skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: POSSIBLE DETECTION OF APPARENT SUPERLUMINAL INWARD MOTION IN MARKARIAN 421 AFTER THE GIANT X-RAY FLARE IN 2010 FEBRUARY

Abstract

We report on the very long baseline interferometry (VLBI) follow-up observations using the Japanese VLBI Network array at 22 GHz for the largest X-ray flare of TeV blazar Mrk 421 that occurred in 2010 mid-February. The total of five epochs of observations were performed at intervals of about 20 days between 2010 March 7 and May 31. No newborn component associated with the flare was seen directly in the total intensity images obtained by our multi-epoch VLBI observations. However, one jet component located at {approx}1 mas northwest from the core was able to be identified, and its proper motion can be measured as -1.66 {+-} 0.46 mas yr{sup -1}, which corresponds to an apparent velocity of -3.48 {+-} 0.97c. Here, this negative velocity indicates that the jet component was apparently moving toward the core. As the most plausible explanation, we discuss that the apparent negative velocity was possibly caused by the ejection of a new component, which could not be resolved with our observations. In this case, the obtained Doppler factor of the new component is around 10-20, which is consistent with the ones typically estimated by model fittings of spectral energy distribution for this source.

Authors:
 [1]; ;  [2];  [3];  [4];  [5];  [6];  [7];  [8];  [9]
  1. Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 753-8511 (Japan)
  2. Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  3. ALMA-J Project, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)
  4. Institute of Space and Astronautics, Japan Aerospace Exploration Agency, Yoshinodai, Chuo, Sagamihara 252-5210 (Japan)
  5. Hungarian Academy of Sciences, Research Group for Physical Geodesy and Geodynamics, FOMI Satellite Geodetic Observatory Budapest, 1592 Budapest (Hungary)
  6. INAF Istituto di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy)
  7. Department of Astronomy, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan)
  8. Academia Sinica Institute of Astronomy and Astrophysics, Taipei 10617, Taiwan (China)
  9. Research Institute for Time Studies, Yamaguchi University, Yamaguchi 753-8511 (Japan)
Publication Date:
OSTI Identifier:
22086427
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; BL LACERTAE OBJECTS; ENERGY SPECTRA; GAMMA ASTRONOMY; GHZ RANGE; IMAGES; INTERFEROMETRY; JETS; PROPER MOTION; QUASARS; RADIATION DETECTION; RADIOASTRONOMY; STELLAR FLARES; TEV RANGE; VELOCITY; X RADIATION

Citation Formats

Niinuma, K., Kino, M., Oyama, T., Nagai, H., Isobe, N., Gabanyi, K. E., Hada, K., Koyama, S., Asada, K., and Fujisawa, K., E-mail: niinuma@yamaguchi-u.ac.jp. POSSIBLE DETECTION OF APPARENT SUPERLUMINAL INWARD MOTION IN MARKARIAN 421 AFTER THE GIANT X-RAY FLARE IN 2010 FEBRUARY. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/2/84.
Niinuma, K., Kino, M., Oyama, T., Nagai, H., Isobe, N., Gabanyi, K. E., Hada, K., Koyama, S., Asada, K., & Fujisawa, K., E-mail: niinuma@yamaguchi-u.ac.jp. POSSIBLE DETECTION OF APPARENT SUPERLUMINAL INWARD MOTION IN MARKARIAN 421 AFTER THE GIANT X-RAY FLARE IN 2010 FEBRUARY. United States. doi:10.1088/0004-637X/759/2/84.
Niinuma, K., Kino, M., Oyama, T., Nagai, H., Isobe, N., Gabanyi, K. E., Hada, K., Koyama, S., Asada, K., and Fujisawa, K., E-mail: niinuma@yamaguchi-u.ac.jp. Sat . "POSSIBLE DETECTION OF APPARENT SUPERLUMINAL INWARD MOTION IN MARKARIAN 421 AFTER THE GIANT X-RAY FLARE IN 2010 FEBRUARY". United States. doi:10.1088/0004-637X/759/2/84.
@article{osti_22086427,
title = {POSSIBLE DETECTION OF APPARENT SUPERLUMINAL INWARD MOTION IN MARKARIAN 421 AFTER THE GIANT X-RAY FLARE IN 2010 FEBRUARY},
author = {Niinuma, K. and Kino, M. and Oyama, T. and Nagai, H. and Isobe, N. and Gabanyi, K. E. and Hada, K. and Koyama, S. and Asada, K. and Fujisawa, K., E-mail: niinuma@yamaguchi-u.ac.jp},
abstractNote = {We report on the very long baseline interferometry (VLBI) follow-up observations using the Japanese VLBI Network array at 22 GHz for the largest X-ray flare of TeV blazar Mrk 421 that occurred in 2010 mid-February. The total of five epochs of observations were performed at intervals of about 20 days between 2010 March 7 and May 31. No newborn component associated with the flare was seen directly in the total intensity images obtained by our multi-epoch VLBI observations. However, one jet component located at {approx}1 mas northwest from the core was able to be identified, and its proper motion can be measured as -1.66 {+-} 0.46 mas yr{sup -1}, which corresponds to an apparent velocity of -3.48 {+-} 0.97c. Here, this negative velocity indicates that the jet component was apparently moving toward the core. As the most plausible explanation, we discuss that the apparent negative velocity was possibly caused by the ejection of a new component, which could not be resolved with our observations. In this case, the obtained Doppler factor of the new component is around 10-20, which is consistent with the ones typically estimated by model fittings of spectral energy distribution for this source.},
doi = {10.1088/0004-637X/759/2/84},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}