Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift

V. A. Acciari, E. Aliu, T. Arlen, T. Aune, M. Bautista, M. Beilicke, W. Benbow, M. Böttcher, D. Boltuch, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, A. Cesarini, Y. C. Chow, L. Ciupik, P. Cogan, W. Cui, C. Duke & 225 others A. Falcone, J. P. Finley, G. Finnegan, L. Fortson, A. Furniss, N. Galante, D. Gall, G. H. Gillanders, S. Godambe, J. Grube, R. Guenette, G. Gyuk, D. Hanna, J. Holder, C. M. Hui, T. B. Humensky, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, S. Lebohec, G. Maier, S. McArthur, A. McCann, M. McCutcheon, J. Millis, P. Moriarty, T. Nagai, R. A. Ong, A. N. Otte, D. Pandel, J. S. Perkins, A. Pichel, M. Pohl, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, E. Roache, H. J. Rose, M. Schroedter, G. H. Sembroski, G. Demet Senturk, A. W. Smith, D. Steele, S. P. Swordy, M. Theiling, S. Thibadeau, A. Varlotta, V. V. Vassiliev, S. Vincent, R. G. Wagner, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, T. Weisgarber, D. A. Williams, S. Wissel, M. Wood, B. Zitzer, A. A. Abdo, M. Ackermann, M. Ajello, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, B. M. Baughman, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, J. Bregeon, A. Brez, M. Brigida, P. Bruel, T. H. Burnett, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, E. Cavazzuti, C. Cecchi, Ö Çelik, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, C. D. Dermer, A. De Angelis, F. De Palma, E. Do Couto E Silva, P. S. Drell, A. Drlica-Wagner, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, S. J. Fegan, W. B. Focke, P. Fortin, M. Frailis, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, S. Germani, B. Giebels, N. Giglietto, P. Giommi, F. Giordano, T. Glanzman, G. Godfrey, I. A. Grenier, J. E. Grove, L. Guillemot, S. Guiriec, Y. Hanabata, E. Hays, R. E. Hughes, M. S. Jackson, G. Jóhannesson, A. S. Johnson, W. N. Johnson, T. Kamae, H. Katagiri, Jun Kataoka, N. Kawai, M. Kerr, J. Knödlseder, M. L. Kocian, M. Kuss, J. Lande, L. Latronico, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Makeev, M. N. Mazziotta, J. E. McEnery, C. Meurer, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, D. Paneque, D. Parent, V. Pelassa, M. Pepe, M. Pesce-Rollins, F. Piron, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, A. Y. Rodriguez, M. Roth, F. Ryde, H. F W Sadrozinski, D. Sanchez, A. Sander, P. M. Saz Parkinson, J. D. Scargle, C. Sgrò, M. S. Shaw, E. J. Siskind, P. D. Smith, G. Spandre, P. Spinelli, M. S. Strickman, D. J. Suson, H. Tajima, H. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, D. J. Thompson, L. Tibaldo, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. L. Usher, V. Vasileiou, N. Vilchez, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, T. Ylinen, M. Ziegler, S. D. Barber, D. M. Terndrup

    Research output: Contribution to journalArticle

    70 Citations (Scopus)

    Abstract

    We report the first detection of very high energy83Gamma-ray emission above 100 GeV. (VHE) gamma-ray emission above 140 GeV from PKS1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 0.5stat 0.3syst and a flux normalization at 200 GeV of (5.1 0.9stat 0.5syst) × 10-11 TeV -1 cm-2 s-1, where stat and syst denote the statistical and systematical uncertainties, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (from 2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high-energy observations with the Fermi Large Area Telescope. Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution is well described by a one-zone synchrotron self-Compton model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.

