V. A. Acciari et al. Detection of persistent VHE gamma-ray emission from PKS 1510–089 by the MAGIC telescopes during low states between 2012 and 2017. A&A 619, A159 (2018), https://doi.org/10.1051/0004-6361/201833618
Detection of persistent VHE gamma-ray emission from PKS 1510–089 by the MAGIC telescopes during low states between 2012 and 2017
|Author:||Acciari, V. A.1; Ansoldi, S.2,3,4,5,6,7; Antonelli, L. A.8;|
1Univ La Laguna, Inst Astrofis Canarias, E-38206 Tenerife, Spain.
2Univ Udine, I-33100 Udine, Italy.
3INFN Trieste, I-34149 Trieste, Italy.
4Univ Tokyo, ICRR, Japanese MAGIC Consortium, Chiba 2778582, Japan.
5Kyoto Univ, Dept Phys, Kyoto 6068502, Japan.
6Tokai Univ, Kyoto, Kanagawa 2591292, Japan.
7RIKEN, Saitama 3510198, Japan.
8Natl Inst Astrophys INAF, I-00136 Rome, Italy.
9Swiss Fed Inst Technol, CH-8093 Zurich, Switzerland.
10Univ Padua, I-35131 Padua, Italy.
11INFN Padova, I-35131 Padua, Italy.
12Tech Univ Dortmund, D-44221 Dortmund, Germany.
13Univ Rijeka, Croatian MAGIC Consortium, Rijeka 51000, Croatia.
14Univ Split, FESB, Split 21000, Croatia.
15Univ Zagreb, FER, Zagreb 10000, Croatia.
16Univ Osijek, Osijek 31000, Croatia.
17Rudjer Boskovic Inst, Zagreb 10000, Croatia.
18HBNI, Saha Inst Nucl Phys, 1-AF Bidhannagar,Salt Lake,Sect 1, Kolkata 700064, India.
19Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany.
20URCA, CBPF, BR-22290180 Rio De Janeiro, RJ, Brazil.
21Univ Complutense, Unidad Particulas & Cosmol UPARCOS, E-28040 Madrid, Spain.
22Univ Lodz, Dept Astrophys, Lodz, Poland.
23Deutsch Elekt Synchrotron DESY, D-15738 Zeuthen, Germany.
24Humboldt Univ, Inst Phys, D-12489 Berlin, Germany.
25Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy.
26BIST, IFAE, Barcelona 08193, Spain.
27Univ Siena, I-53100 Siena, Italy.
28INFN Pisa, I-56127 Pisa, Italy.
29Univ Pisa, I-56126 Pisa, Italy.
30PIC, Barcelona 08193, Spain.
31Univ Wurzburg, D-97074 Wurzburg, Germany.
32Univ Turku, Tuorla Observ Dept Phys & Astron, Finnish MAGIC Consortium, Turku 20014, Finland.
33Univ Oulu, Oulu 90014, Finland.
34Univ Autonoma Barcelona, Dept Fis, Bellaterra 08193, Spain.
35Univ Autonoma Barcelona, CERES IEEC, Bellaterra 08193, Spain.
36Univ Barcelona, ICCUB, IEEC UB, E-08028 Barcelona, Spain.
37Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, BU-1784 Sofia, Bulgaria.
38Univ Bologna, INAF Trieste, Bologna, Italy.
39Univ Bologna, Dept Phys & Astron, Bologna, Italy.
40Osserv Astron Torino, INAF, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
41Univ Insubria, Dipartimento Sci & Alta Tecnol, Via Valleggio 11, I-22100 Como, Italy.
42Osserv Astron Brera, Ist Nazl Astrofis, INAF, Via Bianchi 46, I-23807 Merate, LC, Italy.
43Univ Turku, Tuorla Observ, Vaisalantie 20, Piikkio 21500, Finland.
44CALTECH, Owens Valley Radio Observ, Pasadena, CA 91125 USA.
45Univ Chile, Dept Astron, Camino Observa 1515, Santiago, Chile.
46Aalto Univ, Metsahovi Radio Observ, Metsahovintie 114, Kylmala 02540, Finland.
47Inst Radio Astron Millimetr, Avenida Div Pastora 7,Local 20, Granada 18008, Spain.
48CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain.
49Max Planck Inst Radioastron, Auf dem Hugel 69, D-53121 Bonn, Germany.
|Online Access:||PDF Full Text (PDF, 0.8 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2019093030649
|Publish Date:|| 2019-09-30
Context: PKS 1510–089 is a flat spectrum radio quasar strongly variable in the optical and GeV range. To date, very high-energy (VHE, > 100 GeV) emission has been observed from this source either during long high states of optical and GeV activity or during short flares.
Aims: We search for low-state VHE gamma-ray emission from PKS 1510–089. We characterize and model the source in a broadband context, which would provide a baseline over which high states and flares could be better understood.
Methods: PKS 1510–089 has been monitored by the MAGIC telescopes since 2012. We use daily binned Fermi-LAT flux measurements of PKS 1510–089 to characterize the GeV emission and select the observation periods of MAGIC during low state of activity. For the selected times we compute the average radio, IR, optical, UV, X-ray, and gamma-ray emission to construct a low-state spectral energy distribution of the source. The broadband emission is modeled within an external Compton scenario with a stationary emission region through which plasma and magnetic fields are flowing. We also perform the emission-model-independent calculations of the maximum absorption in the broad line region (BLR) using two different models.
Results: The MAGIC telescopes collected 75 hr of data during times when the Fermi-LAT flux measured above 1 GeV was below 3 × 10−8 cm−2 s−1, which is the threshold adopted for the definition of a low gamma-ray activity state. The data show a strongly significant (9.5σ) VHE gamma-ray emission at the level of (4.27 ± 0.61stat) × 10−12 cm−2 s−1 above 150 GeV, a factor of 80 lower than the highest flare observed so far from this object. Despite the lower flux, the spectral shape is consistent with earlier detections in the VHE band. The broadband emission is compatible with the external Compton scenario assuming a large emission region located beyond the BLR. For the first time the gamma-ray data allow us to place a limit on the location of the emission region during a low gamma-ray state of a FSRQ. For the used model of the BLR, the 95% confidence level on the location of the emission region allows us to place it at a distance > 74% of the outer radius of the BLR.
Astronomy and astrophysics
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
115 Astronomy and space science
The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P, FPA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009-00064), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 184.108.40.206.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382, and by the Brazilian MCTIC, CNPq and FAPERJ. The Fermi-LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States; the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France; the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy; the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK), and Japan Aerospace Exploration Agency (JAXA) in Japan; and the K. A. Wallenberg Foundation, the Swedish Research Council, and the Swedish National Space Board in Sweden.
© ESO 2018.