Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources
| dc.contributor.author | Nesci, R. | |
| dc.contributor.author | Tosti, G. | |
| dc.contributor.author | Pursimo, T. | |
| dc.contributor.author | Ojha, R. | |
| dc.contributor.author | Kadler, M. | |
| dc.date.accessioned | 2020-04-20T14:11:07Z | |
| dc.date.available | 2020-04-20T14:11:07Z | |
| dc.date.issued | 2013-06-18 | |
| dc.description.abstract | Context. Spectral energy distribution and its variability are basic tools for understanding the physical processes operating in active galactic nuclei (AGN). Aims. In this paper we report the results of a one-year near-infrared (NIR) and optical monitoring of a sample of 22 AGN known to be gamma-ray emitters, aimed at discovering correlations between optical and gamma-ray emission. Methods. We observed our objects with the Rapid Eye Mount (REM) telescope in J,H,K, and R bands nearly twice every month during their visibility window and derived light curves and spectral indexes. We also analyzed the gamma-ray data from the Fermi gamma-ray Space Telescope, making weekly averages. Results. Six sources were never detected during our monitoring, proving to be fainter than their historical Two micron all sky survey (2MASS) level. All of the sixteen detected sources showed marked flux density variability, while the spectral indexes remained unchanged within our sensitivity limits. Steeper sources showed, on average, a larger variability. From the NIR light curves we also computed a variability speed index for each detected source. Only one source (PKS 0208-512) underwent an NIR flare during our monitoring. Half of the sources showed a regular flux density trend on a one-year time scale, but do not show any other peculiar characteristic. The broadband spectral index αro appears to be a good proxy of the NIR spectral index only for BL Lac objects. No clear correlation between NIR and gamma-ray data is evident in our data, save for PKS 0537−441, PKS 0521−360, PKS 2155−304, and PKS 1424−418. The gamma-ray/NIR flux ratio showed a large spread, QSO being generally gamma-louder than BL Lac, with a marked correlation with the estimated peak frequency (νpeak) of the synchrotron emission. | en_US |
| dc.description.sponsorship | This research was funded in part by NASA through Fermi Guest Investigator grant NNH09ZDA001N (proposal number 31263) and grant NNH10ZDA001N (proposal number 41213). This research was supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France, and also of the Two Micron All-Sky Survey database, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology. This research has made use of NASA’s Astrophysics Data System Bibliographic Services. 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’Énergie 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. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. | en_US |
| dc.description.uri | https://www.aanda.org/articles/aa/abs/2013/07/aa21094-13/aa21094-13.html | en_US |
| dc.format.extent | 5 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2ubap-lkl6 | |
| dc.identifier.citation | Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources R. Nesci, G. Tosti, T. Pursimo, R. Ojha and M. Kadler A&A, 555 (2013) A2 , https://doi.org/10.1051/0004-6361/201321094 | en_US |
| dc.identifier.uri | https://doi.org/10.1051/0004-6361/201321094 | |
| dc.identifier.uri | http://hdl.handle.net/11603/18137 | |
| dc.identifier.uri | http://simbad.u-strasbg.fr/simbad/sim-ref?querymethod=bib&simbo=on&submit=submit+bibcode&bibcode=2013A%26A...555A...2N | |
| dc.identifier.uri | https://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Search&refcode=2013A%26A...555A...2N | |
| dc.identifier.uri | http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=J/A+A/555/A2 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | EDP sciences | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Physics Department Collection | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II) | |
| dc.rights | This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author. | |
| dc.rights | © ESO 2013 | |
| dc.title | Near-infrared and gamma-ray monitoring of TANAMI gamma-ray bright sources | en_US |
| dc.type | Text | en_US |