    Original languageEnglish
    JournalAstrophysical Journal Letters
    Volume708
    Issue number2 PART 2
    DOIs
    Publication statusPublished - 2010

    Fingerprint

    gamma rays
    photons
    energy
    power law
    observatory
    electromagnetic absorption
    spectral energy distribution
    rays
    observatories
    synchrotrons
    telescopes
    broadband
    index
    x rays
    detection
    distribution
    normalisation

    Keywords

    • BL Lacertae objects: individual (PKS 1424+240 = VER J1427+237)
    • Gamma rays: observations

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Bautista, M., Beilicke, M., ... Terndrup, D. M. (2010). Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift. Astrophysical Journal Letters, 708(2 PART 2). https://doi.org/10.1088/2041-8205/708/2/L100

    Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift. / Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M.; Benbow, W.; Böttcher, M.; Boltuch, D.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Chow, Y. C.; Ciupik, L.; Cogan, P.; Cui, W.; Duke, C.; Falcone, A.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Hui, C. M.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Lebohec, S.; Maier, G.; McArthur, S.; McCann, A.; McCutcheon, M.; Millis, J.; Moriarty, P.; Nagai, T.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pichel, A.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Demet Senturk, G.; Smith, A. W.; Steele, D.; Swordy, S. P.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wagner, R. G.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Zitzer, B.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; Dermer, C. D.; De Angelis, A.; De Palma, F.; Do Couto E Silva, E.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Hays, E.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, Jun; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocian, M. L.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F W; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.; Barber, S. D.; Terndrup, D. M.

    In: Astrophysical Journal Letters, Vol. 708, No. 2 PART 2, 2010.

