X-ray variability in the 7 Ms Chandra Deep Field South

The movie below shows the variability of X-ray sources (mostly AGNs) in the Chandra Deep Field South (Giacconi et al. 2002, Luo et al. 2008, Xue et al. 2011, Luo et al. 2017). The observations span an interval of more than 15 years for a total observing time of 7 Msec, as shown by the bar at the bottom of the image. Although the variability of the faintest sources is enhanced due to the logaritmic intensity scaling, most of the observed flux variations are intrinsic: our work over the last 15 years (Paolillo et al. 2004, Young et al. 2012, Shemmer at al. 2014, Yang et al. 2016, Zheng et al. 2017, Paolillo et al. 2017) shows that virtually all AGNs are variable on long timescales, as expected from the physics of the accretion process. We also showed that variability represents a promising tool to detect AGNs in faint galaxies (Young et al. 2012) and to trace the evolution of accretion over cosmological timescales (Paolillo et al. 2017). Additional work has studied the spectral variability of the brightest CDFS sources (Liu et al. 2017, Falocco et al. 2017).

The movies can be used freely in papers and presentations, acknowledging the original paper (Paolillo et al. 2017). If you need the original lightcurves or the derived variability parameters (excess variance, variability likelyhood etc) contact me at the address in my homepage.

Figure 1: The 7Ms Chandra Deep Field Sources movie. The bar at the bottom of the image shows the epoch of the observations. The weird shape of the background (dark red) is due to the shape of the Chandra camera. The images have been corrected for instrumental effects (exposure variations, PSF broadening etc.) to mimick what a "clean" observation would look like. The colors are shown in logaritmic scale which enhances faint source variability.

Figure 2: Zoomed image of part of the CDFS region. The sqrt colorscale and color map have been chosen to enhance the visibility of both bright and faint sources (AGNs).

References:

Chandra Deep Field South: The 1 Ms Catalog - R. Giacconi, A. Zirm, J. Wang, P. Rosati, M. Nonino, P. Tozzi, R. Gilli, V. Mainieri, G. Hasinger, L. Kewley, J. Bergeron, S. Borgani, R. Gilmozzi, N. Grogin, A. Koekemoer, E. Schreier, W. Zheng, and C. Norman, Astrophys. J. Suppl. Ser. 139, 369 (2002).

Prevalence of X-Ray Variability in the Chandra Deep Field-South - M. Paolillo, E. J. Schreier, R. Giacconi, A. M. Koekemoer, and N. A. Grogin, Astrophys. J. 611, 93 (2004).

The Chandra Deep Field-South Survey: 2 Ms Source Catalogs - B. Luo, F. E. Bauer, W. N. Brandt, D. M. Alexander, B. D. Lehmer, D. P. Schneider, M. Brusa, A. Comastri, A. C. Fabian, A. Finoguenov, R. Gilli, G. Hasinger, A. E. Hornschemeier, A. M. Koekemoer, V. Mainieri, M. Paolillo, P. Rosati, O. Shemmer, J. D. Silverman, I. Smail, a. T. Steffen, and C. Vignali, Astrophys. J. Suppl. Ser. 179, 19 (2008).

The Chandra Deep Field-South Survey: 4 Ms Source Catalogs - Y. Q. Xue, B. Luo, W. N. Brandt, F. E. Bauer, B. D. Lehmer, P. S. Broos, D. P. Schneider, D. M. Alexander, M. Brusa, A. Comastri, A. C. Fabian, R. Gilli, G. Hasinger, A. E. Hornschemeier, A. M. Koekemoer, T. Liu, V. Mainieri, M. Paolillo, D. A. Rafferty, P. Rosati, O. Shemmer, J. D. Silverman, I. Smail, P. Tozzi, and C. Vignali, Astrophys. J. Suppl. Ser. 195, 10 (2011).

Exploratory X-Ray Monitoring of Luminous Radio-quiet Quasars at High Redshift: Initial Results - O. Shemmer, W. N. Brandt, M. Paolillo, S. Kaspi, C. Vignali, M. S. Stein, P. Lira, D. P. Schneider, and R. R. Gibson, Astrophys. J. 783, 116 (2014).

Long-term X-Ray Variability of Typical Active Galactic Nuclei in the Distant Universe - G. Yang, W. N. Brandt, B. Luo, Y. Q. Xue, F. E. Bauer, M. Y. Sun, S. Kim, S. Schulze, X. C. Zheng, M. Paolillo, O. Shemmer, T. Liu, D. P. Schneider, C. Vignali, F. Vito, and J.-X. Wang, Astrophys. J. 831, 145 (2016).

The Chandra Deep Field-South Survey: 7 Ms Source Catalogs - B. Luo, W. N. Brandt, Y. Q. Xue, B. D. Lehmer, D. M. Alexander, F. E. Bauer, F. Vito, G. Yang, A. R. Basu-Zych, A. Comastri, R. Gilli, Q.-S. Gu, A. E. Hornschemeier, A. M. Koekemoer, T. Liu, V. Mainieri, M. Paolillo, P. Ranalli, P. Rosati, D. P. Schneider, O. Shemmer, I. Smail, M. Y. Sun, P. Tozzi, C. Vignali, and J.-X. Wang, Astrophys. J. Suppl. Ser. 228, 2 (2017).

X-Ray Spectral Analyses of AGNs from the 7Ms Chandra Deep Field-South Survey: The Distribution, Variability, and Evolutions of AGN Obscuration - T. Liu, P. Tozzi, J.-X. Wang, W. N. Brandt, C. Vignali, Y. Xue, D. P. Schneider, A. Comastri, G. Yang, F. E. Bauer, M. Paolillo, B. Luo, R. Gilli, Q. D. Wang, M. Giavalisco, Z. Ji, D. M. Alexander, V. Mainieri, O. Shemmer, A. M. Koekemoer, and G. Risaliti, Astrophys. J. Suppl. Ser. 232, 8 (2017).

Exploratory X-Ray Monitoring of Luminous Radio-quiet Quasars at High Redshift: No Evidence for Evolution in X-Ray Variability - O. Shemmer, W. N. Brandt, M. Paolillo, S. Kaspi, C. Vignali, P. Lira, and D. P. Schneider, Astrophys. J. 848, 46 (2017).

Deepest View of AGN X-Ray Variability with the 7 Ms Chandra Deep Field-South Survey - [1] X. C. Zheng, Y. Q. Xue, W. N. Brandt, J. Y. Li, M. Paolillo, G. Yang, S. F. Zhu, B. Luo, M. Y. Sun, T. M. Hughes, F. E. Bauer, F. Vito, J. X. Wang, T. Liu, C. Vignali, and X. W. Shu, Astrophys. J. 849, 127 (2017).

The XMM deep survey in the CDF-S. X. X-ray variability of bright sources - S. Falocco, M. Paolillo, A. Comastri, F. J. Carrera, P. Ranalli, K. Iwasawa, I. Georgantopoulos, C. Vignali, and R. Gilli, 1 (2017).

Tracing the accretion history of supermassive black holes through X-ray variability: results from the ChandraDeep Field-South - M. Paolillo, I. E. Papadakis, W. N. Brandt, B. Luo, Y. Q. Xue, P. Tozzi, O. Shemmer, V. Allevato, F. E. Bauer, A. Comastri, R. Gilli, A. M. Koekemoer, T. Liu, C. Vignali, F. Vito, G. Yang, J. X. Wang, and X. C. Zheng, Mon. Not. R. Astron. Soc. 471, 4398 (2017).