The 2005 outburst of the halo black hole X-ray transient XTE J1118+480

Preprint, Article English OPEN
Zurita, C. ; Torres, M. A. P. ; Steeghs, D. ; Rodríguez-Gil, P. ; Muñoz-Darias, T. ; Casares, J. ; Shahbaz, T. ; Martinez-Pais, I. G. ; Zhao, P. ; Garcia, M. R. ; Piccioni, A. ; Bartolini, C. ; Guarnieri, A. ; Bloom, Joshua S. ; Blake, C. H. ; Falco, E. E. ; Szentgyorgyi, A. ; Skrutskie, M. (2006)
  • Publisher: Institute of Physics Publishing Ltd.
  • Related identifiers: doi: 10.1086/503286, doi: 10.1086/503286
  • Subject: QB | Astrophysics
    arxiv: Astrophysics::Galaxy Astrophysics | Astrophysics::High Energy Astrophysical Phenomena | Astrophysics::Cosmology and Extragalactic Astrophysics | Astrophysics::Solar and Stellar Astrophysics

We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of ~5.7+-0.1 mag in the R band and ~5 mag in the infrared J, H and K_s bands. The hardness ratio HR2 (5-12 keV/3-5 keV) from the RXTE/ASM data is 1.53+-0.02 at the peak of the outburst indicating a hard spectrum. Both the shape of the light curve and the ratio L_X (1-10 keV)/L_opt resemble the mini-outbursts observed in GRO J0422+32 and XTE J1859+226. During early decline, we find a 0.02-mag amplitude variation consistent with a superhump modulation, like the one observed during the 2000 outburst. Similarly, XTE J1118+480 displayed a double-humped ellipsoidal modulation distorted by a superhump wave when settled into a near-quiescence level, suggesting that the disk expanded to the 3:1 resonance radius after outburst where it remained until early quiescence. The system reached quiescence at R=19.02+-0.03 about three months after the onset of the outburst. The optical rise preceded the X-ray rise by at most 4 days. The spectral energy distributions (SEDs) at the different epochs during outburst are all quasi-power laws with F_nu proportional to nu^alpha increasing toward the blue. At the peak of the outburst we derived alpha=0.49+-0.04 for the optical data alone and alpha=0.1+-0.1 when fitting solely the infrared. This difference between the optical and the infrared SEDs suggests that the infrared is dominated by a different component (a jet?) whereas the optical is presumably showing the disk evolution.
  • References (23)
    23 references, page 1 of 3

    Buxton, M. M., & Bailyn, C. D., 2004, ApJ, 615, 880 Callanan, P. J., Garcia, M. R., McClintock, J. E., Zhao, P., Remillard R. A., Bailyn, C. D., Orosz, J. A., Harmon, B. A.; Paciesas, W. S. 1995, ApJ, 441 786

    Cannizzo, J. K.; Chen, W., & Livio, M. 1995, ApJ, 454, 880 Castro-Tirado, A. J., Ortiz, J. L., & Gallego, J., 1997, A&A, 322,507 Charles, P. A., & Coe, M. J. 2004, in Compact Stellar X-Ray Sources, ed. W. H. G. Lewin & M. van der Klis (Cambridge: Cambridge Univ. Press), in press (astro-ph/0308020) Chaty, S., Haswell, C. A., Malzac, J., Hynes, R. I., Shrader, C. R., & Cui, W. 2003, MNRAS, 346, 689

    Chen, W., Shrader, C.R. & Livio, M. 1997, ApJ, 491, 312 Chevalier, C., & Ilovaisky, S. A. 1995, A&A, 297, 103 Chou, Y., Chen, A., Chiang, P. S., Hu, C. P., Hu, R. H. 2005, The Astronomer's Telegram, 412

    Della Valle, M., Jarvis, B. J., & West, R. M., 1991, A&A, 247, 33 Dubus, G., Kim, R.S.J., Menou, K., Szkody, P., Bowen, D.V. 2001, ApJ, 553, 307 Eggleton, P. P. 1983, ApJ, 268, 368 Esin, A. A., McClintock, J. E., Drake, J. J., Garcia, M. R., Haswell, C. A., Hynes, R. I., Muno, M. P. 2001, ApJ, 555, 483

    Fender, R. P., Hjellming, R. M., Tilanus, R. P. J., Pooley, G. G., Deane, J. R., Ogley, R. N., & Spencer, R. E. 2001, MNRAS, 322, 23

    Garcia, M., Brown, W., Pahre, M., McClintock, J., Callanan, P., & Garnavich, P. 2000, IAU Circ., 7392, 2

    Hameury, J. M., Lasota, J. P., McClintock, J. E., & Narayan, R. 1997, ApJ, 489, 234 Hauschildt, P.H., Allard, F., & Baron, E. 1999, ApJ, 512, 377 Homan, J., Buxton, M., Markoff, S., Bailyn C.D., Nespoli, E., & Belloni T. 2005, ApJ, 624, 295

    Hynes, R. I., Mauche, C. W., Haswell, C. A., Shrader, C. R., Cui, W., & Chaty, S. 2000, ApJ, 539, 37

    Hynes, R. I. 2005, ApJ, 623, 1026 Landolt, A. U. 1992, AJ, 104, 340 Levine, A. M., Bradt, H., Cui, W., Jernigan, J. G., Morgan, E. H., Remillard, R., Shirey, R. E., & Smith, D. A. 1996, ApJ, 469, 33L

    Malzac, Julien, Merloni, Andrea, & Fabian, Andrew C. 2004, ApJ, 614, 641 Markoff, S., Falcke, H., & Fender, R. 2001, A&A, 372, 25 McClintock, J. E., Garcia, M. R., Caldwell, N., Falco, E. E., Garnavich, P. M., & Zhao, P. 2001, ApJ, 551, L147

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