    Research output: Contribution to journalArticle

    Acciari, VA, Aliu, E, Arlen, T, Aune, T, Bautista, M, Beilicke, M, Benbow, W, Böttcher, M, Boltuch, D, Bradbury, SM, Buckley, JH, Bugaev, V, Byrum, K, Cannon, A, Cesarini, A, Chow, YC, Ciupik, L, Cogan, P, Cui, W, Duke, C, Falcone, A, Finley, JP, Finnegan, G, Fortson, L, Furniss, A, Galante, N, Gall, D, Gillanders, GH, Godambe, S, Grube, J, Guenette, R, Gyuk, G, Hanna, D, Holder, J, Hui, CM, Humensky, TB, Kaaret, P, Karlsson, N, Kertzman, M, Kieda, D, Konopelko, A, Krawczynski, H, Krennrich, F, Lang, MJ, Lebohec, S, Maier, G, McArthur, S, McCann, A, McCutcheon, M, Millis, J, Moriarty, P, Nagai, T, Ong, RA, Otte, AN, Pandel, D, Perkins, JS, Pichel, A, Pohl, M, Quinn, J, Ragan, K, Reyes, LC, Reynolds, PT, Roache, E, Rose, HJ, Schroedter, M, Sembroski, GH, Demet Senturk, G, Smith, AW, Steele, D, Swordy, SP, Theiling, M, Thibadeau, S, Varlotta, A, Vassiliev, VV, Vincent, S, Wagner, RG, Wakely, SP, Ward, JE, Weekes, TC, Weinstein, A, Weisgarber, T, Williams, DA, Wissel, S, Wood, M, Zitzer, B, Abdo, AA, Ackermann, M, Ajello, M, Baldini, L, Ballet, J, Barbiellini, G, Bastieri, D, Baughman, BM, Bechtol, K, Bellazzini, R, Berenji, B, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bregeon, J, Brez, A, Brigida, M, Bruel, P, Burnett, TH, Caliandro, GA, Cameron, RA, Caraveo, PA, Casandjian, JM, Cavazzuti, E, Cecchi, C, Çelik, Ö, Chekhtman, A, Cheung, CC, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Conrad, J, Cutini, S, Dermer, CD, De Angelis, A, De Palma, F, Do Couto E Silva, E, Drell, PS, Drlica-Wagner, A, Dubois, R, Dumora, D, Farnier, C, Favuzzi, C, Fegan, SJ, Focke, WB, Fortin, P, Frailis, M, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giebels, B, Giglietto, N, Giommi, P, Giordano, F, Glanzman, T, Godfrey, G, Grenier, IA, Grove, JE, Guillemot, L, Guiriec, S, Hanabata, Y, Hays, E, Hughes, RE, Jackson, MS, Jóhannesson, G, Johnson, AS, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Kawai, N, Kerr, M, Knödlseder, J, Kocian, ML, Kuss, M, Lande, J, Latronico, L, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Madejski, GM, Makeev, A, Mazziotta, MN, McEnery, JE, Meurer, C, Michelson, PF, Mitthumsiri, W, Mizuno, T, Moiseev, AA, Monte, C, Monzani, ME, Morselli, A, Moskalenko, IV, Murgia, S, Nolan, PL, Norris, JP, Nuss, E, Ohsugi, T, Omodei, N, Orlando, E, Ormes, JF, Paneque, D, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Porter, TA, Rainò, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Rodriguez, AY, Roth, M, Ryde, F, Sadrozinski, HFW, Sanchez, D, Sander, A, Saz Parkinson, PM, Scargle, JD, Sgrò, C, Shaw, MS, Siskind, EJ, Smith, PD, Spandre, G, Spinelli, P, Strickman, MS, Suson, DJ, Tajima, H, Takahashi, H, Tanaka, T, Thayer, JB, Thayer, JG, Thompson, DJ, Tibaldo, L, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Usher, TL, Vasileiou, V, Vilchez, N, Vitale, V, Waite, AP, Wang, P, Winer, BL, Wood, KS, Ylinen, T, Ziegler, M, Barber, SD & Terndrup, DM 2010, 'Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift', Astrophysical Journal Letters, vol. 708, no. 2 PART 2. https://doi.org/10.1088/2041-8205/708/2/L100
    Acciari, V. A. ; Aliu, E. ; Arlen, T. ; Aune, T. ; Bautista, M. ; Beilicke, M. ; Benbow, W. ; Böttcher, M. ; Boltuch, D. ; Bradbury, S. M. ; Buckley, J. H. ; Bugaev, V. ; Byrum, K. ; Cannon, A. ; Cesarini, A. ; Chow, Y. C. ; Ciupik, L. ; Cogan, P. ; Cui, W. ; Duke, C. ; Falcone, A. ; Finley, J. P. ; Finnegan, G. ; Fortson, L. ; Furniss, A. ; Galante, N. ; Gall, D. ; Gillanders, G. H. ; Godambe, S. ; Grube, J. ; Guenette, R. ; Gyuk, G. ; Hanna, D. ; Holder, J. ; Hui, C. M. ; Humensky, T. B. ; Kaaret, P. ; Karlsson, N. ; Kertzman, M. ; Kieda, D. ; Konopelko, A. ; Krawczynski, H. ; Krennrich, F. ; Lang, M. J. ; Lebohec, S. ; Maier, G. ; McArthur, S. ; McCann, A. ; McCutcheon, M. ; Millis, J. ; Moriarty, P. ; Nagai, T. ; Ong, R. A. ; Otte, A. N. ; Pandel, D. ; Perkins, J. S. ; Pichel, A. ; Pohl, M. ; Quinn, J. ; Ragan, K. ; Reyes, L. C. ; Reynolds, P. T. ; Roache, E. ; Rose, H. J. ; Schroedter, M. ; Sembroski, G. H. ; Demet