Zobrazeno 1 - 10
of 319
pro vyhledávání: '"Shemmer, O."'
Autor:
Paolillo, M., Papadakis, I. E., Brandt, W. N., Bauer, F. E., Lanzuisi, G., Allevato, V., Shemmer, O., Zheng, X. C., De Cicco, D., Gilli, R., Luo, B., Thomas, M., Tozzi, P., Vito, F., Xue, Y. Q.
Publikováno v:
A&A 673, A68 (2023)
We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks $\leq T\leq$ 14 yrs), redshift ($0\leq z \lesssim 3$), luminosities ($10^{40}$ erg s$^{-1}\leq L_X\leq 10^{46}$ erg s$^{-1}$) a
Externí odkaz:
http://arxiv.org/abs/2302.08524
Autor:
Ni, Q., Brandt, W. N., Luo, B., Garmire, G. P., Hall, P. B., Plotkin, R. M., Shemmer, O., Timlin III, J. D., Vito, F., Wu, J., Yi, W.
We present deeper Chandra observations for weak-line quasars (WLQs) in a representative sample that previously had limited X-ray constraints, and perform X-ray photometric analyses to reveal the full range of X-ray properties of WLQs. Only 5 of the 3
Externí odkaz:
http://arxiv.org/abs/2202.05279
Autor:
Ni, Q., Brandt, W. N., Chen, C. -T., Luo, B., Nyland, K., Yang, G., Zou, F., Aird, J., Alexander, D. M., Bauer, F. E., Lacy, M., Lehmer, B. D., Mallick, L., Salvato, M., Schneider, D. P., Tozzi, P., Traulsen, I., Vaccari, M., Vignali, C., Vito, F., Xue, Y., Banerji, M., Chow, K., Comastri, A., Del Moro, A., Gilli, R., Mullaney, J., Paolillo, M., Schwope, A., Shemmer, O., Sun, M., Timlin, J. D., Trump, J. R.
We present the X-ray point-source catalogs in two of the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS) fields, W-CDF-S (4.6 deg$^2$) and ELAIS-S1 (3.2 deg$^2$), aiming to fill the gap between deep pencil-beam X-ray surveys and sh
Externí odkaz:
http://arxiv.org/abs/2106.10572
Autor:
Ni, Qingling, Brandt, W. N., Yi, W., Luo, B., Timlin III, J. D., Hall, P. B., Liu, Hezhen, Plotkin, R. M., Shemmer, O., Vito, F., Wu, Jianfeng
We report the discovery of an extreme X-ray flux rise (by a factor of > 20) of the weak-line quasar SDSS J153913.47+395423.4 (hereafter SDSS J1539+3954) at z = 1.935. SDSS J1539+3954 is the most-luminous object among radio-quiet type 1 AGNs where suc
Externí odkaz:
http://arxiv.org/abs/2001.08216
Autor:
Brandt, W. N., Ni, Q., Yang, G., Anderson, S. F., Assef, R. J., Barth, A. J., Bauer, F. E., Bongiorno, A., Chen, C. -T., De Cicco, D., Gezari, S., Grier, C. J., Hall, P. B., Hoenig, S. F., Lacy, M., Li, J., Luo, B., Paolillo, M., Peterson, B. M., Popović, L. C., Richards, G. T., Shemmer, O., Shen, Y., Sun, M., Timlin, J. D., Trump, J. R., Vito, F., Yu, Z.
This white paper specifies the footprints, cadence requirements, and total-depth requirements needed to allow the most-successful AGN studies in the four currently selected LSST Deep-Drilling Fields (DDFs): ELAIS-S1, XMM-LSS, CDF-S, and COSMOS. The i
Externí odkaz:
http://arxiv.org/abs/1811.06542
Autor:
Ding, N., Luo, B., Brandt, W. N., Paolillo, M., Yang, G., Lehmer, B. D., Shemmer, O., Schneider, D. P., Tozzi, P., Xue, Y. Q., Zheng, X. C., Gu, Q. S., Koekemoer, A. M., Vignali, C., Vito, F., Wang, J. X.
In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, $L_{\mathrm{X}} \lesssim 10^{42}$ erg s$^{-1}$) identification still poses a chal
Externí odkaz:
http://arxiv.org/abs/1810.09465
Autor:
Ni, Qingling, Brandt, W. N., Luo, B., Hall, P. B., Shen, Yue, Anderson, S. F., Plotkin, R. M., Richards, Gordon T., Schneider, D. P., Shemmer, O., Wu, J.
We present X-ray and multiwavelength analyses of 32 weak emission-line quasars (WLQs) selected in a consistent and unbiased manner. New $Chandra$ 3.1-4.8 ks observations were obtained for 14 of these WLQs with C IV rest-frame equivalent widths (REWs)
Externí odkaz:
http://arxiv.org/abs/1807.08757
Autor:
Chen, C. -T. J., Brandt, W. N., Luo, B., Ranalli, P., Yang, G., Alexander, D. M., Bauer, F. E., Kelson, D. D., Lacy, M., Nyland, K., Tozzi, P., Vito, F., Cirasuolo, M., Gilli, R., Jarvis, M. J., Lehmer, B. D., Paolillo, M., Schneider, D. P., Shemmer, O., Smail, I., Sun, M., Tanaka, M., Vaccari, M., Vignali, C., Xue, Y. Q., Banerji, M., Chow, K. E., Häußler, B., Norris, R. P., Silverman, J. D., Trump, J. R.
We present an X-ray point-source catalog from the XMM-Large Scale Structure survey region (XMM-LSS), one of the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS) fields. We target the XMM-LSS region with $1.3$ Ms of new XMM-Newton AO
Externí odkaz:
http://arxiv.org/abs/1804.07763
Autor:
Vito, F., Brandt, W. N., Yang, G., Gilli, R., Luo, B., Vignali, C., Xue, Y. Q., Comastri, A., Koekemoer, A. M., Lehmer, B. D., Liu, T., Paolillo, M., Ranalli, P., Schneider, D. P., Shemmer, O., Volonteri, M., Wang, J.
We investigate the population of high-redshift ($3\leq z < 6$) AGN selected in the two deepest X-ray surveys, the 7 Ms \textit{Chandra} Deep Field-South and 2 Ms \textit{Chandra} Deep Field-North. Their outstanding sensitivity and spectral characteri
Externí odkaz:
http://arxiv.org/abs/1709.07892
Autor:
Paolillo, M., Papadakis, I., Brandt, W. N., Luo, B., Xue, Y. Q., Tozzi, P., Shemmer, O., Allevato, V., Bauer, F. E., Comastri, A., Gilli, R., Koekemoer, A., Liu, T., Vignali, C., Vito, F., Yang, G., Wang, J. X., Zheng, X. C.
We study the X-ray variability properties of distant AGNs in the Chandra Deep Field-South region over 17 years, up to $z\sim 4$, and compare them with those predicted by models based on local samples. We use the results of Monte Carlo simulations to
Externí odkaz:
http://arxiv.org/abs/1707.05332