Report from the SNR/CR Working group of the APS-commissioned White paper on ground-based gamma ray astronomy. More information available at http://cherenkov.physics.iastate.edu/wp

Published
2008

28. A multiwavelength view of the TeV blazar markarian 421: Correlated variability, flaring, and spectral evolution

Author

Blazejowski, M. B., Blaylock, G., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Celik, O., Cogan, P., Cui, W., Daniel, M., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L., Gammell, S., Gibbs, K., Gillanders, G. G., Grube, J., Gutierrez, K., Hall, J., Hanna, D., Holder, J., Horan, D., Humensky, B., Kenny, G., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M., LeBohec, S., Linton, E., Evans, J. L., Maier, G., Mendoza, D., Milovanovic, A., Moriarty, P., Nagai, T. N., Ong, R. A., Mooney, B. P., Quinn, J., Quinn, M., Ragan, K., Reynolds, P. T., Rebillot, P., Rose, H. J., Schroedter, M., Sembroski, G. H., Swordy, S. P., Syson, A., Valcarel, L., Vassiliev, V. V., Wakely, S. P., Walker, G., Weekes, T. C., White, R., Zweerink, J., Mochejska, B., Smith, B., Aller, M., Aller, H., Terasranta, H., Boltwood, P., Sadun, A., Stanek, K., Adams, E., Foster, J., Hartman, J., Lai, K., Bottcher, M., Reimer, A., Jung, I., Blazejowski, M. B., Blaylock, G., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Celik, O., Cogan, P., Cui, W., Daniel, M., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L., Gammell, S., Gibbs, K., Gillanders, G. G., Grube, J., Gutierrez, K., Hall, J., Hanna, D., Holder, J., Horan, D., Humensky, B., Kenny, G., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M., LeBohec, S., Linton, E., Evans, J. L., Maier, G., Mendoza, D., Milovanovic, A., Moriarty, P., Nagai, T. N., Ong, R. A., Mooney, B. P., Quinn, J., Quinn, M., Ragan, K., Reynolds, P. T., Rebillot, P., Rose, H. J., Schroedter, M., Sembroski, G. H., Swordy, S. P., Syson, A., Valcarel, L., Vassiliev, V. V., Wakely, S. P., Walker, G., Weekes, T. C., White, R., Zweerink, J., Mochejska, B., Smith, B., Aller, M., Aller, H., Terasranta, H., Boltwood, P., Sadun, A., Stanek, K., Adams, E., Foster, J., Hartman, J., Lai, K., Bottcher, M., Reimer, A., and Jung, I.

Abstract

We report results from an intensive multiwavelength monitoring campaign on the TeV blazar Mrk 421 over the period of 2003 - 2004. The source was observed simultaneously at TeV energies with the Whipple 10 m telescope and at X-ray energies with the Rossi X-Ray Timing Explorer (RXTE) during each clear night within the Whipple observing windows. Supporting observations were also frequently carried out at optical and radio wavelengths to provide simultaneous or contemporaneous coverages. The large amount of simultaneous data has allowed us to examine the variability of Mrk 421 in detail, including cross-band correlation and broadband spectral variability, over a wide range of flux. The variabilities are generally correlated between the X-ray and gamma-ray bands, although the correlation appears to be fairly loose. The light curves show the presence of flares with varying amplitudes on a wide range of timescales at both X-ray and TeV energies. Of particular interest is the presence of TeV flares that have no coincident counterparts at longer wavelengths, because the phenomenon seems difficult to understand in the context of the proposed emission models for TeV blazars. We have also found that the TeV flux reached its peak days before the X-ray flux did during a giant flare (or outburst) in 2004 (with the peak flux reaching similar to 135mcrab in X-rays, as seen by the RXTE ASM, and similar to 3 crab in gamma rays). Such a difference in the development of the flare presents a further challenge to both the leptonic and hadronic emission models. Mrk 421 varied much less at optical and radio wavelengths. Surprisingly, the normalized variability amplitude in the optical seems to be comparable to that in the radio, perhaps suggesting the presence of different populations of emitting electrons in the jet. The spectral energy distribution of Mrk 421 is seen to vary with flux, with the two characteristic peaks moving toward higher energies at higher fluxes. We have failed to fit