Senturk, G. ; Smith, A. W. ; Steele, D. ; Swordy, S. P. ; Theiling, M. ; Thibadeau, S. ; Varlotta, A. ; Vassiliev, V. V. ; Vincent, S. ; Wagner, R. G. ; Wakely, S. P. ; Ward, J. E. ; Weekes, T. C. ; Weinstein, A. ; Weisgarber, T. ; Williams, D. A. ; Wissel, S. ; Wood, M. ; Zitzer, B. ; Abdo, A. A. ; Ackermann, M. ; Ajello, M. ; Baldini, L. ; Ballet, J. ; Barbiellini, G. ; Bastieri, D. ; Baughman, B. M. ; Bechtol, K. ; Bellazzini, R. ; Berenji, B. ; Blandford, R. D. ; Bloom, E. D. ; Bonamente, E. ; Borgland, A. W. ; Bregeon, J. ; Brez, A. ; Brigida, M. ; Bruel, P. ; Burnett, T. H. ; Caliandro, G. A. ; Cameron, R. A. ; Caraveo, P. A. ; Casandjian, J. M. ; Cavazzuti, E. ; Cecchi, C. ; Çelik, Ö ; Chekhtman, A. ; Cheung, C. C. ; Chiang, J. ; Ciprini, S. ; Claus, R. ; Cohen-Tanugi, J. ; Conrad, J. ; Cutini, S. ; Dermer, C. D. ; De Angelis, A. ; De Palma, F. ; Do Couto E Silva, E. ; Drell, P. S. ; Drlica-Wagner, A. ; Dubois, R. ; Dumora, D. ; Farnier, C. ; Favuzzi, C. ; Fegan, S. J. ; Focke, W. B. ; Fortin, P. ; Frailis, M. ; Fukazawa, Y. ; Fusco, P. ; Gargano, F. ; Gasparrini, D. ; Gehrels, N. ; Germani, S. ; Giebels, B. ; Giglietto, N. ; Giommi, P. ; Giordano, F. ; Glanzman, T. ; Godfrey, G. ; Grenier, I. A. ; Grove, J. E. ; Guillemot, L. ; Guiriec, S. ; Hanabata, Y. ; Hays, E. ; Hughes, R. E. ; Jackson, M. S. ; Jóhannesson, G. ; Johnson, A. S. ; Johnson, W. N. ; Kamae, T. ; Katagiri, H. ; Kataoka, Jun ; Kawai, N. ; Kerr, M. ; Knödlseder, J. ; Kocian, M. L. ; Kuss, M. ; Lande, J. ; Latronico, L. ; Longo, F. ; Loparco, F. ; Lott, B. ; Lovellette, M. N. ; Lubrano, P. ; Madejski, G. M. ; Makeev, A. ; Mazziotta, M. N. ; McEnery, J. E. ; Meurer, C. ; Michelson, P. F. ; Mitthumsiri, W. ; Mizuno, T. ; Moiseev, A. A. ; Monte, C. ; Monzani, M. E. ; Morselli, A. ; Moskalenko, I. V. ; Murgia, S. ; Nolan, P. L. ; Norris, J. P. ; Nuss, E. ; Ohsugi, T. ; Omodei, N. ; Orlando, E. ; Ormes, J. F. ; Paneque, D. ; Parent, D. ; Pelassa, V. ; Pepe, M. ; Pesce-Rollins, M. ; Piron, F. ; Porter, T. A. ; Rainò, S. ; Rando, R. ; Razzano, M. ; Reimer, A. ; Reimer, O. ; Reposeur, T. ; Rodriguez, A. Y. ; Roth, M. ; Ryde, F. ; Sadrozinski, H. F W ; Sanchez, D. ; Sander, A. ; Saz Parkinson, P. M. ; Scargle, J. D. ; Sgrò, C. ; Shaw, M. S. ; Siskind, E. J. ; Smith, P. D. ; Spandre, G. ; Spinelli, P. ; Strickman, M. S. ; Suson, D. J. ; Tajima, H. ; Takahashi, H. ; Tanaka, T. ; Thayer, J. B. ; Thayer, J. G. ; Thompson, D. J. ; Tibaldo, L. ; Torres, D. F. ; Tosti, G. ; Tramacere, A. ; Uchiyama, Y. ; Usher, T. L. ; Vasileiou, V. ; Vilchez, N. ; Vitale, V. ; Waite, A. P. ; Wang, P. ; Winer, B. L. ; Wood, K. S. ; Ylinen, T. ; Ziegler, M. ; Barber, S. D. ; Terndrup, D. M. / Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift. In: Astrophysical Journal Letters. 2010 ; Vol. 708, No. 2 PART 2.
    @article{fc019ddabc1c4235a9504f74bcffafb7,
    title = "Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift",
    abstract = "We report the first detection of very high energy83Gamma-ray emission above 100 GeV. (VHE) gamma-ray emission above 140 GeV from PKS1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 0.5stat 0.3syst and a flux normalization at 200 GeV of (5.1 0.9stat 0.5syst) × 10-11 TeV -1 cm-2 s-1, where stat and syst denote the statistical and systematical uncertainties, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (from 2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high-energy observations with the Fermi Large Area Telescope. Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution is well described by a one-zone synchrotron self-Compton model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.",
    keywords = "BL Lacertae objects: individual (PKS 1424+240 = VER J1427+237), Gamma rays: observations",
