A DOUBLE-PEAKED OUTBURST OF A 0535+26 OBSERVED WITH INTEGRAL, RXTE, AND SUZAKU

Journal Article · Wed Feb 20 00:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/764/2/L23· OSTI ID:22130897

Caballero, I. ^[1]; Pottschmidt, K.; Marcu, D. M. ^[2]; Barragan, L.; Wilms, J.; Kreykenbohm, I. ^[3]; Ferrigno, C. ^[4]; Klochkov, D.; Suchy, S.; Santangelo, A.; Staubert, R. ^[5]; Zurita Heras, J. A. ^[6]; Kretschmar, P. ^[7]; Fuerst, F. ^[8]; Rothschild, R. ^[9]; Finger, M. H. ^[10]; Camero-Arranz, A. ^[11]; Makishima, K. ^[12]; Enoto, T. ^[13]; others, and

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1. Laboratoire AIM, CEA/IRFU, CNRS/INSU, Universite Paris Diderot, CEA DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France)
2. Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)
3. Dr. Karl Remeis-Sternwarte and ECAP, FAU Erlangen-Nuremberg, Sternwartstr. 7, D-96049 Bamberg (Germany)
4. ISDC Data Centre for Astrophysics, University of Geneva, Chemin d'Ecogia 16, CH-1290 Versoix (Switzerland)
5. Institut fuer Astronomie und Astrophysik, Sand 1, D-72076 Tuebingen (Germany)
6. Francois Arago Centre, APC (UMR 7164 Universite Paris Diderot, CNRS/IN2P3, CEA/DSM, Observatoire de Paris), 13 rue Watt, F-75205 Paris Cedex 13 (France)
7. European Space Astronomy Centre (ESA/ESAC), Science Operations Department, Villanueva de la Canada, E-28080 Madrid (Spain)
8. Space Radiation Lab, California Institute of Technology, MC 290-17 Cahill, 1200 E. California Blvd., Pasadena, CA 91125 (United States)
9. Center for Astrophysics and Space Science, UCSD, La Jolla, CA 92093 (United States)
10. National Space Science and Technology Center, 320 Sparkman Drive NW, Huntsville, AL 35805 (United States)
11. Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, Fac. de Ciencies, Torre C5, parell, 2a planta, E-08193 Barcelona (Spain)
12. Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)
13. Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan)

The Be/X-ray binary A 0535+26 showed a normal (type I) outburst in 2009 August. It is the fourth in a series of normal outbursts associated with the periastron, but is unusual because it presented a double-peaked light curve. The two peaks reached a flux of {approx}450 mCrab in the 15-50 keV range. We present results of the timing and spectral analysis of INTEGRAL, RXTE, and Suzaku observations of the outburst. The energy-dependent pulse profiles and their evolution during the outburst are studied. No significant differences with respect to other normal outbursts are observed. The centroid energy of the fundamental cyclotron line shows no significant variation during the outburst. A spectral hardening with increasing luminosity is observed. We conclude that the source is accreting in the sub-critical regime. We discuss possible explanations for the double-peaked outburst.

• OSTI ID: 22130897
• Journal Information: Astrophysical Journal Letters, Vol. 764, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BINARY STARS
COSMIC X-RAY SOURCES
CYCLOTRONS
ENERGY DEPENDENCE
KEV RANGE 10-100
LUMINOSITY
MAGNETIC FIELDS
PULSARS
SPECTRAL HARDENING
VISIBLE RADIATION
X RADIATION