Published
2005

29. A multiwavelength view of the TeV blazar markarian 421: Correlated variability, flaring, and spectral evolution

Author

Blazejowski, M. B., Blaylock, G., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Celik, O., Cogan, P., Cui, W., Daniel, M., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L., Gammell, S., Gibbs, K., Gillanders, G. G., Grube, J., Gutierrez, K., Hall, J., Hanna, D., Holder, J., Horan, D., Humensky, B., Kenny, G., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M., LeBohec, S., Linton, E., Evans, J. L., Maier, G., Mendoza, D., Milovanovic, A., Moriarty, P., Nagai, T. N., Ong, R. A., Mooney, B. P., Quinn, J., Quinn, M., Ragan, K., Reynolds, P. T., Rebillot, P., Rose, H. J., Schroedter, M., Sembroski, G. H., Swordy, S. P., Syson, A., Valcarel, L., Vassiliev, V. V., Wakely, S. P., Walker, G., Weekes, T. C., White, R., Zweerink, J., Mochejska, B., Smith, B., Aller, M., Aller, H., Terasranta, H., Boltwood, P., Sadun, A., Stanek, K., Adams, E., Foster, J., Hartman, J., Lai, K., Bottcher, M., Reimer, A., Jung, I., Blazejowski, M. B., Blaylock, G., Bond, I. H., Bradbury, S. M., Buckley, J. H., Carter-Lewis, D. A., Celik, O., Cogan, P., Cui, W., Daniel, M., Duke, C., Falcone, A., Fegan, D. J., Fegan, S. J., Finley, J. P., Fortson, L., Gammell, S., Gibbs, K., Gillanders, G. G., Grube, J., Gutierrez, K., Hall, J., Hanna, D., Holder, J., Horan, D., Humensky, B., Kenny, G., Kertzman, M., Kieda, D., Kildea, J., Knapp, J., Kosack, K., Krawczynski, H., Krennrich, F., Lang, M., LeBohec, S., Linton, E., Evans, J. L., Maier, G., Mendoza, D., Milovanovic, A., Moriarty, P., Nagai, T. N., Ong, R. A., Mooney, B. P., Quinn, J., Quinn, M., Ragan, K., Reynolds, P. T., Rebillot, P., Rose, H. J., Schroedter, M., Sembroski, G. H., Swordy, S. P., Syson, A., Valcarel, L., Vassiliev, V. V., Wakely, S. P., Walker, G., Weekes, T. C., White, R., Zweerink, J., Mochejska, B., Smith, B., Aller, M., Aller, H., Terasranta, H., Boltwood, P., Sadun, A., Stanek, K., Adams, E., Foster, J., Hartman, J., Lai, K., Bottcher, M., Reimer, A., and Jung, I.

Abstract

We report results from an intensive multiwavelength monitoring campaign on the TeV blazar Mrk 421 over the period of 2003 - 2004. The source was observed simultaneously at TeV energies with the Whipple 10 m telescope and at X-ray energies with the Rossi X-Ray Timing Explorer (RXTE) during each clear night within the Whipple observing windows. Supporting observations were also frequently carried out at optical and radio wavelengths to provide simultaneous or contemporaneous coverages. The large amount of simultaneous data has allowed us to examine the variability of Mrk 421 in detail, including cross-band correlation and broadband spectral variability, over a wide range of flux. The variabilities are generally correlated between the X-ray and gamma-ray bands, although the correlation appears to be fairly loose. The light curves show the presence of flares with varying amplitudes on a wide range of timescales at both X-ray and TeV energies. Of particular interest is the presence of TeV flares that have no coincident counterparts at longer wavelengths, because the phenomenon seems difficult to understand in the context of the proposed emission models for TeV blazars. We have also found that the TeV flux reached its peak days before the X-ray flux did during a giant flare (or outburst) in 2004 (with the peak flux reaching similar to 135mcrab in X-rays, as seen by the RXTE ASM, and similar to 3 crab in gamma rays). Such a difference in the development of the flare presents a further challenge to both the leptonic and hadronic emission models. Mrk 421 varied much less at optical and radio wavelengths. Surprisingly, the normalized variability amplitude in the optical seems to be comparable to that in the radio, perhaps suggesting the presence of different populations of emitting electrons in the jet. The spectral energy distribution of Mrk 421 is seen to vary with flux, with the two characteristic peaks moving toward higher energies at higher fluxes. We have failed to fit

Published
2005

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