    author = "Acciari, {V. A.} and E. Aliu and T. Arlen and T. Aune and M. Bautista and M. Beilicke and W. Benbow and M. B{\"o}ttcher and D. Boltuch and Bradbury, {S. M.} and Buckley, {J. H.} and V. Bugaev and K. Byrum and A. Cannon and A. Cesarini and Chow, {Y. C.} and L. Ciupik and P. Cogan and W. Cui and C. Duke and A. Falcone and Finley, {J. P.} and G. Finnegan and L. Fortson and A. Furniss and N. Galante and D. Gall and Gillanders, {G. H.} and S. Godambe and J. Grube and R. Guenette and G. Gyuk and D. Hanna and J. Holder and Hui, {C. M.} and Humensky, {T. B.} and P. Kaaret and N. Karlsson and M. Kertzman and D. Kieda and A. Konopelko and H. Krawczynski and F. Krennrich and Lang, {M. J.} and S. Lebohec and G. Maier and S. McArthur and A. McCann and M. McCutcheon and J. Millis and P. Moriarty and T. Nagai and Ong, {R. A.} and Otte, {A. N.} and D. Pandel and Perkins, {J. S.} and A. Pichel and M. Pohl and J. Quinn and K. Ragan and Reyes, {L. C.} and Reynolds, {P. T.} and E. Roache and Rose, {H. J.} and M. Schroedter and Sembroski, {G. H.} and {Demet Senturk}, G. and Smith, {A. W.} and D. Steele and Swordy, {S. P.} and M. Theiling and S. Thibadeau and A. Varlotta and Vassiliev, {V. V.} and S. Vincent and Wagner, {R. G.} and Wakely, {S. P.} and Ward, {J. E.} and Weekes, {T. C.} and A. Weinstein and T. Weisgarber and Williams, {D. A.} and S. Wissel and M. Wood and B. Zitzer and Abdo, {A. A.} and M. Ackermann and M. Ajello and L. Baldini and J. Ballet and G. Barbiellini and D. Bastieri and Baughman, {B. M.} and K. Bechtol and R. Bellazzini and B. Berenji and Blandford, {R. D.} and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and J. Bregeon and A. Brez and M. Brigida and P. Bruel and Burnett, {T. H.} and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and Casandjian, {J. M.} and E. Cavazzuti and C. Cecchi and {\"O} {\cC}elik and A. Chekhtman and Cheung, {C. C.} and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and J. Conrad and S. Cutini and Dermer, {C. D.} and {De Angelis}, A. and {De Palma}, F. and {Do Couto E Silva}, E. and Drell, {P. S.} and A. Drlica-Wagner and R. Dubois and D. Dumora and C. Farnier and C. Favuzzi and Fegan, {S. J.} and Focke, {W. B.} and P. Fortin and M. Frailis and Y. Fukazawa and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and S. Germani and B. Giebels and N. Giglietto and P. Giommi and F. Giordano and T. Glanzman and G. Godfrey and Grenier, {I. A.} and Grove, {J. E.} and L. Guillemot and S. Guiriec and Y. Hanabata and E. Hays and Hughes, {R. E.} and Jackson, {M. S.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {W. N.} and T. Kamae and H. Katagiri and Jun Kataoka and N. Kawai and M. Kerr and J. Kn{\"o}dlseder and Kocian, {M. L.} and M. Kuss and J. Lande and L. Latronico and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and Madejski, {G. M.} and A. Makeev and Mazziotta, {M. N.} and McEnery, {J. E.} and C. Meurer and Michelson, {P. F.} and W. Mitthumsiri and T. Mizuno and Moiseev, {A. A.} and C. Monte and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and N. Omodei and E. Orlando and Ormes, {J. F.} and D. Paneque and D. Parent and V. Pelassa and M. Pepe and M. Pesce-Rollins and F. Piron and Porter, {T. A.} and S. Rain{\`o} and R. Rando and M. Razzano and A. Reimer and O. Reimer and T. Reposeur and Rodriguez, {A. Y.} and M. Roth and F. Ryde and Sadrozinski, {H. F W} and D. Sanchez and A. Sander and {Saz Parkinson}, {P. M.} and Scargle, {J. D.} and C. Sgr{\`o} and Shaw, {M. S.} and Siskind, {E. J.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Strickman, {M. S.} and Suson, {D. J.} and H. Tajima and H. Takahashi and T. Tanaka and Thayer, {J. B.} and Thayer, {J. G.} and Thompson, {D. J.} and L. Tibaldo and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and Usher, {T. L.} and V. Vasileiou and N. Vilchez and V. Vitale and Waite, {A. P.} and P. Wang and Winer, {B. L.} and Wood, {K. S.} and T. Ylinen and M. Ziegler and Barber, {S. D.} and Terndrup, {D. M.}",
    year = "2010",
    doi = "10.1088/2041-8205/708/2/L100",
    language = "English",
    volume = "708",
    journal = "Astrophysical Journal Letters",
    issn = "2041-8205",
    publisher = "IOP Publishing Ltd.",
    number = "2 PART 2",

