تقرير
Exploratory X-Ray Monitoring of Luminous Radio-Quiet Quasars at High Redshift: Extended Time-Series Analyses and Stacked Imaging Spectroscopy
| العنوان: | Exploratory X-Ray Monitoring of Luminous Radio-Quiet Quasars at High Redshift: Extended Time-Series Analyses and Stacked Imaging Spectroscopy |
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| المؤلفون: | Thomas, Marcus O., Shemmer, Ohad, Brandt, W. N., Paolillo, Maurizio, Kaspi, Shai, Vignali, Cristian, Lira, Paulina, Schneider, Donald P. |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | We present three new Chandra X-ray epochs along with new ground-based optical-UV observations as the third installment in a time-series analysis of four high-redshift ($z\sim4.1-4.4$) radio-quiet quasars (RQQs). In total, we present nine epochs for these sources with rest-frame temporal baselines of $\sim1300-2000$ days. We utilize the X-ray data to determine basic variability properties, as well as produce mean spectra and stacked images based on effective exposure times of $\sim40-70$ ks per source. We perform time-series analyses in the soft and hard bands, separately, and compare variability properties to those of sources at lower redshifts and luminosities. The magnitude of X-ray variability of our sources remains consistent with or lower than that of similar sources at lower redshifts, in agreement with the variability-luminosity anti-correlation. The mean power-law photon indices in the stacked Chandra spectra of our sources are consistent with the values measured from their archival XMM-Newton spectra separated by about three years in the rest frame. Along with the X-ray observations we provide near-simultaneous optical monitoring of the sources in the optical-UV regime. The overall variability in the optical-to-X-ray spectral slope is consistent with sources at lower redshifts and the optical-UV observations display mild variability on monthly timescales. Comment: 24 pages (AASTeX631), 9 figures. Accepted for publication in ApJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/ac2e00 |
| الوصول الحر: | http://arxiv.org/abs/2110.07065Test |
| رقم الانضمام: | edsarx.2110.07065 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/ac2e00 |
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