Browse > Article
http://dx.doi.org/10.5303/JKAS.2013.46.2.65

HOW TO MONITOR AGN INTRA-DAY VARIABILITY AT 230GHZ  

Kim, Jae-Young (Department of Physics and Astronomy, Seoul National University)
Trippe, Sascha (Department of Physics and Astronomy, Seoul National University)
Publication Information
Journal of The Korean Astronomical Society / v.46, no.2, 2013 , pp. 65-74 More about this Journal
Abstract
We probe the feasibility of high-frequency radio observations of very rapid flux variations in compact active galactic nuclei (AGN). Our study assumes observations at 230GHz with a small 6-meter class observatory, using the SNU Radio Astronomical Observatory (SRAO) as an example. We find that 33 radio-bright sources are observable with signal-to-noise ratios larger than ten. We derive statistical detection limits via exhaustive Monte Carlo simulations assuming (a) periodic, and (b) episodic flaring flux variations on time-scales as small as tens of minutes. We conclude that a wide range of flux variations is observable. This makes high-frequency radio observations-even with small observatories-a powerful probe of AGN intra-day variability; especially, those which complement observations at lower radio frequencies with larger observatories like the Korean VLBI Network (KVN).
Keywords
Galaxies: active; Radiation mechanisms: non-thermal; Methods: statistical;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 Thompson, A. R., Moran, J. M., & Swenson, G. W. 2004, Interferometry and Synthesis in Radio Astronomy (Weinheim: Wiley-VCH)
2 Trippe, S., et al. 2011, The Long-Term Millimeter Activity of Active Galactic Nuclei, A&A, 533, A97   DOI
3 Wagner, S. J., & Witzel, A. 1995, Intraday Variability in Quasars and BL Lac Objects, ARA&A, 33, 163   DOI   ScienceOn
4 Wilson, T. L., Rohlfs, K., & Huttemeister, S. 2008, Tools of Radio Astronomy (Berlin: Springer)
5 Witzel, A., Heeschen, D. S., Schalinski, C., & Krichbaum, T. P. 1986, Kurzzeit-Variabilit¨at Extragalaktischer Radioquellen, Mitt. Astron. Ges., 65, 239
6 Scargle, J. D. 1982, Studies in Astronomical Time Series Analysis. II - Statistical Aspects of Spectral Analysis of Unevenly Spaced Data, ApJ, 263, 835   DOI
7 Starck, J.-L., & Murtagh, F. 2006, Astronomical Image and Data Analysis, 2nd edn. (Berlin: Springer)
8 Fuhrmann, L., et al. 2008, Testing the Inverse-Compton Catastrophe Scenario in the Intra-Day Variable Blazar S5 0716+71. III. Rapid and Correlated Flux Density Variability from Radio to Sub-mm Bands, A&A, 490, 1019   DOI   ScienceOn
9 Gabanyi, K. E., et al. 2007, The IDV Source J1128+5925, a New Candidate for Annual Modulation?, A&A, 470, 83   DOI   ScienceOn
10 Kedziora-Chudczer, L. L., Jauncey, D. L., Wieringa, M. H., Tzioumis, A. K., & Reynolds, J. E. 2001, The ATCA Intraday Variability Survey of Extragalactic Radio Sources, MNRAS, 325, 1411   DOI   ScienceOn
11 Kellermann, K. I., & Pauliny-Toth, I. I. K. 1969, The Spectra of Opaque Radio Sources, ApJ, 155, L71   DOI
12 Kim, K.-T., et al. 2011, 100-GHz Band Test Observations of the KVN 21-m Radio Telescopes, JKAS, 44, 81
13 Koo, B.-C., Park, Y.-S., Hong, S. S., et al. 2003, Performance of the SRAO 6-meter Radio Telescope, JKAS, 36, 43
14 Kraus, A., Krichbaum, T. P., Wegner, R., et al. 2003, Intraday Variability in Compact Extragalactic Radio Sources. II. Observations with the Effelsberg 100m Radio Telescope, A&A, 401, 161   DOI   ScienceOn
15 Lee, S.-S., et al. 2008, A Global 86GHz VLBI Survey of Compact Radio Sources, AJ, 136, 159   DOI   ScienceOn
16 Lee, S.-S., et al. 2001, Single-Dish Performance of KVN 21 m Radio Telescopes: Simultaneous Observations at 22 and 43GHz, PASP, 123, 1398
17 Liu, X., Song, H.-G., Marchili, N., Liu, B.-R., Liu, J., Krichbaum, T. P., Fuhrmann, L., & Zensus, J. A. 2012, Intra- Day Variability Observations of S5 0716+714 over 4.5 Years at 4.8 GHz, A&A, 543, A78   DOI
18 Lovell, J. E. J., Jauncey, D. L., Bignall, H. E., Kedziora- Chudczer, L., Macquart, J.-P., Rickett, B. J., & Tzioumis, A. K. 2003, First Results from MASIV: The Microarcsecond Scintillation-induced Variability Survey, AJ, 126, 1699   DOI   ScienceOn
19 Marchili, N., et al. 2012, A Seasonal Cycle and an Abrupt Change in the Variability Characteristics of the Intraday Variable Source S4 0954+65, A&A, 542, A121   DOI
20 Lovell, J. E. J., Rickett, B. J., Macquart, J.-P., et al. 2008, The Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey. II. The First Four Epochs, ApJ, 689, 108   DOI
21 Ojha, R., Fey, A. L., Jauncey, D. L., Lovell, J. E. J., & Johnston, K. J. 2004, Milliarcsecond Structure of Microarcsecond Sources: Comparison of Scintillating and Nonscintillating Extragalactic Radio Sources, ApJ, 614, 607   DOI
22 Park, J.-H., & Trippe, S. 2012, Multiple Emission States in Active Galactic Nuclei, JKAS, 45, 147
23 Blandford, R. D., & Konigl, A. 1979, Relativistic Jets as Compact Radio Sources, ApJ, 232, 34   DOI
24 Quirrenbach, A., et al. 1992, Statistics of Intraday Variability in Extragalactic Radio Sources, A&A, 258, 279
25 Quirrenbach, A., et al. 2000, Intraday Variability in Compact Extragalactic Radio Sources. I. VLA Observations, A&AS, 141, 221   DOI   ScienceOn
26 Rickett, B. J., Coles, W. A., & Bourgois, G. 1984, Slow Scintillation in the Interstellar Medium, A&A, 134, 390
27 Beckmann, V., & Shrader, C. 2012, Active Galactic Nuclei (Weinheim: Wiley-VCH)