    }

    TY - JOUR

    T1 - Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on ITS redshift

    AU - Acciari, V. A.

    AU - Aliu, E.

    AU - Arlen, T.

    AU - Aune, T.

    AU - Bautista, M.

    AU - Beilicke, M.

    AU - Benbow, W.

    AU - Böttcher, M.

    AU - Boltuch, D.

    AU - Bradbury, S. M.

    AU - Buckley, J. H.

    AU - Bugaev, V.

    AU - Byrum, K.

    AU - Cannon, A.

    AU - Cesarini, A.

    AU - Chow, Y. C.

    AU - Ciupik, L.

    AU - Cogan, P.

    AU - Cui, W.

    AU - Duke, C.

    AU - Falcone, A.

    AU - Finley, J. P.

    AU - Finnegan, G.

    AU - Fortson, L.

    AU - Furniss, A.

    AU - Galante, N.

    AU - Gall, D.

    AU - Gillanders, G. H.

    AU - Godambe, S.

    AU - Grube, J.

    AU - Guenette, R.

    AU - Gyuk, G.

    AU - Hanna, D.

    AU - Holder, J.

    AU - Hui, C. M.

    AU - Humensky, T. B.

    AU - Kaaret, P.

    AU - Karlsson, N.

    AU - Kertzman, M.

    AU - Kieda, D.

    AU - Konopelko, A.

    AU - Krawczynski, H.

    AU - Krennrich, F.

    AU - Lang, M. J.

    AU - Lebohec, S.

    AU - Maier, G.

    AU - McArthur, S.

    AU - McCann, A.

    AU - McCutcheon, M.

    AU - Millis, J.

    AU - Moriarty, P.

    AU - Nagai, T.

    AU - Ong, R. A.

    AU - Otte, A. N.

    AU - Pandel, D.

    AU - Perkins, J. S.

    AU - Pichel, A.

    AU - Pohl, M.

    AU - Quinn, J.

    AU - Ragan, K.

    AU - Reyes, L. C.

    AU - Reynolds, P. T.

    AU - Roache, E.

    AU - Rose, H. J.

    AU - Schroedter, M.

    AU - Sembroski, G. H.

    AU - Demet Senturk, G.

    AU - Smith, A. W.

    AU - Steele, D.

    AU - Swordy, S. P.

    AU - Theiling, M.

    AU - Thibadeau, S.

    AU - Varlotta, A.

    AU - Vassiliev, V. V.

    AU - Vincent, S.

    AU - Wagner, R. G.

    AU - Wakely, S. P.

    AU - Ward, J. E.

    AU - Weekes, T. C.

    AU - Weinstein, A.

    AU - Weisgarber, T.

    AU - Williams, D. A.

    AU - Wissel, S.

    AU - Wood, M.

    AU - Zitzer, B.

    AU - Abdo, A. A.

    AU - Ackermann, M.

    AU - Ajello, M.

    AU - Baldini, L.

    AU - Ballet, J.

    AU - Barbiellini, G.

    AU - Bastieri, D.

    AU - Baughman, B. M.

    AU - Bechtol, K.

    AU - Bellazzini, R.

    AU - Berenji, B.

    AU - Blandford, R. D.

    AU - Bloom, E. D.

    AU - Bonamente, E.

    AU - Borgland, A. W.

    AU - Bregeon, J.

    AU - Brez, A.

    AU - Brigida, M.

    AU - Bruel, P.

    AU - Burnett, T. H.

    AU - Caliandro, G. A.

    AU - Cameron, R. A.

    AU - Caraveo, P. A.

    AU - Casandjian, J. M.

    AU - Cavazzuti, E.

    AU - Cecchi, C.

    AU - Çelik, Ö

    AU - Chekhtman, A.

    AU - Cheung, C. C.

    AU - Chiang, J.

    AU - Ciprini, S.

    AU - Claus, R.

    AU - Cohen-Tanugi, J.

    AU - Conrad, J.

    AU - Cutini, S.

    AU - Dermer, C. D.

    AU - De Angelis, A.

    AU - De Palma, F.

    AU - Do Couto E Silva, E.

    AU - Drell, P. S.

    AU - Drlica-Wagner, A.

    AU - Dubois, R.

    AU - Dumora, D.

    AU - Farnier, C.

    AU - Favuzzi, C.

    AU - Fegan, S. J.

    AU - Focke, W. B.

    AU - Fortin, P.

    AU - Frailis, M.

    AU - Fukazawa, Y.

    AU - Fusco, P.

    AU - Gargano, F.

    AU - Gasparrini, D.

    AU - Gehrels, N.

    AU - Germani, S.

    AU - Giebels, B.

    AU - Giglietto, N.

    AU - Giommi, P.

    AU - Giordano, F.

    AU - Glanzman, T.

    AU - Godfrey, G.

    AU - Grenier, I. A.

    AU - Grove, J. E.

    AU - Guillemot, L.

    AU - Guiriec, S.

    AU - Hanabata, Y.

    AU - Hays, E.

    AU - Hughes, R. E.

    AU - Jackson, M. S.

    AU - Jóhannesson, G.

    AU - Johnson, A. S.

    AU - Johnson, W. N.

    AU - Kamae, T.

    AU - Katagiri, H.

    AU - Kataoka, Jun

    AU - Kawai, N.

    AU - Kerr, M.

    AU - Knödlseder, J.

    AU - Kocian, M. L.

    AU - Kuss, M.

    AU - Lande, J.

    AU - Latronico, L.

    AU - Longo, F.

    AU - Loparco, F.

    AU - Lott, B.

    AU - Lovellette, M. N.

    AU - Lubrano, P.

    AU - Madejski, G. M.

    AU - Makeev, A.

    AU - Mazziotta, M. N.

    AU - McEnery, J. E.

    AU - Meurer, C.

    AU - Michelson, P. F.

    AU - Mitthumsiri, W.

    AU - Mizuno, T.

    AU - Moiseev, A. A.

    AU - Monte, C.

    AU - Monzani, M. E.

    AU - Morselli, A.

    AU - Moskalenko, I. V.

    AU - Murgia, S.

    AU - Nolan, P. L.

    AU - Norris, J. P.

    AU - Nuss, E.

    AU - Ohsugi, T.

    AU - Omodei, N.

    AU - Orlando, E.

    AU - Ormes, J. F.

    AU - Paneque, D.

    AU - Parent, D.

    AU - Pelassa, V.

    AU - Pepe, M.

    AU - Pesce-Rollins, M.

    AU - Piron, F.

    AU - Porter, T. A.

    AU - Rainò, S.

    AU - Rando, R.

    AU - Razzano, M.

    AU - Reimer, A.

    AU - Reimer, O.

    AU - Reposeur, T.

    AU - Rodriguez, A. Y.

    AU - Roth, M.

    AU - Ryde, F.

    AU - Sadrozinski, H. F W

    AU - Sanchez, D.

    AU - Sander, A.

    AU - Saz Parkinson, P. M.

    AU - Scargle, J. D.

    AU - Sgrò, C.

    AU - Shaw, M. S.

    AU - Siskind, E. J.

    AU - Smith, P. D.

    AU - Spandre, G.

    AU - Spinelli, P.

    AU - Strickman, M. S.

    AU - Suson, D. J.

    AU - Tajima, H.

    AU - Takahashi, H.

    AU - Tanaka, T.

    AU - Thayer, J. B.

    AU - Thayer, J. G.

    AU - Thompson, D. J.

    AU - Tibaldo, L.

    AU - Torres, D. F.

    AU - Tosti, G.

    AU - Tramacere, A.

    AU - Uchiyama, Y.

    AU - Usher, T. L.

    AU - Vasileiou, V.

    AU - Vilchez, N.

    AU - Vitale, V.

    AU - Waite, A. P.

    AU - Wang, P.

    AU - Winer, B. L.

    AU - Wood, K. S.

    AU - Ylinen, T.

    AU - Ziegler, M.

    AU - Barber, S. D.

    AU - Terndrup, D. M.

    PY - 2010

    Y1 - 2010

    N2 - We report the first detection of very high energy83Gamma-ray emission above 100 GeV. (VHE) gamma-ray emission above 140 GeV from PKS1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 0.5stat 0.3syst and a flux normalization at 200 GeV of (5.1 0.9stat 0.5syst) × 10-11 TeV -1 cm-2 s-1, where stat and syst denote the statistical and systematical uncertainties, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (from 2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high-energy observations with the Fermi Large Area Telescope. Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution is well described by a one-zone synchrotron self-Compton model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.

    AB - We report the first detection of very high energy83Gamma-ray emission above 100 GeV. (VHE) gamma-ray emission above 140 GeV from PKS1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 0.5stat 0.3syst and a flux normalization at 200 GeV of (5.1 0.9stat 0.5syst) × 10-11 TeV -1 cm-2 s-1, where stat and syst denote the statistical and systematical uncertainties, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (from 2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high-energy observations with the Fermi Large Area Telescope. Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution is well described by a one-zone synchrotron self-Compton model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.

    KW - BL Lacertae objects: individual (PKS 1424+240 = VER J1427+237)

    KW - Gamma rays: observations

    UR - http://www.scopus.com/inward/record.url?scp=77949547554&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=77949547554&partnerID=8YFLogxK

    U2 - 10.1088/2041-8205/708/2/L100

    DO - 10.1088/2041-8205/708/2/L100

    M3 - Article

    VL - 708

    JO - Astrophysical Journal Letters

    JF - Astrophysical Journal Letters

    SN - 2041-8205

    IS - 2 PART 2

    ER -